Spring Security is a framework that provides authentication, authorization, and protection against common attacks. With first class support for both imperative and reactive applications, it is the de-facto standard for securing Spring-based applications.

Preface

This section discusses the logistics of Spring Security.

1. Prerequisites

Spring Security requires a Java 8 or higher Runtime Environment.

As Spring Security aims to operate in a self-contained manner, you do not need to place any special configuration files in your Java Runtime Environment. In particular, you need not configure a special Java Authentication and Authorization Service (JAAS) policy file or place Spring Security into common classpath locations.

Similarly, if you use an EJB Container or Servlet Container, you need not put any special configuration files anywhere nor include Spring Security in a server classloader. All the required files are contained within your application.

This design offers maximum deployment time flexibility, as you can copy your target artifact (be it a JAR, WAR, or EAR) from one system to another and it immediately works.

2. Spring Security Community

Welcome to the Spring Security Community! This section discusses how you can make the most of our vast community.

2.1. Getting Help

If you need help with Spring Security, we are here to help. The following are some of the best ways to get help:

2.2. Becoming Involved

We welcome your involvement in the Spring Security project. There are many ways to contribute, including answering questions on StackOverflow, writing new code, improving existing code, assisting with documentation, developing samples or tutorials, reporting bugs, or simply making suggestions. For more information, see our Contributing documentation.

2.3. Source Code

You can find Spring Security’s source code on GitHub at https://github.com/spring-projects/spring-security/

2.4. Apache 2 License

Spring Security is Open Source software released under the Apache 2.0 license.

2.5. Social Media

You can follow @SpringSecurity and the Spring Security team on Twitter to stay up to date with the latest news. You can also follow @SpringCentral to keep up to date with the entire Spring portfolio.

3. What’s New in Spring Security 5.3

Spring Security 5.3 provides a number of new features. Below are the highlights of the release.

3.1. Documentation Updates

We will continue our effort to rewrite the documentation.

Here’s what you’ll see in this release:

3.4. RSocket

3.5. Additional Updates

3.6. Build Changes

4. Getting Spring Security

This section discusses all you need to know about getting the Spring Security binaries. See Source Code for how to obtain the source code.

4.1. Release Numbering

Spring Security versions are formatted as MAJOR.MINOR.PATCH such that:

  • MAJOR versions may contain breaking changes. Typically, these are done to provide improved security to match modern security practices.

  • MINOR versions contain enhancements but are considered passive updates

  • PATCH level should be perfectly compatible, forwards and backwards, with the possible exception of changes that fix bugs.

4.2. Usage with Maven

As most open source projects, Spring Security deploys its dependencies as Maven artifacts. The topics in this section provide detail on how to consume Spring Security when using Maven.

4.2.1. Spring Boot with Maven

Spring Boot provides a spring-boot-starter-security starter that aggregates Spring Security-related dependencies together. The simplest and preferred way to use the starter is to use Spring Initializr by using an IDE integration (Eclipse, IntelliJ, NetBeans) or through https://start.spring.io.

Alternatively, you can manually add the starter, as the following example shows:

Example 1. pom.xml
<dependencies>
    <!-- ... other dependency elements ... -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
</dependencies>

Since Spring Boot provides a Maven BOM to manage dependency versions, you do not need to specify a version. If you wish to override the Spring Security version, you may do so by providing a Maven property, as the following example shows:

Example 2. pom.xml
<properties>
    <!-- ... -->
    <spring-security.version>5.3.6.BUILD-SNAPSHOT</spring-security.version>
</dependencies>

Since Spring Security makes breaking changes only in major releases, it is safe to use a newer version of Spring Security with Spring Boot. However, at times, you may need to update the version of Spring Framework as well. You can do so by adding a Maven property, as the following example shows:

Example 3. pom.xml
<properties>
    <!-- ... -->
    <spring.version>5.2.10.BUILD-SNAPSHOT</spring.version>
</dependencies>

If you use additional features (such as LDAP, OpenID, and others), you need to also include the appropriate Project Modules.

4.2.2. Maven Without Spring Boot

When you use Spring Security without Spring Boot, the preferred way is to use Spring Security’s BOM to ensure a consistent version of Spring Security is used throughout the entire project. The following example shows how to do so:

Example 4. pom.xml
<dependencyManagement>
    <dependencies>
        <!-- ... other dependency elements ... -->
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-bom</artifactId>
            <version>{spring-security-version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

A minimal Spring Security Maven set of dependencies typically looks like the following:

Example 5. pom.xml
<dependencies>
    <!-- ... other dependency elements ... -->
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-config</artifactId>
    </dependency>
</dependencies>

If you use additional features (such as LDAP, OpenID, and others), you need to also include the appropriate Project Modules.

Spring Security builds against Spring Framework 5.2.10.BUILD-SNAPSHOT but should generally work with any newer version of Spring Framework 5.x. Many users are likely to run afoul of the fact that Spring Security’s transitive dependencies resolve Spring Framework 5.2.10.BUILD-SNAPSHOT, which can cause strange classpath problems. The easiest way to resolve this is to use the spring-framework-bom within the <dependencyManagement> section of your pom.xml as the following example shows:

Example 6. pom.xml
<dependencyManagement>
    <dependencies>
        <!-- ... other dependency elements ... -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-framework-bom</artifactId>
            <version>5.2.10.BUILD-SNAPSHOT</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

The preceding example ensures that all the transitive dependencies of Spring Security use the Spring 5.2.10.BUILD-SNAPSHOT modules.

This approach uses Maven’s “bill of materials” (BOM) concept and is only available in Maven 2.0.9+. For additional details about how dependencies are resolved, see Maven’s Introduction to the Dependency Mechanism documentation.

4.2.3. Maven Repositories

All GA releases (that is, versions ending in .RELEASE) are deployed to Maven Central, so no additional Maven repositories need to be declared in your pom.

If you use a SNAPSHOT version, you need to ensure that you have the Spring Snapshot repository defined, as the following example shows:

Example 7. pom.xml
<repositories>
    <!-- ... possibly other repository elements ... -->
    <repository>
        <id>spring-snapshot</id>
        <name>Spring Snapshot Repository</name>
        <url>https://repo.spring.io/snapshot</url>
    </repository>
</repositories>

If you use a milestone or release candidate version, you need to ensure that you have the Spring Milestone repository defined, as the following example shows:

Example 8. pom.xml
<repositories>
    <!-- ... possibly other repository elements ... -->
    <repository>
        <id>spring-milestone</id>
        <name>Spring Milestone Repository</name>
        <url>https://repo.spring.io/milestone</url>
    </repository>
</repositories>

4.3. Gradle

As most open source projects, Spring Security deploys its dependencies as Maven artifacts, which allows for first-class Gradle support. The following topics provide detail on how to consume Spring Security when using Gradle.

4.3.1. Spring Boot with Gradle

Spring Boot provides a spring-boot-starter-security starter that aggregates Spring Security related dependencies together. The simplest and preferred method to use the starter is to use Spring Initializr by using an IDE integration (Eclipse, IntelliJ, NetBeans) or through https://start.spring.io.

Alternatively, you can manually add the starter, as the following example shows:

Example 9. build.gradle
dependencies {
    compile "org.springframework.boot:spring-boot-starter-security"
}

Since Spring Boot provides a Maven BOM to manage dependency versions, you need not specify a version. If you wish to override the Spring Security version, you may do so by providing a Gradle property, as the following example shows:

Example 10. build.gradle
ext['spring-security.version']='5.3.6.BUILD-SNAPSHOT'

Since Spring Security makes breaking changes only in major releases, it is safe to use a newer version of Spring Security with Spring Boot. However, at times, you may need to update the version of Spring Framework as well. You can do so by adding a Gradle property, as the following example shows:

Example 11. build.gradle
ext['spring.version']='5.2.10.BUILD-SNAPSHOT'

If you use additional features (such as LDAP, OpenID, and others), you need to also include the appropriate Project Modules.

4.3.2. Gradle Without Spring Boot

When you use Spring Security without Spring Boot, the preferred way is to use Spring Security’s BOM to ensure a consistent version of Spring Security is used throughout the entire project. You can do so by using the Dependency Management Plugin, as the following example shows:

Example 12. build.gradle
plugins {
    id "io.spring.dependency-management" version "1.0.6.RELEASE"
}

dependencyManagement {
    imports {
        mavenBom 'org.springframework.security:spring-security-bom:5.3.6.BUILD-SNAPSHOT'
    }
}

A minimal Spring Security Maven set of dependencies typically looks like the following:

Example 13. build.gradle
dependencies {
    compile "org.springframework.security:spring-security-web"
    compile "org.springframework.security:spring-security-config"
}

If you use additional features (such as LDAP, OpenID, and others), you need to also include the appropriate Project Modules.

Spring Security builds against Spring Framework 5.2.10.BUILD-SNAPSHOT but should generally work with any newer version of Spring Framework 5.x. Many users are likely to run afoul of the fact that Spring Security’s transitive dependencies resolve Spring Framework 5.2.10.BUILD-SNAPSHOT, which can cause strange classpath problems. The easiest way to resolve this is to use the spring-framework-bom within your <dependencyManagement> section of your pom.xml. You can do so by using the Dependency Management Plugin, as the following example shows:

Example 14. build.gradle
plugins {
    id "io.spring.dependency-management" version "1.0.6.RELEASE"
}

dependencyManagement {
    imports {
        mavenBom 'org.springframework:spring-framework-bom:5.2.10.BUILD-SNAPSHOT'
    }
}

The preceding example ensures that all the transitive dependencies of Spring Security use the Spring 5.2.10.BUILD-SNAPSHOT modules.

4.3.3. Gradle Repositories

All GA releases (that is, versions ending in .RELEASE) are deployed to Maven Central, so using the mavenCentral() repository is sufficient for GA releases. The following example shows how to do so:

Example 15. build.gradle
repositories {
    mavenCentral()
}

If you use a SNAPSHOT version, you need to ensure you have the Spring Snapshot repository defined, as the following example shows:

Example 16. build.gradle
repositories {
    maven { url 'https://repo.spring.io/snapshot' }
}

If you use a milestone or release candidate version, you need to ensure that you have the Spring Milestone repository defined, as the following example shows:

Example 17. build.gradle
repositories {
    maven { url 'https://repo.spring.io/milestone' }
}

5. Features

Spring Security provides comprehensive support for authentication, authorization, and protection against common exploits. It also provides integration with other libraries to simplify its usage.

5.1. Authentication

Spring Security provides comprehensive support for authentication. Authentication is how we verify the identity of who is trying to access a particular resource. A common way to authenticate users is by requiring the user to enter a username and password. Once authentication is performed we know the identity and can perform authorization.

5.1.1. Authentication Support

Spring Security provides built in support for authenticating users. Refer to the sections on authentication for Servlet and WebFlux for details on what is supported for each stack.

5.1.2. Password Storage

Spring Security’s PasswordEncoder interface is used to perform a one way transformation of a password to allow the password to be stored securely. Given PasswordEncoder is a one way transformation, it is not intended when the password transformation needs to be two way (i.e. storing credentials used to authenticate to a database). Typically PasswordEncoder is used for storing a password that needs to be compared to a user provided password at the time of authentication.

Password Storage History

Throughout the years the standard mechanism for storing passwords has evolved. In the beginning passwords were stored in plain text. The passwords were assumed to be safe because the data store the passwords were saved in required credentials to access it. However, malicious users were able to find ways to get large "data dumps" of usernames and passwords using attacks like SQL Injection. As more and more user credentials became public security experts realized we needed to do more to protect users' passwords.

Developers were then encouraged to store passwords after running them through a one way hash such as SHA-256. When a user tried to authenticate, the hashed password would be compared to the hash of the password that they typed. This meant that the system only needed to store the one way hash of the password. If a breach occurred, then only the one way hashes of the passwords were exposed. Since the hashes were one way and it was computationally difficult to guess the passwords given the hash, it would not be worth the effort to figure out each password in the system. To defeat this new system malicious users decided to create lookup tables known as Rainbow Tables. Rather than doing the work of guessing each password every time, they computed the password once and stored it in a lookup table.

To mitigate the effectiveness of Rainbow Tables, developers were encouraged to use salted passwords. Instead of using just the password as input to the hash function, random bytes (known as salt) would be generated for every users' password. The salt and the user’s password would be ran through the hash function which produced a unique hash. The salt would be stored alongside the user’s password in clear text. Then when a user tried to authenticate, the hashed password would be compared to the hash of the stored salt and the password that they typed. The unique salt meant that Rainbow Tables were no longer effective because the hash was different for every salt and password combination.

In modern times we realize that cryptographic hashes (like SHA-256) are no longer secure. The reason is that with modern hardware we can perform billions of hash calculations a second. This means that we can crack each password individually with ease.

Developers are now encouraged to leverage adaptive one-way functions to store a password. Validation of passwords with adaptive one-way functions are intentionally resource (i.e. CPU, memory, etc) intensive. An adaptive one-way function allows configuring a "work factor" which can grow as hardware gets better. It is recommended that the "work factor" be tuned to take about 1 second to verify a password on your system. This trade off is to make it difficult for attackers to crack the password, but not so costly it puts excessive burden on your own system. Spring Security has attempted to provide a good starting point for the "work factor", but users are encouraged to customize the "work factor" for their own system since the performance will vary drastically from system to system. Examples of adaptive one-way functions that should be used include bcrypt, PBKDF2, scrypt, and argon2.

Because adaptive one-way functions are intentionally resource intensive, validating a username and password for every request will degrade performance of an application significantly. There is nothing Spring Security (or any other library) can do to speed up the validation of the password since security is gained by making the validation resource intensive. Users are encouraged to exchange the long term credentials (i.e. username and password) for a short term credential (i.e. session, OAuth Token, etc). The short term credential can be validated quickly without any loss in security.

DelegatingPasswordEncoder

Prior to Spring Security 5.0 the default PasswordEncoder was NoOpPasswordEncoder which required plain text passwords. Based upon the Password History section you might expect that the default PasswordEncoder is now something like BCryptPasswordEncoder. However, this ignores three real world problems:

  • There are many applications using old password encodings that cannot easily migrate

  • The best practice for password storage will change again.

  • As a framework Spring Security cannot make breaking changes frequently

Instead Spring Security introduces DelegatingPasswordEncoder which solves all of the problems by:

  • Ensuring that passwords are encoded using the current password storage recommendations

  • Allowing for validating passwords in modern and legacy formats

  • Allowing for upgrading the encoding in the future

You can easily construct an instance of DelegatingPasswordEncoder using PasswordEncoderFactories.

Example 18. Create Default DelegatingPasswordEncoder
PasswordEncoder passwordEncoder =
    PasswordEncoderFactories.createDelegatingPasswordEncoder();

Alternatively, you may create your own custom instance. For example:

Example 19. Create Custom DelegatingPasswordEncoder
String idForEncode = "bcrypt";
Map encoders = new HashMap<>();
encoders.put(idForEncode, new BCryptPasswordEncoder());
encoders.put("noop", NoOpPasswordEncoder.getInstance());
encoders.put("pbkdf2", new Pbkdf2PasswordEncoder());
encoders.put("scrypt", new SCryptPasswordEncoder());
encoders.put("sha256", new StandardPasswordEncoder());

PasswordEncoder passwordEncoder =
    new DelegatingPasswordEncoder(idForEncode, encoders);
Password Storage Format

The general format for a password is:

Example 20. DelegatingPasswordEncoder Storage Format
{id}encodedPassword

Such that id is an identifier used to look up which PasswordEncoder should be used and encodedPassword is the original encoded password for the selected PasswordEncoder. The id must be at the beginning of the password, start with { and end with }. If the id cannot be found, the id will be null. For example, the following might be a list of passwords encoded using different id. All of the original passwords are "password".

Example 21. DelegatingPasswordEncoder Encoded Passwords Example
{bcrypt}$2a$10$dXJ3SW6G7P50lGmMkkmwe.20cQQubK3.HZWzG3YB1tlRy.fqvM/BG (1)
{noop}password (2)
{pbkdf2}5d923b44a6d129f3ddf3e3c8d29412723dcbde72445e8ef6bf3b508fbf17fa4ed4d6b99ca763d8dc (3)
{scrypt}$e0801$8bWJaSu2IKSn9Z9kM+TPXfOc/9bdYSrN1oD9qfVThWEwdRTnO7re7Ei+fUZRJ68k9lTyuTeUp4of4g24hHnazw==$OAOec05+bXxvuu/1qZ6NUR+xQYvYv7BeL1QxwRpY5Pc=  (4)
{sha256}97cde38028ad898ebc02e690819fa220e88c62e0699403e94fff291cfffaf8410849f27605abcbc0 (5)
1 The first password would have a PasswordEncoder id of bcrypt and encodedPassword of $2a$10$dXJ3SW6G7P50lGmMkkmwe.20cQQubK3.HZWzG3YB1tlRy.fqvM/BG. When matching it would delegate to BCryptPasswordEncoder
2 The second password would have a PasswordEncoder id of noop and encodedPassword of password. When matching it would delegate to NoOpPasswordEncoder
3 The third password would have a PasswordEncoder id of pbkdf2 and encodedPassword of 5d923b44a6d129f3ddf3e3c8d29412723dcbde72445e8ef6bf3b508fbf17fa4ed4d6b99ca763d8dc. When matching it would delegate to Pbkdf2PasswordEncoder
4 The fourth password would have a PasswordEncoder id of scrypt and encodedPassword of $e0801$8bWJaSu2IKSn9Z9kM+TPXfOc/9bdYSrN1oD9qfVThWEwdRTnO7re7Ei+fUZRJ68k9lTyuTeUp4of4g24hHnazw==$OAOec05+bXxvuu/1qZ6NUR+xQYvYv7BeL1QxwRpY5Pc= When matching it would delegate to SCryptPasswordEncoder
5 The final password would have a PasswordEncoder id of sha256 and encodedPassword of 97cde38028ad898ebc02e690819fa220e88c62e0699403e94fff291cfffaf8410849f27605abcbc0. When matching it would delegate to StandardPasswordEncoder

Some users might be concerned that the storage format is provided for a potential hacker. This is not a concern because the storage of the password does not rely on the algorithm being a secret. Additionally, most formats are easy for an attacker to figure out without the prefix. For example, BCrypt passwords often start with $2a$.

Password Encoding

The idForEncode passed into the constructor determines which PasswordEncoder will be used for encoding passwords. In the DelegatingPasswordEncoder we constructed above, that means that the result of encoding password would be delegated to BCryptPasswordEncoder and be prefixed with {bcrypt}. The end result would look like:

Example 22. DelegatingPasswordEncoder Encode Example
{bcrypt}$2a$10$dXJ3SW6G7P50lGmMkkmwe.20cQQubK3.HZWzG3YB1tlRy.fqvM/BG
Password Matching

Matching is done based upon the {id} and the mapping of the id to the PasswordEncoder provided in the constructor. Our example in Password Storage Format provides a working example of how this is done. By default, the result of invoking matches(CharSequence, String) with a password and an id that is not mapped (including a null id) will result in an IllegalArgumentException. This behavior can be customized using DelegatingPasswordEncoder.setDefaultPasswordEncoderForMatches(PasswordEncoder).

By using the id we can match on any password encoding, but encode passwords using the most modern password encoding. This is important, because unlike encryption, password hashes are designed so that there is no simple way to recover the plaintext. Since there is no way to recover the plaintext, it makes it difficult to migrate the passwords. While it is simple for users to migrate NoOpPasswordEncoder, we chose to include it by default to make it simple for the getting started experience.

Getting Started Experience

If you are putting together a demo or a sample, it is a bit cumbersome to take time to hash the passwords of your users. There are convenience mechanisms to make this easier, but this is still not intended for production.

Example 23. withDefaultPasswordEncoder Example
User user = User.withDefaultPasswordEncoder()
  .username("user")
  .password("password")
  .roles("user")
  .build();
System.out.println(user.getPassword());
// {bcrypt}$2a$10$dXJ3SW6G7P50lGmMkkmwe.20cQQubK3.HZWzG3YB1tlRy.fqvM/BG

If you are creating multiple users, you can also reuse the builder.

Example 24. withDefaultPasswordEncoder Reusing the Builder
UserBuilder users = User.withDefaultPasswordEncoder();
User user = users
  .username("user")
  .password("password")
  .roles("USER")
  .build();
User admin = users
  .username("admin")
  .password("password")
  .roles("USER","ADMIN")
  .build();

This does hash the password that is stored, but the passwords are still exposed in memory and in the compiled source code. Therefore, it is still not considered secure for a production environment. For production, you should hash your passwords externally.

Encode with Spring Boot CLI

The easiest way to properly encode your password is to use the Spring Boot CLI.

For example, the following will encode the password of password for use with DelegatingPasswordEncoder:

Example 25. Spring Boot CLI encodepassword Example
spring encodepassword password
{bcrypt}$2a$10$X5wFBtLrL/kHcmrOGGTrGufsBX8CJ0WpQpF3pgeuxBB/H73BK1DW6
Troubleshooting

The following error occurs when one of the passwords that are stored has no id as described in Password Storage Format.

java.lang.IllegalArgumentException: There is no PasswordEncoder mapped for the id "null"
    at org.springframework.security.crypto.password.DelegatingPasswordEncoder$UnmappedIdPasswordEncoder.matches(DelegatingPasswordEncoder.java:233)
    at org.springframework.security.crypto.password.DelegatingPasswordEncoder.matches(DelegatingPasswordEncoder.java:196)

The easiest way to resolve the error is to switch to explicitly provide the PasswordEncoder that you passwords are encoded with. The easiest way to resolve it is to figure out how your passwords are currently being stored and explicitly provide the correct PasswordEncoder.

If you are migrating from Spring Security 4.2.x you can revert to the previous behavior by exposing a NoOpPasswordEncoder bean.

Alternatively, you can prefix all of your passwords with the correct id and continue to use DelegatingPasswordEncoder. For example, if you are using BCrypt, you would migrate your password from something like:

$2a$10$dXJ3SW6G7P50lGmMkkmwe.20cQQubK3.HZWzG3YB1tlRy.fqvM/BG

to

{bcrypt}$2a$10$dXJ3SW6G7P50lGmMkkmwe.20cQQubK3.HZWzG3YB1tlRy.fqvM/BG

For a complete listing of the mappings refer to the Javadoc on PasswordEncoderFactories.

BCryptPasswordEncoder

The BCryptPasswordEncoder implementation uses the widely supported bcrypt algorithm to hash the passwords. In order to make it more resistent to password cracking, bcrypt is deliberately slow. Like other adaptive one-way functions, it should be tuned to take about 1 second to verify a password on your system. The default implementation of BCryptPasswordEncoder uses strength 10 as mentioned in the Javadoc of BCryptPasswordEncoder. You are encouraged to tune and test the strength parameter on your own system so that it takes roughly 1 second to verify a password.

// Create an encoder with strength 16
BCryptPasswordEncoder encoder = new BCryptPasswordEncoder(16);
String result = encoder.encode("myPassword");
assertTrue(encoder.matches("myPassword", result));
Argon2PasswordEncoder

The Argon2PasswordEncoder implementation uses the Argon2 algorithm to hash the passwords. Argon2 is the winner of the Password Hashing Competition. In order to defeat password cracking on custom hardware, Argon2 is a deliberately slow algorithm that requires large amounts of memory. Like other adaptive one-way functions, it should be tuned to take about 1 second to verify a password on your system. The current implementation if the Argon2PasswordEncoder requires BouncyCastle.

// Create an encoder with all the defaults
Argon2PasswordEncoder encoder = new Argon2PasswordEncoder();
String result = encoder.encode("myPassword");
assertTrue(encoder.matches("myPassword", result));
Pbkdf2PasswordEncoder

The Pbkdf2PasswordEncoder implementation uses the PBKDF2 algorithm to hash the passwords. In order to defeat password cracking PBKDF2 is a deliberately slow algorithm. Like other adaptive one-way functions, it should be tuned to take about 1 second to verify a password on your system. This algorithm is a good choice when FIPS certification is required.

// Create an encoder with all the defaults
Pbkdf2PasswordEncoder encoder = new Pbkdf2PasswordEncoder();
String result = encoder.encode("myPassword");
assertTrue(encoder.matches("myPassword", result));
SCryptPasswordEncoder

The SCryptPasswordEncoder implementation uses scrypt algorithm to hash the passwords. In order to defeat password cracking on custom hardware scrypt is a deliberately slow algorithm that requires large amounts of memory. Like other adaptive one-way functions, it should be tuned to take about 1 second to verify a password on your system.

// Create an encoder with all the defaults
SCryptPasswordEncoder encoder = new SCryptPasswordEncoder();
String result = encoder.encode("myPassword");
assertTrue(encoder.matches("myPassword", result));
Other PasswordEncoders

There are a significant number of other PasswordEncoder implementations that exist entirely for backward compatibility. They are all deprecated to indicate that they are no longer considered secure. However, there are no plans to remove them since it is difficult to migrate existing legacy systems.

Password Storage Configuration

Spring Security uses DelegatingPasswordEncoder by default. However, this can be customized by exposing a PasswordEncoder as a Spring bean.

If you are migrating from Spring Security 4.2.x you can revert to the previous behavior by exposing a NoOpPasswordEncoder bean.

Reverting to NoOpPasswordEncoder is not considered to be secure. You should instead migrate to using DelegatingPasswordEncoder to support secure password encoding.

Example 26. NoOpPasswordEncoder
Java
@Bean
public static NoOpPasswordEncoder passwordEncoder() {
    return NoOpPasswordEncoder.getInstance();
}
XML
<b:bean id="passwordEncoder"
        class="org.springframework.security.crypto.password.NoOpPasswordEncoder" factory-method="getInstance"/>
Kotlin
@Bean
fun passwordEncoder(): PasswordEncoder {
    return NoOpPasswordEncoder.getInstance();
}

XML Configuration requires the NoOpPasswordEncoder bean name to be passwordEncoder.

5.2. Protection Against Exploits

Spring Security provides protection against common exploits. Whenever possible, the protection is enabled by default. Below you will find high level description of the various exploits that Spring Security protects against.

5.2.1. Cross Site Request Forgery (CSRF)

Spring provides comprehensive support for protecting against Cross Site Request Forgery (CSRF) attacks. In the following sections we will explore:

This portion of the documentation discusses the general topic of CSRF protection. Refer to the relevant sections for specific information on CSRF protection for servlet and WebFlux based applications.

What is a CSRF Attack?

The best way to understand a CSRF attack is by taking a look at a concrete example.

Assume that your bank’s website provides a form that allows transferring money from the currently logged in user to another bank account. For example, the transfer form might look like:

Example 27. Transfer form
<form method="post"
    action="/transfer">
<input type="text"
    name="amount"/>
<input type="text"
    name="routingNumber"/>
<input type="text"
    name="account"/>
<input type="submit"
    value="Transfer"/>
</form>

The corresponding HTTP request might look like:

Example 28. Transfer HTTP request
POST /transfer HTTP/1.1
Host: bank.example.com
Cookie: JSESSIONID=randomid
Content-Type: application/x-www-form-urlencoded

amount=100.00&routingNumber=1234&account=9876

Now pretend you authenticate to your bank’s website and then, without logging out, visit an evil website. The evil website contains an HTML page with the following form:

Example 29. Evil transfer form
<form method="post"
    action="https://bank.example.com/transfer">
<input type="hidden"
    name="amount"
    value="100.00"/>
<input type="hidden"
    name="routingNumber"
    value="evilsRoutingNumber"/>
<input type="hidden"
    name="account"
    value="evilsAccountNumber"/>
<input type="submit"
    value="Win Money!"/>
</form>

You like to win money, so you click on the submit button. In the process, you have unintentionally transferred $100 to a malicious user. This happens because, while the evil website cannot see your cookies, the cookies associated with your bank are still sent along with the request.

Worst yet, this whole process could have been automated using JavaScript. This means you didn’t even need to click on the button. Furthermore, it could just as easily happen when visiting an honest site that is a victim of a XSS attack. So how do we protect our users from such attacks?

Protecting Against CSRF Attacks

The reason that a CSRF attack is possible is that the HTTP request from the victim’s website and the request from the attacker’s website are exactly the same. This means there is no way to reject requests coming from the evil website and allow requests coming from the bank’s website. To protect against CSRF attacks we need to ensure there is something in the request that the evil site is unable to provide so we can differentiate the two requests.

Spring provides two mechanisms to protect against CSRF attacks:

Both protections require that Safe Methods Must be Idempotent

Safe Methods Must be Idempotent

In order for either protection against CSRF to work, the application must ensure that "safe" HTTP methods are idempotent. This means that requests with the HTTP method GET, HEAD, OPTIONS, and TRACE should not change the state of the application.

Synchronizer Token Pattern

The predominant and most comprehensive way to protect against CSRF attacks is to use the Synchronizer Token Pattern. This solution is to ensure that each HTTP request requires, in addition to our session cookie, a secure random generated value called a CSRF token must be present in the HTTP request.

When an HTTP request is submitted, the server must look up the expected CSRF token and compare it against the actual CSRF token in the HTTP request. If the values do not match, the HTTP request should be rejected.

The key to this working is that the actual CSRF token should be in a part of the HTTP request that is not automatically included by the browser. For example, requiring the actual CSRF token in an HTTP parameter or an HTTP header will protect against CSRF attacks. Requiring the actual CSRF token in a cookie does not work because cookies are automatically included in the HTTP request by the browser.

We can relax the expectations to only require the actual CSRF token for each HTTP request that updates state of the application. For that to work, our application must ensure that safe HTTP methods are idempotent. This improves usability since we want to allow linking to our website using links from external sites. Additionally, we do not want to include the random token in HTTP GET as this can cause the tokens to be leaked.

Let’s take a look at how our example would change when using the Synchronizer Token Pattern. Assume the actual CSRF token is required to be in an HTTP parameter named _csrf. Our application’s transfer form would look like:

Example 30. Synchronizer Token Form
<form method="post"
    action="/transfer">
<input type="hidden"
    name="_csrf"
    value="4bfd1575-3ad1-4d21-96c7-4ef2d9f86721"/>
<input type="text"
    name="amount"/>
<input type="text"
    name="routingNumber"/>
<input type="hidden"
    name="account"/>
<input type="submit"
    value="Transfer"/>
</form>

The form now contains a hidden input with the value of the CSRF token. External sites cannot read the CSRF token since the same origin policy ensures the evil site cannot read the response.

The corresponding HTTP request to transfer money would look like this:

Example 31. Synchronizer Token request
POST /transfer HTTP/1.1
Host: bank.example.com
Cookie: JSESSIONID=randomid
Content-Type: application/x-www-form-urlencoded

amount=100.00&routingNumber=1234&account=9876&_csrf=4bfd1575-3ad1-4d21-96c7-4ef2d9f86721

You will notice that the HTTP request now contains the _csrf parameter with a secure random value. The evil website will not be able to provide the correct value for the _csrf parameter (which must be explicitly provided on the evil website) and the transfer will fail when the server compares the actual CSRF token to the expected CSRF token.

SameSite Attribute

An emerging way to protect against CSRF Attacks is to specify the SameSite Attribute on cookies. A server can specify the SameSite attribute when setting a cookie to indicate that the cookie should not be sent when coming from external sites.

Spring Security does not directly control the creation of the session cookie, so it does not provide support for the SameSite attribute. Spring Session provides support for the SameSite attribute in servlet based applications. Spring Framework’s CookieWebSessionIdResolver provides out of the box support for the SameSite attribute in WebFlux based applications.

An example, HTTP response header with the SameSite attribute might look like:

Example 32. SameSite HTTP response
Set-Cookie: JSESSIONID=randomid; Domain=bank.example.com; Secure; HttpOnly; SameSite=Lax

Valid values for the SameSite attribute are:

  • Strict - when specified any request coming from the same-site will include the cookie. Otherwise, the cookie will not be included in the HTTP request.

  • Lax - when specified cookies will be sent when coming from the same-site or when the request comes from top-level navigations and the method is idempotent. Otherwise, the cookie will not be included in the HTTP request.

Let’s take a look at how our example could be protected using the SameSite attribute. The bank application can protect against CSRF by specifying the SameSite attribute on the session cookie.

With the SameSite attribute set on our session cookie, the browser will continue to send the JSESSIONID cookie with requests coming from the banking website. However, the browser will no longer send the JSESSIONID cookie with a transfer request coming from the evil website. Since the session is no longer present in the transfer request coming from the evil website, the application is protected from the CSRF attack.

There are some important considerations that one should be aware about when using SameSite attribute to protect against CSRF attacks.

Setting the SameSite attribute to Strict provides a stronger defense but can confuse users. Consider a user that stays logged into a social media site hosted at https://social.example.com. The user receives an email at https://email.example.org that includes a link to the social media site. If the user clicks on the link, they would rightfully expect to be authenticated to the social media site. However, if the SameSite attribute is Strict the cookie would not be sent and so the user would not be authenticated.

We could improve the protection and usability of SameSite protection against CSRF attacks by implementing gh-7537.

Another obvious consideration is that in order for the SameSite attribute to protect users, the browser must support the SameSite attribute. Most modern browsers do support the SameSite attribute. However, older browsers that are still in use may not.

For this reason, it is generally recommended to use the SameSite attribute as a defense in depth rather than the sole protection against CSRF attacks.

When to use CSRF protection

When should you use CSRF protection? Our recommendation is to use CSRF protection for any request that could be processed by a browser by normal users. If you are only creating a service that is used by non-browser clients, you will likely want to disable CSRF protection.

CSRF protection and JSON

A common question is "do I need to protect JSON requests made by javascript?" The short answer is, it depends. However, you must be very careful as there are CSRF exploits that can impact JSON requests. For example, a malicious user can create a CSRF with JSON using the following form:

Example 33. CSRF with JSON form
<form action="https://bank.example.com/transfer" method="post" enctype="text/plain">
    <input name='{"amount":100,"routingNumber":"evilsRoutingNumber","account":"evilsAccountNumber", "ignore_me":"' value='test"}' type='hidden'>
    <input type="submit"
        value="Win Money!"/>
</form>

This will produce the following JSON structure

Example 34. CSRF with JSON request
{ "amount": 100,
"routingNumber": "evilsRoutingNumber",
"account": "evilsAccountNumber",
"ignore_me": "=test"
}

If an application were not validating the Content-Type, then it would be exposed to this exploit. Depending on the setup, a Spring MVC application that validates the Content-Type could still be exploited by updating the URL suffix to end with .json as shown below:

Example 35. CSRF with JSON Spring MVC form
<form action="https://bank.example.com/transfer.json" method="post" enctype="text/plain">
    <input name='{"amount":100,"routingNumber":"evilsRoutingNumber","account":"evilsAccountNumber", "ignore_me":"' value='test"}' type='hidden'>
    <input type="submit"
        value="Win Money!"/>
</form>
CSRF and Stateless Browser Applications

What if my application is stateless? That doesn’t necessarily mean you are protected. In fact, if a user does not need to perform any actions in the web browser for a given request, they are likely still vulnerable to CSRF attacks.

For example, consider an application that uses a custom cookie that contains all the state within it for authentication instead of the JSESSIONID. When the CSRF attack is made the custom cookie will be sent with the request in the same manner that the JSESSIONID cookie was sent in our previous example. This application will be vulnerable to CSRF attacks.

Applications that use basic authentication are also vulnerable to CSRF attacks. The application is vulnerable since the browser will automatically include the username and password in any requests in the same manner that the JSESSIONID cookie was sent in our previous example.

CSRF Considerations

There are a few special considerations to consider when implementing protection against CSRF attacks.

Logging In

In order to protect against forging log in requests the log in HTTP request should be protected against CSRF attacks. Protecting against forging log in requests is necessary so that a malicious user cannot read a victim’s sensitive information. The attack is executed by:

  • A malicious user performs a CSRF log in using the malicious user’s credentials. The victim is now authenticated as the malicious user.

  • The malicious user then tricks the victim to visit the compromised website and enter sensitive information

  • The information is associated to the malicious user’s account so the malicious user can log in with their own credentials and view the vicitim’s sensitive information

A possible complication to ensuring log in HTTP requests are protected against CSRF attacks is that the user might experience a session timeout that causes the request to be rejected. A session timeout is surprising to users who do not expect to need to have a session in order to log in. For more information refer to CSRF and Session Timeouts.

Logging Out

In order to protect against forging log out requests, the log out HTTP request should be protected against CSRF attacks. Protecting against forging log out requests is necessary so a malicious user cannot read a victim’s sensitive information. For details on the attack refer to this blog post.

A possible complication to ensuring log out HTTP requests are protected against CSRF attacks is that the user might experience a session timeout that causes the request to be rejected. A session timeout is surprising to users who do not expect to need to have a session in order to log out. For more information refer to CSRF and Session Timeouts.

CSRF and Session Timeouts

More often than not, the expected CSRF token is stored in the session. This means that as soon as the session expires the server will not find an expected CSRF token and reject the HTTP request. There are a number of options to solve timeouts each of which come with trade offs.

  • The best way to mitigate the timeout is by using JavaScript to request a CSRF token on form submission. The form is then updated with the CSRF token and submitted.

  • Another option is to have some JavaScript that lets the user know their session is about to expire. The user can click a button to continue and refresh the session.

  • Finally, the expected CSRF token could be stored in a cookie. This allows the expected CSRF token to outlive the session.

    One might ask why the expected CSRF token isn’t stored in a cookie by default. This is because there are known exploits in which headers (i.e. specify the cookies) can be set by another domain. This is the same reason Ruby on Rails no longer skips CSRF checks when the header X-Requested-With is present. See this webappsec.org thread for details on how to perform the exploit. Another disadvantage is that by removing the state (i.e. the timeout) you lose the ability to forcibly terminate the token if it is compromised.

Multipart (file upload)

Protecting multipart requests (file uploads) from CSRF attacks causes a chicken and the egg problem. In order to prevent a CSRF attack from occurring, the body of the HTTP request must be read to obtain actual CSRF token. However, reading the body means that the file will be uploaded which means an external site can upload a file.

There are two options to using CSRF protection with multipart/form-data. Each option has its trade-offs.

Before you integrate Spring Security’s CSRF protection with multipart file upload, ensure that you can upload without the CSRF protection first. More information about using multipart forms with Spring can be found within the 1.1.11. Multipart Resolver section of the Spring reference and the MultipartFilter javadoc.

Place CSRF Token in the Body

The first option is to include the actual CSRF token in the body of the request. By placing the CSRF token in the body, the body will be read before authorization is performed. This means that anyone can place temporary files on your server. However, only authorized users will be able to submit a File that is processed by your application. In general, this is the recommended approach because the temporary file upload should have a negligible impact on most servers.

Include CSRF Token in URL

If allowing unauthorized users to upload temporary files is not acceptable, an alternative is to include the expected CSRF token as a query parameter in the action attribute of the form. The disadvantage to this approach is that query parameters can be leaked. More generally, it is considered best practice to place sensitive data within the body or headers to ensure it is not leaked. Additional information can be found in RFC 2616 Section 15.1.3 Encoding Sensitive Information in URI’s.

HiddenHttpMethodFilter

In some applications a form parameter can be used to override the HTTP method. For example, the form below could be used to treat the HTTP method as a delete rather than a post.

Example 36. CSRF Hidden HTTP Method Form
<form action="/process"
    method="post">
    <!-- ... -->
    <input type="hidden"
        name="_method"
        value="delete"/>
</form>

Overriding the HTTP method occurs in a filter. That filter must be placed before Spring Security’s support. Note that overriding only happens on a post, so this is actually unlikely to cause any real problems. However, it is still best practice to ensure it is placed before Spring Security’s filters.

5.2.2. Security HTTP Response Headers

This portion of the documentation discusses the general topic of Security HTTP Response Headers. Refer to the relevant sections for specific information on Security HTTP Response Headers servlet and WebFlux based applications.

There are many HTTP response headers that can be used to increase the security of web applications. This section is dedicated to the various HTTP response headers that Spring Security provides explicit support for. If necessary, Spring Security can also be configured to provide custom headers.

Default Security Headers

Refer to the relevant sections to see how to customize the defaults for both servlet and webflux based applications.

Spring Security provides a default set of security related HTTP response headers to provide secure defaults.

The default for Spring Security is to include the following headers:

Example 37. Default Security HTTP Response Headers
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: 0
X-Content-Type-Options: nosniff
Strict-Transport-Security: max-age=31536000 ; includeSubDomains
X-Frame-Options: DENY
X-XSS-Protection: 1; mode=block
Strict-Transport-Security is only added on HTTPS requests

If the defaults do not meet your needs, you can easily remove, modify, or add headers from these defaults. For additional details on each of these headers, refer to the corresponding sections:

Cache Control

Refer to the relevant sections to see how to customize the defaults for both servlet and webflux based applications.

Spring Security’s default is to disable caching to protect user’s content.

If a user authenticates to view sensitive information and then logs out, we don’t want a malicious user to be able to click the back button to view the sensitive information. The cache control headers that are sent by default are:

Example 38. Default Cache Control HTTP Response Headers
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: 0

In order to be secure by default, Spring Security adds these headers by default. However, if your application provides it’s own cache control headers Spring Security will back out of the way. This allows for applications to ensure that static resources like CSS and JavaScript can be cached.

Content Type Options

Refer to the relevant sections to see how to customize the defaults for both servlet and webflux based applications.

Historically browsers, including Internet Explorer, would try to guess the content type of a request using content sniffing. This allowed browsers to improve the user experience by guessing the content type on resources that had not specified the content type. For example, if a browser encountered a JavaScript file that did not have the content type specified, it would be able to guess the content type and then execute it.

There are many additional things one should do (i.e. only display the document in a distinct domain, ensure Content-Type header is set, sanitize the document, etc) when allowing content to be uploaded. However, these measures are out of the scope of what Spring Security provides. It is also important to point out when disabling content sniffing, you must specify the content type in order for things to work properly.

The problem with content sniffing is that this allowed malicious users to use polyglots (i.e. a file that is valid as multiple content types) to execute XSS attacks. For example, some sites may allow users to submit a valid postscript document to a website and view it. A malicious user might create a postscript document that is also a valid JavaScript file and execute a XSS attack with it.

Spring Security disables content sniffing by default by adding the following header to HTTP responses:

Example 39. nosniff HTTP Response Header
X-Content-Type-Options: nosniff
HTTP Strict Transport Security (HSTS)

Refer to the relevant sections to see how to customize the defaults for both servlet and webflux based applications.

When you type in your bank’s website, do you enter mybank.example.com or do you enter https://mybank.example.com? If you omit the https protocol, you are potentially vulnerable to Man in the Middle attacks. Even if the website performs a redirect to https://mybank.example.com a malicious user could intercept the initial HTTP request and manipulate the response (i.e. redirect to https://mibank.example.com and steal their credentials).

Many users omit the https protocol and this is why HTTP Strict Transport Security (HSTS) was created. Once mybank.example.com is added as a HSTS host, a browser can know ahead of time that any request to mybank.example.com should be interpreted as https://mybank.example.com. This greatly reduces the possibility of a Man in the Middle attack occurring.

In accordance with RFC6797, the HSTS header is only injected into HTTPS responses. In order for the browser to acknowledge the header, the browser must first trust the CA that signed the SSL certificate used to make the connection (not just the SSL certificate).

One way for a site to be marked as a HSTS host is to have the host preloaded into the browser. Another is to add the Strict-Transport-Security header to the response. For example, Spring Security’s default behavior is to add the following header which instructs the browser to treat the domain as an HSTS host for a year (there are approximately 31536000 seconds in a year):

Example 40. Strict Transport Security HTTP Response Header
Strict-Transport-Security: max-age=31536000 ; includeSubDomains ; preload

The optional includeSubDomains directive instructs the browser that subdomains (i.e. secure.mybank.example.com) should also be treated as an HSTS domain.

The optional preload directive instructs the browser that domain should be preloaded in browser as HSTS domain. For more details on HSTS preload please see https://hstspreload.org.

HTTP Public Key Pinning (HPKP)

In order to remain passive Spring Security still provides support for HPKP in servlet environments, but for the reasons listed above HPKP is no longer recommended by the security team.

HTTP Public Key Pinning (HPKP) specifies to a web client which public key to use with certain web server to prevent Man in the Middle (MITM) attacks with forged certificates. When used correctly, HPKP could add additional layers of protection against compromised certificates. However, due to the complexity of HPKP many experts no longer recommend using it and Chrome has even removed support for it.

For additional details around why HPKP is no longer recommended read Is HTTP Public Key Pinning Dead? and I’m giving up on HPKP.

X-Frame-Options

Refer to the relevant sections to see how to customize the defaults for both servlet and webflux based applications.

Allowing your website to be added to a frame can be a security issue. For example, using clever CSS styling users could be tricked into clicking on something that they were not intending (video demo). For example, a user that is logged into their bank might click a button that grants access to other users. This sort of attack is known as Clickjacking.

Another modern approach to dealing with clickjacking is to use Content Security Policy (CSP).

There are a number ways to mitigate clickjacking attacks. For example, to protect legacy browsers from clickjacking attacks you can use frame breaking code. While not perfect, the frame breaking code is the best you can do for the legacy browsers.

A more modern approach to address clickjacking is to use X-Frame-Options header. By default Spring Security disables rendering pages within an iframe using with the following header:

X-Frame-Options: DENY
X-XSS-Protection

Refer to the relevant sections to see how to customize the defaults for both servlet and webflux based applications.

Some browsers have built in support for filtering out reflected XSS attacks. This is by no means foolproof, but does assist in XSS protection.

The filtering is typically enabled by default, so adding the header typically just ensures it is enabled and instructs the browser what to do when a XSS attack is detected. For example, the filter might try to change the content in the least invasive way to still render everything. At times, this type of replacement can become a XSS vulnerability in itself. Instead, it is best to block the content rather than attempt to fix it. By default Spring Security blocks the content using the following header:

X-XSS-Protection: 1; mode=block
Content Security Policy (CSP)

Refer to the relevant sections to see how to configure both servlet and webflux based applications.

Content Security Policy (CSP) is a mechanism that web applications can leverage to mitigate content injection vulnerabilities, such as cross-site scripting (XSS). CSP is a declarative policy that provides a facility for web application authors to declare and ultimately inform the client (user-agent) about the sources from which the web application expects to load resources.

Content Security Policy is not intended to solve all content injection vulnerabilities. Instead, CSP can be leveraged to help reduce the harm caused by content injection attacks. As a first line of defense, web application authors should validate their input and encode their output.

A web application may employ the use of CSP by including one of the following HTTP headers in the response:

  • Content-Security-Policy

  • Content-Security-Policy-Report-Only

Each of these headers are used as a mechanism to deliver a security policy to the client. A security policy contains a set of security policy directives, each responsible for declaring the restrictions for a particular resource representation.

For example, a web application can declare that it expects to load scripts from specific, trusted sources, by including the following header in the response:

Example 41. Content Security Policy Example
Content-Security-Policy: script-src https://trustedscripts.example.com

An attempt to load a script from another source other than what is declared in the script-src directive will be blocked by the user-agent. Additionally, if the report-uri directive is declared in the security policy, then the violation will be reported by the user-agent to the declared URL.

For example, if a web application violates the declared security policy, the following response header will instruct the user-agent to send violation reports to the URL specified in the policy’s report-uri directive.

Example 42. Content Security Policy with report-uri
Content-Security-Policy: script-src https://trustedscripts.example.com; report-uri /csp-report-endpoint/

Violation reports are standard JSON structures that can be captured either by the web application’s own API or by a publicly hosted CSP violation reporting service, such as, https://report-uri.io/.

The Content-Security-Policy-Report-Only header provides the capability for web application authors and administrators to monitor security policies, rather than enforce them. This header is typically used when experimenting and/or developing security policies for a site. When a policy is deemed effective, it can be enforced by using the Content-Security-Policy header field instead.

Given the following response header, the policy declares that scripts may be loaded from one of two possible sources.

Example 43. Content Security Policy Report Only
Content-Security-Policy-Report-Only: script-src 'self' https://trustedscripts.example.com; report-uri /csp-report-endpoint/

If the site violates this policy, by attempting to load a script from evil.com, the user-agent will send a violation report to the declared URL specified by the report-uri directive, but still allow the violating resource to load nevertheless.

Applying Content Security Policy to a web application is often a non-trivial undertaking. The following resources may provide further assistance in developing effective security policies for your site.

Referrer Policy

Refer to the relevant sections to see how to configure both servlet and webflux based applications.

Referrer Policy is a mechanism that web applications can leverage to manage the referrer field, which contains the last page the user was on.

Spring Security’s approach is to use Referrer Policy header, which provides different policies:

Example 44. Referrer Policy Example
Referrer-Policy: same-origin

The Referrer-Policy response header instructs the browser to let the destination knows the source where the user was previously.

Feature Policy

Refer to the relevant sections to see how to configure both servlet and webflux based applications.

Feature Policy is a mechanism that allows web developers to selectively enable, disable, and modify the behavior of certain APIs and web features in the browser.

Example 45. Feature Policy Example
Feature-Policy: geolocation 'self'

With Feature Policy, developers can opt-in to a set of "policies" for the browser to enforce on specific features used throughout your site. These policies restrict what APIs the site can access or modify the browser’s default behavior for certain features.

Clear Site Data

Refer to the relevant sections to see how to configure both servlet and webflux based applications.

Clear Site Data is a mechanism by which any browser-side data - cookies, local storage, and the like - can be removed when an HTTP response contains this header:

Clear-Site-Data: "cache", "cookies", "storage", "executionContexts"

This is a nice clean-up action to perform on logout.

Custom Headers

Refer to the relevant sections to see how to configure both servlet based applications.

Spring Security has mechanisms to make it convenient to add the more common security headers to your application. However, it also provides hooks to enable adding custom headers.

5.2.3. HTTP

All HTTP based communication, including static resources, should be protected using TLS.

As a framework, Spring Security does not handle HTTP connections and thus does not provide support for HTTPS directly. However, it does provide a number of features that help with HTTPS usage.

Redirect to HTTPS

When a client uses HTTP, Spring Security can be configured to redirect to HTTPS both Servlet and WebFlux environments.

Strict Transport Security

Spring Security provides support for Strict Transport Security and enables it by default.

Proxy Server Configuration

When using a proxy server it is important to ensure that you have configured your application properly. For example, many applications will have a load balancer that responds to request for https://example.com/ by forwarding the request to an application server at https://192.168.1:8080 Without proper configuration, the application server will not know that the load balancer exists and treat the request as though https://192.168.1:8080 was requested by the client.

To fix this you can use RFC 7239 to specify that a load balancer is being used. To make the application aware of this, you need to either configure your application server aware of the X-Forwarded headers. For example Tomcat uses the RemoteIpValve and Jetty uses ForwardedRequestCustomizer. Alternatively, Spring users can leverage ForwardedHeaderFilter.

Spring Boot users may use the server.use-forward-headers property to configure the application. See the Spring Boot documentation for further details.

6. Project Modules

In Spring Security 3.0, the codebase was sub-divided into separate jars which more clearly separate different functionality areas and third-party dependencies. If you use Maven to build your project, these are the modules you should add to your pom.xml. Even if you do not use Maven, we recommend that you consult the pom.xml files to get an idea of third-party dependencies and versions. Another good idea is to examine the libraries that are included in the sample applications.

6.1. Core — spring-security-core.jar

This module contains core authentication and access-contol classes and interfaces, remoting support, and basic provisioning APIs. It is required by any application that uses Spring Security. It supports standalone applications, remote clients, method (service layer) security, and JDBC user provisioning. It contains the following top-level packages:

  • org.springframework.security.core

  • org.springframework.security.access

  • org.springframework.security.authentication

  • org.springframework.security.provisioning

6.2. Remoting — spring-security-remoting.jar

This module provides integration with Spring Remoting. You do not need this unless you are writing a remote client that uses Spring Remoting. The main package is org.springframework.security.remoting.

6.3. Web — spring-security-web.jar

This module contains filters and related web-security infrastructure code. It contains anything with a servlet API dependency. You need it if you require Spring Security web authentication services and URL-based access-control. The main package is org.springframework.security.web.

6.4. Config — spring-security-config.jar

This module contains the security namespace parsing code and Java configuration code. You need it if you use the Spring Security XML namespace for configuration or Spring Security’s Java Configuration support. The main package is org.springframework.security.config. None of the classes are intended for direct use in an application.

6.5. LDAP — spring-security-ldap.jar

This module provides LDAP authentication and provisioning code. It is required if you need to use LDAP authentication or manage LDAP user entries. The top-level package is org.springframework.security.ldap.

6.6. OAuth 2.0 Core — spring-security-oauth2-core.jar

spring-security-oauth2-core.jar contains core classes and interfaces that provide support for the OAuth 2.0 Authorization Framework and for OpenID Connect Core 1.0. It is required by applications that use OAuth 2.0 or OpenID Connect Core 1.0, such as client, resource server, and authorization server. The top-level package is org.springframework.security.oauth2.core.

6.7. OAuth 2.0 Client — spring-security-oauth2-client.jar

spring-security-oauth2-client.jar contains Spring Security’s client support for OAuth 2.0 Authorization Framework and OpenID Connect Core 1.0. It is required by applications that use OAuth 2.0 Login or OAuth Client support. The top-level package is org.springframework.security.oauth2.client.

6.8. OAuth 2.0 JOSE — spring-security-oauth2-jose.jar

spring-security-oauth2-jose.jar contains Spring Security’s support for the JOSE (Javascript Object Signing and Encryption) framework. The JOSE framework is intended to provide a method to securely transfer claims between parties. It is built from a collection of specifications:

  • JSON Web Token (JWT)

  • JSON Web Signature (JWS)

  • JSON Web Encryption (JWE)

  • JSON Web Key (JWK)

It contains the following top-level packages:

  • org.springframework.security.oauth2.jwt

  • org.springframework.security.oauth2.jose

6.9. OAuth 2.0 Resource Server — spring-security-oauth2-resource-server.jar

spring-security-oauth2-resource-server.jar contains Spring Security’s support for OAuth 2.0 Resource Servers. It is used to protect APIs via OAuth 2.0 Bearer Tokens. The top-level package is org.springframework.security.oauth2.server.resource.

6.10. ACL — spring-security-acl.jar

This module contains a specialized domain object ACL implementation. It is used to apply security to specific domain object instances within your application. The top-level package is org.springframework.security.acls.

6.11. CAS — spring-security-cas.jar

This module contains Spring Security’s CAS client integration. You should use it if you want to use Spring Security web authentication with a CAS single sign-on server. The top-level package is org.springframework.security.cas.

6.12. OpenID — spring-security-openid.jar

This module contains OpenID web authentication support. It is used to authenticate users against an external OpenID server. The top-level package is org.springframework.security.openid. It requires OpenID4Java.

6.13. Test — spring-security-test.jar

This module contains support for testing with Spring Security.

7. Samples

Spring Security includes many samples applications.

Servlet Applications

Spring Security integrates with the Servlet Container by using a standard Servlet Filter. This means it works with any application that runs in a Servlet Container. More concretely, you do not need to use Spring in your Servlet-based application to take advantage of Spring Security.

8. Hello Spring Security

This section covers the minimum setup for how to use Spring Security with Spring Boot.

The completed application can be found at samples/boot/helloworld For your convenience, you can download a minimal Spring Boot + Spring Security application by clicking here.

8.1. Updating Dependencies

The only step you need to do is update the dependencies by using Maven or Gradle.

8.2. Starting Hello Spring Security Boot

You can now run the Spring Boot application by using the Maven Plugin’s run goal. The following example shows how to do so (and the beginning of the output from doing so):

Example 46. Running Spring Boot Application
$ ./mvn spring-boot:run
...
INFO 23689 --- [  restartedMain] .s.s.UserDetailsServiceAutoConfiguration :

Using generated security password: 8e557245-73e2-4286-969a-ff57fe326336

...

8.3. Spring Boot Auto Configuration

Spring Boot automatically:

  • Enables Spring Security’s default configuration, which creates a servlet Filter as a bean named springSecurityFilterChain. This bean is responsible for all the security (protecting the application URLs, validating submitted username and passwords, redirecting to the log in form, and so on) within your application.

  • Creates a UserDetailsService bean with a username of user and a randomly generated password that is logged to the console.

  • Registers the Filter with a bean named springSecurityFilterChain with the Servlet container for every request.

Spring Boot is not configuring much, but it does a lot. A summary of the features follows:

9. Servlet Security: The Big Picture

This section discusses Spring Security’s high level architecture within Servlet based applications. We build on this high level understanding within Authentication, Authorization, Protection Against Exploits sections of the reference.

9.1. A Review of Filters

Spring Security’s Servlet support is based on Servlet Filters, so it is helpful to look at the role of Filters generally first. The picture below shows the typical layering of the handlers for a single HTTP request.

filterchain
Figure 1. FilterChain

The client sends a request to the application, and the container creates a FilterChain which contains the Filters and Servlet that should process the HttpServletRequest based on the path of the request URI. In a Spring MVC application the Servlet is an instance of DispatcherServlet. At most one Servlet can handle a single HttpServletRequest and HttpServletResponse. However, more than one Filter can be used to:

  • Prevent downstream Filters or the Servlet from being invoked. In this instance the Filter will typically write the HttpServletResponse.

  • Modify the HttpServletRequest or HttpServletResponse used by the downstream Filters and Servlet

The power of the Filter comes from the FilterChain that is passed into it.

Example 47. FilterChain Usage Example
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) {
    // do something before the rest of the application
    chain.doFilter(request, response); // invoke the rest of the application
    // do something after the rest of the application
}

Since a Filter only impacts downstream Filters and the Servlet, the order each Filter is invoked is extremely important.

9.2. DelegatingFilterProxy

Spring provides a Filter implementation named DelegatingFilterProxy that allows bridging between the Servlet container’s lifecycle and Spring’s ApplicationContext. The Servlet container allows registering Filters using its own standards, but it is not aware of Spring defined Beans. DelegatingFilterProxy can be registered via standard Servlet container mechanisms, but delegate all the work to a Spring Bean that implements Filter.

Here is a picture of how DelegatingFilterProxy fits into the Filters and the FilterChain.

delegatingfilterproxy
Figure 2. DelegatingFilterProxy

DelegatingFilterProxy looks up Bean Filter0 from the ApplicationContext and then invokes Bean Filter0. The pseudo code of DelegatingFilterProxy can be seen below.

Example 48. DelegatingFilterProxy Pseudo Code
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) {
    // Lazily get Filter that was registered as a Spring Bean
    // For the example in DelegatingFilterProxy delegate is an instance of Bean Filter0
    Filter delegate = getFilterBean(someBeanName);
    // delegate work to the Spring Bean
    delegate.doFilter(request, response);
}

Another benefit of DelegatingFilterProxy is that it allows delaying looking Filter bean instances. This is important because the container needs to register the Filter instances before the container can startup. However, Spring typically uses a ContextLoaderListener to load the Spring Beans which will not be done until after the Filter instances need to be registered.

9.3. FilterChainProxy

Spring Security’s Servlet support is contained within FilterChainProxy. FilterChainProxy is a special Filter provided by Spring Security that allows delegating to many Filter instances through SecurityFilterChain. Since FilterChainProxy is a Bean, it is typically wrapped in a DelegatingFilterProxy.

filterchainproxy
Figure 3. FilterChainProxy

9.4. SecurityFilterChain

SecurityFilterChain is used by FilterChainProxy to determine which Spring Security Filters should be invoked for this request.

securityfilterchain
Figure 4. SecurityFilterChain

The Security Filters in SecurityFilterChain are typically Beans, but they are registered with FilterChainProxy instead of DelegatingFilterProxy. FilterChainProxy provides a number of advantages to registering directly with the Servlet container or DelegatingFilterProxy. First, it provides a starting point for all of Spring Security’s Servlet support. For that reason, if you are attempting to troubleshoot Spring Security’s Servlet support, adding a debug point in FilterChainProxy is a great place to start.

Second, since FilterChainProxy is central to Spring Security usage it can perform tasks that are not viewed as optional. For example, it clears out the SecurityContext to avoid memory leaks. It also applies Spring Security’s HttpFirewall to protect applications against certain types of attacks.

In addition, it provides more flexibility in determining when a SecurityFilterChain should be invoked. In a Servlet container, Filters are invoked based upon the URL alone. However, FilterChainProxy can determine invocation based upon anything in the HttpServletRequest by leveraging the RequestMatcher interface.

In fact, FilterChainProxy can be used to determine which SecurityFilterChain should be used. This allows providing a totally separate configuration for different slices if your application.

multi securityfilterchain
Figure 5. Multiple SecurityFilterChain

In the Multiple SecurityFilterChain Figure FilterChainProxy decides which SecurityFilterChain should be used. Only the first SecurityFilterChain that matches will be invoked. If a URL of /api/messages/ is requested, it will first match on SecurityFilterChain0's pattern of /api/**, so only SecurityFilterChain0 will be invoked even though it also matches on SecurityFilterChainn. If a URL of /messages/ is requested, it will not match on SecurityFilterChain0's pattern of /api/**, so FilterChainProxy will continue trying each SecurityFilterChain. Assuming that no other, SecurityFilterChain instances match SecurityFilterChainn will be invoked.

Notice that SecurityFilterChain0 has only three security Filters instances configured. However, SecurityFilterChainn has four security Filters configured. It is important to note that each SecurityFilterChain can be unique and configured in isolation. In fact, a SecurityFilterChain might have zero security Filters if the application wants Spring Security to ignore certain requests.

9.5. Security Filters

The Security Filters are inserted into the FilterChainProxy with the SecurityFilterChain API. The order of Filters matters. It is typically not necessary to know the ordering of Spring Security’s Filters. However, there are times that it is beneficial to know the ordering

Below is a comprehensive list of Spring Security Filter ordering:

  • ChannelProcessingFilter

  • ConcurrentSessionFilter

  • WebAsyncManagerIntegrationFilter

  • SecurityContextPersistenceFilter

  • HeaderWriterFilter

  • CorsFilter

  • CsrfFilter

  • LogoutFilter

  • OAuth2AuthorizationRequestRedirectFilter

  • Saml2WebSsoAuthenticationRequestFilter

  • X509AuthenticationFilter

  • AbstractPreAuthenticatedProcessingFilter

  • CasAuthenticationFilter

  • OAuth2LoginAuthenticationFilter

  • Saml2WebSsoAuthenticationFilter

  • UsernamePasswordAuthenticationFilter

  • ConcurrentSessionFilter

  • OpenIDAuthenticationFilter

  • DefaultLoginPageGeneratingFilter

  • DefaultLogoutPageGeneratingFilter

  • DigestAuthenticationFilter

  • BearerTokenAuthenticationFilter

  • BasicAuthenticationFilter

  • RequestCacheAwareFilter

  • SecurityContextHolderAwareRequestFilter

  • JaasApiIntegrationFilter

  • RememberMeAuthenticationFilter

  • AnonymousAuthenticationFilter

  • OAuth2AuthorizationCodeGrantFilter

  • SessionManagementFilter

  • ExceptionTranslationFilter

  • FilterSecurityInterceptor

  • SwitchUserFilter

9.6. Handling Security Exceptions

The ExceptionTranslationFilter allows translation of AccessDeniedException and AuthenticationException into HTTP responses.

ExceptionTranslationFilter is inserted into the FilterChainProxy as one of the Security Filters.

exceptiontranslationfilter
  • number 1 First, the ExceptionTranslationFilter invokes FilterChain.doFilter(request, response) to invoke the rest of the application.

  • number 2 If the user is not authenticated or it is an AuthenticationException, then Start Authentication.

    • The SecurityContextHolder is cleared out

    • The HttpServletRequest is saved in the RequestCache. When the user successfully authenticates, the RequestCache is used to replay the original request.

    • The AuthenticationEntryPoint is used to request credentials from the client. For example, it might redirect to a log in page or send a WWW-Authenticate header.

  • number 3 Otherwise if it is an AccessDeniedException, then Access Denied. The AccessDeniedHandler is invoked to handle access denied.

If the application does not throw an AccessDeniedException or an AuthenticationException, then ExceptionTranslationFilter does not do anything.

The pseudocode for ExceptionTranslationFilter looks something like this:

ExceptionTranslationFilter pseudocode
try {
    filterChain.doFilter(request, response); (1)
} catch (AccessDeniedException | AuthenticationException e) {
    if (!authenticated || e instanceof AuthenticationException) {
        startAuthentication(); (2)
    } else {
        accessDenied(); (3)
    }
}
1 You will recall from A Review of Filters that invoking FilterChain.doFilter(request, response) is the equivalent of invoking the rest of the application. This means that if another part of the application, (i.e. FilterSecurityInterceptor or method security) throws an AuthenticationException or AccessDeniedException it will be caught and handled here.
2 If the user is not authenticated or it is an AuthenticationException, then Start Authentication.
3 Otherwise, Access Denied

10. Authentication

Spring Security provides comprehensive support for Authentication. This section discusses:

Architecture Components

This section describes the main architectural components of Spring Security’s used in Servlet authentication. If you need concrete flows that explain how these pieces fit together, look at the Authentication Mechanism specific sections.

Authentication Mechanisms

10.1. SecurityContextHolder

At the heart of Spring Security’s authentication model is the SecurityContextHolder. It contains the SecurityContext.

securitycontextholder

The SecurityContextHolder is where Spring Security stores the details of who is authenticated. Spring Security does not care how the SecurityContextHolder is populated. If it contains a value, then it is used as the currently authenticated user.

The simplest way to indicate a user is authenticated is to set the SecurityContextHolder directly.

Example 49. Setting SecurityContextHolder
SecurityContext context = SecurityContextHolder.createEmptyContext(); (1)
Authentication authentication =
    new TestingAuthenticationToken("username", "password", "ROLE_USER"); (2)
context.setAuthentication(authentication);

SecurityContextHolder.setContext(context); (3)
1 We start by creating an empty SecurityContext. It is important to create a new SecurityContext instance instead of using SecurityContextHolder.getContext().setAuthentication(authentication) to avoid race conditions across multiple threads.
2 Next we create a new Authentication object. Spring Security does not care what type of Authentication implementation is set on the SecurityContext. Here we use TestingAuthenticationToken because it is very simple. A more common production scenario is UsernamePasswordAuthenticationToken(userDetails, password, authorities).
3 Finally, we set the SecurityContext on the SecurityContextHolder. Spring Security will use this information for authorization.

If you wish to obtain information about the authenticated principal, you can do so by accessing the SecurityContextHolder.

Example 50. Access Currently Authenticated User
SecurityContext context = SecurityContextHolder.getContext();
Authentication authentication = context.getAuthentication();
String username = authentication.getName();
Object principal = authentication.getPrincipal();
Collection<? extends GrantedAuthority> authorities = authentication.getAuthorities();

By default the SecurityContextHolder uses a ThreadLocal to store these details, which means that the SecurityContext is always available to methods in the same thread of execution, even if the SecurityContext is not explicitly passed around as an argument to those methods. Using a ThreadLocal in this way is quite safe if care is taken to clear the thread after the present principal’s request is processed. Spring Security’s FilterChainProxy ensures that the SecurityContext is always cleared.

Some applications aren’t entirely suitable for using a ThreadLocal, because of the specific way they work with threads. For example, a Swing client might want all threads in a Java Virtual Machine to use the same security context. SecurityContextHolder can be configured with a strategy on startup to specify how you would like the context to be stored. For a standalone application you would use the SecurityContextHolder.MODE_GLOBAL strategy. Other applications might want to have threads spawned by the secure thread also assume the same security identity. This is achieved by using SecurityContextHolder.MODE_INHERITABLETHREADLOCAL. You can change the mode from the default SecurityContextHolder.MODE_THREADLOCAL in two ways. The first is to set a system property, the second is to call a static method on SecurityContextHolder. Most applications won’t need to change from the default, but if you do, take a look at the JavaDoc for SecurityContextHolder to learn more.

10.2. SecurityContext

The SecurityContext is obtained from the SecurityContextHolder. The SecurityContext contains an Authentication object.

10.3. Authentication

The Authentication serves two main purposes within Spring Security:

  • An input to AuthenticationManager to provide the credentials a user has provided to authenticate. When used in this scenario, isAuthenticated() returns false.

  • Represents the currently authenticated user. The current Authentication can be obtained from the SecurityContext.

The Authentication contains:

  • principal - identifies the user. When authenticating with a username/password this is often an instance of UserDetails.

  • credentials - Often a password. In many cases this will be cleared after the user is authenticated to ensure it is not leaked.

  • authorities - the GrantedAuthoritys are high level permissions the user is granted. A few examples are roles or scopes.

10.4. GrantedAuthority

GrantedAuthoritys are high level permissions the user is granted. A few examples are roles or scopes.

GrantedAuthoritys can be obtained from the Authentication.getAuthorities() method. This method provides a Collection of GrantedAuthority objects. A GrantedAuthority is, not surprisingly, an authority that is granted to the principal. Such authorities are usually "roles", such as ROLE_ADMINISTRATOR or ROLE_HR_SUPERVISOR. These roles are later on configured for web authorization, method authorization and domain object authorization. Other parts of Spring Security are capable of interpreting these authorities, and expect them to be present. When using username/password based authentication GrantedAuthoritys are usually loaded by the UserDetailsService.

Usually the GrantedAuthority objects are application-wide permissions. They are not specific to a given domain object. Thus, you wouldn’t likely have a GrantedAuthority to represent a permission to Employee object number 54, because if there are thousands of such authorities you would quickly run out of memory (or, at the very least, cause the application to take a long time to authenticate a user). Of course, Spring Security is expressly designed to handle this common requirement, but you’d instead use the project’s domain object security capabilities for this purpose.

10.5. AuthenticationManager

AuthenticationManager is the API that defines how Spring Security’s Filters perform authentication. The Authentication that is returned is then set on the SecurityContextHolder by the controller (i.e. Spring Security’s Filterss) that invoked the AuthenticationManager. If you are not integrating with Spring Security’s Filterss you can set the SecurityContextHolder directly and are not required to use an AuthenticationManager.

While the implementation of AuthenticationManager could be anything, the most common implementation is ProviderManager.

10.6. ProviderManager

ProviderManager is the most commonly used implementation of AuthenticationManager. ProviderManager delegates to a List of AuthenticationProviders. Each AuthenticationProvider has an opportunity to indicate that authentication should be successful, fail, or indicate it cannot make a decision and allow a downstream AuthenticationProvider to decide. If none of the configured AuthenticationProviders can authenticate, then authentication will fail with a ProviderNotFoundException which is a special AuthenticationException that indicates the ProviderManager was not configured support the type of Authentication that was passed into it.

providermanager

In practice each AuthenticationProvider knows how to perform a specific type of authentication. For example, one AuthenticationProvider might be able to validate a username/password, while another might be able to authenticate a SAML assertion. This allows each AuthenticationProvider to do a very specific type of authentication, while supporting multiple types of authentication and only exposing a single AuthenticationManager bean.

ProviderManager also allows configuring an optional parent AuthenticationManager which is consulted in the event that no AuthenticationProvider can perform authentication. The parent can be any type of AuthenticationManager, but it is often an instance of ProviderManager.

providermanager parent

In fact, multiple ProviderManager instances might share the same parent AuthenticationManager. This is somewhat common in scenarios where there are multiple SecurityFilterChain instances that have some authentication in common (the shared parent AuthenticationManager), but also different authentication mechanisms (the different ProviderManager instances).

providermanagers parent

By default ProviderManager will attempt to clear any sensitive credentials information from the Authentication object which is returned by a successful authentication request. This prevents information like passwords being retained longer than necessary in the HttpSession.

This may cause issues when you are using a cache of user objects, for example, to improve performance in a stateless application. If the Authentication contains a reference to an object in the cache (such as a UserDetails instance) and this has its credentials removed, then it will no longer be possible to authenticate against the cached value. You need to take this into account if you are using a cache. An obvious solution is to make a copy of the object first, either in the cache implementation or in the AuthenticationProvider which creates the returned Authentication object. Alternatively, you can disable the eraseCredentialsAfterAuthentication property on ProviderManager. See the Javadoc for more information.

10.7. AuthenticationProvider

Multiple AuthenticationProviders can be injected into ProviderManager. Each AuthenticationProvider performs a specific type of authentication. For example, DaoAuthenticationProvider supports username/password based authentication while JwtAuthenticationProvider supports authenticating a JWT token.

10.8. Request Credentials with AuthenticationEntryPoint

AuthenticationEntryPoint is used to send an HTTP response that requests credentials from a client.

Sometimes a client will proactively include credentials such as a username/password to request a resource. In these cases, Spring Security does not need to provide an HTTP response that requests credentials from the client since they are already included.

In other cases, a client will make an unauthenticated request to a resource that they are not authorized to access. In this case, an implementation of AuthenticationEntryPoint is used to request credentials from the client. The AuthenticationEntryPoint implementation might perform a redirect to a log in page, respond with an WWW-Authenticate header, etc.

10.9. AbstractAuthenticationProcessingFilter

AbstractAuthenticationProcessingFilter is used as a base Filter for authenticating a user’s credentials. Before the credentials can be authenticated, Spring Security typically requests the credentials using AuthenticationEntryPoint.

Next, the AbstractAuthenticationProcessingFilter can authenticate any authentication requests that are submitted to it.

abstractauthenticationprocessingfilter

number 1 When the user submits their credentials, the AbstractAuthenticationProcessingFilter creates an Authentication from the HttpServletRequest to be authenticated. The type of Authentication created depends on the subclass of AbstractAuthenticationProcessingFilter. For example, UsernamePasswordAuthenticationFilter creates a UsernamePasswordAuthenticationToken from a username and password that are submitted in the HttpServletRequest.

number 2 Next, the Authentication is passed into the AuthenticationManager to be authenticated.

number 3 If authentication fails, then Failure

  • The SecurityContextHolder is cleared out.

  • RememberMeServices.loginFail is invoked. If remember me is not configured, this is a no-op.

  • AuthenticationFailureHandler is invoked.

number 4 If authentication is successful, then Success.

  • SessionAuthenticationStrategy is notified of a new log in.

  • The Authentication is set on the SecurityContextHolder. Later the SecurityContextPersistenceFilter saves the SecurityContext to the HttpSession.

  • RememberMeServices.loginSuccess is invoked. If remember me is not configured, this is a no-op.

  • ApplicationEventPublisher publishes an InteractiveAuthenticationSuccessEvent.

10.10. Username/Password Authentication

One of the most common ways to authenticate a user is by validating a username and password. As such, Spring Security provides comprehensive support for authenticating with a username and password.

Reading the Username & Password

Spring Security provides the following built in mechanisms for reading a username and password from the HttpServletRequest:

Storage Mechanisms

Each of the supported mechanisms for reading a username and password can leverage any of the supported storage mechanisms:

10.10.1. Form Login

Spring Security provides support for username and password being provided through an html form. This section provides details on how form based authentication works within Spring Security.

Let’s take a look at how form based log in works within Spring Security. First, we see how the user is redirected to the log in form.

loginurlauthenticationentrypoint
Figure 6. Redirecting to the Log In Page

The figure builds off our SecurityFilterChain diagram.

number 1 First, a user makes an unauthenticated request to the resource /private for which it is not authorized.

number 2 Spring Security’s FilterSecurityInterceptor indicates that the unauthenticated request is Denied by throwing an AccessDeniedException.

number 3 Since the user is not authenticated, ExceptionTranslationFilter initiates Start Authentication and sends a redirect to the log in page with the configured AuthenticationEntryPoint. In most cases the AuthenticationEntryPoint is an instance of LoginUrlAuthenticationEntryPoint.

number 4 The browser will then request the log in page that it was redirected to.

number 5 Something within the application, must render the log in page.

When the username and password are submitted, the UsernamePasswordAuthenticationFilter authenticates the username and password. The UsernamePasswordAuthenticationFilter extends AbstractAuthenticationProcessingFilter, so this diagram should look pretty similar.

usernamepasswordauthenticationfilter
Figure 7. Authenticating Username and Password

The figure builds off our SecurityFilterChain diagram.

number 1 When the user submits their username and password, the UsernamePasswordAuthenticationFilter creates a UsernamePasswordAuthenticationToken which is a type of Authentication by extracting the username and password from the HttpServletRequest.

number 2 Next, the UsernamePasswordAuthenticationToken is passed into the AuthenticationManager to be authenticated. The details of what AuthenticationManager look like depend on how the user information is stored.

number 3 If authentication fails, then Failure

  • The SecurityContextHolder is cleared out.

  • RememberMeServices.loginFail is invoked. If remember me is not configured, this is a no-op.

  • AuthenticationFailureHandler is invoked.

number 4 If authentication is successful, then Success.

  • SessionAuthenticationStrategy is notified of a new log in.

  • The Authentication is set on the SecurityContextHolder.

  • RememberMeServices.loginSuccess is invoked. If remember me is not configured, this is a no-op.

  • ApplicationEventPublisher publishes an InteractiveAuthenticationSuccessEvent.

  • The AuthenticationSuccessHandler is invoked. Typically this is a SimpleUrlAuthenticationSuccessHandler which will redirect to a request saved by ExceptionTranslationFilter when we redirect to the log in page.

Spring Security form log in is enabled by default. However, as soon as any servlet based configuration is provided, form based log in must be explicitly provided. A minimal, explicit Java configuration can be found below:

Example 51. Form Log In
Java
protected void configure(HttpSecurity http) {
    http
        // ...
        .formLogin(withDefaults());
}
XML
<http>
    <!-- ... -->
    <form-login />
</http>
Kotlin
fun configure(http: HttpSecurity) {
    http {
        // ...
        formLogin { }
    }
}

In this configuration Spring Security will render a default log in page. Most production applications will require a custom log in form.

The configuration below demonstrates how to provide a custom log in form.

Example 52. Custom Log In Form Configuration
Java
protected void configure(HttpSecurity http) throws Exception {
    http
        // ...
        .formLogin(form -> form
            .loginPage("/login")
            .permitAll()
        );
}
XML
<http>
    <!-- ... -->
    <intercept-url pattern="/login" access="permitAll" />
    <form-login login-page="/login" />
</http>
Kotlin
fun configure(http: HttpSecurity) {
    http {
        // ...
        formLogin {
            loginPage = "/login"
            permitAll()
        }
    }
}

When the login page is specified in the Spring Security configuration, you are responsible for rendering the page. Below is a Thymeleaf template that produces an HTML login form that complies with a login page of /login.:

Example 53. Log In Form
src/main/resources/templates/login.html
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="https://www.thymeleaf.org">
    <head>
        <title>Please Log In</title>
    </head>
    <body>
        <h1>Please Log In</h1>
        <div th:if="${param.error}">
            Invalid username and password.</div>
        <div th:if="${param.logout}">
            You have been logged out.</div>
        <form th:action="@{/login}" method="post">
            <div>
            <input type="text" name="username" placeholder="Username"/>
            </div>
            <div>
            <input type="password" name="password" placeholder="Password"/>
            </div>
            <input type="submit" value="Log in" />
        </form>
    </body>
</html>

There are a few key points about the default HTML form:

  • The form should perform a post to /login

  • The form will need to include a CSRF Token which is automatically included by Thymeleaf.

  • The form should specify the username in a parameter named username

  • The form should specify the password in a parameter named password

  • If the HTTP parameter error is found, it indicates the user failed to provide a valid username / password

  • If the HTTP parameter logout is found, it indicates the user has logged out successfully

Many users will not need much more than to customize the log in page. However, if needed everything above can be customized with additional configuration.

If you are using Spring MVC, you will need a controller that maps GET /login to the login template we created. A minimal sample LoginController can be see below:

Example 54. LoginController
src/main/java/example/LoginController.java
@Controller
class LoginController {
    @GetMapping("/login")
    String login() {
        return "login";
    }
}

10.10.2. Basic Authentication

This section provides details on how Spring Security provides support for Basic HTTP Authentication for servlet based applications.

Let’s take a look at how HTTP Basic Authentication works within Spring Security. First, we see the WWW-Authenticate header is sent back to an unauthenticated client.

basicauthenticationentrypoint
Figure 8. Sending WWW-Authenticate Header

The figure builds off our SecurityFilterChain diagram.

number 1 First, a user makes an unauthenticated request to the resource /private for which it is not authorized.

number 2 Spring Security’s FilterSecurityInterceptor indicates that the unauthenticated request is Denied by throwing an AccessDeniedException.

number 3 Since the user is not authenticated, ExceptionTranslationFilter initiates Start Authentication. The configured AuthenticationEntryPoint is an instance of BasicAuthenticationEntryPoint which sends a WWW-Authenticate header. The RequestCache is typically a NullRequestCache that does not save the request since the client is capable of replaying the requests it originally requested.

When a client receives the WWW-Authenticate header it knows it should retry with a username and password. Below is the flow for the username and password being processed.

basicauthenticationfilter
Figure 9. Authenticating Username and Password

The figure builds off our SecurityFilterChain diagram.

number 1 When the user submits their username and password, the BasicAuthenticationFilter creates a UsernamePasswordAuthenticationToken which is a type of Authentication by extracting the username and password from the HttpServletRequest.

number 2 Next, the UsernamePasswordAuthenticationToken is passed into the AuthenticationManager to be authenticated. The details of what AuthenticationManager look like depend on how the user information is stored.

number 3 If authentication fails, then Failure

  • The SecurityContextHolder is cleared out.

  • RememberMeServices.loginFail is invoked. If remember me is not configured, this is a no-op.

  • AuthenticationEntryPoint is invoked to trigger the WWW-Authenticate to be sent again.

number 4 If authentication is successful, then Success.

  • The Authentication is set on the SecurityContextHolder.

  • RememberMeServices.loginSuccess is invoked. If remember me is not configured, this is a no-op.

  • The BasicAuthenticationFilter invokes FilterChain.doFilter(request,response) to continue with the rest of the application logic.

Spring Security’s HTTP Basic Authentication support in is enabled by default. However, as soon as any servlet based configuration is provided, HTTP Basic must be explicitly provided.

A minimal, explicit configuration can be found below:

Example 55. Explicit HTTP Basic Configuration
Java
protected void configure(HttpSecurity http) {
    http
        // ...
        .httpBasic(withDefaults());
}
XML
<http>
    <!-- ... -->
    <http-basic />
</http>
Kotlin
fun configure(http: HttpSecurity) {
    http {
        // ...
        httpBasic { }
    }
}

10.10.3. Digest Authentication

This section provides details on how Spring Security provides support for Digest Authentication which is provided DigestAuthenticationFilter.

You should not use Digest Authentication in modern applications because it is not considered secure. The most obvious problem is that you must store your passwords in plaintext, encrypted, or an MD5 format. All of these storage formats are considered insecure. Instead, you should store credentials using a one way adaptive password hash (i.e. bCrypt, PBKDF2, SCrypt, etc) which is not supported by Digest Authentication.

Digest Authentication attempts to solve many of the weaknesses of Basic authentication, specifically by ensuring credentials are never sent in clear text across the wire. Many browsers support Digest Authentication.

The standard governing HTTP Digest Authentication is defined by RFC 2617, which updates an earlier version of the Digest Authentication standard prescribed by RFC 2069. Most user agents implement RFC 2617. Spring Security’s Digest Authentication support is compatible with the “auth” quality of protection (qop) prescribed by RFC 2617, which also provides backward compatibility with RFC 2069. Digest Authentication was seen as a more attractive option if you need to use unencrypted HTTP (i.e. no TLS/HTTPS) and wish to maximise security of the authentication process. However, everyone should use HTTPS.

Central to Digest Authentication is a "nonce". This is a value the server generates. Spring Security’s nonce adopts the following format:

Example 56. Digest Syntax
base64(expirationTime + ":" + md5Hex(expirationTime + ":" + key))
expirationTime:   The date and time when the nonce expires, expressed in milliseconds
key:              A private key to prevent modification of the nonce token

You will need to ensure you configure insecure plain text Password Storage using NoOpPasswordEncoder`. The following provides an example of configuring Digest Authentication with Java Configuration:

Example 57. Digest Authentication
Java
@Autowired
UserDetailsService userDetailsService;

DigestAuthenticationEntryPoint entryPoint() {
    DigestAuthenticationEntryPoint result = new DigestAuthenticationEntryPoint();
    result.setRealmName("My App Relam");
    result.setKey("3028472b-da34-4501-bfd8-a355c42bdf92");
}

DigestAuthenticationFilter digestAuthenticationFilter() {
    DigestAuthenticationFilter result = new DigestAuthenticationFilter();
    result.setUserDetailsService(userDetailsService);
    result.setAuthenticationEntryPoint(entryPoint());
}

protected void configure(HttpSecurity http) throws Exception {
    http
        // ...
        .exceptionHandling(e -> e.authenticationEntryPoint(authenticationEntryPoint()))
        .addFilterBefore(digestFilter());
}
XML
<b:bean id="digestFilter"
        class="org.springframework.security.web.authentication.www.DigestAuthenticationFilter"
    p:userDetailsService-ref="jdbcDaoImpl"
    p:authenticationEntryPoint-ref="digestEntryPoint"
/>

<b:bean id="digestEntryPoint"
        class="org.springframework.security.web.authentication.www.DigestAuthenticationEntryPoint"
    p:realmName="My App Realm"
    p:key="3028472b-da34-4501-bfd8-a355c42bdf92"
/>

<http>
    <!-- ... -->
    <custom-filter ref="userFilter" position="DIGEST_AUTH_FILTER"/>
</http>

10.10.4. In-Memory Authentication

Spring Security’s InMemoryUserDetailsManager implements UserDetailsService to provide support for username/password based authentication that is retrieved in memory. InMemoryUserDetailsManager provides management of UserDetails by implementing the UserDetailsManager interface. UserDetails based authentication is used by Spring Security when it is configured to accept a username/password for authentication.

In this sample we use Spring Boot CLI to encode the password of password and get the encoded password of {bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW.

Example 58. InMemoryUserDetailsManager Java Configuration
Java
@Bean
public UserDetailsService users() {
    UserDetails user = User.builder()
        .username("user")
        .password("{bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW")
        .roles("USER")
        .build();
    UserDetails admin = User.builder()
        .username("admin")
        .password("{bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW")
        .roles("USER", "ADMIN")
        .build();
    return new InMemoryUserDetailsManager(user, admin);
}
XML
<user-service>
    <user name="user"
        password="{bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW"
        authorities="ROLE_USER" />
    <user name="admin"
        password="{bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW"
        authorities="ROLE_USER,ROLE_ADMIN" />
</user-service>
Kotlin
@Bean
fun users(): UserDetailsService {
    val user = User.builder()
        .username("user")
        .password("{bcrypt}$2a$10\$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW")
        .roles("USER")
        .build()
    val admin = User.builder()
        .username("admin")
        .password("{bcrypt}$2a$10\$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW")
        .roles("USER", "ADMIN")
        .build()
    return InMemoryUserDetailsManager(user, admin)
}

The samples above store the passwords in a secure format, but leave a lot to be desired in terms of getting started experience.

In the sample below we leverage User.withDefaultPasswordEncoder to ensure that the password stored in memory is protected. However, it does not protect the password against obtaining the password by decompiling the source code. For this reason, User.withDefaultPasswordEncoder should only be used for "getting started" and is not intended for production.

Example 59. InMemoryUserDetailsManager with User.withDefaultPasswordEncoder
Java
@Bean
public UserDetailsService users() {
    // The builder will ensure the passwords are encoded before saving in memory
    UserBuilder users = User.withDefaultPasswordEncoder();
    UserDetails user = users
        .username("user")
        .password("password")
        .roles("USER")
        .build();
    UserDetails admin = users
        .username("admin")
        .password("password")
        .roles("USER", "ADMIN")
        .build();
    return new InMemoryUserDetailsManager(user, admin);
}
Kotlin
@Bean
fun users(): UserDetailsService {
    // The builder will ensure the passwords are encoded before saving in memory
    val users = User.withDefaultPasswordEncoder()
    val user = users
        .username("user")
        .password("password")
        .roles("USER")
        .build()
    val admin = users
        .username("admin")
        .password("password")
        .roles("USER", "ADMIN")
        .build()
    return InMemoryUserDetailsManager(user, admin)
}

There is no simple way to use User.withDefaultPasswordEncoder with XML based configuration. For demos or just getting started, you can choose to prefix the password with {noop} to indicate no encoding should be used.

Example 60. <user-service> {noop} XML Configuration
<user-service>
    <user name="user"
        password="{noop}password"
        authorities="ROLE_USER" />
    <user name="admin"
        password="{noop}password"
        authorities="ROLE_USER,ROLE_ADMIN" />
</user-service>

10.10.5. JDBC Authentication

Spring Security’s JdbcDaoImpl implements UserDetailsService to provide support for username/password based authentication that is retrieved using JDBC. JdbcUserDetailsManager extends JdbcDaoImpl to provide management of UserDetails through the UserDetailsManager interface. UserDetails based authentication is used by Spring Security when it is configured to accept a username/password for authentication.

In the following sections we will discuss:

Default Schema

Spring Security provides default queries for JDBC based authentication. This section provides the corresponding default schemas used with the default queries. You will need to adjust the schema to match any customizations to the queries and the database dialect you are using.

User Schema

JdbcDaoImpl requires tables to load the password, account status (enabled or disabled) and a list of authorities (roles) for the user. The default schema required can be found below.

The default schema is also exposed as a classpath resource named org/springframework/security/core/userdetails/jdbc/users.ddl.

Example 61. Default User Schema
create table users(
    username varchar_ignorecase(50) not null primary key,
    password varchar_ignorecase(500) not null,
    enabled boolean not null
);

create table authorities (
    username varchar_ignorecase(50) not null,
    authority varchar_ignorecase(50) not null,
    constraint fk_authorities_users foreign key(username) references users(username)
);
create unique index ix_auth_username on authorities (username,authority);

Oracle is a popular database choice, but requires a slightly different schema. You can find the default Oracle Schema for users below.

Example 62. Default User Schema for Oracle Databases
CREATE TABLE USERS (
    USERNAME NVARCHAR2(128) PRIMARY KEY,
    PASSWORD NVARCHAR2(128) NOT NULL,
    ENABLED CHAR(1) CHECK (ENABLED IN ('Y','N') ) NOT NULL
);


CREATE TABLE AUTHORITIES (
    USERNAME NVARCHAR2(128) NOT NULL,
    AUTHORITY NVARCHAR2(128) NOT NULL
);
ALTER TABLE AUTHORITIES ADD CONSTRAINT AUTHORITIES_UNIQUE UNIQUE (USERNAME, AUTHORITY);
ALTER TABLE AUTHORITIES ADD CONSTRAINT AUTHORITIES_FK1 FOREIGN KEY (USERNAME) REFERENCES USERS (USERNAME) ENABLE;
Group Schema

If your application is leveraging groups, you will need to provide the groups schema. The default schema for groups can be found below.

Example 63. Default Group Schema
create table groups (
    id bigint generated by default as identity(start with 0) primary key,
    group_name varchar_ignorecase(50) not null
);

create table group_authorities (
    group_id bigint not null,
    authority varchar(50) not null,
    constraint fk_group_authorities_group foreign key(group_id) references groups(id)
);

create table group_members (
    id bigint generated by default as identity(start with 0) primary key,
    username varchar(50) not null,
    group_id bigint not null,
    constraint fk_group_members_group foreign key(group_id) references groups(id)
);
Setting up a DataSource

Before we configure JdbcUserDetailsManager, we must create a DataSource. In our example, we will setup an embedded DataSource that is initialized with the default user schema.

Example 64. Embedded Data Source
Java
@Bean
DataSource dataSource() {
    return new EmbeddedDatabaseBuilder()
        .setType(H2)
        .addScript("classpath:org/springframework/security/core/userdetails/jdbc/users.ddl")
        .build();
}
XML
<jdbc:embedded-database>
    <jdbc:script location="classpath:org/springframework/security/core/userdetails/jdbc/users.ddl"/>
</jdbc:embedded-database>
Kotlin
@Bean
fun dataSource(): DataSource {
    return EmbeddedDatabaseBuilder()
        .setType(H2)
        .addScript("classpath:org/springframework/security/core/userdetails/jdbc/users.ddl")
        .build()
}

In a production environment, you will want to ensure you setup a connection to an external database.

JdbcUserDetailsManager Bean

In this sample we use Spring Boot CLI to encode the password of password and get the encoded password of {bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW. See the PasswordEncoder section for more details about how to store passwords.

Example 65. JdbcUserDetailsManager
Java
@Bean
UserDetailsManager users(DataSource dataSource) {
    UserDetails user = User.builder()
        .username("user")
        .password("{bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW")
        .roles("USER")
        .build();
    UserDetails admin = User.builder()
        .username("admin")
        .password("{bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW")
        .roles("USER", "ADMIN")
        .build();
    JdbcUserDetailsManager users = new JdbcUserDetailsManager(dataSource);
    users.createUser(user);
    users.createUser(admin);
}
XML
<jdbc-user-service>
    <user name="user"
        password="{bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW"
        authorities="ROLE_USER" />
    <user name="admin"
        password="{bcrypt}$2a$10$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW"
        authorities="ROLE_USER,ROLE_ADMIN" />
</jdbc-user-service>
Kotlin
@Bean
fun users(dataSource: DataSource): UserDetailsManager {
    val user = User.builder()
            .username("user")
            .password("{bcrypt}$2a$10\$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW")
            .roles("USER")
            .build();
    val admin = User.builder()
            .username("admin")
            .password("{bcrypt}$2a$10\$GRLdNijSQMUvl/au9ofL.eDwmoohzzS7.rmNSJZ.0FxO/BTk76klW")
            .roles("USER", "ADMIN")
            .build();
    val users = JdbcUserDetailsManager(dataSource)
    users.createUser(user)
    users.createUser(admin)
    return users
}

10.10.6. UserDetails

UserDetails is returned by the UserDetailsService. The DaoAuthenticationProvider validates the UserDetails and then returns an Authentication that has a principal that is the UserDetails returned by the configured UserDetailsService.

10.10.7. UserDetailsService

UserDetailsService is used by DaoAuthenticationProvider for retrieving a username, password, and other attributes for authenticating with a username and password. Spring Security provides in-memory and JDBC implementations of UserDetailsService.

You can define custom authentication by exposing a custom UserDetailsService as a bean. For example, the following will customize authentication assuming that CustomUserDetailsService implements UserDetailsService:

This is only used if the AuthenticationManagerBuilder has not been populated and no AuthenticationProviderBean is defined.
Example 66. Custom UserDetailsService Bean
Java
@Bean
CustomUserDetailsService customUserDetailsService() {
    return new CustomUserDetailsService();
}
XML
<b:bean class="example.CustomUserDetailsService"/>
Kotlin
@Bean
fun customUserDetailsService() = CustomUserDetailsService()

10.10.8. PasswordEncoder

Spring Security’s servlet support storing passwords securely by integrating with PasswordEncoder. Customizing the PasswordEncoder implementation used by Spring Security can be done by exposing a PasswordEncoder Bean.

10.10.9. DaoAuthenticationProvider

DaoAuthenticationProvider is an AuthenticationProvider implementation that leverages a UserDetailsService and PasswordEncoder to authenticate a username and password.

Let’s take a look at how DaoAuthenticationProvider works within Spring Security. The figure explains details of how the AuthenticationManager in figures from Reading the Username & Password works.

daoauthenticationprovider
Figure 10. DaoAuthenticationProvider Usage

number 1 The authentication Filter from Reading the Username & Password passes a UsernamePasswordAuthenticationToken to the AuthenticationManager which is implemented by ProviderManager.

number 2 The ProviderManager is configured to use an AuthenticationProvider of type DaoAuthenticationProvider.

number 3 DaoAuthenticationProvider looks up the UserDetails from the UserDetailsService.

number 4 DaoAuthenticationProvider then uses the PasswordEncoder to validate the password on the UserDetails returned in the previous step.

number 5 When authentication is successful, the Authentication that is returned is of type UsernamePasswordAuthenticationToken and has a principal that is the UserDetails returned by the configured UserDetailsService. Ultimately, the returned UsernamePasswordAuthenticationToken will be set on the SecurityContextHolder by the authentication Filter.

10.10.10. LDAP Authentication

LDAP is often used by organizations as a central repository for user information and as an authentication service. It can also be used to store the role information for application users.

Spring Security’s LDAP based authentication is used by Spring Security when it is configured to accept a username/password for authentication. However, despite leveraging a username/password for authentication it does not integrate using UserDetailsService because in bind authentication the LDAP server does not return the password so the application cannot perform validation of the password.

There are many different scenarios for how an LDAP server may be configured so Spring Security’s LDAP provider is fully configurable. It uses separate strategy interfaces for authentication and role retrieval and provides default implementations which can be configured to handle a wide range of situations.

Prerequisites

You should be familiar with LDAP before trying to use it with Spring Security. The following link provides a good introduction to the concepts involved and a guide to setting up a directory using the free LDAP server OpenLDAP: https://www.zytrax.com/books/ldap/. Some familiarity with the JNDI APIs used to access LDAP from Java may also be useful. We don’t use any third-party LDAP libraries (Mozilla, JLDAP etc.) in the LDAP provider, but extensive use is made of Spring LDAP, so some familiarity with that project may be useful if you plan on adding your own customizations.

When using LDAP authentication, it is important to ensure that you configure LDAP connection pooling properly. If you are unfamiliar with how to do this, you can refer to the Java LDAP documentation.

Setting up an Embedded LDAP Server

The first thing you will need to do is to ensure that you have an LDAP Server to point your configuration to. For simplicity, it often best to start with an embedded LDAP Server. Spring Security supports using either:

In the samples below, we expose the following as users.ldif as a classpath resource to initialize the embedded LDAP server with the users user and admin both of which have a password of password.

users.ldif
dn: ou=groups,dc=springframework,dc=org
objectclass: top
objectclass: organizationalUnit
ou: groups

dn: ou=people,dc=springframework,dc=org
objectclass: top
objectclass: organizationalUnit
ou: people

dn: uid=admin,ou=people,dc=springframework,dc=org
objectclass: top
objectclass: person
objectclass: organizationalPerson
objectclass: inetOrgPerson
cn: Rod Johnson
sn: Johnson
uid: admin
userPassword: password

dn: uid=user,ou=people,dc=springframework,dc=org
objectclass: top
objectclass: person
objectclass: organizationalPerson
objectclass: inetOrgPerson
cn: Dianne Emu
sn: Emu
uid: user
userPassword: password

dn: cn=user,ou=groups,dc=springframework,dc=org
objectclass: top
objectclass: groupOfNames
cn: user
uniqueMember: uid=admin,ou=people,dc=springframework,dc=org
uniqueMember: uid=user,ou=people,dc=springframework,dc=org

dn: cn=admin,ou=groups,dc=springframework,dc=org
objectclass: top
objectclass: groupOfNames
cn: admin
uniqueMember: uid=admin,ou=people,dc=springframework,dc=org
Embedded UnboundID Server

If you wish to use UnboundID, then specify the following dependencies:

Example 67. UnboundID Dependencies
Maven
<dependency>
    <groupId>com.unboundid</groupId>
    <artifactId>unboundid-ldapsdk</artifactId>
    <version>4.0.14</version>
    <scope>runtime</scope>
</dependency>
Gradle
depenendencies {
    runtimeOnly "com.unboundid:unboundid-ldapsdk:4.0.14"
}

You can then configure the Embedded LDAP Server

Example 68. Embedded LDAP Server Configuration
Java
@Bean
UnboundIdContainer ldapContainer() {
    return new UnboundIdContainer("dc=springframework,dc=org",
                "classpath:users.ldif");
}
XML
<b:bean class="org.springframework.security.ldap.server.UnboundIdContainer"
    c:defaultPartitionSuffix="dc=springframework,dc=org"
    c:ldif="classpath:users.ldif"/>
Kotlin
@Bean
fun ldapContainer(): UnboundIdContainer {
    return UnboundIdContainer("dc=springframework,dc=org","classpath:users.ldif")
}
Embedded ApacheDS Server

Spring Security uses ApacheDS 1.x which is no longer maintained. Unfortunately, ApacheDS 2.x has only released milestone versions with no stable release. Once a stable release of ApacheDS 2.x is available, we will consider updating.

If you wish to use Apache DS, then specify the following dependencies:

Example 69. ApacheDS Dependencies
Maven
<dependency>
    <groupId>org.apache.directory.server</groupId>
    <artifactId>apacheds-core</artifactId>
    <version>1.5.5</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>org.apache.directory.server</groupId>
    <artifactId>apacheds-server-jndi</artifactId>
    <version>1.5.5</version>
    <scope>runtime</scope>
</dependency>
Gradle
depenendencies {
    runtimeOnly "org.apache.directory.server:apacheds-core:1.5.5"
    runtimeOnly "org.apache.directory.server:apacheds-server-jndi:1.5.5"
}

You can then configure the Embedded LDAP Server

Example 70. Embedded LDAP Server Configuration
Java
@Bean
ApacheDSContainer ldapContainer() {
    return new ApacheDSContainer("dc=springframework,dc=org",
                "classpath:users.ldif");
}
XML
<b:bean class="org.springframework.security.ldap.server.ApacheDSContainer"
    c:defaultPartitionSuffix="dc=springframework,dc=org"
    c:ldif="classpath:users.ldif"/>
Kotlin
@Bean
fun ldapContainer(): ApacheDSContainer {
    return ApacheDSContainer("dc=springframework,dc=org", "classpath:users.ldif")
}
LDAP ContextSource

Once you have an LDAP Server to point your configuration to, you need configure Spring Security to point to an LDAP server that should be used to authenticate users. This is done by creating an LDAP ContextSource, which is the equivalent of a JDBC DataSource.

Example 71. LDAP Context Source
Java
ContextSource contextSource(UnboundIdContainer container) {
    return new DefaultSpringSecurityContextSource("ldap://localhost:53389/dc=springframework,dc=org");
}
XML
<ldap-server
    url="ldap://localhost:53389/dc=springframework,dc=org" />
Kotlin
fun contextSource(container: UnboundIdContainer): ContextSource {
    return DefaultSpringSecurityContextSource("ldap://localhost:53389/dc=springframework,dc=org")
}
Authentication

Spring Security’s LDAP support does not use the UserDetailsService because LDAP bind authentication does not allow clients to read the password or even a hashed version of the password. This means there is no way a password to be read and then authenticated by Spring Security.

For this reason, LDAP support is implemented using the LdapAuthenticator interface. The LdapAuthenticator is also responsible for retrieving any required user attributes. This is because the permissions on the attributes may depend on the type of authentication being used. For example, if binding as the user, it may be necessary to read them with the user’s own permissions.

There are two LdapAuthenticator implementations supplied with Spring Security:

Using Bind Authentication

Bind Authentication is the most common mechanism for authenticating users with LDAP. In bind authentication the users credentials (i.e. username/password) are submitted to the LDAP server which authenticates them. The advantage to using bind authentication is that the user’s secrets (i.e. password) do not need to be exposed to clients which helps to protect them from leaking.

An example of bind authentication configuration can be found below.

Example 72. Bind Authentication
Java
@Bean
BindAuthenticator authenticator(BaseLdapPathContextSource contextSource) {
    BindAuthenticator authenticator = new BindAuthenticator(contextSource);
    authenticator.setUserDnPatterns(new String[] { "uid={0},ou=people" });
    return authenticator;
}

@Bean
LdapAuthenticationProvider authenticationProvider(LdapAuthenticator authenticator) {
    return new LdapAuthenticationProvider(authenticator);
}
XML
<ldap-authentication-provider
    user-dn-pattern="uid={0},ou=people"/>
Kotlin
@Bean
fun authenticator(contextSource: BaseLdapPathContextSource): BindAuthenticator {
    val authenticator = BindAuthenticator(contextSource)
    authenticator.setUserDnPatterns(arrayOf("uid={0},ou=people"))
    return authenticator
}

@Bean
fun authenticationProvider(authenticator: LdapAuthenticator): LdapAuthenticationProvider {
    return LdapAuthenticationProvider(authenticator)
}

This simple example would obtain the DN for the user by substituting the user login name in the supplied pattern and attempting to bind as that user with the login password. This is OK if all your users are stored under a single node in the directory. If instead you wished to configure an LDAP search filter to locate the user, you could use the following:

Example 73. Bind Authentication with Search Filter
Java
@Bean
BindAuthenticator authenticator(BaseLdapPathContextSource contextSource) {
    String searchBase = "ou=people";
    String filter = "(uid={0})";
    FilterBasedLdapUserSearch search =
        new FilterBasedLdapUserSearch(searchBase, filter, contextSource);
    BindAuthenticator authenticator = new BindAuthenticator(contextSource);
    authenticator.setUserSearch(search);
    return authenticator;
}

@Bean
LdapAuthenticationProvider authenticationProvider(LdapAuthenticator authenticator) {
    return new LdapAuthenticationProvider(authenticator);
}
XML
<ldap-authentication-provider
        user-search-filter="(uid={0})"
    user-search-base="ou=people"/>
Kotlin
@Bean
fun authenticator(contextSource: BaseLdapPathContextSource): BindAuthenticator {
    val searchBase = "ou=people"
    val filter = "(uid={0})"
    val search = FilterBasedLdapUserSearch(searchBase, filter, contextSource)
    val authenticator = BindAuthenticator(contextSource)
    authenticator.setUserSearch(search)
    return authenticator
}

@Bean
fun authenticationProvider(authenticator: LdapAuthenticator): LdapAuthenticationProvider {
    return LdapAuthenticationProvider(authenticator)
}

If used with the ContextSource definition above, this would perform a search under the DN ou=people,dc=springframework,dc=org using (uid={0}) as a filter. Again the user login name is substituted for the parameter in the filter name, so it will search for an entry with the uid attribute equal to the user name. If a user search base isn’t supplied, the search will be performed from the root.

Using Password Authentication

Password comparison is when the password supplied by the user is compared with the one stored in the repository. This can either be done by retrieving the value of the password attribute and checking it locally or by performing an LDAP "compare" operation, where the supplied password is passed to the server for comparison and the real password value is never retrieved. An LDAP compare cannot be done when the password is properly hashed with a random salt.

Example 74. Minimal Password Compare Configuration
Java
@Bean
PasswordComparisonAuthenticator authenticator(BaseLdapPathContextSource contextSource) {
    return new PasswordComparisonAuthenticator(contextSource);
}

@Bean
LdapAuthenticationProvider authenticationProvider(LdapAuthenticator authenticator) {
    return new LdapAuthenticationProvider(authenticator);
}
XML
<ldap-authentication-provider
        user-dn-pattern="uid={0},ou=people">
    <password-compare />
</ldap-authentication-provider>
Kotlin
@Bean
fun authenticator(contextSource: BaseLdapPathContextSource): PasswordComparisonAuthenticator {
    return PasswordComparisonAuthenticator(contextSource)
}

@Bean
fun authenticationProvider(authenticator: LdapAuthenticator): LdapAuthenticationProvider {
    return LdapAuthenticationProvider(authenticator)
}

A more advanced configuration with some customizations can be found below.

Example 75. Password Compare Configuration
Java
@Bean
PasswordComparisonAuthenticator authenticator(BaseLdapPathContextSource contextSource) {
    PasswordComparisonAuthenticator authenticator =
        new PasswordComparisonAuthenticator(contextSource);
    authenticator.setPasswordAttributeName("pwd"); (1)
    authenticator.setPasswordEncoder(new BCryptPasswordEncoder()); (2)
    return authenticator;
}

@Bean
LdapAuthenticationProvider authenticationProvider(LdapAuthenticator authenticator) {
    return new LdapAuthenticationProvider(authenticator);
}
XML
<ldap-authentication-provider
        user-dn-pattern="uid={0},ou=people">
    <password-compare password-attribute="pwd"> (1)
        <password-encoder ref="passwordEncoder" /> (2)
    </password-compare>
</ldap-authentication-provider>
<b:bean id="passwordEncoder"
    class="org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder" />
Kotlin
@Bean
fun authenticator(contextSource: BaseLdapPathContextSource): PasswordComparisonAuthenticator {
    val authenticator = PasswordComparisonAuthenticator(contextSource)
    authenticator.setPasswordAttributeName("pwd") (1)
    authenticator.setPasswordEncoder(BCryptPasswordEncoder()) (2)
    return authenticator
}

@Bean
fun authenticationProvider(authenticator: LdapAuthenticator): LdapAuthenticationProvider {
    return LdapAuthenticationProvider(authenticator)
}
1 Specify the password attribute as pwd
2 Use BCryptPasswordEncoder
LdapAuthoritiesPopulator

Spring Security’s LdapAuthoritiesPopulator is used to determine what authorites are returned for the user.

Example 76. Minimal Password Compare Configuration
Java
@Bean
LdapAuthoritiesPopulator authorities(BaseLdapPathContextSource contextSource) {
    String groupSearchBase = "";
    DefaultLdapAuthoritiesPopulator authorities =
        new DefaultLdapAuthoritiesPopulator(contextSource, groupSearchBase);
    authorities.setGroupSearchFilter("member={0}");
    return authorities;
}

@Bean
LdapAuthenticationProvider authenticationProvider(LdapAuthenticator authenticator, LdapAuthoritiesPopulator authorities) {
    return new LdapAuthenticationProvider(authenticator, authorities);
}
XML
<ldap-authentication-provider
    user-dn-pattern="uid={0},ou=people"
    group-search-filter="member={0}"/>
Kotlin
@Bean
fun authorities(contextSource: BaseLdapPathContextSource): LdapAuthoritiesPopulator {
    val groupSearchBase = ""
    val authorities = DefaultLdapAuthoritiesPopulator(contextSource, groupSearchBase)
    authorities.setGroupSearchFilter("member={0}")
    return authorities
}

@Bean
fun authenticationProvider(authenticator: LdapAuthenticator, authorities: LdapAuthoritiesPopulator): LdapAuthenticationProvider {
    return LdapAuthenticationProvider(authenticator, authorities)
}
Active Directory

Active Directory supports its own non-standard authentication options, and the normal usage pattern doesn’t fit too cleanly with the standard LdapAuthenticationProvider. Typically authentication is performed using the domain username (in the form [email protected]), rather than using an LDAP distinguished name. To make this easier, Spring Security has an authentication provider which is customized for a typical Active Directory setup.

Configuring ActiveDirectoryLdapAuthenticationProvider is quite straightforward. You just need to supply the domain name and an LDAP URL supplying the address of the server [1]. An example configuration can be seen below:

Example 77. Example Active Directory Configuration
Java
@Bean
ActiveDirectoryLdapAuthenticationProvider authenticationProvider() {
    return new ActiveDirectoryLdapAuthenticationProvider("example.com", "ldap://company.example.com/");
}
XML
<bean id="authenticationProvider"
        class="org.springframework.security.ldap.authentication.ad.ActiveDirectoryLdapAuthenticationProvider">
    <constructor-arg value="example.com" />
    <constructor-arg value="ldap://company.example.com/" />
</bean>
Kotlin
@Bean
fun authenticationProvider(): ActiveDirectoryLdapAuthenticationProvider {
    return ActiveDirectoryLdapAuthenticationProvider("example.com", "ldap://company.example.com/")
}

10.11. Session Management

HTTP session related functionality is handled by a combination of the SessionManagementFilter and the SessionAuthenticationStrategy interface, which the filter delegates to. Typical usage includes session-fixation protection attack prevention, detection of session timeouts and restrictions on how many sessions an authenticated user may have open concurrently.

10.11.1. Detecting Timeouts

You can configure Spring Security to detect the submission of an invalid session ID and redirect the user to an appropriate URL. This is achieved through the session-management element:

<http>
...
<session-management invalid-session-url="/invalidSession.htm" />
</http>

Note that if you use this mechanism to detect session timeouts, it may falsely report an error if the user logs out and then logs back in without closing the browser. This is because the session cookie is not cleared when you invalidate the session and will be resubmitted even if the user has logged out. You may be able to explicitly delete the JSESSIONID cookie on logging out, for example by using the following syntax in the logout handler:

<http>
<logout delete-cookies="JSESSIONID" />
</http>

Unfortunately this can’t be guaranteed to work with every servlet container, so you will need to test it in your environment

If you are running your application behind a proxy, you may also be able to remove the session cookie by configuring the proxy server. For example, using Apache HTTPD’s mod_headers, the following directive would delete the JSESSIONID cookie by expiring it in the response to a logout request (assuming the application is deployed under the path /tutorial):

<LocationMatch "/tutorial/logout">
Header always set Set-Cookie "JSESSIONID=;Path=/tutorial;Expires=Thu, 01 Jan 1970 00:00:00 GMT"
</LocationMatch>

10.11.2. Concurrent Session Control

If you wish to place constraints on a single user’s ability to log in to your application, Spring Security supports this out of the box with the following simple additions. First you need to add the following listener to your web.xml file to keep Spring Security updated about session lifecycle events:

<listener>
<listener-class>
    org.springframework.security.web.session.HttpSessionEventPublisher
</listener-class>
</listener>

Then add the following lines to your application context:

<http>
...
<session-management>
    <concurrency-control max-sessions="1" />
</session-management>
</http>

This will prevent a user from logging in multiple times - a second login will cause the first to be invalidated. Often you would prefer to prevent a second login, in which case you can use

<http>
...
<session-management>
    <concurrency-control max-sessions="1" error-if-maximum-exceeded="true" />
</session-management>
</http>

The second login will then be rejected. By "rejected", we mean that the user will be sent to the authentication-failure-url if form-based login is being used. If the second authentication takes place through another non-interactive mechanism, such as "remember-me", an "unauthorized" (401) error will be sent to the client. If instead you want to use an error page, you can add the attribute session-authentication-error-url to the session-management element.

If you are using a customized authentication filter for form-based login, then you have to configure concurrent session control support explicitly. More details can be found in the Session Management chapter.

10.11.3. Session Fixation Attack Protection

Session fixation attacks are a potential risk where it is possible for a malicious attacker to create a session by accessing a site, then persuade another user to log in with the same session (by sending them a link containing the session identifier as a parameter, for example). Spring Security protects against this automatically by creating a new session or otherwise changing the session ID when a user logs in. If you don’t require this protection, or it conflicts with some other requirement, you can control the behavior using the session-fixation-protection attribute on <session-management>, which has four options

  • none - Don’t do anything. The original session will be retained.

  • newSession - Create a new "clean" session, without copying the existing session data (Spring Security-related attributes will still be copied).

  • migrateSession - Create a new session and copy all existing session attributes to the new session. This is the default in Servlet 3.0 or older containers.

  • changeSessionId - Do not create a new session. Instead, use the session fixation protection provided by the Servlet container (HttpServletRequest#changeSessionId()). This option is only available in Servlet 3.1 (Java EE 7) and newer containers. Specifying it in older containers will result in an exception. This is the default in Servlet 3.1 and newer containers.

When session fixation protection occurs, it results in a SessionFixationProtectionEvent being published in the application context. If you use changeSessionId, this protection will also result in any javax.servlet.http.HttpSessionIdListener s being notified, so use caution if your code listens for both events. See the Session Management chapter for additional information.

10.11.4. SessionManagementFilter

The SessionManagementFilter checks the contents of the SecurityContextRepository against the current contents of the SecurityContextHolder to determine whether a user has been authenticated during the current request, typically by a non-interactive authentication mechanism, such as pre-authentication or remember-me [2]. If the repository contains a security context, the filter does nothing. If it doesn’t, and the thread-local SecurityContext contains a (non-anonymous) Authentication object, the filter assumes they have been authenticated by a previous filter in the stack. It will then invoke the configured SessionAuthenticationStrategy.

If the user is not currently authenticated, the filter will check whether an invalid session ID has been requested (because of a timeout, for example) and will invoke the configured InvalidSessionStrategy, if one is set. The most common behaviour is just to redirect to a fixed URL and this is encapsulated in the standard implementation SimpleRedirectInvalidSessionStrategy. The latter is also used when configuring an invalid session URL through the namespace,as described earlier.

10.11.5. SessionAuthenticationStrategy

SessionAuthenticationStrategy is used by both SessionManagementFilter and AbstractAuthenticationProcessingFilter, so if you are using a customized form-login class, for example, you will need to inject it into both of these. In this case, a typical configuration, combining the namespace and custom beans might look like this:

<http>
<custom-filter position="FORM_LOGIN_FILTER" ref="myAuthFilter" />
<session-management session-authentication-strategy-ref="sas"/>
</http>

<beans:bean id="myAuthFilter" class=
"org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter">
    <beans:property name="sessionAuthenticationStrategy" ref="sas" />
    ...
</beans:bean>

<beans:bean id="sas" class=
"org.springframework.security.web.authentication.session.SessionFixationProtectionStrategy" />

Note that the use of the default, SessionFixationProtectionStrategy may cause issues if you are storing beans in the session which implement HttpSessionBindingListener, including Spring session-scoped beans. See the Javadoc for this class for more information.

10.11.6. Concurrency Control

Spring Security is able to prevent a principal from concurrently authenticating to the same application more than a specified number of times. Many ISVs take advantage of this to enforce licensing, whilst network administrators like this feature because it helps prevent people from sharing login names. You can, for example, stop user "Batman" from logging onto the web application from two different sessions. You can either expire their previous login or you can report an error when they try to log in again, preventing the second login. Note that if you are using the second approach, a user who has not explicitly logged out (but who has just closed their browser, for example) will not be able to log in again until their original session expires.

Concurrency control is supported by the namespace, so please check the earlier namespace chapter for the simplest configuration. Sometimes you need to customize things though.

The implementation uses a specialized version of SessionAuthenticationStrategy, called ConcurrentSessionControlAuthenticationStrategy.

Previously the concurrent authentication check was made by the ProviderManager, which could be injected with a ConcurrentSessionController. The latter would check if the user was attempting to exceed the number of permitted sessions. However, this approach required that an HTTP session be created in advance, which is undesirable. In Spring Security 3, the user is first authenticated by the AuthenticationManager and once they are successfully authenticated, a session is created and the check is made whether they are allowed to have another session open.

To use concurrent session support, you’ll need to add the following to web.xml:

<listener>
    <listener-class>
    org.springframework.security.web.session.HttpSessionEventPublisher
    </listener-class>
</listener>

In addition, you will need to add the ConcurrentSessionFilter to your FilterChainProxy. The ConcurrentSessionFilter requires two constructor arguments, sessionRegistry, which generally points to an instance of SessionRegistryImpl, and sessionInformationExpiredStrategy, which defines the strategy to apply when a session has expired. A configuration using the namespace to create the FilterChainProxy and other default beans might look like this:

<http>
<custom-filter position="CONCURRENT_SESSION_FILTER" ref="concurrencyFilter" />
<custom-filter position="FORM_LOGIN_FILTER" ref="myAuthFilter" />

<session-management session-authentication-strategy-ref="sas"/>
</http>

<beans:bean id="redirectSessionInformationExpiredStrategy"
class="org.springframework.security.web.session.SimpleRedirectSessionInformationExpiredStrategy">
<beans:constructor-arg name="invalidSessionUrl" value="/session-expired.htm" />
</beans:bean>

<beans:bean id="concurrencyFilter"
class="org.springframework.security.web.session.ConcurrentSessionFilter">
<beans:constructor-arg name="sessionRegistry" ref="sessionRegistry" />
<beans:constructor-arg name="sessionInformationExpiredStrategy" ref="redirectSessionInformationExpiredStrategy" />
</beans:bean>

<beans:bean id="myAuthFilter" class=
"org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter">
<beans:property name="sessionAuthenticationStrategy" ref="sas" />
<beans:property name="authenticationManager" ref="authenticationManager" />
</beans:bean>

<beans:bean id="sas" class="org.springframework.security.web.authentication.session.CompositeSessionAuthenticationStrategy">
<beans:constructor-arg>
    <beans:list>
    <beans:bean class="org.springframework.security.web.authentication.session.ConcurrentSessionControlAuthenticationStrategy">
        <beans:constructor-arg ref="sessionRegistry"/>
        <beans:property name="maximumSessions" value="1" />
        <beans:property name="exceptionIfMaximumExceeded" value="true" />
    </beans:bean>
    <beans:bean class="org.springframework.security.web.authentication.session.SessionFixationProtectionStrategy">
    </beans:bean>
    <beans:bean class="org.springframework.security.web.authentication.session.RegisterSessionAuthenticationStrategy">
        <beans:constructor-arg ref="sessionRegistry"/>
    </beans:bean>
    </beans:list>
</beans:constructor-arg>
</beans:bean>

<beans:bean id="sessionRegistry"
    class="org.springframework.security.core.session.SessionRegistryImpl" />

Adding the listener to web.xml causes an ApplicationEvent to be published to the Spring ApplicationContext every time a HttpSession commences or terminates. This is critical, as it allows the SessionRegistryImpl to be notified when a session ends. Without it, a user will never be able to log back in again once they have exceeded their session allowance, even if they log out of another session or it times out.

Querying the SessionRegistry for currently authenticated users and their sessions

Setting up concurrency-control, either through the namespace or using plain beans has the useful side effect of providing you with a reference to the SessionRegistry which you can use directly within your application, so even if you don’t want to restrict the number of sessions a user may have, it may be worth setting up the infrastructure anyway. You can set the maximumSession property to -1 to allow unlimited sessions. If you’re using the namespace, you can set an alias for the internally-created SessionRegistry using the session-registry-alias attribute, providing a reference which you can inject into your own beans.

The getAllPrincipals() method supplies you with a list of the currently authenticated users. You can list a user’s sessions by calling the getAllSessions(Object principal, boolean includeExpiredSessions) method, which returns a list of SessionInformation objects. You can also expire a user’s session by calling expireNow() on a SessionInformation instance. When the user returns to the application, they will be prevented from proceeding. You may find these methods useful in an administration application, for example. Have a look at the Javadoc for more information.

10.12. Remember-Me Authentication

10.12.1. Overview

Remember-me or persistent-login authentication refers to web sites being able to remember the identity of a principal between sessions. This is typically accomplished by sending a cookie to the browser, with the cookie being detected during future sessions and causing automated login to take place. Spring Security provides the necessary hooks for these operations to take place, and has two concrete remember-me implementations. One uses hashing to preserve the security of cookie-based tokens and the other uses a database or other persistent storage mechanism to store the generated tokens.

Note that both implementations require a UserDetailsService. If you are using an authentication provider which doesn’t use a UserDetailsService (for example, the LDAP provider) then it won’t work unless you also have a UserDetailsService bean in your application context.

10.12.2. Simple Hash-Based Token Approach

This approach uses hashing to achieve a useful remember-me strategy. In essence a cookie is sent to the browser upon successful interactive authentication, with the cookie being composed as follows:

base64(username + ":" + expirationTime + ":" +
md5Hex(username + ":" + expirationTime + ":" password + ":" + key))

username:          As identifiable to the UserDetailsService
password:          That matches the one in the retrieved UserDetails
expirationTime:    The date and time when the remember-me token expires, expressed in milliseconds
key:               A private key to prevent modification of the remember-me token

As such the remember-me token is valid only for the period specified, and provided that the username, password and key does not change. Notably, this has a potential security issue in that a captured remember-me token will be usable from any user agent until such time as the token expires. This is the same issue as with digest authentication. If a principal is aware a token has been captured, they can easily change their password and immediately invalidate all remember-me tokens on issue. If more significant security is needed you should use the approach described in the next section. Alternatively remember-me services should simply not be used at all.

If you are familiar with the topics discussed in the chapter on namespace configuration, you can enable remember-me authentication just by adding the <remember-me> element:

<http>
...
<remember-me key="myAppKey"/>
</http>

The UserDetailsService will normally be selected automatically. If you have more than one in your application context, you need to specify which one should be used with the user-service-ref attribute, where the value is the name of your UserDetailsService bean.

10.12.3. Persistent Token Approach

This approach is based on the article http://jaspan.com/improved_persistent_login_cookie_best_practice with some minor modifications [3]. To use the this approach with namespace configuration, you would supply a datasource reference:

<http>
...
<remember-me data-source-ref="someDataSource"/>
</http>

The database should contain a persistent_logins table, created using the following SQL (or equivalent):

create table persistent_logins (username varchar(64) not null,
                                series varchar(64) primary key,
                                token varchar(64) not null,
                                last_used timestamp not null)

10.12.4. Remember-Me Interfaces and Implementations

Remember-me is used with UsernamePasswordAuthenticationFilter, and is implemented via hooks in the AbstractAuthenticationProcessingFilter superclass. It is also used within BasicAuthenticationFilter. The hooks will invoke a concrete RememberMeServices at the appropriate times. The interface looks like this:

Authentication autoLogin(HttpServletRequest request, HttpServletResponse response);

void loginFail(HttpServletRequest request, HttpServletResponse response);

void loginSuccess(HttpServletRequest request, HttpServletResponse response,
    Authentication successfulAuthentication);

Please refer to the Javadoc for a fuller discussion on what the methods do, although note at this stage that AbstractAuthenticationProcessingFilter only calls the loginFail() and loginSuccess() methods. The autoLogin() method is called by RememberMeAuthenticationFilter whenever the SecurityContextHolder does not contain an Authentication. This interface therefore provides the underlying remember-me implementation with sufficient notification of authentication-related events, and delegates to the implementation whenever a candidate web request might contain a cookie and wish to be remembered. This design allows any number of remember-me implementation strategies. We’ve seen above that Spring Security provides two implementations. We’ll look at these in turn.

TokenBasedRememberMeServices

This implementation supports the simpler approach described in Simple Hash-Based Token Approach. TokenBasedRememberMeServices generates a RememberMeAuthenticationToken, which is processed by RememberMeAuthenticationProvider. A key is shared between this authentication provider and the TokenBasedRememberMeServices. In addition, TokenBasedRememberMeServices requires A UserDetailsService from which it can retrieve the username and password for signature comparison purposes, and generate the RememberMeAuthenticationToken to contain the correct GrantedAuthority s. Some sort of logout command should be provided by the application that invalidates the cookie if the user requests this. TokenBasedRememberMeServices also implements Spring Security’s LogoutHandler interface so can be used with LogoutFilter to have the cookie cleared automatically.

The beans required in an application context to enable remember-me services are as follows:

<bean id="rememberMeFilter" class=
"org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter">
<property name="rememberMeServices" ref="rememberMeServices"/>
<property name="authenticationManager" ref="theAuthenticationManager" />
</bean>

<bean id="rememberMeServices" class=
"org.springframework.security.web.authentication.rememberme.TokenBasedRememberMeServices">
<property name="userDetailsService" ref="myUserDetailsService"/>
<property name="key" value="springRocks"/>
</bean>

<bean id="rememberMeAuthenticationProvider" class=
"org.springframework.security.authentication.RememberMeAuthenticationProvider">
<property name="key" value="springRocks"/>
</bean>

Don’t forget to add your RememberMeServices implementation to your UsernamePasswordAuthenticationFilter.setRememberMeServices() property, include the RememberMeAuthenticationProvider in your AuthenticationManager.setProviders() list, and add RememberMeAuthenticationFilter into your FilterChainProxy (typically immediately after your UsernamePasswordAuthenticationFilter).

PersistentTokenBasedRememberMeServices

This class can be used in the same way as TokenBasedRememberMeServices, but it additionally needs to be configured with a PersistentTokenRepository to store the tokens. There are two standard implementations.

  • InMemoryTokenRepositoryImpl which is intended for testing only.

  • JdbcTokenRepositoryImpl which stores the tokens in a database.

The database schema is described above in Persistent Token Approach.

10.13. OpenID Support

The namespace supports OpenID login either instead of, or in addition to normal form-based login, with a simple change:

<http>
<intercept-url pattern="/**" access="ROLE_USER" />
<openid-login />
</http>

You should then register yourself with an OpenID provider (such as myopenid.com), and add the user information to your in-memory <user-service>:

<user name="https://jimi.hendrix.myopenid.com/" authorities="ROLE_USER" />

You should be able to login using the myopenid.com site to authenticate. It is also possible to select a specific UserDetailsService bean for use OpenID by setting the user-service-ref attribute on the openid-login element. Note that we have omitted the password attribute from the above user configuration, since this set of user data is only being used to load the authorities for the user. A random password will be generated internally, preventing you from accidentally using this user data as an authentication source elsewhere in your configuration.

10.13.1. Attribute Exchange

Support for OpenID attribute exchange. As an example, the following configuration would attempt to retrieve the email and full name from the OpenID provider, for use by the application:

<openid-login>
<attribute-exchange>
    <openid-attribute name="email" type="https://axschema.org/contact/email" required="true"/>
    <openid-attribute name="name" type="https://axschema.org/namePerson"/>
</attribute-exchange>
</openid-login>

The "type" of each OpenID attribute is a URI, determined by a particular schema, in this case https://axschema.org/. If an attribute must be retrieved for successful authentication, the required attribute can be set. The exact schema and attributes supported will depend on your OpenID provider. The attribute values are returned as part of the authentication process and can be accessed afterwards using the following code:

OpenIDAuthenticationToken token =
    (OpenIDAuthenticationToken)SecurityContextHolder.getContext().getAuthentication();
List<OpenIDAttribute> attributes = token.getAttributes();

We can obtain the OpenIDAuthenticationToken from the SecurityContextHolder. The OpenIDAttribute contains the attribute type and the retrieved value (or values in the case of multi-valued attributes). You can supply multiple attribute-exchange elements, using an identifier-matcher attribute on each. This contains a regular expression which will be matched against the OpenID identifier supplied by the user. See the OpenID sample application in the codebase for an example configuration, providing different attribute lists for the Google, Yahoo and MyOpenID providers.

10.14. Anonymous Authentication

10.14.1. Overview

It’s generally considered good security practice to adopt a "deny-by-default" where you explicitly specify what is allowed and disallow everything else. Defining what is accessible to unauthenticated users is a similar situation, particularly for web applications. Many sites require that users must be authenticated for anything other than a few URLs (for example the home and login pages). In this case it is easiest to define access configuration attributes for these specific URLs rather than have for every secured resource. Put differently, sometimes it is nice to say ROLE_SOMETHING is required by default and only allow certain exceptions to this rule, such as for login, logout and home pages of an application. You could also omit these pages from the filter chain entirely, thus bypassing the access control checks, but this may be undesirable for other reasons, particularly if the pages behave differently for authenticated users.

This is what we mean by anonymous authentication. Note that there is no real conceptual difference between a user who is "anonymously authenticated" and an unauthenticated user. Spring Security’s anonymous authentication just gives you a more convenient way to configure your access-control attributes. Calls to servlet API calls such as getCallerPrincipal, for example, will still return null even though there is actually an anonymous authentication object in the SecurityContextHolder.

There are other situations where anonymous authentication is useful, such as when an auditing interceptor queries the SecurityContextHolder to identify which principal was responsible for a given operation. Classes can be authored more robustly if they know the SecurityContextHolder always contains an Authentication object, and never null.

10.14.2. Configuration

Anonymous authentication support is provided automatically when using the HTTP configuration Spring Security 3.0 and can be customized (or disabled) using the <anonymous> element. You don’t need to configure the beans described here unless you are using traditional bean configuration.

Three classes that together provide the anonymous authentication feature. AnonymousAuthenticationToken is an implementation of Authentication, and stores the GrantedAuthority s which apply to the anonymous principal. There is a corresponding AnonymousAuthenticationProvider, which is chained into the ProviderManager so that AnonymousAuthenticationToken s are accepted. Finally, there is an AnonymousAuthenticationFilter, which is chained after the normal authentication mechanisms and automatically adds an AnonymousAuthenticationToken to the SecurityContextHolder if there is no existing Authentication held there. The definition of the filter and authentication provider appears as follows:

<bean id="anonymousAuthFilter"
    class="org.springframework.security.web.authentication.AnonymousAuthenticationFilter">
<property name="key" value="foobar"/>
<property name="userAttribute" value="anonymousUser,ROLE_ANONYMOUS"/>
</bean>

<bean id="anonymousAuthenticationProvider"
    class="org.springframework.security.authentication.AnonymousAuthenticationProvider">
<property name="key" value="foobar"/>
</bean>

The key is shared between the filter and authentication provider, so that tokens created by the former are accepted by the latter [4]. The userAttribute is expressed in the form of usernameInTheAuthenticationToken,grantedAuthority[,grantedAuthority]. This is the same syntax as used after the equals sign for the userMap property of InMemoryDaoImpl.

As explained earlier, the benefit of anonymous authentication is that all URI patterns can have security applied to them. For example:

<bean id="filterSecurityInterceptor"
    class="org.springframework.security.web.access.intercept.FilterSecurityInterceptor">
<property name="authenticationManager" ref="authenticationManager"/>
<property name="accessDecisionManager" ref="httpRequestAccessDecisionManager"/>
<property name="securityMetadata">
    <security:filter-security-metadata-source>
    <security:intercept-url pattern='/index.jsp' access='ROLE_ANONYMOUS,ROLE_USER'/>
    <security:intercept-url pattern='/hello.htm' access='ROLE_ANONYMOUS,ROLE_USER'/>
    <security:intercept-url pattern='/logoff.jsp' access='ROLE_ANONYMOUS,ROLE_USER'/>
    <security:intercept-url pattern='/login.jsp' access='ROLE_ANONYMOUS,ROLE_USER'/>
    <security:intercept-url pattern='/**' access='ROLE_USER'/>
    </security:filter-security-metadata-source>" +
</property>
</bean>

10.14.3. AuthenticationTrustResolver

Rounding out the anonymous authentication discussion is the AuthenticationTrustResolver interface, with its corresponding AuthenticationTrustResolverImpl implementation. This interface provides an isAnonymous(Authentication) method, which allows interested classes to take into account this special type of authentication status. The ExceptionTranslationFilter uses this interface in processing AccessDeniedException s. If an AccessDeniedException is thrown, and the authentication is of an anonymous type, instead of throwing a 403 (forbidden) response, the filter will instead commence the AuthenticationEntryPoint so the principal can authenticate properly. This is a necessary distinction, otherwise principals would always be deemed "authenticated" and never be given an opportunity to login via form, basic, digest or some other normal authentication mechanism.

You will often see the ROLE_ANONYMOUS attribute in the above interceptor configuration replaced with IS_AUTHENTICATED_ANONYMOUSLY, which is effectively the same thing when defining access controls. This is an example of the use of the AuthenticatedVoter which we will see in the authorization chapter. It uses an AuthenticationTrustResolver to process this particular configuration attribute and grant access to anonymous users. The AuthenticatedVoter approach is more powerful, since it allows you to differentiate between anonymous, remember-me and fully-authenticated users. If you don’t need this functionality though, then you can stick with ROLE_ANONYMOUS, which will be processed by Spring Security’s standard RoleVoter.

10.15. Pre-Authentication Scenarios

There are situations where you want to use Spring Security for authorization, but the user has already been reliably authenticated by some external system prior to accessing the application. We refer to these situations as "pre-authenticated" scenarios. Examples include X.509, Siteminder and authentication by the Java EE container in which the application is running. When using pre-authentication, Spring Security has to

  • Identify the user making the request.

  • Obtain the authorities for the user.

The details will depend on the external authentication mechanism. A user might be identified by their certificate information in the case of X.509, or by an HTTP request header in the case of Siteminder. If relying on container authentication, the user will be identified by calling the getUserPrincipal() method on the incoming HTTP request. In some cases, the external mechanism may supply role/authority information for the user but in others the authorities must be obtained from a separate source, such as a UserDetailsService.

10.15.1. Pre-Authentication Framework Classes

Because most pre-authentication mechanisms follow the same pattern, Spring Security has a set of classes which provide an internal framework for implementing pre-authenticated authentication providers. This removes duplication and allows new implementations to be added in a structured fashion, without having to write everything from scratch. You don’t need to know about these classes if you want to use something like X.509 authentication, as it already has a namespace configuration option which is simpler to use and get started with. If you need to use explicit bean configuration or are planning on writing your own implementation then an understanding of how the provided implementations work will be useful. You will find classes under the org.springframework.security.web.authentication.preauth. We just provide an outline here so you should consult the Javadoc and source where appropriate.

AbstractPreAuthenticatedProcessingFilter

This class will check the current contents of the security context and, if empty, it will attempt to extract user information from the HTTP request and submit it to the AuthenticationManager. Subclasses override the following methods to obtain this information:

protected abstract Object getPreAuthenticatedPrincipal(HttpServletRequest request);

protected abstract Object getPreAuthenticatedCredentials(HttpServletRequest request);

After calling these, the filter will create a PreAuthenticatedAuthenticationToken containing the returned data and submit it for authentication. By "authentication" here, we really just mean further processing to perhaps load the user’s authorities, but the standard Spring Security authentication architecture is followed.

Like other Spring Security authentication filters, the pre-authentication filter has an authenticationDetailsSource property which by default will create a WebAuthenticationDetails object to store additional information such as the session-identifier and originating IP address in the details property of the Authentication object. In cases where user role information can be obtained from the pre-authentication mechanism, the data is also stored in this property, with the details implementing the GrantedAuthoritiesContainer interface. This enables the authentication provider to read the authorities which were externally allocated to the user. We’ll look at a concrete example next.

J2eeBasedPreAuthenticatedWebAuthenticationDetailsSource

If the filter is configured with an authenticationDetailsSource which is an instance of this class, the authority information is obtained by calling the isUserInRole(String role) method for each of a pre-determined set of "mappable roles". The class gets these from a configured MappableAttributesRetriever. Possible implementations include hard-coding a list in the application context and reading the role information from the <security-role> information in a web.xml file. The pre-authentication sample application uses the latter approach.

There is an additional stage where the roles (or attributes) are mapped to Spring Security GrantedAuthority objects using a configured Attributes2GrantedAuthoritiesMapper. The default will just add the usual ROLE_ prefix to the names, but it gives you full control over the behaviour.

PreAuthenticatedAuthenticationProvider

The pre-authenticated provider has little more to do than load the UserDetails object for the user. It does this by delegating to an AuthenticationUserDetailsService. The latter is similar to the standard UserDetailsService but takes an Authentication object rather than just user name:

public interface AuthenticationUserDetailsService {
    UserDetails loadUserDetails(Authentication token) throws UsernameNotFoundException;
}

This interface may have also other uses but with pre-authentication it allows access to the authorities which were packaged in the Authentication object, as we saw in the previous section. The PreAuthenticatedGrantedAuthoritiesUserDetailsService class does this. Alternatively, it may delegate to a standard UserDetailsService via the UserDetailsByNameServiceWrapper implementation.

Http403ForbiddenEntryPoint

The AuthenticationEntryPoint is responsible for kick-starting the authentication process for an unauthenticated user (when they try to access a protected resource), but in the pre-authenticated case this doesn’t apply. You would only configure the ExceptionTranslationFilter with an instance of this class if you aren’t using pre-authentication in combination with other authentication mechanisms. It will be called if the user is rejected by the AbstractPreAuthenticatedProcessingFilter resulting in a null authentication. It always returns a 403-forbidden response code if called.

10.15.2. Concrete Implementations

X.509 authentication is covered in its own chapter. Here we’ll look at some classes which provide support for other pre-authenticated scenarios.

Request-Header Authentication (Siteminder)

An external authentication system may supply information to the application by setting specific headers on the HTTP request. A well-known example of this is Siteminder, which passes the username in a header called SM_USER. This mechanism is supported by the class RequestHeaderAuthenticationFilter which simply extracts the username from the header. It defaults to using the name SM_USER as the header name. See the Javadoc for more details.

Note that when using a system like this, the framework performs no authentication checks at all and it is extremely important that the external system is configured properly and protects all access to the application. If an attacker is able to forge the headers in their original request without this being detected then they could potentially choose any username they wished.

Siteminder Example Configuration

A typical configuration using this filter would look like this:

<security:http>
<!-- Additional http configuration omitted -->
<security:custom-filter position="PRE_AUTH_FILTER" ref="siteminderFilter" />
</security:http>

<bean id="siteminderFilter" class="org.springframework.security.web.authentication.preauth.RequestHeaderAuthenticationFilter">
<property name="principalRequestHeader" value="SM_USER"/>
<property name="authenticationManager" ref="authenticationManager" />
</bean>

<bean id="preauthAuthProvider" class="org.springframework.security.web.authentication.preauth.PreAuthenticatedAuthenticationProvider">
<property name="preAuthenticatedUserDetailsService">
    <bean id="userDetailsServiceWrapper"
        class="org.springframework.security.core.userdetails.UserDetailsByNameServiceWrapper">
    <property name="userDetailsService" ref="userDetailsService"/>
    </bean>
</property>
</bean>

<security:authentication-manager alias="authenticationManager">
<security:authentication-provider ref="preauthAuthProvider" />
</security:authentication-manager>

We’ve assumed here that the security namespace is being used for configuration. It’s also assumed that you have added a UserDetailsService (called "userDetailsService") to your configuration to load the user’s roles.

Java EE Container Authentication

The class J2eePreAuthenticatedProcessingFilter will extract the username from the userPrincipal property of the HttpServletRequest. Use of this filter would usually be combined with the use of Java EE roles as described above in J2eeBasedPreAuthenticatedWebAuthenticationDetailsSource.

There is a sample application in the codebase which uses this approach, so get hold of the code from github and have a look at the application context file if you are interested. The code is in the samples/xml/preauth directory.

10.16. Java Authentication and Authorization Service (JAAS) Provider

10.16.1. Overview

Spring Security provides a package able to delegate authentication requests to the Java Authentication and Authorization Service (JAAS). This package is discussed in detail below.

10.16.2. AbstractJaasAuthenticationProvider

The AbstractJaasAuthenticationProvider is the basis for the provided JAAS AuthenticationProvider implementations. Subclasses must implement a method that creates the LoginContext. The AbstractJaasAuthenticationProvider has a number of dependencies that can be injected into it that are discussed below.

JAAS CallbackHandler

Most JAAS LoginModule s require a callback of some sort. These callbacks are usually used to obtain the username and password from the user.

In a Spring Security deployment, Spring Security is responsible for this user interaction (via the authentication mechanism). Thus, by the time the authentication request is delegated through to JAAS, Spring Security’s authentication mechanism will already have fully-populated an Authentication object containing all the information required by the JAAS LoginModule.

Therefore, the JAAS package for Spring Security provides two default callback handlers, JaasNameCallbackHandler and JaasPasswordCallbackHandler. Each of these callback handlers implement JaasAuthenticationCallbackHandler. In most cases these callback handlers can simply be used without understanding the internal mechanics.

For those needing full control over the callback behavior, internally AbstractJaasAuthenticationProvider wraps these JaasAuthenticationCallbackHandler s with an InternalCallbackHandler. The InternalCallbackHandler is the class that actually implements JAAS normal CallbackHandler interface. Any time that the JAAS LoginModule is used, it is passed a list of application context configured InternalCallbackHandler s. If the LoginModule requests a callback against the InternalCallbackHandler s, the callback is in-turn passed to the JaasAuthenticationCallbackHandler s being wrapped.

JAAS AuthorityGranter

JAAS works with principals. Even "roles" are represented as principals in JAAS. Spring Security, on the other hand, works with Authentication objects. Each Authentication object contains a single principal, and multiple GrantedAuthority s. To facilitate mapping between these different concepts, Spring Security’s JAAS package includes an AuthorityGranter interface.

An AuthorityGranter is responsible for inspecting a JAAS principal and returning a set of String s, representing the authorities assigned to the principal. For each returned authority string, the AbstractJaasAuthenticationProvider creates a JaasGrantedAuthority (which implements Spring Security’s GrantedAuthority interface) containing the authority string and the JAAS principal that the AuthorityGranter was passed. The AbstractJaasAuthenticationProvider obtains the JAAS principals by firstly successfully authenticating the user’s credentials using the JAAS LoginModule, and then accessing the LoginContext it returns. A call to LoginContext.getSubject().getPrincipals() is made, with each resulting principal passed to each AuthorityGranter defined against the AbstractJaasAuthenticationProvider.setAuthorityGranters(List) property.

Spring Security does not include any production AuthorityGranter s given that every JAAS principal has an implementation-specific meaning. However, there is a TestAuthorityGranter in the unit tests that demonstrates a simple AuthorityGranter implementation.

10.16.3. DefaultJaasAuthenticationProvider

The DefaultJaasAuthenticationProvider allows a JAAS Configuration object to be injected into it as a dependency. It then creates a LoginContext using the injected JAAS Configuration. This means that DefaultJaasAuthenticationProvider is not bound any particular implementation of Configuration as JaasAuthenticationProvider is.

InMemoryConfiguration

In order to make it easy to inject a Configuration into DefaultJaasAuthenticationProvider, a default in-memory implementation named InMemoryConfiguration is provided. The implementation constructor accepts a Map where each key represents a login configuration name and the value represents an Array of AppConfigurationEntry s. InMemoryConfiguration also supports a default Array of AppConfigurationEntry objects that will be used if no mapping is found within the provided Map. For details, refer to the class level javadoc of InMemoryConfiguration.

DefaultJaasAuthenticationProvider Example Configuration

While the Spring configuration for InMemoryConfiguration can be more verbose than the standarad JAAS configuration files, using it in conjuction with DefaultJaasAuthenticationProvider is more flexible than JaasAuthenticationProvider since it not dependant on the default Configuration implementation.

An example configuration of DefaultJaasAuthenticationProvider using InMemoryConfiguration is provided below. Note that custom implementations of Configuration can easily be injected into DefaultJaasAuthenticationProvider as well.

<bean id="jaasAuthProvider"
class="org.springframework.security.authentication.jaas.DefaultJaasAuthenticationProvider">
<property name="configuration">
<bean class="org.springframework.security.authentication.jaas.memory.InMemoryConfiguration">
<constructor-arg>
    <map>
    <!--
    SPRINGSECURITY is the default loginContextName
    for AbstractJaasAuthenticationProvider
    -->
    <entry key="SPRINGSECURITY">
    <array>
    <bean class="javax.security.auth.login.AppConfigurationEntry">
        <constructor-arg value="sample.SampleLoginModule" />
        <constructor-arg>
        <util:constant static-field=
            "javax.security.auth.login.AppConfigurationEntry$LoginModuleControlFlag.REQUIRED"/>
        </constructor-arg>
        <constructor-arg>
        <map></map>
        </constructor-arg>
        </bean>
    </array>
    </entry>
    </map>
    </constructor-arg>
</bean>
</property>
<property name="authorityGranters">
<list>
    <!-- You will need to write your own implementation of AuthorityGranter -->
    <bean class="org.springframework.security.authentication.jaas.TestAuthorityGranter"/>
</list>
</property>
</bean>

10.16.4. JaasAuthenticationProvider

The JaasAuthenticationProvider assumes the default Configuration is an instance of ConfigFile. This assumption is made in order to attempt to update the Configuration. The JaasAuthenticationProvider then uses the default Configuration to create the LoginContext.

Let’s assume we have a JAAS login configuration file, /WEB-INF/login.conf, with the following contents:

JAASTest {
    sample.SampleLoginModule required;
};

Like all Spring Security beans, the JaasAuthenticationProvider is configured via the application context. The following definitions would correspond to the above JAAS login configuration file:

<bean id="jaasAuthenticationProvider"
class="org.springframework.security.authentication.jaas.JaasAuthenticationProvider">
<property name="loginConfig" value="/WEB-INF/login.conf"/>
<property name="loginContextName" value="JAASTest"/>
<property name="callbackHandlers">
<list>
<bean
    class="org.springframework.security.authentication.jaas.JaasNameCallbackHandler"/>
<bean
    class="org.springframework.security.authentication.jaas.JaasPasswordCallbackHandler"/>
</list>
</property>
<property name="authorityGranters">
    <list>
    <bean class="org.springframework.security.authentication.jaas.TestAuthorityGranter"/>
    </list>
</property>
</bean>

10.16.5. Running as a Subject

If configured, the JaasApiIntegrationFilter will attempt to run as the Subject on the JaasAuthenticationToken. This means that the Subject can be accessed using:

Subject subject = Subject.getSubject(AccessController.getContext());

This integration can easily be configured using the jaas-api-provision attribute. This feature is useful when integrating with legacy or external API’s that rely on the JAAS Subject being populated.

10.17. CAS Authentication

10.17.1. Overview

JA-SIG produces an enterprise-wide single sign on system known as CAS. Unlike other initiatives, JA-SIG’s Central Authentication Service is open source, widely used, simple to understand, platform independent, and supports proxy capabilities. Spring Security fully supports CAS, and provides an easy migration path from single-application deployments of Spring Security through to multiple-application deployments secured by an enterprise-wide CAS server.

You can learn more about CAS at https://www.apereo.org. You will also need to visit this site to download the CAS Server files.

10.17.2. How CAS Works

Whilst the CAS web site contains documents that detail the architecture of CAS, we present the general overview again here within the context of Spring Security. Spring Security 3.x supports CAS 3. At the time of writing, the CAS server was at version 3.4.

Somewhere in your enterprise you will need to setup a CAS server. The CAS server is simply a standard WAR file, so there isn’t anything difficult about setting up your server. Inside the WAR file you will customise the login and other single sign on pages displayed to users.

When deploying a CAS 3.4 server, you will also need to specify an AuthenticationHandler in the deployerConfigContext.xml included with CAS. The AuthenticationHandler has a simple method that returns a boolean as to whether a given set of Credentials is valid. Your AuthenticationHandler implementation will need to link into some type of backend authentication repository, such as an LDAP server or database. CAS itself includes numerous AuthenticationHandler s out of the box to assist with this. When you download and deploy the server war file, it is set up to successfully authenticate users who enter a password matching their username, which is useful for testing.

Apart from the CAS server itself, the other key players are of course the secure web applications deployed throughout your enterprise. These web applications are known as "services". There are three types of services. Those that authenticate service tickets, those that can obtain proxy tickets, and those that authenticate proxy tickets. Authenticating a proxy ticket differs because the list of proxies must be validated and often times a proxy ticket can be reused.

Spring Security and CAS Interaction Sequence

The basic interaction between a web browser, CAS server and a Spring Security-secured service is as follows:

  • The web user is browsing the service’s public pages. CAS or Spring Security is not involved.

  • The user eventually requests a page that is either secure or one of the beans it uses is secure. Spring Security’s ExceptionTranslationFilter will detect the AccessDeniedException or AuthenticationException.

  • Because the user’s Authentication object (or lack thereof) caused an AuthenticationException, the ExceptionTranslationFilter will call the configured AuthenticationEntryPoint. If using CAS, this will be the CasAuthenticationEntryPoint class.

  • The CasAuthenticationEntryPoint will redirect the user’s browser to the CAS server. It will also indicate a service parameter, which is the callback URL for the Spring Security service (your application). For example, the URL to which the browser is redirected might be https://my.company.com/cas/login?service=https%3A%2F%2Fserver3.company.com%2Fwebapp%2Flogin/cas.

  • After the user’s browser redirects to CAS, they will be prompted for their username and password. If the user presents a session cookie which indicates they’ve previously logged on, they will not be prompted to login again (there is an exception to this procedure, which we’ll cover later). CAS will use the PasswordHandler (or AuthenticationHandler if using CAS 3.0) discussed above to decide whether the username and password is valid.

  • Upon successful login, CAS will redirect the user’s browser back to the original service. It will also include a ticket parameter, which is an opaque string representing the "service ticket". Continuing our earlier example, the URL the browser is redirected to might be https://server3.company.com/webapp/login/cas?ticket=ST-0-ER94xMJmn6pha35CQRoZ.

  • Back in the service web application, the CasAuthenticationFilter is always listening for requests to /login/cas (this is configurable, but we’ll use the defaults in this introduction). The processing filter will construct a UsernamePasswordAuthenticationToken representing the service ticket. The principal will be equal to CasAuthenticationFilter.CAS_STATEFUL_IDENTIFIER, whilst the credentials will be the service ticket opaque value. This authentication request will then be handed to the configured AuthenticationManager.

  • The AuthenticationManager implementation will be the ProviderManager, which is in turn configured with the CasAuthenticationProvider. The CasAuthenticationProvider only responds to UsernamePasswordAuthenticationToken s containing the CAS-specific principal (such as CasAuthenticationFilter.CAS_STATEFUL_IDENTIFIER) and CasAuthenticationToken s (discussed later).

  • CasAuthenticationProvider will validate the service ticket using a TicketValidator implementation. This will typically be a Cas20ServiceTicketValidator which is one of the classes included in the CAS client library. In the event the application needs to validate proxy tickets, the Cas20ProxyTicketValidator is used. The TicketValidator makes an HTTPS request to the CAS server in order to validate the service ticket. It may also include a proxy callback URL, which is included in this example: https://my.company.com/cas/proxyValidate?service=https%3A%2F%2Fserver3.company.com%2Fwebapp%2Flogin/cas&ticket=ST-0-ER94xMJmn6pha35CQRoZ&pgtUrl=https://server3.company.com/webapp/login/cas/proxyreceptor.

  • Back on the CAS server, the validation request will be received. If the presented service ticket matches the service URL the ticket was issued to, CAS will provide an affirmative response in XML indicating the username. If any proxy was involved in the authentication (discussed below), the list of proxies is also included in the XML response.

  • [OPTIONAL] If the request to the CAS validation service included the proxy callback URL (in the pgtUrl parameter), CAS will include a pgtIou string in the XML response. This pgtIou represents a proxy-granting ticket IOU. The CAS server will then create its own HTTPS connection back to the pgtUrl. This is to mutually authenticate the CAS server and the claimed service URL. The HTTPS connection will be used to send a proxy granting ticket to the original web application. For example, https://server3.company.com/webapp/login/cas/proxyreceptor?pgtIou=PGTIOU-0-R0zlgrl4pdAQwBvJWO3vnNpevwqStbSGcq3vKB2SqSFFRnjPHt&pgtId=PGT-1-si9YkkHLrtACBo64rmsi3v2nf7cpCResXg5MpESZFArbaZiOKH.

  • The Cas20TicketValidator will parse the XML received from the CAS server. It will return to the CasAuthenticationProvider a TicketResponse, which includes the username (mandatory), proxy list (if any were involved), and proxy-granting ticket IOU (if the proxy callback was requested).

  • Next CasAuthenticationProvider will call a configured CasProxyDecider. The CasProxyDecider indicates whether the proxy list in the TicketResponse is acceptable to the service. Several implementations are provided with Spring Security: RejectProxyTickets, AcceptAnyCasProxy and NamedCasProxyDecider. These names are largely self-explanatory, except NamedCasProxyDecider which allows a List of trusted proxies to be provided.

  • CasAuthenticationProvider will next request a AuthenticationUserDetailsService to load the GrantedAuthority objects that apply to the user contained in the Assertion.

  • If there were no problems, CasAuthenticationProvider constructs a CasAuthenticationToken including the details contained in the TicketResponse and the GrantedAuthoritys.

  • Control then returns to CasAuthenticationFilter, which places the created CasAuthenticationToken in the security context.

  • The user’s browser is redirected to the original page that caused the AuthenticationException (or a custom destination depending on the configuration).

It’s good that you’re still here! Let’s now look at how this is configured

10.17.3. Configuration of CAS Client

The web application side of CAS is made easy due to Spring Security. It is assumed you already know the basics of using Spring Security, so these are not covered again below. We’ll assume a namespace based configuration is being used and add in the CAS beans as required. Each section builds upon the previous section. A full CAS sample application can be found in the Spring Security Samples.

Service Ticket Authentication

This section describes how to setup Spring Security to authenticate Service Tickets. Often times this is all a web application requires. You will need to add a ServiceProperties bean to your application context. This represents your CAS service:

<bean id="serviceProperties"
    class="org.springframework.security.cas.ServiceProperties">
<property name="service"
    value="https://localhost:8443/cas-sample/login/cas"/>
<property name="sendRenew" value="false"/>
</bean>

The service must equal a URL that will be monitored by the CasAuthenticationFilter. The sendRenew defaults to false, but should be set to true if your application is particularly sensitive. What this parameter does is tell the CAS login service that a single sign on login is unacceptable. Instead, the user will need to re-enter their username and password in order to gain access to the service.

The following beans should be configured to commence the CAS authentication process (assuming you’re using a namespace configuration):

<security:http entry-point-ref="casEntryPoint">
...
<security:custom-filter position="CAS_FILTER" ref="casFilter" />
</security:http>

<bean id="casFilter"
    class="org.springframework.security.cas.web.CasAuthenticationFilter">
<property name="authenticationManager" ref="authenticationManager"/>
</bean>

<bean id="casEntryPoint"
    class="org.springframework.security.cas.web.CasAuthenticationEntryPoint">
<property name="loginUrl" value="https://localhost:9443/cas/login"/>
<property name="serviceProperties" ref="serviceProperties"/>
</bean>

For CAS to operate, the ExceptionTranslationFilter must have its authenticationEntryPoint property set to the CasAuthenticationEntryPoint bean. This can easily be done using entry-point-ref as is done in the example above. The CasAuthenticationEntryPoint must refer to the ServiceProperties bean (discussed above), which provides the URL to the enterprise’s CAS login server. This is where the user’s browser will be redirected.

The CasAuthenticationFilter has very similar properties to the UsernamePasswordAuthenticationFilter (used for form-based logins). You can use these properties to customize things like behavior for authentication success and failure.

Next you need to add a CasAuthenticationProvider and its collaborators:

<security:authentication-manager alias="authenticationManager">
<security:authentication-provider ref="casAuthenticationProvider" />
</security:authentication-manager>

<bean id="casAuthenticationProvider"
    class="org.springframework.security.cas.authentication.CasAuthenticationProvider">
<property name="authenticationUserDetailsService">
    <bean class="org.springframework.security.core.userdetails.UserDetailsByNameServiceWrapper">
    <constructor-arg ref="userService" />
    </bean>
</property>
<property name="serviceProperties" ref="serviceProperties" />
<property name="ticketValidator">
    <bean class="org.jasig.cas.client.validation.Cas20ServiceTicketValidator">
    <constructor-arg index="0" value="https://localhost:9443/cas" />
    </bean>
</property>
<property name="key" value="an_id_for_this_auth_provider_only"/>
</bean>

<security:user-service id="userService">
<!-- Password is prefixed with {noop} to indicate to DelegatingPasswordEncoder that
NoOpPasswordEncoder should be used.
This is not safe for production, but makes reading
in samples easier.
Normally passwords should be hashed using BCrypt -->
<security:user name="joe" password="{noop}joe" authorities="ROLE_USER" />
...
</security:user-service>

The CasAuthenticationProvider uses a UserDetailsService instance to load the authorities for a user, once they have been authenticated by CAS. We’ve shown a simple in-memory setup here. Note that the CasAuthenticationProvider does not actually use the password for authentication, but it does use the authorities.

The beans are all reasonably self-explanatory if you refer back to the How CAS Works section.

This completes the most basic configuration for CAS. If you haven’t made any mistakes, your web application should happily work within the framework of CAS single sign on. No other parts of Spring Security need to be concerned about the fact CAS handled authentication. In the following sections we will discuss some (optional) more advanced configurations.

Single Logout

The CAS protocol supports Single Logout and can be easily added to your Spring Security configuration. Below are updates to the Spring Security configuration that handle Single Logout

<security:http entry-point-ref="casEntryPoint">
...
<security:logout logout-success-url="/cas-logout.jsp"/>
<security:custom-filter ref="requestSingleLogoutFilter" before="LOGOUT_FILTER"/>
<security:custom-filter ref="singleLogoutFilter" before="CAS_FILTER"/>
</security:http>

<!-- This filter handles a Single Logout Request from the CAS Server -->
<bean id="singleLogoutFilter" class="org.jasig.cas.client.session.SingleSignOutFilter"/>

<!-- This filter redirects to the CAS Server to signal Single Logout should be performed -->
<bean id="requestSingleLogoutFilter"
    class="org.springframework.security.web.authentication.logout.LogoutFilter">
<constructor-arg value="https://localhost:9443/cas/logout"/>
<constructor-arg>
    <bean class=
        "org.springframework.security.web.authentication.logout.SecurityContextLogoutHandler"/>
</constructor-arg>
<property name="filterProcessesUrl" value="/logout/cas"/>
</bean>

The logout element logs the user out of the local application, but does not terminate the session with the CAS server or any other applications that have been logged into. The requestSingleLogoutFilter filter will allow the URL of /spring_security_cas_logout to be requested to redirect the application to the configured CAS Server logout URL. Then the CAS Server will send a Single Logout request to all the services that were signed into. The singleLogoutFilter handles the Single Logout request by looking up the HttpSession in a static Map and then invalidating it.

It might be confusing why both the logout element and the singleLogoutFilter are needed. It is considered best practice to logout locally first since the SingleSignOutFilter just stores the HttpSession in a static Map in order to call invalidate on it. With the configuration above, the flow of logout would be:

  • The user requests /logout which would log the user out of the local application and send the user to the logout success page.

  • The logout success page, /cas-logout.jsp, should instruct the user to click a link pointing to /logout/cas in order to logout out of all applications.

  • When the user clicks the link, the user is redirected to the CAS single logout URL (https://localhost:9443/cas/logout).

  • On the CAS Server side, the CAS single logout URL then submits single logout requests to all the CAS Services. On the CAS Service side, JASIG’s SingleSignOutFilter processes the logout request by invalidating the original session.

The next step is to add the following to your web.xml

<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>
    org.springframework.web.filter.CharacterEncodingFilter
</filter-class>
<init-param>
    <param-name>encoding</param-name>
    <param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>
    org.jasig.cas.client.session.SingleSignOutHttpSessionListener
</listener-class>
</listener>

When using the SingleSignOutFilter you might encounter some encoding issues. Therefore it is recommended to add the CharacterEncodingFilter to ensure that the character encoding is correct when using the SingleSignOutFilter. Again, refer to JASIG’s documentation for details. The SingleSignOutHttpSessionListener ensures that when an HttpSession expires, the mapping used for single logout is removed.

Authenticating to a Stateless Service with CAS

This section describes how to authenticate to a service using CAS. In other words, this section discusses how to setup a client that uses a service that authenticates with CAS. The next section describes how to setup a stateless service to Authenticate using CAS.

Configuring CAS to Obtain Proxy Granting Tickets

In order to authenticate to a stateless service, the application needs to obtain a proxy granting ticket (PGT). This section describes how to configure Spring Security to obtain a PGT building upon thencas-st[Service Ticket Authentication] configuration.

The first step is to include a ProxyGrantingTicketStorage in your Spring Security configuration. This is used to store PGT’s that are obtained by the CasAuthenticationFilter so that they can be used to obtain proxy tickets. An example configuration is shown below

<!--
NOTE: In a real application you should not use an in memory implementation.
You will also want to ensure to clean up expired tickets by calling
ProxyGrantingTicketStorage.cleanup()
-->
<bean id="pgtStorage" class="org.jasig.cas.client.proxy.ProxyGrantingTicketStorageImpl"/>

The next step is to update the CasAuthenticationProvider to be able to obtain proxy tickets. To do this replace the Cas20ServiceTicketValidator with a Cas20ProxyTicketValidator. The proxyCallbackUrl should be set to a URL that the application will receive PGT’s at. Last, the configuration should also reference the ProxyGrantingTicketStorage so it can use a PGT to obtain proxy tickets. You can find an example of the configuration changes that should be made below.

<bean id="casAuthenticationProvider"
    class="org.springframework.security.cas.authentication.CasAuthenticationProvider">
...
<property name="ticketValidator">
    <bean class="org.jasig.cas.client.validation.Cas20ProxyTicketValidator">
    <constructor-arg value="https://localhost:9443/cas"/>
        <property name="proxyCallbackUrl"
        value="https://localhost:8443/cas-sample/login/cas/proxyreceptor"/>
    <property name="proxyGrantingTicketStorage" ref="pgtStorage"/>
    </bean>
</property>
</bean>

The last step is to update the CasAuthenticationFilter to accept PGT and to store them in the ProxyGrantingTicketStorage. It is important the proxyReceptorUrl matches the proxyCallbackUrl of the Cas20ProxyTicketValidator. An example configuration is shown below.

<bean id="casFilter"
        class="org.springframework.security.cas.web.CasAuthenticationFilter">
    ...
    <property name="proxyGrantingTicketStorage" ref="pgtStorage"/>
    <property name="proxyReceptorUrl" value="/login/cas/proxyreceptor"/>
</bean>
Calling a Stateless Service Using a Proxy Ticket

Now that Spring Security obtains PGTs, you can use them to create proxy tickets which can be used to authenticate to a stateless service. The CAS sample application contains a working example in the ProxyTicketSampleServlet. Example code can be found below:

protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
// NOTE: The CasAuthenticationToken can also be obtained using
// SecurityContextHolder.getContext().getAuthentication()
final CasAuthenticationToken token = (CasAuthenticationToken) request.getUserPrincipal();
// proxyTicket could be reused to make calls to the CAS service even if the
// target url differs
final String proxyTicket = token.getAssertion().getPrincipal().getProxyTicketFor(targetUrl);

// Make a remote call using the proxy ticket
final String serviceUrl = targetUrl+"?ticket="+URLEncoder.encode(proxyTicket, "UTF-8");
String proxyResponse = CommonUtils.getResponseFromServer(serviceUrl, "UTF-8");
...
}
Proxy Ticket Authentication

The CasAuthenticationProvider distinguishes between stateful and stateless clients. A stateful client is considered any that submits to the filterProcessUrl of the CasAuthenticationFilter. A stateless client is any that presents an authentication request to CasAuthenticationFilter on a URL other than the filterProcessUrl.

Because remoting protocols have no way of presenting themselves within the context of an HttpSession, it isn’t possible to rely on the default practice of storing the security context in the session between requests. Furthermore, because the CAS server invalidates a ticket after it has been validated by the TicketValidator, presenting the same proxy ticket on subsequent requests will not work.

One obvious option is to not use CAS at all for remoting protocol clients. However, this would eliminate many of the desirable features of CAS. As a middle-ground, the CasAuthenticationProvider uses a StatelessTicketCache. This is used solely for stateless clients which use a principal equal to CasAuthenticationFilter.CAS_STATELESS_IDENTIFIER. What happens is the CasAuthenticationProvider will store the resulting CasAuthenticationToken in the StatelessTicketCache, keyed on the proxy ticket. Accordingly, remoting protocol clients can present the same proxy ticket and the CasAuthenticationProvider will not need to contact the CAS server for validation (aside from the first request). Once authenticated, the proxy ticket could be used for URLs other than the original target service.

This section builds upon the previous sections to accommodate proxy ticket authentication. The first step is to specify to authenticate all artifacts as shown below.

<bean id="serviceProperties"
    class="org.springframework.security.cas.ServiceProperties">
...
<property name="authenticateAllArtifacts" value="true"/>
</bean>

The next step is to specify serviceProperties and the authenticationDetailsSource for the CasAuthenticationFilter. The serviceProperties property instructs the CasAuthenticationFilter to attempt to authenticate all artifacts instead of only ones present on the filterProcessUrl. The ServiceAuthenticationDetailsSource creates a ServiceAuthenticationDetails that ensures the current URL, based upon the HttpServletRequest, is used as the service URL when validating the ticket. The method for generating the service URL can be customized by injecting a custom AuthenticationDetailsSource that returns a custom ServiceAuthenticationDetails.

<bean id="casFilter"
    class="org.springframework.security.cas.web.CasAuthenticationFilter">
...
<property name="serviceProperties" ref="serviceProperties"/>
<property name="authenticationDetailsSource">
    <bean class=
    "org.springframework.security.cas.web.authentication.ServiceAuthenticationDetailsSource">
    <constructor-arg ref="serviceProperties"/>
    </bean>
</property>
</bean>

You will also need to update the CasAuthenticationProvider to handle proxy tickets. To do this replace the Cas20ServiceTicketValidator with a Cas20ProxyTicketValidator. You will need to configure the statelessTicketCache and which proxies you want to accept. You can find an example of the updates required to accept all proxies below.

<bean id="casAuthenticationProvider"
    class="org.springframework.security.cas.authentication.CasAuthenticationProvider">
...
<property name="ticketValidator">
    <bean class="org.jasig.cas.client.validation.Cas20ProxyTicketValidator">
    <constructor-arg value="https://localhost:9443/cas"/>
    <property name="acceptAnyProxy" value="true"/>
    </bean>
</property>
<property name="statelessTicketCache">
    <bean class="org.springframework.security.cas.authentication.EhCacheBasedTicketCache">
    <property name="cache">
        <bean class="net.sf.ehcache.Cache"
            init-method="initialise" destroy-method="dispose">
        <constructor-arg value="casTickets"/>
        <constructor-arg value="50"/>
        <constructor-arg value="true"/>
        <constructor-arg value="false"/>
        <constructor-arg value="3600"/>
        <constructor-arg value="900"/>
        </bean>
    </property>
    </bean>
</property>
</bean>

10.18. X.509 Authentication

10.18.1. Overview

The most common use of X.509 certificate authentication is in verifying the identity of a server when using SSL, most commonly when using HTTPS from a browser. The browser will automatically check that the certificate presented by a server has been issued (ie digitally signed) by one of a list of trusted certificate authorities which it maintains.

You can also use SSL with "mutual authentication"; the server will then request a valid certificate from the client as part of the SSL handshake. The server will authenticate the client by checking that its certificate is signed by an acceptable authority. If a valid certificate has been provided, it can be obtained through the servlet API in an application. Spring Security X.509 module extracts the certificate using a filter. It maps the certificate to an application user and loads that user’s set of granted authorities for use with the standard Spring Security infrastructure.

You should be familiar with using certificates and setting up client authentication for your servlet container before attempting to use it with Spring Security. Most of the work is in creating and installing suitable certificates and keys. For example, if you’re using Tomcat then read the instructions here https://tomcat.apache.org/tomcat-9.0-doc/ssl-howto.html. It’s important that you get this working before trying it out with Spring Security

10.18.2. Adding X.509 Authentication to Your Web Application

Enabling X.509 client authentication is very straightforward. Just add the <x509/> element to your http security namespace configuration.

<http>
...
    <x509 subject-principal-regex="CN=(.*?)," user-service-ref="userService"/>;
</http>

The element has two optional attributes:

  • subject-principal-regex. The regular expression used to extract a username from the certificate’s subject name. The default value is shown above. This is the username which will be passed to the UserDetailsService to load the authorities for the user.

  • user-service-ref. This is the bean Id of the UserDetailsService to be used with X.509. It isn’t needed if there is only one defined in your application context.

The subject-principal-regex should contain a single group. For example the default expression "CN=(.*?)," matches the common name field. So if the subject name in the certificate is "CN=Jimi Hendrix, OU=…​", this will give a user name of "Jimi Hendrix". The matches are case insensitive. So "emailAddress=(.*?)," will match "EMAILADDRESS=[email protected],CN=…​" giving a user name "[email protected]". If the client presents a certificate and a valid username is successfully extracted, then there should be a valid Authentication object in the security context. If no certificate is found, or no corresponding user could be found then the security context will remain empty. This means that you can easily use X.509 authentication with other options such as a form-based login.

10.18.3. Setting up SSL in Tomcat

There are some pre-generated certificates in the samples/certificate directory in the Spring Security project. You can use these to enable SSL for testing if you don’t want to generate your own. The file server.jks contains the server certificate, private key and the issuing certificate authority certificate. There are also some client certificate files for the users from the sample applications. You can install these in your browser to enable SSL client authentication.

To run tomcat with SSL support, drop the server.jks file into the tomcat conf directory and add the following connector to the server.xml file

<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true" scheme="https" secure="true"
            clientAuth="true" sslProtocol="TLS"
            keystoreFile="${catalina.home}/conf/server.jks"
            keystoreType="JKS" keystorePass="password"
            truststoreFile="${catalina.home}/conf/server.jks"
            truststoreType="JKS" truststorePass="password"
/>

clientAuth can also be set to want if you still want SSL connections to succeed even if the client doesn’t provide a certificate. Clients which don’t present a certificate won’t be able to access any objects secured by Spring Security unless you use a non-X.509 authentication mechanism, such as form authentication.

10.19. Run-As Authentication Replacement

10.19.1. Overview

The AbstractSecurityInterceptor is able to temporarily replace the Authentication object in the SecurityContext and SecurityContextHolder during the secure object callback phase. This only occurs if the original Authentication object was successfully processed by the AuthenticationManager and AccessDecisionManager. The RunAsManager will indicate the replacement Authentication object, if any, that should be used during the SecurityInterceptorCallback.

By temporarily replacing the Authentication object during the secure object callback phase, the secured invocation will be able to call other objects which require different authentication and authorization credentials. It will also be able to perform any internal security checks for specific GrantedAuthority objects. Because Spring Security provides a number of helper classes that automatically configure remoting protocols based on the contents of the SecurityContextHolder, these run-as replacements are particularly useful when calling remote web services

10.19.2. Configuration

A RunAsManager interface is provided by Spring Security:

Authentication buildRunAs(Authentication authentication, Object object,
    List<ConfigAttribute> config);

boolean supports(ConfigAttribute attribute);

boolean supports(Class clazz);

The first method returns the Authentication object that should replace the existing Authentication object for the duration of the method invocation. If the method returns null, it indicates no replacement should be made. The second method is used by the AbstractSecurityInterceptor as part of its startup validation of configuration attributes. The supports(Class) method is called by a security interceptor implementation to ensure the configured RunAsManager supports the type of secure object that the security interceptor will present.

One concrete implementation of a RunAsManager is provided with Spring Security. The RunAsManagerImpl class returns a replacement RunAsUserToken if any ConfigAttribute starts with RUN_AS_. If any such ConfigAttribute is found, the replacement RunAsUserToken will contain the same principal, credentials and granted authorities as the original Authentication object, along with a new SimpleGrantedAuthority for each RUN_AS_ ConfigAttribute. Each new SimpleGrantedAuthority will be prefixed with ROLE_, followed by the RUN_AS ConfigAttribute. For example, a RUN_AS_SERVER will result in the replacement RunAsUserToken containing a ROLE_RUN_AS_SERVER granted authority.

The replacement RunAsUserToken is just like any other Authentication object. It needs to be authenticated by the AuthenticationManager, probably via delegation to a suitable AuthenticationProvider. The RunAsImplAuthenticationProvider performs such authentication. It simply accepts as valid any RunAsUserToken presented.

To ensure malicious code does not create a RunAsUserToken and present it for guaranteed acceptance by the RunAsImplAuthenticationProvider, the hash of a key is stored in all generated tokens. The RunAsManagerImpl and RunAsImplAuthenticationProvider is created in the bean context with the same key:

<bean id="runAsManager"
    class="org.springframework.security.access.intercept.RunAsManagerImpl">
<property name="key" value="my_run_as_password"/>
</bean>

<bean id="runAsAuthenticationProvider"
    class="org.springframework.security.access.intercept.RunAsImplAuthenticationProvider">
<property name="key" value="my_run_as_password"/>
</bean>

By using the same key, each RunAsUserToken can be validated it was created by an approved RunAsManagerImpl. The RunAsUserToken is immutable after creation for security reasons

10.20. Handling Logouts

10.20.1. Logout Java Configuration

When using the WebSecurityConfigurerAdapter, logout capabilities are automatically applied. The default is that accessing the URL /logout will log the user out by:

  • Invalidating the HTTP Session

  • Cleaning up any RememberMe authentication that was configured

  • Clearing the SecurityContextHolder

  • Redirect to /login?logout

Similar to configuring login capabilities, however, you also have various options to further customize your logout requirements:

protected void configure(HttpSecurity http) throws Exception {
    http
        .logout(logout -> logout                                                (1)
            .logoutUrl("/my/logout")                                            (2)
            .logoutSuccessUrl("/my/index")                                      (3)
            .logoutSuccessHandler(logoutSuccessHandler)                         (4)
            .invalidateHttpSession(true)                                        (5)
            .addLogoutHandler(logoutHandler)                                    (6)
            .deleteCookies(cookieNamesToClear)                                  (7)
        )
        ...
}
1 Provides logout support. This is automatically applied when using WebSecurityConfigurerAdapter.
2 The URL that triggers log out to occur (default is /logout). If CSRF protection is enabled (default), then the request must also be a POST. For more information, please consult the JavaDoc.
3 The URL to redirect to after logout has occurred. The default is /login?logout. For more information, please consult the JavaDoc.
4 Let’s you specify a custom LogoutSuccessHandler. If this is specified, logoutSuccessUrl() is ignored. For more information, please consult the JavaDoc.
5 Specify whether to invalidate the HttpSession at the time of logout. This is true by default. Configures the SecurityContextLogoutHandler under the covers. For more information, please consult the JavaDoc.
6 Adds a LogoutHandler. SecurityContextLogoutHandler is added as the last LogoutHandler by default.
7 Allows specifying the names of cookies to be removed on logout success. This is a shortcut for adding a CookieClearingLogoutHandler explicitly.

Logouts can of course also be configured using the XML Namespace notation. Please see the documentation for the logout element in the Spring Security XML Namespace section for further details.

Generally, in order to customize logout functionality, you can add LogoutHandler and/or LogoutSuccessHandler implementations. For many common scenarios, these handlers are applied under the covers when using the fluent API.

10.20.2. Logout XML Configuration

The logout element adds support for logging out by navigating to a particular URL. The default logout URL is /logout, but you can set it to something else using the logout-url attribute. More information on other available attributes may be found in the namespace appendix.

10.20.3. LogoutHandler

Generally, LogoutHandler implementations indicate classes that are able to participate in logout handling. They are expected to be invoked to perform necessary clean-up. As such they should not throw exceptions. Various implementations are provided:

Instead of providing LogoutHandler implementations directly, the fluent API also provides shortcuts that provide the respective LogoutHandler implementations under the covers. E.g. deleteCookies() allows specifying the names of one or more cookies to be removed on logout success. This is a shortcut compared to adding a CookieClearingLogoutHandler.

10.20.4. LogoutSuccessHandler

The LogoutSuccessHandler is called after a successful logout by the LogoutFilter, to handle e.g. redirection or forwarding to the appropriate destination. Note that the interface is almost the same as the LogoutHandler but may raise an exception.

The following implementations are provided:

As mentioned above, you don’t need to specify the SimpleUrlLogoutSuccessHandler directly. Instead, the fluent API provides a shortcut by setting the logoutSuccessUrl(). This will setup the SimpleUrlLogoutSuccessHandler under the covers. The provided URL will be redirected to after a logout has occurred. The default is /login?logout.

The HttpStatusReturningLogoutSuccessHandler can be interesting in REST API type scenarios. Instead of redirecting to a URL upon the successful logout, this LogoutSuccessHandler allows you to provide a plain HTTP status code to be returned. If not configured a status code 200 will be returned by default.

10.20.5. Further Logout-Related References

10.21. Authentication Events

For each authentication that succeeds or fails, a AuthenticationSuccessEvent or AuthenticationFailureEvent is fired, respectively.

To listen for these events, you must first publish an AuthenticationEventPublisher. Spring Security’s DefaultAuthenticationEventPublisher will probably do fine:

@Bean
public AuthenticationEventPublisher authenticationEventPublisher
        (ApplicationEventPublisher applicationEventPublisher) {
    return new DefaultAuthenticationEventPublisher(applicationEventPublisher);
}

Then, you can use Spring’s @EventListener support:

@Component
public class AuthenticationEvents {
    @EventListener
    public void onSuccess(AuthenticationSuccessEvent success) {
        // ...
    }

    @EventListener
    public void onFailure(AuthenticationFailureEvent failures) {
        // ...
    }
}

While similar to AuthenticationSuccessHandler and AuthenticationFailureHandler, these are nice in that they can be used independently from the servlet API.

10.21.1. Adding Exception Mappings

DefaultAuthenticationEventPublisher by default will publish an AuthenticationFailureEvent for the following events:

Exception

Event

BadCredentialsException

AuthenticationFailureBadCredentialsEvent

UsernameNotFoundException

AuthenticationFailureBadCredentialsEvent

AccountExpiredException

AuthenticationFailureExpiredEvent

ProviderNotFoundException

AuthenticationFailureProviderNotFoundEvent

DisabledException

AuthenticationFailureDisabledEvent

LockedException

AuthenticationFailureLockedEvent

AuthenticationServiceException

AuthenticationFailureServiceExceptionEvent

CredentialsExpiredException

AuthenticationFailureCredentialsExpiredEvent

InvalidBearerTokenException

AuthenticationFailureBadCredentialsEvent

The publisher does an exact Exception match, which means that sub-classes of these exceptions won’t also produce events.

To that end, you may want to supply additional mappings to the publisher via the setAdditionalExceptionMappings method:

@Bean
public AuthenticationEventPublisher authenticationEventPublisher
        (ApplicationEventPublisher applicationEventPublisher) {
    Map<Class<? extends AuthenticationException>,
        Class<? extends AuthenticationFailureEvent>> mapping =
            Collections.singletonMap(FooException.class, FooEvent.class);
    AuthenticationEventPublisher authenticationEventPublisher =
        new DefaultAuthenticationEventPublisher(applicationEventPublisher);
    authenticationEventPublisher.setAdditionalExceptionMappings(mapping);
    return authenticationEventPublisher;
}

10.21.2. Default Event

And, you can supply a catch-all event to fire in the case of any AuthenticationException:

@Bean
public AuthenticationEventPublisher authenticationEventPublisher
        (ApplicationEventPublisher applicationEventPublisher) {
    AuthenticationEventPublisher authenticationEventPublisher =
        new DefaultAuthenticationEventPublisher(applicationEventPublisher);
    authenticationEventPublisher.setDefaultAuthenticationFailureEvent
        (GenericAuthenticationFailureEvent.class);
    return authenticationEventPublisher;
}

11. Authorization

The advanced authorization capabilities within Spring Security represent one of the most compelling reasons for its popularity. Irrespective of how you choose to authenticate - whether using a Spring Security-provided mechanism and provider, or integrating with a container or other non-Spring Security authentication authority - you will find the authorization services can be used within your application in a consistent and simple way.

In this part we’ll explore the different AbstractSecurityInterceptor implementations, which were introduced in Part I. We then move on to explore how to fine-tune authorization through use of domain access control lists.

11.1. Authorization Architecture

11.1.1. Authorities

Authentication, discusses how all Authentication implementations store a list of GrantedAuthority objects. These represent the authorities that have been granted to the principal. the GrantedAuthority objects are inserted into the Authentication object by the AuthenticationManager and are later read by AccessDecisionManager s when making authorization decisions.

GrantedAuthority is an interface with only one method:

String getAuthority();

This method allows AccessDecisionManager s to obtain a precise String representation of the GrantedAuthority. By returning a representation as a String, a GrantedAuthority can be easily "read" by most AccessDecisionManager s. If a GrantedAuthority cannot be precisely represented as a String, the GrantedAuthority is considered "complex" and getAuthority() must return null.

An example of a "complex" GrantedAuthority would be an implementation that stores a list of operations and authority thresholds that apply to different customer account numbers. Representing this complex GrantedAuthority as a String would be quite difficult, and as a result the getAuthority() method should return null. This will indicate to any AccessDecisionManager that it will need to specifically support the GrantedAuthority implementation in order to understand its contents.

Spring Security includes one concrete GrantedAuthority implementation, SimpleGrantedAuthority. This allows any user-specified String to be converted into a GrantedAuthority. All AuthenticationProvider s included with the security architecture use SimpleGrantedAuthority to populate the Authentication object.

11.1.2. Pre-Invocation Handling

Spring Security provides interceptors which control access to secure objects such as method invocations or web requests. A pre-invocation decision on whether the invocation is allowed to proceed is made by the AccessDecisionManager.

The AccessDecisionManager

The AccessDecisionManager is called by the AbstractSecurityInterceptor and is responsible for making final access control decisions. The AccessDecisionManager interface contains three methods:

void decide(Authentication authentication, Object secureObject,
    Collection<ConfigAttribute> attrs) throws AccessDeniedException;

boolean supports(ConfigAttribute attribute);

boolean supports(Class clazz);

The AccessDecisionManager's decide method is passed all the relevant information it needs in order to make an authorization decision. In particular, passing the secure Object enables those arguments contained in the actual secure object invocation to be inspected. For example, let’s assume the secure object was a MethodInvocation. It would be easy to query the MethodInvocation for any Customer argument, and then implement some sort of security logic in the AccessDecisionManager to ensure the principal is permitted to operate on that customer. Implementations are expected to throw an AccessDeniedException if access is denied.

The supports(ConfigAttribute) method is called by the AbstractSecurityInterceptor at startup time to determine if the AccessDecisionManager can process the passed ConfigAttribute. The supports(Class) method is called by a security interceptor implementation to ensure the configured AccessDecisionManager supports the type of secure object that the security interceptor will present.

Voting-Based AccessDecisionManager Implementations

Whilst users can implement their own AccessDecisionManager to control all aspects of authorization, Spring Security includes several AccessDecisionManager implementations that are based on voting. Voting Decision Manager illustrates the relevant classes.

access decision voting
Figure 11. Voting Decision Manager

Using this approach, a series of AccessDecisionVoter implementations are polled on an authorization decision. The AccessDecisionManager then decides whether or not to throw an AccessDeniedException based on its assessment of the votes.

The AccessDecisionVoter interface has three methods:

int vote(Authentication authentication, Object object, Collection<ConfigAttribute> attrs);

boolean supports(ConfigAttribute attribute);

boolean supports(Class clazz);

Concrete implementations return an int, with possible values being reflected in the AccessDecisionVoter static fields ACCESS_ABSTAIN, ACCESS_DENIED and ACCESS_GRANTED. A voting implementation will return ACCESS_ABSTAIN if it has no opinion on an authorization decision. If it does have an opinion, it must return either ACCESS_DENIED or ACCESS_GRANTED.

There are three concrete AccessDecisionManager s provided with Spring Security that tally the votes. The ConsensusBased implementation will grant or deny access based on the consensus of non-abstain votes. Properties are provided to control behavior in the event of an equality of votes or if all votes are abstain. The AffirmativeBased implementation will grant access if one or more ACCESS_GRANTED votes were received (i.e. a deny vote will be ignored, provided there was at least one grant vote). Like the ConsensusBased implementation, there is a parameter that controls the behavior if all voters abstain. The UnanimousBased provider expects unanimous ACCESS_GRANTED votes in order to grant access, ignoring abstains. It will deny access if there is any ACCESS_DENIED vote. Like the other implementations, there is a parameter that controls the behaviour if all voters abstain.

It is possible to implement a custom AccessDecisionManager that tallies votes differently. For example, votes from a particular AccessDecisionVoter might receive additional weighting, whilst a deny vote from a particular voter may have a veto effect.

RoleVoter

The most commonly used AccessDecisionVoter provided with Spring Security is the simple RoleVoter, which treats configuration attributes as simple role names and votes to grant access if the user has been assigned that role.

It will vote if any ConfigAttribute begins with the prefix ROLE_. It will vote to grant access if there is a GrantedAuthority which returns a String representation (via the getAuthority() method) exactly equal to one or more ConfigAttributes starting with the prefix ROLE_. If there is no exact match of any ConfigAttribute starting with ROLE_, the RoleVoter will vote to deny access. If no ConfigAttribute begins with ROLE_, the voter will abstain.

AuthenticatedVoter

Another voter which we’ve implicitly seen is the AuthenticatedVoter, which can be used to differentiate between anonymous, fully-authenticated and remember-me authenticated users. Many sites allow certain limited access under remember-me authentication, but require a user to confirm their identity by logging in for full access.

When we’ve used the attribute IS_AUTHENTICATED_ANONYMOUSLY to grant anonymous access, this attribute was being processed by the AuthenticatedVoter. See the Javadoc for this class for more information.

Custom Voters

Obviously, you can also implement a custom AccessDecisionVoter and you can put just about any access-control logic you want in it. It might be specific to your application (business-logic related) or it might implement some security administration logic. For example, you’ll find a blog article on the Spring web site which describes how to use a voter to deny access in real-time to users whose accounts have been suspended.

11.1.3. After Invocation Handling

Whilst the AccessDecisionManager is called by the AbstractSecurityInterceptor before proceeding with the secure object invocation, some applications need a way of modifying the object actually returned by the secure object invocation. Whilst you could easily implement your own AOP concern to achieve this, Spring Security provides a convenient hook that has several concrete implementations that integrate with its ACL capabilities.

After Invocation Implementation illustrates Spring Security’s AfterInvocationManager and its concrete implementations.

after invocation
Figure 12. After Invocation Implementation

Like many other parts of Spring Security, AfterInvocationManager has a single concrete implementation, AfterInvocationProviderManager, which polls a list of AfterInvocationProvider s. Each AfterInvocationProvider is allowed to modify the return object or throw an AccessDeniedException. Indeed multiple providers can modify the object, as the result of the previous provider is passed to the next in the list.

Please be aware that if you’re using AfterInvocationManager, you will still need configuration attributes that allow the MethodSecurityInterceptor's AccessDecisionManager to allow an operation. If you’re using the typical Spring Security included AccessDecisionManager implementations, having no configuration attributes defined for a particular secure method invocation will cause each AccessDecisionVoter to abstain from voting. In turn, if the AccessDecisionManager property “allowIfAllAbstainDecisions” is false, an AccessDeniedException will be thrown. You may avoid this potential issue by either (i) setting “allowIfAllAbstainDecisions” to true (although this is generally not recommended) or (ii) simply ensure that there is at least one configuration attribute that an AccessDecisionVoter will vote to grant access for. This latter (recommended) approach is usually achieved through a ROLE_USER or ROLE_AUTHENTICATED configuration attribute.

11.1.4. Hierarchical Roles

It is a common requirement that a particular role in an application should automatically "include" other roles. For example, in an application which has the concept of an "admin" and a "user" role, you may want an admin to be able to do everything a normal user can. To achieve this, you can either make sure that all admin users are also assigned the "user" role. Alternatively, you can modify every access constraint which requires the "user" role to also include the "admin" role. This can get quite complicated if you have a lot of different roles in your application.

The use of a role-hierarchy allows you to configure which roles (or authorities) should include others. An extended version of Spring Security’s RoleVoter, RoleHierarchyVoter, is configured with a RoleHierarchy, from which it obtains all the "reachable authorities" which the user is assigned. A typical configuration might look like this:

<bean id="roleVoter" class="org.springframework.security.access.vote.RoleHierarchyVoter">
    <constructor-arg ref="roleHierarchy" />
</bean>
<bean id="roleHierarchy"
        class="org.springframework.security.access.hierarchicalroles.RoleHierarchyImpl">
    <property name="hierarchy">
        <value>
            ROLE_ADMIN > ROLE_STAFF
            ROLE_STAFF > ROLE_USER
            ROLE_USER > ROLE_GUEST
        </value>
    </property>
</bean>

Here we have four roles in a hierarchy ROLE_ADMIN ⇒ ROLE_STAFF ⇒ ROLE_USER ⇒ ROLE_GUEST. A user who is authenticated with ROLE_ADMIN, will behave as if they have all four roles when security constraints are evaluated against an AccessDecisionManager configured with the above RoleHierarchyVoter. The > symbol can be thought of as meaning "includes".

Role hierarchies offer a convenient means of simplifying the access-control configuration data for your application and/or reducing the number of authorities which you need to assign to a user. For more complex requirements you may wish to define a logical mapping between the specific access-rights your application requires and the roles that are assigned to users, translating between the two when loading the user information.

11.2. Authorize HttpServletRequest with FilterSecurityInterceptor

This section builds on Servlet Architecture and Implementation by digging deeper into how authorization works within Servlet based applications.

The FilterSecurityInterceptor provides authorization for HttpServletRequests. It is inserted into the FilterChainProxy as one of the Security Filters.

filtersecurityinterceptor
Figure 13. Authorize HttpServletRequest
  • number 1 First, the FilterSecurityInterceptor obtains an Authentication from the SecurityContextHolder.

  • number 2 Second, FilterSecurityInterceptor creates a FilterInvocation from the HttpServletRequest, HttpServletResponse, and FilterChain that are passed into the FilterSecurityInterceptor.

  • number 3 Next, it passes the FilterInvocation to SecurityMetadataSource to get the ConfigAttributes.

  • number 4 Finally, it passes the Authentication, FilterInvocation, and ConfigAttributes to the AccessDecisionManager.

    • number 5 If authorization is denied, an AccessDeniedException is thrown. In this case the ExceptionTranslationFilter handles the AccessDeniedException.

    • number 6 If access is granted, FilterSecurityInterceptor continues with the FilterChain which allows the application to process normally.

By default, Spring Security’s authorization will require all requests to be authenticated. The explicit configuration looks like:

Example 78. Every Request Must be Authenticated
Java
protected void configure(HttpSecurity http) throws Exception {
    http
        // ...
        .authorizeRequests(authorize -> authorize
            .anyRequest().authenticated()
        );
}
XML
<http>
    <!-- ... -->
    <intercept-url pattern="/**" access="authenticated"/>
</http>
Kotlin
fun configure(http: HttpSecurity) {
    http {
        // ...
        authorizeRequests {
            authorize(anyRequest, authenticated)
        }
    }
}

We can configure Spring Security to have different rules by adding more rules in order of precedence.

Example 79. Authorize Requests
Java
protected void configure(HttpSecurity http) throws Exception {
    http
        // ...
        .authorizeRequests(authorize -> authorize                                  (1)
            .mvcMatchers("/resources/**", "/signup", "/about").permitAll()         (2)
            .mvcMatchers("/admin/**").hasRole("ADMIN")                             (3)
            .mvcMatchers("/db/**").access("hasRole('ADMIN') and hasRole('DBA')")   (4)
            .anyRequest().denyAll()                                                (5)
        );
}
XML
<http> (1)
    <!-- ... -->
    (2)
    <intercept-url pattern="/resources/**" access="permitAll"/>
    <intercept-url pattern="/signup" access="permitAll"/>
    <intercept-url pattern="/about" access="permitAll"/>

    <intercept-url pattern="/admin/**" access="hasRole('ADMIN')"/> (3)
    <intercept-url pattern="/db/**" access="hasRole('ADMIN') and hasRole('DBA')"/> (4)
    <intercept-url pattern="/**" access="denyAll"/> (5)
</http>
Kotlin
fun configure(http: HttpSecurity) {
   http {
        authorizeRequests { (1)
            authorize("/resources/**", permitAll) (2)
            authorize("/signup", permitAll)
            authorize("/about", permitAll)

            authorize("/admin/**", hasRole("ADMIN")) (3)
            authorize("/db/**", "hasRole('ADMIN') and hasRole('DBA')") (4)
            authorize(anyRequest, denyAll) (5)
        }
    }
}
1 There are multiple authorization rules specified. Each rule is considered in the order they were declared.
2 We specified multiple URL patterns that any user can access. Specifically, any user can access a request if the URL starts with "/resources/", equals "/signup", or equals "/about".
3 Any URL that starts with "/admin/" will be restricted to users who have the role "ROLE_ADMIN". You will notice that since we are invoking the hasRole method we do not need to specify the "ROLE_" prefix.
4 Any URL that starts with "/db/" requires the user to have both "ROLE_ADMIN" and "ROLE_DBA". You will notice that since we are using the hasRole expression we do not need to specify the "ROLE_" prefix.
5 Any URL that has not already been matched on is denied access. This is a good strategy if you do not want to accidentally forget to update your authorization rules.

11.3. Expression-Based Access Control

Spring Security 3.0 introduced the ability to use Spring EL expressions as an authorization mechanism in addition to the simple use of configuration attributes and access-decision voters which have seen before. Expression-based access control is built on the same architecture but allows complicated Boolean logic to be encapsulated in a single expression.

11.3.1. Overview

Spring Security uses Spring EL for expression support and you should look at how that works if you are interested in understanding the topic in more depth. Expressions are evaluated with a "root object" as part of the evaluation context. Spring Security uses specific classes for web and method security as the root object, in order to provide built-in expressions and access to values such as the current principal.

Common Built-In Expressions

The base class for expression root objects is SecurityExpressionRoot. This provides some common expressions which are available in both web and method security.

Table 1. Common built-in expressions
Expression Description

hasRole(String role)

Returns true if the current principal has the specified role.

For example, hasRole('admin')

By default if the supplied role does not start with 'ROLE_' it will be added. This can be customized by modifying the defaultRolePrefix on DefaultWebSecurityExpressionHandler.

hasAnyRole(String…​ roles)

Returns true if the current principal has any of the supplied roles (given as a comma-separated list of strings).

For example, hasAnyRole('admin', 'user')

By default if the supplied role does not start with 'ROLE_' it will be added. This can be customized by modifying the defaultRolePrefix on DefaultWebSecurityExpressionHandler.

hasAuthority(String authority)

Returns true if the current principal has the specified authority.

For example, hasAuthority('read')

hasAnyAuthority(String…​ authorities)

Returns true if the current principal has any of the supplied authorities (given as a comma-separated list of strings)

For example, hasAnyAuthority('read', 'write')

principal

Allows direct access to the principal object representing the current user

authentication

Allows direct access to the current Authentication object obtained from the SecurityContext

permitAll

Always evaluates to true

denyAll

Always evaluates to false

isAnonymous()

Returns true if the current principal is an anonymous user

isRememberMe()

Returns true if the current principal is a remember-me user

isAuthenticated()

Returns true if the user is not anonymous

isFullyAuthenticated()

Returns true if the user is not an anonymous or a remember-me user

hasPermission(Object target, Object permission)

Returns true if the user has access to the provided target for the given permission. For example, hasPermission(domainObject, 'read')

hasPermission(Object targetId, String targetType, Object permission)

Returns true if the user has access to the provided target for the given permission. For example, hasPermission(1, 'com.example.domain.Message', 'read')

11.3.2. Web Security Expressions

To use expressions to secure individual URLs, you would first need to set the use-expressions attribute in the <http> element to true. Spring Security will then expect the access attributes of the <intercept-url> elements to contain Spring EL expressions. The expressions should evaluate to a Boolean, defining whether access should be allowed or not. For example:

<http>
    <intercept-url pattern="/admin*"
        access="hasRole('admin') and hasIpAddress('192.168.1.0/24')"/>
    ...
</http>

Here we have defined that the "admin" area of an application (defined by the URL pattern) should only be available to users who have the granted authority "admin" and whose IP address matches a local subnet. We’ve already seen the built-in hasRole expression in the previous section. The expression hasIpAddress is an additional built-in expression which is specific to web security. It is defined by the WebSecurityExpressionRoot class, an instance of which is used as the expression root object when evaluation web-access expressions. This object also directly exposed the HttpServletRequest object under the name request so you can invoke the request directly in an expression. If expressions are being used, a WebExpressionVoter will be added to the AccessDecisionManager which is used by the namespace. So if you aren’t using the namespace and want to use expressions, you will have to add one of these to your configuration.

Referring to Beans in Web Security Expressions

If you wish to extend the expressions that are available, you can easily refer to any Spring Bean you expose. For example, assuming you have a Bean with the name of webSecurity that contains the following method signature:

public class WebSecurity {
        public boolean check(Authentication authentication, HttpServletRequest request) {
                ...
        }
}

You could refer to the method using:

<http>
    <intercept-url pattern="/user/**"
        access="@webSecurity.check(authentication,request)"/>
    ...
</http>

or in Java configuration

http
    .authorizeRequests(authorize -> authorize
        .antMatchers("/user/**").access("@webSecurity.check(authentication,request)")
        ...
    )
Path Variables in Web Security Expressions

At times it is nice to be able to refer to path variables within a URL. For example, consider a RESTful application that looks up a user by id from the URL path in the format /user/{userId}.

You can easily refer to the path variable by placing it in the pattern. For example, if you had a Bean with the name of webSecurity that contains the following method signature:

public class WebSecurity {
        public boolean checkUserId(Authentication authentication, int id) {
                ...
        }
}

You could refer to the method using:

<http>
    <intercept-url pattern="/user/{userId}/**"
        access="@webSecurity.checkUserId(authentication,#userId)"/>
    ...
</http>

or in Java configuration

http
    .authorizeRequests(authorize -> authorize
        .antMatchers("/user/{userId}/**").access("@webSecurity.checkUserId(authentication,#userId)")
        ...
    );

In both configurations URLs that match would pass in the path variable (and convert it) into checkUserId method. For example, if the URL were /user/123/resource, then the id passed in would be 123.

11.3.3. Method Security Expressions

Method security is a bit more complicated than a simple allow or deny rule. Spring Security 3.0 introduced some new annotations in order to allow comprehensive support for the use of expressions.

@Pre and @Post Annotations

There are four annotations which support expression attributes to allow pre and post-invocation authorization checks and also to support filtering of submitted collection arguments or return values. They are @PreAuthorize, @PreFilter, @PostAuthorize and @PostFilter. Their use is enabled through the global-method-security namespace element:

<global-method-security pre-post-annotations="enabled"/>
Access Control using @PreAuthorize and @PostAuthorize

The most obviously useful annotation is @PreAuthorize which decides whether a method can actually be invoked or not. For example (from the"Contacts" sample application)

@PreAuthorize("hasRole('USER')")
public void create(Contact contact);

which means that access will only be allowed for users with the role "ROLE_USER". Obviously the same thing could easily be achieved using a traditional configuration and a simple configuration attribute for the required role. But what about:

@PreAuthorize("hasPermission(#contact, 'admin')")
public void deletePermission(Contact contact, Sid recipient, Permission permission);

Here we’re actually using a method argument as part of the expression to decide whether the current user has the "admin"permission for the given contact. The built-in hasPermission() expression is linked into the Spring Security ACL module through the application context, as we’llsee below. You can access any of the method arguments by name as expression variables.

There are a number of ways in which Spring Security can resolve the method arguments. Spring Security uses DefaultSecurityParameterNameDiscoverer to discover the parameter names. By default, the following options are tried for a method as a whole.

  • If Spring Security’s @P annotation is present on a single argument to the method, the value will be used. This is useful for interfaces compiled with a JDK prior to JDK 8 which do not contain any information about the parameter names. For example:

    import org.springframework.security.access.method.P;
    
    ...
    
    @PreAuthorize("#c.name == authentication.name")
    public void doSomething(@P("c") Contact contact);

    Behind the scenes this use implemented using AnnotationParameterNameDiscoverer which can be customized to support the value attribute of any specified annotation.

  • If Spring Data’s @Param annotation is present on at least one parameter for the method, the value will be used. This is useful for interfaces compiled with a JDK prior to JDK 8 which do not contain any information about the parameter names. For example:

    import org.springframework.data.repository.query.Param;
    
    ...
    
    @PreAuthorize("#n == authentication.name")
    Contact findContactByName(@Param("n") String name);

    Behind the scenes this use implemented using AnnotationParameterNameDiscoverer which can be customized to support the value attribute of any specified annotation.

  • If JDK 8 was used to compile the source with the -parameters argument and Spring 4+ is being used, then the standard JDK reflection API is used to discover the parameter names. This works on both classes and interfaces.

  • Last, if the code was compiled with the debug symbols, the parameter names will be discovered using the debug symbols. This will not work for interfaces since they do not have debug information about the parameter names. For interfaces, annotations or the JDK 8 approach must be used.

Any Spring-EL functionality is available within the expression, so you can also access properties on the arguments. For example, if you wanted a particular method to only allow access to a user whose username matched that of the contact, you could write

@PreAuthorize("#contact.name == authentication.name")
public void doSomething(Contact contact);

Here we are accessing another built-in expression, authentication, which is the Authentication stored in the security context. You can also access its "principal" property directly, using the expression principal. The value will often be a UserDetails instance, so you might use an expression like principal.username or principal.enabled.

Less commonly, you may wish to perform an access-control check after the method has been invoked. This can be achieved using the @PostAuthorize annotation. To access the return value from a method, use the built-in name returnObject in the expression.

Filtering using @PreFilter and @PostFilter

As you may already be aware, Spring Security supports filtering of collections and arrays and this can now be achieved using expressions. This is most commonly performed on the return value of a method. For example:

@PreAuthorize("hasRole('USER')")
@PostFilter("hasPermission(filterObject, 'read') or hasPermission(filterObject, 'admin')")
public List<Contact> getAll();

When using the @PostFilter annotation, Spring Security iterates through the returned collection and removes any elements for which the supplied expression is false. The name filterObject refers to the current object in the collection. You can also filter before the method call, using @PreFilter, though this is a less common requirement. The syntax is just the same, but if there is more than one argument which is a collection type then you have to select one by name using the filterTarget property of this annotation.

Note that filtering is obviously not a substitute for tuning your data retrieval queries. If you are filtering large collections and removing many of the entries then this is likely to be inefficient.

Built-In Expressions

There are some built-in expressions which are specific to method security, which we have already seen in use above. The filterTarget and returnValue values are simple enough, but the use of the hasPermission() expression warrants a closer look.

The PermissionEvaluator interface

hasPermission() expressions are delegated to an instance of PermissionEvaluator. It is intended to bridge between the expression system and Spring Security’s ACL system, allowing you to specify authorization constraints on domain objects, based on abstract permissions. It has no explicit dependencies on the ACL module, so you could swap that out for an alternative implementation if required. The interface has two methods:

boolean hasPermission(Authentication authentication, Object targetDomainObject,
                            Object permission);

boolean hasPermission(Authentication authentication, Serializable targetId,
                            String targetType, Object permission);

which map directly to the available versions of the expression, with the exception that the first argument (the Authentication object) is not supplied. The first is used in situations where the domain object, to which access is being controlled, is already loaded. Then expression will return true if the current user has the given permission for that object. The second version is used in cases where the object is not loaded, but its identifier is known. An abstract "type" specifier for the domain object is also required, allowing the correct ACL permissions to be loaded. This has traditionally been the Java class of the object, but does not have to be as long as it is consistent with how the permissions are loaded.

To use hasPermission() expressions, you have to explicitly configure a PermissionEvaluator in your application context. This would look something like this:

<security:global-method-security pre-post-annotations="enabled">
<security:expression-handler ref="expressionHandler"/>
</security:global-method-security>

<bean id="expressionHandler" class=
"org.springframework.security.access.expression.method.DefaultMethodSecurityExpressionHandler">
    <property name="permissionEvaluator" ref="myPermissionEvaluator"/>
</bean>

Where myPermissionEvaluator is the bean which implements PermissionEvaluator. Usually this will be the implementation from the ACL module which is called AclPermissionEvaluator. See the "Contacts" sample application configuration for more details.

Method Security Meta Annotations

You can make use of meta annotations for method security to make your code more readable. This is especially convenient if you find that you are repeating the same complex expression throughout your code base. For example, consider the following:

@PreAuthorize("#contact.name == authentication.name")

Instead of repeating this everywhere, we can create a meta annotation that can be used instead.

@Retention(RetentionPolicy.RUNTIME)
@PreAuthorize("#contact.name == authentication.name")
public @interface ContactPermission {}

Meta annotations can be used for any of the Spring Security method security annotations. In order to remain compliant with the specification JSR-250 annotations do not support meta annotations.

11.4. Secure Object Implementations

11.4.1. AOP Alliance (MethodInvocation) Security Interceptor

Prior to Spring Security 2.0, securing MethodInvocation s needed quite a lot of boiler plate configuration. Now the recommended approach for method security is to use namespace configuration. This way the method security infrastructure beans are configured automatically for you so you don’t really need to know about the implementation classes. We’ll just provide a quick overview of the classes that are involved here.

Method security is enforced using a MethodSecurityInterceptor, which secures MethodInvocation s. Depending on the configuration approach, an interceptor may be specific to a single bean or shared between multiple beans. The interceptor uses a MethodSecurityMetadataSource instance to obtain the configuration attributes that apply to a particular method invocation. MapBasedMethodSecurityMetadataSource is used to store configuration attributes keyed by method names (which can be wildcarded) and will be used internally when the attributes are defined in the application context using the <intercept-methods> or <protect-point> elements. Other implementations will be used to handle annotation-based configuration.

Explicit MethodSecurityInterceptor Configuration

You can of course configure a MethodSecurityInterceptor directly in your application context for use with one of Spring AOP’s proxying mechanisms:

<bean id="bankManagerSecurity" class=
    "org.springframework.security.access.intercept.aopalliance.MethodSecurityInterceptor">
<property name="authenticationManager" ref="authenticationManager"/>
<property name="accessDecisionManager" ref="accessDecisionManager"/>
<property name="afterInvocationManager" ref="afterInvocationManager"/>
<property name="securityMetadataSource">
    <sec:method-security-metadata-source>
    <sec:protect method="com.mycompany.BankManager.delete*" access="ROLE_SUPERVISOR"/>
    <sec:protect method="com.mycompany.BankManager.getBalance" access="ROLE_TELLER,ROLE_SUPERVISOR"/>
    </sec:method-security-metadata-source>
</property>
</bean>

11.4.2. AspectJ (JoinPoint) Security Interceptor

The AspectJ security interceptor is very similar to the AOP Alliance security interceptor discussed in the previous section. Indeed we will only discuss the differences in this section.

The AspectJ interceptor is named AspectJSecurityInterceptor. Unlike the AOP Alliance security interceptor, which relies on the Spring application context to weave in the security interceptor via proxying, the AspectJSecurityInterceptor is weaved in via the AspectJ compiler. It would not be uncommon to use both types of security interceptors in the same application, with AspectJSecurityInterceptor being used for domain object instance security and the AOP Alliance MethodSecurityInterceptor being used for services layer security.

Let’s first consider how the AspectJSecurityInterceptor is configured in the Spring application context:

<bean id="bankManagerSecurity" class=
    "org.springframework.security.access.intercept.aspectj.AspectJMethodSecurityInterceptor">
<property name="authenticationManager" ref="authenticationManager"/>
<property name="accessDecisionManager" ref="accessDecisionManager"/>
<property name="afterInvocationManager" ref="afterInvocationManager"/>
<property name="securityMetadataSource">
    <sec:method-security-metadata-source>
    <sec:protect method="com.mycompany.BankManager.delete*" access="ROLE_SUPERVISOR"/>
    <sec:protect method="com.mycompany.BankManager.getBalance" access="ROLE_TELLER,ROLE_SUPERVISOR"/>
    </sec:method-security-metadata-source>
</property>
</bean>

As you can see, aside from the class name, the AspectJSecurityInterceptor is exactly the same as the AOP Alliance security interceptor. Indeed the two interceptors can share the same securityMetadataSource, as the SecurityMetadataSource works with java.lang.reflect.Method s rather than an AOP library-specific class. Of course, your access decisions have access to the relevant AOP library-specific invocation (ie MethodInvocation or JoinPoint) and as such can consider a range of addition criteria when making access decisions (such as method arguments).

Next you’ll need to define an AspectJ aspect. For example:

package org.springframework.security.samples.aspectj;

import org.springframework.security.access.intercept.aspectj.AspectJSecurityInterceptor;
import org.springframework.security.access.intercept.aspectj.AspectJCallback;
import org.springframework.beans.factory.InitializingBean;

public aspect DomainObjectInstanceSecurityAspect implements InitializingBean {

    private AspectJSecurityInterceptor securityInterceptor;

    pointcut domainObjectInstanceExecution(): target(PersistableEntity)
        && execution(public * *(..)) && !within(DomainObjectInstanceSecurityAspect);

    Object around(): domainObjectInstanceExecution() {
        if (this.securityInterceptor == null) {
            return proceed();
        }

        AspectJCallback callback = new AspectJCallback() {
            public Object proceedWithObject() {
                return proceed();
            }
        };

        return this.securityInterceptor.invoke(thisJoinPoint, callback);
    }

    public AspectJSecurityInterceptor getSecurityInterceptor() {
        return securityInterceptor;
    }

    public void setSecurityInterceptor(AspectJSecurityInterceptor securityInterceptor) {
        this.securityInterceptor = securityInterceptor;
    }

    public void afterPropertiesSet() throws Exception {
        if (this.securityInterceptor == null)
            throw new IllegalArgumentException("securityInterceptor required");
        }
    }
}

In the above example, the security interceptor will be applied to every instance of PersistableEntity, which is an abstract class not shown (you can use any other class or pointcut expression you like). For those curious, AspectJCallback is needed because the proceed(); statement has special meaning only within an around() body. The AspectJSecurityInterceptor calls this anonymous AspectJCallback class when it wants the target object to continue.

You will need to configure Spring to load the aspect and wire it with the AspectJSecurityInterceptor. A bean declaration which achieves this is shown below:

<bean id="domainObjectInstanceSecurityAspect"
    class="security.samples.aspectj.DomainObjectInstanceSecurityAspect"
    factory-method="aspectOf">
<property name="securityInterceptor" ref="bankManagerSecurity"/>
</bean>

That’s it! Now you can create your beans from anywhere within your application, using whatever means you think fit (eg new Person();) and they will have the security interceptor applied.

11.5. Method Security

From version 2.0 onwards Spring Security has improved support substantially for adding security to your service layer methods. It provides support for JSR-250 annotation security as well as the framework’s original @Secured annotation. From 3.0 you can also make use of new expression-based annotations. You can apply security to a single bean, using the intercept-methods element to decorate the bean declaration, or you can secure multiple beans across the entire service layer using the AspectJ style pointcuts.

11.5.1. EnableGlobalMethodSecurity

We can enable annotation-based security using the @EnableGlobalMethodSecurity annotation on any @Configuration instance. For example, the following would enable Spring Security’s @Secured annotation.

@EnableGlobalMethodSecurity(securedEnabled = true)
public class MethodSecurityConfig {
// ...
}

Adding an annotation to a method (on a class or interface) would then limit the access to that method accordingly. Spring Security’s native annotation support defines a set of attributes for the method. These will be passed to the AccessDecisionManager for it to make the actual decision:

public interface BankService {

@Secured("IS_AUTHENTICATED_ANONYMOUSLY")
public Account readAccount(Long id);

@Secured("IS_AUTHENTICATED_ANONYMOUSLY")
public Account[] findAccounts();

@Secured("ROLE_TELLER")
public Account post(Account account, double amount);
}

Support for JSR-250 annotations can be enabled using

@EnableGlobalMethodSecurity(jsr250Enabled = true)
public class MethodSecurityConfig {
// ...
}

These are standards-based and allow simple role-based constraints to be applied but do not have the power Spring Security’s native annotations. To use the new expression-based syntax, you would use

@EnableGlobalMethodSecurity(prePostEnabled = true)
public class MethodSecurityConfig {
// ...
}

and the equivalent Java code would be

public interface BankService {

@PreAuthorize("isAnonymous()")
public Account readAccount(Long id);

@PreAuthorize("isAnonymous()")
public Account[] findAccounts();

@PreAuthorize("hasAuthority('ROLE_TELLER')")
public Account post(Account account, double amount);
}

11.5.2. GlobalMethodSecurityConfiguration

Sometimes you may need to perform operations that are more complicated than are possible with the @EnableGlobalMethodSecurity annotation allow. For these instances, you can extend the GlobalMethodSecurityConfiguration ensuring that the @EnableGlobalMethodSecurity annotation is present on your subclass. For example, if you wanted to provide a custom MethodSecurityExpressionHandler, you could use the following configuration:

@EnableGlobalMethodSecurity(prePostEnabled = true)
public class MethodSecurityConfig extends GlobalMethodSecurityConfiguration {
    @Override
    protected MethodSecurityExpressionHandler createExpressionHandler() {
        // ... create and return custom MethodSecurityExpressionHandler ...
        return expressionHandler;
    }
}

For additional information about methods that can be overridden, refer to the GlobalMethodSecurityConfiguration Javadoc.

11.5.3. The <global-method-security> Element

This element is used to enable annotation-based security in your application (by setting the appropriate attributes on the element), and also to group together security pointcut declarations which will be applied across your entire application context. You should only declare one <global-method-security> element. The following declaration would enable support for Spring Security’s @Secured:

<global-method-security secured-annotations="enabled" />

Adding an annotation to a method (on an class or interface) would then limit the access to that method accordingly. Spring Security’s native annotation support defines a set of attributes for the method. These will be passed to the AccessDecisionManager for it to make the actual decision:

public interface BankService {

@Secured("IS_AUTHENTICATED_ANONYMOUSLY")
public Account readAccount(Long id);

@Secured("IS_AUTHENTICATED_ANONYMOUSLY")
public Account[] findAccounts();

@Secured("ROLE_TELLER")
public Account post(Account account, double amount);
}

Support for JSR-250 annotations can be enabled using

<global-method-security jsr250-annotations="enabled" />

These are standards-based and allow simple role-based constraints to be applied but do not have the power Spring Security’s native annotations. To use the new expression-based syntax, you would use

<global-method-security pre-post-annotations="enabled" />

and the equivalent Java code would be

public interface BankService {

@PreAuthorize("isAnonymous()")
public Account readAccount(Long id);

@PreAuthorize("isAnonymous()")
public Account[] findAccounts();

@PreAuthorize("hasAuthority('ROLE_TELLER')")
public Account post(Account account, double amount);
}

Expression-based annotations are a good choice if you need to define simple rules that go beyond checking the role names against the user’s list of authorities.

The annotated methods will only be secured for instances which are defined as Spring beans (in the same application context in which method-security is enabled). If you want to secure instances which are not created by Spring (using the new operator, for example) then you need to use AspectJ.

You can enable more than one type of annotation in the same application, but only one type should be used for any interface or class as the behaviour will not be well-defined otherwise. If two annotations are found which apply to a particular method, then only one of them will be applied.

11.5.4. Adding Security Pointcuts using protect-pointcut

The use of protect-pointcut is particularly powerful, as it allows you to apply security to many beans with only a simple declaration. Consider the following example:

<global-method-security>
<protect-pointcut expression="execution(* com.mycompany.*Service.*(..))"
    access="ROLE_USER"/>
</global-method-security>

This will protect all methods on beans declared in the application context whose classes are in the com.mycompany package and whose class names end in "Service". Only users with the ROLE_USER role will be able to invoke these methods. As with URL matching, the most specific matches must come first in the list of pointcuts, as the first matching expression will be used. Security annotations take precedence over pointcuts.

11.6. Domain Object Security (ACLs)

11.6.1. Overview

Complex applications often will find the need to define access permissions not simply at a web request or method invocation level. Instead, security decisions need to comprise both who (Authentication), where (MethodInvocation) and what (SomeDomainObject). In other words, authorization decisions also need to consider the actual domain object instance subject of a method invocation.

Imagine you’re designing an application for a pet clinic. There will be two main groups of users of your Spring-based application: staff of the pet clinic, as well as the pet clinic’s customers. The staff will have access to all of the data, whilst your customers will only be able to see their own customer records. To make it a little more interesting, your customers can allow other users to see their customer records, such as their "puppy preschool" mentor or president of their local "Pony Club". Using Spring Security as the foundation, you have several approaches that can be used:

  • Write your business methods to enforce the security. You could consult a collection within the Customer domain object instance to determine which users have access. By using the SecurityContextHolder.getContext().getAuthentication(), you’ll be able to access the Authentication object.

  • Write an AccessDecisionVoter to enforce the security from the GrantedAuthority[] s stored in the Authentication object. This would mean your AuthenticationManager would need to populate the Authentication with custom GrantedAuthority[]s representing each of the Customer domain object instances the principal has access to.

  • Write an AccessDecisionVoter to enforce the security and open the target Customer domain object directly. This would mean your voter needs access to a DAO that allows it to retrieve the Customer object. It would then access the Customer object’s collection of approved users and make the appropriate decision.

Each one of these approaches is perfectly legitimate. However, the first couples your authorization checking to your business code. The main problems with this include the enhanced difficulty of unit testing and the fact it would be more difficult to reuse the Customer authorization logic elsewhere. Obtaining the GrantedAuthority[] s from the Authentication object is also fine, but will not scale to large numbers of Customer s. If a user might be able to access 5,000 Customer s (unlikely in this case, but imagine if it were a popular vet for a large Pony Club!) the amount of memory consumed and time required to construct the Authentication object would be undesirable. The final method, opening the Customer directly from external code, is probably the best of the three. It achieves separation of concerns, and doesn’t misuse memory or CPU cycles, but it is still inefficient in that both the AccessDecisionVoter and the eventual business method itself will perform a call to the DAO responsible for retrieving the Customer object. Two accesses per method invocation is clearly undesirable. In addition, with every approach listed you’ll need to write your own access control list (ACL) persistence and business logic from scratch.

Fortunately, there is another alternative, which we’ll talk about below.

11.6.2. Key Concepts

Spring Security’s ACL services are shipped in the spring-security-acl-xxx.jar. You will need to add this JAR to your classpath to use Spring Security’s domain object instance security capabilities.

Spring Security’s domain object instance security capabilities centre on the concept of an access control list (ACL). Every domain object instance in your system has its own ACL, and the ACL records details of who can and can’t work with that domain object. With this in mind, Spring Security delivers three main ACL-related capabilities to your application:

  • A way of efficiently retrieving ACL entries for all of your domain objects (and modifying those ACLs)

  • A way of ensuring a given principal is permitted to work with your objects, before methods are called

  • A way of ensuring a given principal is permitted to work with your objects (or something they return), after methods are called

As indicated by the first bullet point, one of the main capabilities of the Spring Security ACL module is providing a high-performance way of retrieving ACLs. This ACL repository capability is extremely important, because every domain object instance in your system might have several access control entries, and each ACL might inherit from other ACLs in a tree-like structure (this is supported out-of-the-box by Spring Security, and is very commonly used). Spring Security’s ACL capability has been carefully designed to provide high performance retrieval of ACLs, together with pluggable caching, deadlock-minimizing database updates, independence from ORM frameworks (we use JDBC directly), proper encapsulation, and transparent database updating.

Given databases are central to the operation of the ACL module, let’s explore the four main tables used by default in the implementation. The tables are presented below in order of size in a typical Spring Security ACL deployment, with the table with the most rows listed last:

  • ACL_SID allows us to uniquely identify any principal or authority in the system ("SID" stands for "security identity"). The only columns are the ID, a textual representation of the SID, and a flag to indicate whether the textual representation refers to a principal name or a GrantedAuthority. Thus, there is a single row for each unique principal or GrantedAuthority. When used in the context of receiving a permission, a SID is generally called a "recipient".

  • ACL_CLASS allows us to uniquely identify any domain object class in the system. The only columns are the ID and the Java class name. Thus, there is a single row for each unique Class we wish to store ACL permissions for.

  • ACL_OBJECT_IDENTITY stores information for each unique domain object instance in the system. Columns include the ID, a foreign key to the ACL_CLASS table, a unique identifier so we know which ACL_CLASS instance we’re providing information for, the parent, a foreign key to the ACL_SID table to represent the owner of the domain object instance, and whether we allow ACL entries to inherit from any parent ACL. We have a single row for every domain object instance we’re storing ACL permissions for.

  • Finally, ACL_ENTRY stores the individual permissions assigned to each recipient. Columns include a foreign key to the ACL_OBJECT_IDENTITY, the recipient (ie a foreign key to ACL_SID), whether we’ll be auditing or not, and the integer bit mask that represents the actual permission being granted or denied. We have a single row for every recipient that receives a permission to work with a domain object.

As mentioned in the last paragraph, the ACL system uses integer bit masking. Don’t worry, you need not be aware of the finer points of bit shifting to use the ACL system, but suffice to say that we have 32 bits we can switch on or off. Each of these bits represents a permission, and by default the permissions are read (bit 0), write (bit 1), create (bit 2), delete (bit 3) and administer (bit 4). It’s easy to implement your own Permission instance if you wish to use other permissions, and the remainder of the ACL framework will operate without knowledge of your extensions.

It is important to understand that the number of domain objects in your system has absolutely no bearing on the fact we’ve chosen to use integer bit masking. Whilst you have 32 bits available for permissions, you could have billions of domain object instances (which will mean billions of rows in ACL_OBJECT_IDENTITY and quite probably ACL_ENTRY). We make this point because we’ve found sometimes people mistakenly believe they need a bit for each potential domain object, which is not the case.

Now that we’ve provided a basic overview of what the ACL system does, and what it looks like at a table structure, let’s explore the key interfaces. The key interfaces are:

  • Acl: Every domain object has one and only one Acl object, which internally holds the AccessControlEntry s as well as knows the owner of the Acl. An Acl does not refer directly to the domain object, but instead to an ObjectIdentity. The Acl is stored in the ACL_OBJECT_IDENTITY table.

  • AccessControlEntry: An Acl holds multiple AccessControlEntry s, which are often abbreviated as ACEs in the framework. Each ACE refers to a specific tuple of Permission, Sid and Acl. An ACE can also be granting or non-granting and contain audit settings. The ACE is stored in the ACL_ENTRY table.

  • Permission: A permission represents a particular immutable bit mask, and offers convenience functions for bit masking and outputting information. The basic permissions presented above (bits 0 through 4) are contained in the BasePermission class.

  • Sid: The ACL module needs to refer to principals and GrantedAuthority[] s. A level of indirection is provided by the Sid interface, which is an abbreviation of "security identity". Common classes include PrincipalSid (to represent the principal inside an Authentication object) and GrantedAuthoritySid. The security identity information is stored in the ACL_SID table.

  • ObjectIdentity: Each domain object is represented internally within the ACL module by an ObjectIdentity. The default implementation is called ObjectIdentityImpl.

  • AclService: Retrieves the Acl applicable for a given ObjectIdentity. In the included implementation (JdbcAclService), retrieval operations are delegated to a LookupStrategy. The LookupStrategy provides a highly optimized strategy for retrieving ACL information, using batched retrievals (BasicLookupStrategy) and supporting custom implementations that leverage materialized views, hierarchical queries and similar performance-centric, non-ANSI SQL capabilities.

  • MutableAclService: Allows a modified Acl to be presented for persistence. It is not essential to use this interface if you do not wish.

Please note that our out-of-the-box AclService and related database classes all use ANSI SQL. This should therefore work with all major databases. At the time of writing, the system had been successfully tested using Hypersonic SQL, PostgreSQL, Microsoft SQL Server and Oracle.

Two samples ship with Spring Security that demonstrate the ACL module. The first is the Contacts Sample, and the other is the Document Management System (DMS) Sample. We suggest taking a look over these for examples.

11.6.3. Getting Started

To get starting using Spring Security’s ACL capability, you will need to store your ACL information somewhere. This necessitates the instantiation of a DataSource using Spring. The DataSource is then injected into a JdbcMutableAclService and BasicLookupStrategy instance. The latter provides high-performance ACL retrieval capabilities, and the former provides mutator capabilities. Refer to one of the samples that ship with Spring Security for an example configuration. You’ll also need to populate the database with the four ACL-specific tables listed in the last section (refer to the ACL samples for the appropriate SQL statements).

Once you’ve created the required schema and instantiated JdbcMutableAclService, you’ll next need to ensure your domain model supports interoperability with the Spring Security ACL package. Hopefully ObjectIdentityImpl will prove sufficient, as it provides a large number of ways in which it can be used. Most people will have domain objects that contain a public Serializable getId() method. If the return type is long, or compatible with long (eg an int), you will find you need not give further consideration to ObjectIdentity issues. Many parts of the ACL module rely on long identifiers. If you’re not using long (or an int, byte etc), there is a very good chance you’ll need to reimplement a number of classes. We do not intend to support non-long identifiers in Spring Security’s ACL module, as longs are already compatible with all database sequences, the most common identifier data type, and are of sufficient length to accommodate all common usage scenarios.

The following fragment of code shows how to create an Acl, or modify an existing Acl:

// Prepare the information we'd like in our access control entry (ACE)
ObjectIdentity oi = new ObjectIdentityImpl(Foo.class, new Long(44));
Sid sid = new PrincipalSid("Samantha");
Permission p = BasePermission.ADMINISTRATION;

// Create or update the relevant ACL
MutableAcl acl = null;
try {
acl = (MutableAcl) aclService.readAclById(oi);
} catch (NotFoundException nfe) {
acl = aclService.createAcl(oi);
}

// Now grant some permissions via an access control entry (ACE)
acl.insertAce(acl.getEntries().length, p, sid, true);
aclService.updateAcl(acl);

In the example above, we’re retrieving the ACL associated with the "Foo" domain object with identifier number 44. We’re then adding an ACE so that a principal named "Samantha" can "administer" the object. The code fragment is relatively self-explanatory, except the insertAce method. The first argument to the insertAce method is determining at what position in the Acl the new entry will be inserted. In the example above, we’re just putting the new ACE at the end of the existing ACEs. The final argument is a Boolean indicating whether the ACE is granting or denying. Most of the time it will be granting (true), but if it is denying (false), the permissions are effectively being blocked.

Spring Security does not provide any special integration to automatically create, update or delete ACLs as part of your DAO or repository operations. Instead, you will need to write code like shown above for your individual domain objects. It’s worth considering using AOP on your services layer to automatically integrate the ACL information with your services layer operations. We’ve found this quite an effective approach in the past.

Once you’ve used the above techniques to store some ACL information in the database, the next step is to actually use the ACL information as part of authorization decision logic. You have a number of choices here. You could write your own AccessDecisionVoter or AfterInvocationProvider that respectively fires before or after a method invocation. Such classes would use AclService to retrieve the relevant ACL and then call Acl.isGranted(Permission[] permission, Sid[] sids, boolean administrativeMode) to decide whether permission is granted or denied. Alternately, you could use our AclEntryVoter, AclEntryAfterInvocationProvider or AclEntryAfterInvocationCollectionFilteringProvider classes. All of these classes provide a declarative-based approach to evaluating ACL information at runtime, freeing you from needing to write any code. Please refer to the sample applications to learn how to use these classes.

12. OAuth2

12.1. OAuth 2.0 Login

The OAuth 2.0 Login feature provides an application with the capability to have users log in to the application by using their existing account at an OAuth 2.0 Provider (e.g. GitHub) or OpenID Connect 1.0 Provider (such as Google). OAuth 2.0 Login implements the use cases: "Login with Google" or "Login with GitHub".

OAuth 2.0 Login is implemented by using the Authorization Code Grant, as specified in the OAuth 2.0 Authorization Framework and OpenID Connect Core 1.0.

12.1.1. Spring Boot 2.x Sample

Spring Boot 2.x brings full auto-configuration capabilities for OAuth 2.0 Login.

This section shows how to configure the OAuth 2.0 Login sample using Google as the Authentication Provider and covers the following topics:

Initial setup

To use Google’s OAuth 2.0 authentication system for login, you must set up a project in the Google API Console to obtain OAuth 2.0 credentials.

Google’s OAuth 2.0 implementation for authentication conforms to the OpenID Connect 1.0 specification and is OpenID Certified.

Follow the instructions on the OpenID Connect page, starting in the section, "Setting up OAuth 2.0".

After completing the "Obtain OAuth 2.0 credentials" instructions, you should have a new OAuth Client with credentials consisting of a Client ID and a Client Secret.

Setting the redirect URI

The redirect URI is the path in the application that the end-user’s user-agent is redirected back to after they have authenticated with Google and have granted access to the OAuth Client (created in the previous step) on the Consent page.

In the "Set a redirect URI" sub-section, ensure that the Authorized redirect URIs field is set to http://localhost:8080/login/oauth2/code/google.

The default redirect URI template is {baseUrl}/login/oauth2/code/{registrationId}. The registrationId is a unique identifier for the ClientRegistration.
If the OAuth Client is running behind a proxy server, it is recommended to check Proxy Server Configuration to ensure the application is correctly configured. Also, see the supported URI template variables for redirect-uri.
Configure application.yml

Now that you have a new OAuth Client with Google, you need to configure the application to use the OAuth Client for the authentication flow. To do so:

  1. Go to application.yml and set the following configuration:

    spring:
      security:
        oauth2:
          client:
            registration:   (1)
              google:   (2)
                client-id: google-client-id
                client-secret: google-client-secret
    Example 80. OAuth Client properties
    1 spring.security.oauth2.client.registration is the base property prefix for OAuth Client properties.
    2 Following the base property prefix is the ID for the ClientRegistration, such as google.
  2. Replace the values in the client-id and client-secret property with the OAuth 2.0 credentials you created earlier.

Boot up the application

Launch the Spring Boot 2.x sample and go to http://localhost:8080. You are then redirected to the default auto-generated login page, which displays a link for Google.

Click on the Google link, and you are then redirected to Google for authentication.

After authenticating with your Google account credentials, the next page presented to you is the Consent screen. The Consent screen asks you to either allow or deny access to the OAuth Client you created earlier. Click Allow to authorize the OAuth Client to access your email address and basic profile information.

At this point, the OAuth Client retrieves your email address and basic profile information from the UserInfo Endpoint and establishes an authenticated session.

12.1.2. Spring Boot 2.x Property Mappings

The following table outlines the mapping of the Spring Boot 2.x OAuth Client properties to the ClientRegistration properties.

Spring Boot 2.x ClientRegistration

spring.security.oauth2.client.registration.[registrationId]

registrationId

spring.security.oauth2.client.registration.[registrationId].client-id

clientId

spring.security.oauth2.client.registration.[registrationId].client-secret

clientSecret

spring.security.oauth2.client.registration.[registrationId].client-authentication-method

clientAuthenticationMethod

spring.security.oauth2.client.registration.[registrationId].authorization-grant-type

authorizationGrantType

spring.security.oauth2.client.registration.[registrationId].redirect-uri

redirectUriTemplate

spring.security.oauth2.client.registration.[registrationId].scope

scopes

spring.security.oauth2.client.registration.[registrationId].client-name

clientName

spring.security.oauth2.client.provider.[providerId].authorization-uri

providerDetails.authorizationUri

spring.security.oauth2.client.provider.[providerId].token-uri

providerDetails.tokenUri

spring.security.oauth2.client.provider.[providerId].jwk-set-uri

providerDetails.jwkSetUri

spring.security.oauth2.client.provider.[providerId].user-info-uri

providerDetails.userInfoEndpoint.uri

spring.security.oauth2.client.provider.[providerId].user-info-authentication-method

providerDetails.userInfoEndpoint.authenticationMethod

spring.security.oauth2.client.provider.[providerId].user-name-attribute

providerDetails.userInfoEndpoint.userNameAttributeName

A ClientRegistration can be initially configured using discovery of an OpenID Connect Provider’s Configuration endpoint or an Authorization Server’s Metadata endpoint, by specifying the spring.security.oauth2.client.provider.[providerId].issuer-uri property.

12.1.3. CommonOAuth2Provider

CommonOAuth2Provider pre-defines a set of default client properties for a number of well known providers: Google, GitHub, Facebook, and Okta.

For example, the authorization-uri, token-uri, and user-info-uri do not change often for a Provider. Therefore, it makes sense to provide default values in order to reduce the required configuration.

As demonstrated previously, when we configured a Google client, only the client-id and client-secret properties are required.

The following listing shows an example:

spring:
  security:
    oauth2:
      client:
        registration:
          google:
            client-id: google-client-id
            client-secret: google-client-secret
The auto-defaulting of client properties works seamlessly here because the registrationId (google) matches the GOOGLE enum (case-insensitive) in CommonOAuth2Provider.

For cases where you may want to specify a different registrationId, such as google-login, you can still leverage auto-defaulting of client properties by configuring the provider property.

The following listing shows an example:

spring:
  security:
    oauth2:
      client:
        registration:
          google-login: (1)
            provider: google    (2)
            client-id: google-client-id
            client-secret: google-client-secret
1 The registrationId is set to google-login.
2 The provider property is set to google, which will leverage the auto-defaulting of client properties set in CommonOAuth2Provider.GOOGLE.getBuilder().

12.1.4. Configuring Custom Provider Properties

There are some OAuth 2.0 Providers that support multi-tenancy, which results in different protocol endpoints for each tenant (or sub-domain).

For example, an OAuth Client registered with Okta is assigned to a specific sub-domain and have their own protocol endpoints.

For these cases, Spring Boot 2.x provides the following base property for configuring custom provider properties: spring.security.oauth2.client.provider.[providerId].

The following listing shows an example:

spring:
  security:
    oauth2:
      client:
        registration:
          okta:
            client-id: okta-client-id
            client-secret: okta-client-secret
        provider:
          okta: (1)
            authorization-uri: https://your-subdomain.oktapreview.com/oauth2/v1/authorize
            token-uri: https://your-subdomain.oktapreview.com/oauth2/v1/token
            user-info-uri: https://your-subdomain.oktapreview.com/oauth2/v1/userinfo
            user-name-attribute: sub
            jwk-set-uri: https://your-subdomain.oktapreview.com/oauth2/v1/keys
1 The base property (spring.security.oauth2.client.provider.okta) allows for custom configuration of protocol endpoint locations.

12.1.5. Overriding Spring Boot 2.x Auto-configuration

The Spring Boot 2.x auto-configuration class for OAuth Client support is OAuth2ClientAutoConfiguration.

It performs the following tasks:

  • Registers a ClientRegistrationRepository @Bean composed of ClientRegistration(s) from the configured OAuth Client properties.

  • Provides a WebSecurityConfigurerAdapter @Configuration and enables OAuth 2.0 Login through httpSecurity.oauth2Login().

If you need to override the auto-configuration based on your specific requirements, you may do so in the following ways:

Register a ClientRegistrationRepository @Bean

The following example shows how to register a ClientRegistrationRepository @Bean:

@Configuration
public class OAuth2LoginConfig {

    @Bean
    public ClientRegistrationRepository clientRegistrationRepository() {
        return new InMemoryClientRegistrationRepository(this.googleClientRegistration());
    }

    private ClientRegistration googleClientRegistration() {
        return ClientRegistration.withRegistrationId("google")
            .clientId("google-client-id")
            .clientSecret("google-client-secret")
            .clientAuthenticationMethod(ClientAuthenticationMethod.BASIC)
            .authorizationGrantType(AuthorizationGrantType.AUTHORIZATION_CODE)
            .redirectUriTemplate("{baseUrl}/login/oauth2/code/{registrationId}")
            .scope("openid", "profile", "email", "address", "phone")
            .authorizationUri("https://accounts.google.com/o/oauth2/v2/auth")
            .tokenUri("https://www.googleapis.com/oauth2/v4/token")
            .userInfoUri("https://www.googleapis.com/oauth2/v3/userinfo")
            .userNameAttributeName(IdTokenClaimNames.SUB)
            .jwkSetUri("https://www.googleapis.com/oauth2/v3/certs")
            .clientName("Google")
            .build();
    }
}
Provide a WebSecurityConfigurerAdapter

The following example shows how to provide a WebSecurityConfigurerAdapter with @EnableWebSecurity and enable OAuth 2.0 login through httpSecurity.oauth2Login():

Example 81. OAuth2 Login Configuration
Java
@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .oauth2Login(withDefaults());
    }
}
Kotlin
@EnableWebSecurity
class OAuth2LoginSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            authorizeRequests {
                authorize(anyRequest, authenticated)
            }
            oauth2Login { }
        }
    }
}
Completely Override the Auto-configuration

The following example shows how to completely override the auto-configuration by registering a ClientRegistrationRepository @Bean and providing a WebSecurityConfigurerAdapter.

Example 82. Overriding the auto-configuration
Java
@Configuration
public class OAuth2LoginConfig {

    @EnableWebSecurity
    public static class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

        @Override
        protected void configure(HttpSecurity http) throws Exception {
            http
                .authorizeRequests(authorize -> authorize
                    .anyRequest().authenticated()
                )
                .oauth2Login(withDefaults());
        }
    }

    @Bean
    public ClientRegistrationRepository clientRegistrationRepository() {
        return new InMemoryClientRegistrationRepository(this.googleClientRegistration());
    }

    private ClientRegistration googleClientRegistration() {
        return ClientRegistration.withRegistrationId("google")
            .clientId("google-client-id")
            .clientSecret("google-client-secret")
            .clientAuthenticationMethod(ClientAuthenticationMethod.BASIC)
            .authorizationGrantType(AuthorizationGrantType.AUTHORIZATION_CODE)
            .redirectUriTemplate("{baseUrl}/login/oauth2/code/{registrationId}")
            .scope("openid", "profile", "email", "address", "phone")
            .authorizationUri("https://accounts.google.com/o/oauth2/v2/auth")
            .tokenUri("https://www.googleapis.com/oauth2/v4/token")
            .userInfoUri("https://www.googleapis.com/oauth2/v3/userinfo")
            .userNameAttributeName(IdTokenClaimNames.SUB)
            .jwkSetUri("https://www.googleapis.com/oauth2/v3/certs")
            .clientName("Google")
            .build();
    }
}
Kotlin
@Configuration
class OAuth2LoginConfig {

    @EnableWebSecurity
    class OAuth2LoginSecurityConfig: WebSecurityConfigurerAdapter() {

        override fun configure(http: HttpSecurity) {
            http {
                authorizeRequests {
                    authorize(anyRequest, authenticated)
                }
                oauth2Login { }
            }
        }
    }

    @Bean
    fun clientRegistrationRepository(): ClientRegistrationRepository {
        return InMemoryClientRegistrationRepository(googleClientRegistration())
    }

    private fun googleClientRegistration(): ClientRegistration {
        return ClientRegistration.withRegistrationId("google")
                .clientId("google-client-id")
                .clientSecret("google-client-secret")
                .clientAuthenticationMethod(ClientAuthenticationMethod.BASIC)
                .authorizationGrantType(AuthorizationGrantType.AUTHORIZATION_CODE)
                .redirectUriTemplate("{baseUrl}/login/oauth2/code/{registrationId}")
                .scope("openid", "profile", "email", "address", "phone")
                .authorizationUri("https://accounts.google.com/o/oauth2/v2/auth")
                .tokenUri("https://www.googleapis.com/oauth2/v4/token")
                .userInfoUri("https://www.googleapis.com/oauth2/v3/userinfo")
                .userNameAttributeName(IdTokenClaimNames.SUB)
                .jwkSetUri("https://www.googleapis.com/oauth2/v3/certs")
                .clientName("Google")
                .build()
    }
}

12.1.6. Java Configuration without Spring Boot 2.x

If you are not able to use Spring Boot 2.x and would like to configure one of the pre-defined providers in CommonOAuth2Provider (for example, Google), apply the following configuration:

Example 83. OAuth2 Login Configuration
Java
@Configuration
public class OAuth2LoginConfig {

    @EnableWebSecurity
    public static class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

        @Override
        protected void configure(HttpSecurity http) throws Exception {
            http
                .authorizeRequests(authorize -> authorize
                    .anyRequest().authenticated()
                )
                .oauth2Login(withDefaults());
        }
    }

    @Bean
    public ClientRegistrationRepository clientRegistrationRepository() {
        return new InMemoryClientRegistrationRepository(this.googleClientRegistration());
    }

    @Bean
    public OAuth2AuthorizedClientService authorizedClientService(
            ClientRegistrationRepository clientRegistrationRepository) {
        return new InMemoryOAuth2AuthorizedClientService(clientRegistrationRepository);
    }

    @Bean
    public OAuth2AuthorizedClientRepository authorizedClientRepository(
            OAuth2AuthorizedClientService authorizedClientService) {
        return new AuthenticatedPrincipalOAuth2AuthorizedClientRepository(authorizedClientService);
    }

    private ClientRegistration googleClientRegistration() {
        return CommonOAuth2Provider.GOOGLE.getBuilder("google")
            .clientId("google-client-id")
            .clientSecret("google-client-secret")
            .build();
    }
}
Xml
<http auto-config="true">
    <intercept-url pattern="/**" access="authenticated"/>
    <oauth2-login authorized-client-repository-ref="authorizedClientRepository"/>
</http>

<client-registrations>
    <client-registration registration-id="google"
                         client-id="google-client-id"
                         client-secret="google-client-secret"
                         provider-id="google"/>
</client-registrations>

<b:bean id="authorizedClientService"
        class="org.springframework.security.oauth2.client.InMemoryOAuth2AuthorizedClientService"
        autowire="constructor"/>

<b:bean id="authorizedClientRepository"
        class="org.springframework.security.oauth2.client.web.AuthenticatedPrincipalOAuth2AuthorizedClientRepository">
    <b:constructor-arg ref="authorizedClientService"/>
</b:bean>

12.1.7. Advanced Configuration

HttpSecurity.oauth2Login() provides a number of configuration options for customizing OAuth 2.0 Login. The main configuration options are grouped into their protocol endpoint counterparts.

For example, oauth2Login().authorizationEndpoint() allows configuring the Authorization Endpoint, whereas oauth2Login().tokenEndpoint() allows configuring the Token Endpoint.

The following code shows an example:

Example 84. Advanced OAuth2 Login Configuration
Java
@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .authorizationEndpoint(authorization -> authorization
                        ...
                )
                .redirectionEndpoint(redirection -> redirection
                        ...
                )
                .tokenEndpoint(token -> token
                        ...
                )
                .userInfoEndpoint(userInfo -> userInfo
                        ...
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class OAuth2LoginSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Login {
                authorizationEndpoint {
                    ...
                }
                redirectionEndpoint {
                    ...
                }
                tokenEndpoint {
                    ...
                }
                userInfoEndpoint {
                    ...
                }
            }
        }
    }
}

The main goal of the oauth2Login() DSL was to closely align with the naming, as defined in the specifications.

The OAuth 2.0 Authorization Framework defines the Protocol Endpoints as follows:

The authorization process utilizes two authorization server endpoints (HTTP resources):

  • Authorization Endpoint: Used by the client to obtain authorization from the resource owner via user-agent redirection.

  • Token Endpoint: Used by the client to exchange an authorization grant for an access token, typically with client authentication.

As well as one client endpoint:

  • Redirection Endpoint: Used by the authorization server to return responses containing authorization credentials to the client via the resource owner user-agent.

The OpenID Connect Core 1.0 specification defines the UserInfo Endpoint as follows:

The UserInfo Endpoint is an OAuth 2.0 Protected Resource that returns claims about the authenticated end-user. To obtain the requested claims about the end-user, the client makes a request to the UserInfo Endpoint by using an access token obtained through OpenID Connect Authentication. These claims are normally represented by a JSON object that contains a collection of name-value pairs for the claims.

The following code shows the complete configuration options available for the oauth2Login() DSL:

Example 85. OAuth2 Login Configuration Options
Java
@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .clientRegistrationRepository(this.clientRegistrationRepository())
                .authorizedClientRepository(this.authorizedClientRepository())
                .authorizedClientService(this.authorizedClientService())
                .loginPage("/login")
                .authorizationEndpoint(authorization -> authorization
                    .baseUri(this.authorizationRequestBaseUri())
                    .authorizationRequestRepository(this.authorizationRequestRepository())
                    .authorizationRequestResolver(this.authorizationRequestResolver())
                )
                .redirectionEndpoint(redirection -> redirection
                    .baseUri(this.authorizationResponseBaseUri())
                )
                .tokenEndpoint(token -> token
                    .accessTokenResponseClient(this.accessTokenResponseClient())
                )
                .userInfoEndpoint(userInfo -> userInfo
                    .userAuthoritiesMapper(this.userAuthoritiesMapper())
                    .userService(this.oauth2UserService())
                    .oidcUserService(this.oidcUserService())
                    .customUserType(GitHubOAuth2User.class, "github")
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class OAuth2LoginSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Login {
                clientRegistrationRepository = clientRegistrationRepository()
                authorizedClientRepository = authorizedClientRepository()
                authorizedClientService = authorizedClientService()
                loginPage = "/login"
                authorizationEndpoint {
                    baseUri = authorizationRequestBaseUri()
                    authorizationRequestRepository = authorizationRequestRepository()
                    authorizationRequestResolver = authorizationRequestResolver()
                }
                redirectionEndpoint {
                    baseUri = authorizationResponseBaseUri()
                }
                tokenEndpoint {
                    accessTokenResponseClient = accessTokenResponseClient()
                }
                userInfoEndpoint {
                    userAuthoritiesMapper = userAuthoritiesMapper()
                    userService = oauth2UserService()
                    oidcUserService = oidcUserService()
                    customUserType(GitHubOAuth2User::class.java, "github")
                }
            }
        }
    }
}

In addition to the oauth2Login() DSL, XML configuration is also supported.

The following code shows the complete configuration options available in the security namespace:

Example 86. OAuth2 Login XML Configuration Options
<http>
    <oauth2-login client-registration-repository-ref="clientRegistrationRepository"
                  authorized-client-repository-ref="authorizedClientRepository"
                  authorized-client-service-ref="authorizedClientService"
                  authorization-request-repository-ref="authorizationRequestRepository"
                  authorization-request-resolver-ref="authorizationRequestResolver"
                  access-token-response-client-ref="accessTokenResponseClient"
                  user-authorities-mapper-ref="userAuthoritiesMapper"
                  user-service-ref="oauth2UserService"
                  oidc-user-service-ref="oidcUserService"
                  login-processing-url="/login/oauth2/code/*"
                  login-page="/login"
                  authentication-success-handler-ref="authenticationSuccessHandler"
                  authentication-failure-handler-ref="authenticationFailureHandler"
                  jwt-decoder-factory-ref="jwtDecoderFactory"/>
</http>

The following sections go into more detail on each of the configuration options available:

OAuth 2.0 Login Page

By default, the OAuth 2.0 Login Page is auto-generated by the DefaultLoginPageGeneratingFilter. The default login page shows each configured OAuth Client with its ClientRegistration.clientName as a link, which is capable of initiating the Authorization Request (or OAuth 2.0 Login).

In order for DefaultLoginPageGeneratingFilter to show links for configured OAuth Clients, the registered ClientRegistrationRepository needs to also implement Iterable<ClientRegistration>. See InMemoryClientRegistrationRepository for reference.

The link’s destination for each OAuth Client defaults to the following:

OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI + "/{registrationId}"

The following line shows an example:

<a href="/oauth2/authorization/google">Google</a>

To override the default login page, configure oauth2Login().loginPage() and (optionally) oauth2Login().authorizationEndpoint().baseUri().

The following listing shows an example:

Example 87. OAuth2 Login Page Configuration
Java
@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .loginPage("/login/oauth2")
                ...
                .authorizationEndpoint(authorization -> authorization
                    .baseUri("/login/oauth2/authorization")
                    ...
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class OAuth2LoginSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Login {
                loginPage = "/login/oauth2"
                authorizationEndpoint {
                    baseUri = "/login/oauth2/authorization"
                }
            }
        }
    }
}
Xml
<http>
    <oauth2-login login-page="/login/oauth2"
                  ...
    />
</http>
You need to provide a @Controller with a @RequestMapping("/login/oauth2") that is capable of rendering the custom login page.

As noted earlier, configuring oauth2Login().authorizationEndpoint().baseUri() is optional. However, if you choose to customize it, ensure the link to each OAuth Client matches the authorizationEndpoint().baseUri().

The following line shows an example:

<a href="/login/oauth2/authorization/google">Google</a>
Redirection Endpoint

The Redirection Endpoint is used by the Authorization Server for returning the Authorization Response (which contains the authorization credentials) to the client via the Resource Owner user-agent.

OAuth 2.0 Login leverages the Authorization Code Grant. Therefore, the authorization credential is the authorization code.

The default Authorization Response baseUri (redirection endpoint) is /login/oauth2/code/*, which is defined in OAuth2LoginAuthenticationFilter.DEFAULT_FILTER_PROCESSES_URI.

If you would like to customize the Authorization Response baseUri, configure it as shown in the following example:

Example 88. Redirection Endpoint Configuration
Java
@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .redirectionEndpoint(redirection -> redirection
                    .baseUri("/login/oauth2/callback/*")
                    ...
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class OAuth2LoginSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Login {
                redirectionEndpoint {
                    baseUri = "/login/oauth2/callback/*"
                }
            }
        }
    }
}
Xml
<http>
    <oauth2-login login-processing-url="/login/oauth2/callback/*"
                  ...
    />
</http>

You also need to ensure the ClientRegistration.redirectUriTemplate matches the custom Authorization Response baseUri.

The following listing shows an example:

return CommonOAuth2Provider.GOOGLE.getBuilder("google")
    .clientId("google-client-id")
    .clientSecret("google-client-secret")
    .redirectUriTemplate("{baseUrl}/login/oauth2/callback/{registrationId}")
    .build();
UserInfo Endpoint

The UserInfo Endpoint includes a number of configuration options, as described in the following sub-sections:

Mapping User Authorities

After the user successfully authenticates with the OAuth 2.0 Provider, the OAuth2User.getAuthorities() (or OidcUser.getAuthorities()) may be mapped to a new set of GrantedAuthority instances, which will be supplied to OAuth2AuthenticationToken when completing the authentication.

OAuth2AuthenticationToken.getAuthorities() is used for authorizing requests, such as in hasRole('USER') or hasRole('ADMIN').

There are a couple of options to choose from when mapping user authorities:

Using a GrantedAuthoritiesMapper

Provide an implementation of GrantedAuthoritiesMapper and configure it as shown in the following example:

Example 89. Granted Authorities Mapper Configuration
Java
@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .userInfoEndpoint(userInfo -> userInfo
                    .userAuthoritiesMapper(this.userAuthoritiesMapper())
                    ...
                )
            );
    }

    private GrantedAuthoritiesMapper userAuthoritiesMapper() {
        return (authorities) -> {
            Set<GrantedAuthority> mappedAuthorities = new HashSet<>();

            authorities.forEach(authority -> {
                if (OidcUserAuthority.class.isInstance(authority)) {
                    OidcUserAuthority oidcUserAuthority = (OidcUserAuthority)authority;

                    OidcIdToken idToken = oidcUserAuthority.getIdToken();
                    OidcUserInfo userInfo = oidcUserAuthority.getUserInfo();

                    // Map the claims found in idToken and/or userInfo
                    // to one or more GrantedAuthority's and add it to mappedAuthorities

                } else if (OAuth2UserAuthority.class.isInstance(authority)) {
                    OAuth2UserAuthority oauth2UserAuthority = (OAuth2UserAuthority)authority;

                    Map<String, Object> userAttributes = oauth2UserAuthority.getAttributes();

                    // Map the attributes found in userAttributes
                    // to one or more GrantedAuthority's and add it to mappedAuthorities

                }
            });

            return mappedAuthorities;
        };
    }
}
Kotlin
@EnableWebSecurity
class OAuth2LoginSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Login {
                userInfoEndpoint {
                    userAuthoritiesMapper = userAuthoritiesMapper()
                }
            }
        }
    }

    private fun userAuthoritiesMapper(): GrantedAuthoritiesMapper = GrantedAuthoritiesMapper { authorities: Collection<GrantedAuthority> ->
        val mappedAuthorities = emptySet<GrantedAuthority>()

        authorities.forEach { authority ->
            if (authority is OidcUserAuthority) {
                val idToken = authority.idToken
                val userInfo = authority.userInfo
                // Map the claims found in idToken and/or userInfo
                // to one or more GrantedAuthority's and add it to mappedAuthorities
            } else if (authority is OAuth2UserAuthority) {
                val userAttributes = authority.attributes
                // Map the attributes found in userAttributes
                // to one or more GrantedAuthority's and add it to mappedAuthorities
            }
        }

        mappedAuthorities
    }
}
Xml
<http>
    <oauth2-login user-authorities-mapper-ref="userAuthoritiesMapper"
                  ...
    />
</http>

Alternatively, you may register a GrantedAuthoritiesMapper @Bean to have it automatically applied to the configuration, as shown in the following example:

Example 90. Granted Authorities Mapper Bean Configuration
Java
@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(withDefaults());
    }

    @Bean
    public GrantedAuthoritiesMapper userAuthoritiesMapper() {
        ...
    }
}
Kotlin
@EnableWebSecurity
class OAuth2LoginSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Login { }
        }
    }

    @Bean
    fun userAuthoritiesMapper(): GrantedAuthoritiesMapper {
        ...
    }
}
Delegation-based strategy with OAuth2UserService

This strategy is advanced compared to using a GrantedAuthoritiesMapper, however, it’s also more flexible as it gives you access to the OAuth2UserRequest and OAuth2User (when using an OAuth 2.0 UserService) or OidcUserRequest and OidcUser (when using an OpenID Connect 1.0 UserService).

The OAuth2UserRequest (and OidcUserRequest) provides you access to the associated OAuth2AccessToken, which is very useful in the cases where the delegator needs to fetch authority information from a protected resource before it can map the custom authorities for the user.

The following example shows how to implement and configure a delegation-based strategy using an OpenID Connect 1.0 UserService:

Example 91. OAuth2UserService Configuration
Java
@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .userInfoEndpoint(userInfo -> userInfo
                    .oidcUserService(this.oidcUserService())
                    ...
                )
            );
    }

    private OAuth2UserService<OidcUserRequest, OidcUser> oidcUserService() {
        final OidcUserService delegate = new OidcUserService();

        return (userRequest) -> {
            // Delegate to the default implementation for loading a user
            OidcUser oidcUser = delegate.loadUser(userRequest);

            OAuth2AccessToken accessToken = userRequest.getAccessToken();
            Set<GrantedAuthority> mappedAuthorities = new HashSet<>();

            // TODO
            // 1) Fetch the authority information from the protected resource using accessToken
            // 2) Map the authority information to one or more GrantedAuthority's and add it to mappedAuthorities

            // 3) Create a copy of oidcUser but use the mappedAuthorities instead
            oidcUser = new DefaultOidcUser(mappedAuthorities, oidcUser.getIdToken(), oidcUser.getUserInfo());

            return oidcUser;
        };
    }
}
Kotlin
@EnableWebSecurity
class OAuth2LoginSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Login {
                userInfoEndpoint {
                    oidcUserService = oidcUserService()
                }
            }
        }
    }

    @Bean
    fun oidcUserService(): OAuth2UserService<OidcUserRequest, OidcUser> {
        val delegate = OidcUserService()

        return OAuth2UserService { userRequest ->
            // Delegate to the default implementation for loading a user
            var oidcUser = delegate.loadUser(userRequest)

            val accessToken = userRequest.accessToken
            val mappedAuthorities = HashSet<GrantedAuthority>()

            // TODO
            // 1) Fetch the authority information from the protected resource using accessToken
            // 2) Map the authority information to one or more GrantedAuthority's and add it to mappedAuthorities
            // 3) Create a copy of oidcUser but use the mappedAuthorities instead
            oidcUser = DefaultOidcUser(mappedAuthorities, oidcUser.idToken, oidcUser.userInfo)

            oidcUser
        }
    }
}
Xml
<http>
    <oauth2-login oidc-user-service-ref="oidcUserService"
                  ...
    />
</http>
Configuring a Custom OAuth2User

CustomUserTypesOAuth2UserService is an implementation of an OAuth2UserService that provides support for custom OAuth2User types.

If the default implementation (DefaultOAuth2User) does not suit your needs, you can define your own implementation of OAuth2User.

The following code demonstrates how you would register a custom OAuth2User type for GitHub:

@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .userInfoEndpoint(userInfo -> userInfo
                    .customUserType(GitHubOAuth2User.class, "github")
                    ...
                )
            );
    }
}

The following code shows an example of a custom OAuth2User type for GitHub:

public class GitHubOAuth2User implements OAuth2User {
    private List<GrantedAuthority> authorities =
        AuthorityUtils.createAuthorityList("ROLE_USER");
    private Map<String, Object> attributes;
    private String id;
    private String name;
    private String login;
    private String email;

    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return this.authorities;
    }

    @Override
    public Map<String, Object> getAttributes() {
        if (this.attributes == null) {
            this.attributes = new HashMap<>();
            this.attributes.put("id", this.getId());
            this.attributes.put("name", this.getName());
            this.attributes.put("login", this.getLogin());
            this.attributes.put("email", this.getEmail());
        }
        return attributes;
    }

    public String getId() {
        return this.id;
    }

    public void setId(String id) {
        this.id = id;
    }

    @Override
    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getLogin() {
        return this.login;
    }

    public void setLogin(String login) {
        this.login = login;
    }

    public String getEmail() {
        return this.email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}
id, name, login, and email are attributes returned in GitHub’s UserInfo Response. For detailed information returned from the UserInfo Endpoint, see the API documentation for "Get the authenticated user".
OAuth 2.0 UserService

DefaultOAuth2UserService is an implementation of an OAuth2UserService that supports standard OAuth 2.0 Provider’s.

OAuth2UserService obtains the user attributes of the end-user (the resource owner) from the UserInfo Endpoint (by using the access token granted to the client during the authorization flow) and returns an AuthenticatedPrincipal in the form of an OAuth2User.

DefaultOAuth2UserService uses a RestOperations when requesting the user attributes at the UserInfo Endpoint.

If you need to customize the pre-processing of the UserInfo Request, you can provide DefaultOAuth2UserService.setRequestEntityConverter() with a custom Converter<OAuth2UserRequest, RequestEntity<?>>. The default implementation OAuth2UserRequestEntityConverter builds a RequestEntity representation of a UserInfo Request that sets the OAuth2AccessToken in the Authorization header by default.

On the other end, if you need to customize the post-handling of the UserInfo Response, you will need to provide DefaultOAuth2UserService.setRestOperations() with a custom configured RestOperations. The default RestOperations is configured as follows:

RestTemplate restTemplate = new RestTemplate();
restTemplate.setErrorHandler(new OAuth2ErrorResponseErrorHandler());

OAuth2ErrorResponseErrorHandler is a ResponseErrorHandler that can handle an OAuth 2.0 Error (400 Bad Request). It uses an OAuth2ErrorHttpMessageConverter for converting the OAuth 2.0 Error parameters to an OAuth2Error.

Whether you customize DefaultOAuth2UserService or provide your own implementation of OAuth2UserService, you’ll need to configure it as shown in the following example:

@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .userInfoEndpoint(userInfo -> userInfo
                    .userService(this.oauth2UserService())
                    ...
                )
            );
    }

    private OAuth2UserService<OAuth2UserRequest, OAuth2User> oauth2UserService() {
        ...
    }
}
OpenID Connect 1.0 UserService

OidcUserService is an implementation of an OAuth2UserService that supports OpenID Connect 1.0 Provider’s.

The OidcUserService leverages the DefaultOAuth2UserService when requesting the user attributes at the UserInfo Endpoint.

If you need to customize the pre-processing of the UserInfo Request and/or the post-handling of the UserInfo Response, you will need to provide OidcUserService.setOauth2UserService() with a custom configured DefaultOAuth2UserService.

Whether you customize OidcUserService or provide your own implementation of OAuth2UserService for OpenID Connect 1.0 Provider’s, you’ll need to configure it as shown in the following example:

@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Login(oauth2 -> oauth2
                .userInfoEndpoint(userInfo -> userInfo
                    .oidcUserService(this.oidcUserService())
                    ...
                )
            );
    }

    private OAuth2UserService<OidcUserRequest, OidcUser> oidcUserService() {
        ...
    }
}
ID Token Signature Verification

OpenID Connect 1.0 Authentication introduces the ID Token, which is a security token that contains Claims about the Authentication of an End-User by an Authorization Server when used by a Client.

The ID Token is represented as a JSON Web Token (JWT) and MUST be signed using JSON Web Signature (JWS).

The OidcIdTokenDecoderFactory provides a JwtDecoder used for OidcIdToken signature verification. The default algorithm is RS256 but may be different when assigned during client registration. For these cases, a resolver may be configured to return the expected JWS algorithm assigned for a specific client.

The JWS algorithm resolver is a Function that accepts a ClientRegistration and returns the expected JwsAlgorithm for the client, eg. SignatureAlgorithm.RS256 or MacAlgorithm.HS256

The following code shows how to configure the OidcIdTokenDecoderFactory @Bean to default to MacAlgorithm.HS256 for all ClientRegistration:

@Bean
public JwtDecoderFactory<ClientRegistration> idTokenDecoderFactory() {
    OidcIdTokenDecoderFactory idTokenDecoderFactory = new OidcIdTokenDecoderFactory();
    idTokenDecoderFactory.setJwsAlgorithmResolver(clientRegistration -> MacAlgorithm.HS256);
    return idTokenDecoderFactory;
}
For MAC based algorithms such as HS256, HS384 or HS512, the client-secret corresponding to the client-id is used as the symmetric key for signature verification.
If more than one ClientRegistration is configured for OpenID Connect 1.0 Authentication, the JWS algorithm resolver may evaluate the provided ClientRegistration to determine which algorithm to return.
OpenID Connect 1.0 Logout

OpenID Connect Session Management 1.0 allows the ability to log out the End-User at the Provider using the Client. One of the strategies available is RP-Initiated Logout.

If the OpenID Provider supports both Session Management and Discovery, the client may obtain the end_session_endpoint URL from the OpenID Provider’s Discovery Metadata. This can be achieved by configuring the ClientRegistration with the issuer-uri, as in the following example:

spring:
  security:
    oauth2:
      client:
        registration:
          okta:
            client-id: okta-client-id
            client-secret: okta-client-secret
            ...
        provider:
          okta:
            issuer-uri: https://dev-1234.oktapreview.com

…​and the OidcClientInitiatedLogoutSuccessHandler, which implements RP-Initiated Logout, may be configured as follows:

@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private ClientRegistrationRepository clientRegistrationRepository;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .oauth2Login(withDefaults())
            .logout(logout -> logout
                .logoutSuccessHandler(oidcLogoutSuccessHandler())
            );
    }

    private LogoutSuccessHandler oidcLogoutSuccessHandler() {
        OidcClientInitiatedLogoutSuccessHandler oidcLogoutSuccessHandler =
                new OidcClientInitiatedLogoutSuccessHandler(this.clientRegistrationRepository);

        // Sets the location that the End-User's User Agent will be redirected to
        // after the logout has been performed at the Provider
        oidcLogoutSuccessHandler.setPostLogoutRedirectUri("{baseUrl}");

        return oidcLogoutSuccessHandler;
    }
}

NOTE: `OidcClientInitiatedLogoutSuccessHandler` supports the `{baseUrl}` placeholder.
If used, the application's base URL, like `https://app.example.org`, will replace it at request time.

12.2. OAuth 2.0 Client

The OAuth 2.0 Client features provide support for the Client role as defined in the OAuth 2.0 Authorization Framework.

At a high-level, the core features available are:

HTTP Client support

The HttpSecurity.oauth2Client() DSL provides a number of configuration options for customizing the core components used by OAuth 2.0 Client. In addition, HttpSecurity.oauth2Client().authorizationCodeGrant() enables the customization of the Authorization Code grant.

The following code shows the complete configuration options provided by the HttpSecurity.oauth2Client() DSL:

Example 92. OAuth2 Client Configuration Options
Java
@EnableWebSecurity
public class OAuth2ClientSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Client(oauth2 -> oauth2
                .clientRegistrationRepository(this.clientRegistrationRepository())
                .authorizedClientRepository(this.authorizedClientRepository())
                .authorizedClientService(this.authorizedClientService())
                .authorizationCodeGrant(codeGrant -> codeGrant
                    .authorizationRequestRepository(this.authorizationRequestRepository())
                    .authorizationRequestResolver(this.authorizationRequestResolver())
                    .accessTokenResponseClient(this.accessTokenResponseClient())
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class OAuth2ClientSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Client {
                clientRegistrationRepository = clientRegistrationRepository()
                authorizedClientRepository = authorizedClientRepository()
                authorizedClientService = authorizedClientService()
                authorizationCodeGrant {
                    authorizationRequestRepository = authorizationRequestRepository()
                    authorizationRequestResolver = authorizationRequestResolver()
                    accessTokenResponseClient = accessTokenResponseClient()
                }
            }
        }
    }
}

In addition to the HttpSecurity.oauth2Client() DSL, XML configuration is also supported.

The following code shows the complete configuration options available in the security namespace:

Example 93. OAuth2 Client XML Configuration Options
<http>
    <oauth2-client client-registration-repository-ref="clientRegistrationRepository"
                   authorized-client-repository-ref="authorizedClientRepository"
                   authorized-client-service-ref="authorizedClientService">
        <authorization-code-grant
                authorization-request-repository-ref="authorizationRequestRepository"
                authorization-request-resolver-ref="authorizationRequestResolver"
                access-token-response-client-ref="accessTokenResponseClient"/>
    </oauth2-client>
</http>

The OAuth2AuthorizedClientManager is responsible for managing the authorization (or re-authorization) of an OAuth 2.0 Client, in collaboration with one or more OAuth2AuthorizedClientProvider(s).

The following code shows an example of how to register an OAuth2AuthorizedClientManager @Bean and associate it with an OAuth2AuthorizedClientProvider composite that provides support for the authorization_code, refresh_token, client_credentials and password authorization grant types:

@Bean
public OAuth2AuthorizedClientManager authorizedClientManager(
        ClientRegistrationRepository clientRegistrationRepository,
        OAuth2AuthorizedClientRepository authorizedClientRepository) {

    OAuth2AuthorizedClientProvider authorizedClientProvider =
            OAuth2AuthorizedClientProviderBuilder.builder()
                    .authorizationCode()
                    .refreshToken()
                    .clientCredentials()
                    .password()
                    .build();

    DefaultOAuth2AuthorizedClientManager authorizedClientManager =
            new DefaultOAuth2AuthorizedClientManager(
                    clientRegistrationRepository, authorizedClientRepository);
    authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);

    return authorizedClientManager;
}

The following sections will go into more detail on the core components used by OAuth 2.0 Client and the configuration options available:

12.2.1. Core Interfaces / Classes

ClientRegistration

ClientRegistration is a representation of a client registered with an OAuth 2.0 or OpenID Connect 1.0 Provider.

A client registration holds information, such as client id, client secret, authorization grant type, redirect URI, scope(s), authorization URI, token URI, and other details.

ClientRegistration and its properties are defined as follows:

public final class ClientRegistration {
    private String registrationId;  (1)
    private String clientId;    (2)
    private String clientSecret;    (3)
    private ClientAuthenticationMethod clientAuthenticationMethod;  (4)
    private AuthorizationGrantType authorizationGrantType;  (5)
    private String redirectUriTemplate; (6)
    private Set<String> scopes; (7)
    private ProviderDetails providerDetails;
    private String clientName;  (8)

    public class ProviderDetails {
        private String authorizationUri;    (9)
        private String tokenUri;    (10)
        private UserInfoEndpoint userInfoEndpoint;
        private String jwkSetUri;   (11)
        private Map<String, Object> configurationMetadata;  (12)

        public class UserInfoEndpoint {
            private String uri; (13)
            private AuthenticationMethod authenticationMethod;  (14)
            private String userNameAttributeName;   (15)

        }
    }
}
1 registrationId: The ID that uniquely identifies the ClientRegistration.
2 clientId: The client identifier.
3 clientSecret: The client secret.
4 clientAuthenticationMethod: The method used to authenticate the Client with the Provider. The supported values are basic, post and none (public clients).
5 authorizationGrantType: The OAuth 2.0 Authorization Framework defines four Authorization Grant types. The supported values are authorization_code, client_credentials and password.
6 redirectUriTemplate: The client’s registered redirect URI that the Authorization Server redirects the end-user’s user-agent to after the end-user has authenticated and authorized access to the client.
7 scopes: The scope(s) requested by the client during the Authorization Request flow, such as openid, email, or profile.
8 clientName: A descriptive name used for the client. The name may be used in certain scenarios, such as when displaying the name of the client in the auto-generated login page.
9 authorizationUri: The Authorization Endpoint URI for the Authorization Server.
10 tokenUri: The Token Endpoint URI for the Authorization Server.
11 jwkSetUri: The URI used to retrieve the JSON Web Key (JWK) Set from the Authorization Server, which contains the cryptographic key(s) used to verify the JSON Web Signature (JWS) of the ID Token and optionally the UserInfo Response.
12 configurationMetadata: The OpenID Provider Configuration Information. This information will only be available if the Spring Boot 2.x property spring.security.oauth2.client.provider.[providerId].issuerUri is configured.
13 (userInfoEndpoint)uri: The UserInfo Endpoint URI used to access the claims/attributes of the authenticated end-user.
14 (userInfoEndpoint)authenticationMethod: The authentication method used when sending the access token to the UserInfo Endpoint. The supported values are header, form and query.
15 userNameAttributeName: The name of the attribute returned in the UserInfo Response that references the Name or Identifier of the end-user.

A ClientRegistration can be initially configured using discovery of an OpenID Connect Provider’s Configuration endpoint or an Authorization Server’s Metadata endpoint.

ClientRegistrations provides convenience methods for configuring a ClientRegistration in this way, as can be seen in the following example:

ClientRegistration clientRegistration =
    ClientRegistrations.fromIssuerLocation("https://idp.example.com/issuer").build();

As an alternative, you can use ClientRegistrations.fromOidcIssuerLocation() to only query the OpenID Connect Provider’s Configuration endpoint.

ClientRegistrationRepository

The ClientRegistrationRepository serves as a repository for OAuth 2.0 / OpenID Connect 1.0 ClientRegistration(s).

Client registration information is ultimately stored and owned by the associated Authorization Server. This repository provides the ability to retrieve a sub-set of the primary client registration information, which is stored with the Authorization Server.

Spring Boot 2.x auto-configuration binds each of the properties under spring.security.oauth2.client.registration.[registrationId] to an instance of ClientRegistration and then composes each of the ClientRegistration instance(s) within a ClientRegistrationRepository.

The default implementation of ClientRegistrationRepository is InMemoryClientRegistrationRepository.

The auto-configuration also registers the ClientRegistrationRepository as a @Bean in the ApplicationContext so that it is available for dependency-injection, if needed by the application.

The following listing shows an example:

@Controller
public class OAuth2ClientController {

    @Autowired
    private ClientRegistrationRepository clientRegistrationRepository;

    @GetMapping("/")
    public String index() {
        ClientRegistration oktaRegistration =
            this.clientRegistrationRepository.findByRegistrationId("okta");

        ...

        return "index";
    }
}
OAuth2AuthorizedClient

OAuth2AuthorizedClient is a representation of an Authorized Client. A client is considered to be authorized when the end-user (Resource Owner) has granted authorization to the client to access its protected resources.

OAuth2AuthorizedClient serves the purpose of associating an OAuth2AccessToken (and optional OAuth2RefreshToken) to a ClientRegistration (client) and resource owner, who is the Principal end-user that granted the authorization.

OAuth2AuthorizedClientRepository / OAuth2AuthorizedClientService

OAuth2AuthorizedClientRepository is responsible for persisting OAuth2AuthorizedClient(s) between web requests. Whereas, the primary role of OAuth2AuthorizedClientService is to manage OAuth2AuthorizedClient(s) at the application-level.

From a developer perspective, the OAuth2AuthorizedClientRepository or OAuth2AuthorizedClientService provides the capability to lookup an OAuth2AccessToken associated with a client so that it may be used to initiate a protected resource request.

The following listing shows an example:

@Controller
public class OAuth2ClientController {

    @Autowired
    private OAuth2AuthorizedClientService authorizedClientService;

    @GetMapping("/")
    public String index(Authentication authentication) {
        OAuth2AuthorizedClient authorizedClient =
            this.authorizedClientService.loadAuthorizedClient("okta", authentication.getName());

        OAuth2AccessToken accessToken = authorizedClient.getAccessToken();

        ...

        return "index";
    }
}
Spring Boot 2.x auto-configuration registers an OAuth2AuthorizedClientRepository and/or OAuth2AuthorizedClientService @Bean in the ApplicationContext. However, the application may choose to override and register a custom OAuth2AuthorizedClientRepository or OAuth2AuthorizedClientService @Bean.

The default implementation of OAuth2AuthorizedClientService is InMemoryOAuth2AuthorizedClientService, which stores OAuth2AuthorizedClient(s) in-memory.

Alternatively, the JDBC implementation JdbcOAuth2AuthorizedClientService may be configured for persisting OAuth2AuthorizedClient(s) in a database.

JdbcOAuth2AuthorizedClientService depends on the table definition described in OAuth 2.0 Client Schema.
OAuth2AuthorizedClientManager / OAuth2AuthorizedClientProvider

The OAuth2AuthorizedClientManager is responsible for the overall management of OAuth2AuthorizedClient(s).

The primary responsibilities include:

  • Authorizing (or re-authorizing) an OAuth 2.0 Client, using an OAuth2AuthorizedClientProvider.

  • Delegating the persistence of an OAuth2AuthorizedClient, typically using an OAuth2AuthorizedClientService or OAuth2AuthorizedClientRepository.

  • Delegating to an OAuth2AuthorizationSuccessHandler when an OAuth 2.0 Client has been successfully authorized (or re-authorized).

  • Delegating to an OAuth2AuthorizationFailureHandler when an OAuth 2.0 Client fails to authorize (or re-authorize).

An OAuth2AuthorizedClientProvider implements a strategy for authorizing (or re-authorizing) an OAuth 2.0 Client. Implementations will typically implement an authorization grant type, eg. authorization_code, client_credentials, etc.

The default implementation of OAuth2AuthorizedClientManager is DefaultOAuth2AuthorizedClientManager, which is associated with an OAuth2AuthorizedClientProvider that may support multiple authorization grant types using a delegation-based composite. The OAuth2AuthorizedClientProviderBuilder may be used to configure and build the delegation-based composite.

The following code shows an example of how to configure and build an OAuth2AuthorizedClientProvider composite that provides support for the authorization_code, refresh_token, client_credentials and password authorization grant types:

@Bean
public OAuth2AuthorizedClientManager authorizedClientManager(
        ClientRegistrationRepository clientRegistrationRepository,
        OAuth2AuthorizedClientRepository authorizedClientRepository) {

    OAuth2AuthorizedClientProvider authorizedClientProvider =
            OAuth2AuthorizedClientProviderBuilder.builder()
                    .authorizationCode()
                    .refreshToken()
                    .clientCredentials()
                    .password()
                    .build();

    DefaultOAuth2AuthorizedClientManager authorizedClientManager =
            new DefaultOAuth2AuthorizedClientManager(
                    clientRegistrationRepository, authorizedClientRepository);
    authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);

    return authorizedClientManager;
}

When an authorization attempt succeeds, the DefaultOAuth2AuthorizedClientManager will delegate to the OAuth2AuthorizationSuccessHandler, which (by default) will save the OAuth2AuthorizedClient via the OAuth2AuthorizedClientRepository. In the case of a re-authorization failure, eg. a refresh token is no longer valid, the previously saved OAuth2AuthorizedClient will be removed from the OAuth2AuthorizedClientRepository via the RemoveAuthorizedClientOAuth2AuthorizationFailureHandler. The default behaviour may be customized via setAuthorizationSuccessHandler(OAuth2AuthorizationSuccessHandler) and setAuthorizationFailureHandler(OAuth2AuthorizationFailureHandler).

The DefaultOAuth2AuthorizedClientManager is also associated with a contextAttributesMapper of type Function<OAuth2AuthorizeRequest, Map<String, Object>>, which is responsible for mapping attribute(s) from the OAuth2AuthorizeRequest to a Map of attributes to be associated to the OAuth2AuthorizationContext. This can be useful when you need to supply an OAuth2AuthorizedClientProvider with required (supported) attribute(s), eg. the PasswordOAuth2AuthorizedClientProvider requires the resource owner’s username and password to be available in OAuth2AuthorizationContext.getAttributes().

The following code shows an example of the contextAttributesMapper:

@Bean
public OAuth2AuthorizedClientManager authorizedClientManager(
        ClientRegistrationRepository clientRegistrationRepository,
        OAuth2AuthorizedClientRepository authorizedClientRepository) {

    OAuth2AuthorizedClientProvider authorizedClientProvider =
            OAuth2AuthorizedClientProviderBuilder.builder()
                    .password()
                    .refreshToken()
                    .build();

    DefaultOAuth2AuthorizedClientManager authorizedClientManager =
            new DefaultOAuth2AuthorizedClientManager(
                    clientRegistrationRepository, authorizedClientRepository);
    authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);

    // Assuming the `username` and `password` are supplied as `HttpServletRequest` parameters,
    // map the `HttpServletRequest` parameters to `OAuth2AuthorizationContext.getAttributes()`
    authorizedClientManager.setContextAttributesMapper(contextAttributesMapper());

    return authorizedClientManager;
}

private Function<OAuth2AuthorizeRequest, Map<String, Object>> contextAttributesMapper() {
    return authorizeRequest -> {
        Map<String, Object> contextAttributes = Collections.emptyMap();
        HttpServletRequest servletRequest = authorizeRequest.getAttribute(HttpServletRequest.class.getName());
        String username = servletRequest.getParameter(OAuth2ParameterNames.USERNAME);
        String password = servletRequest.getParameter(OAuth2ParameterNames.PASSWORD);
        if (StringUtils.hasText(username) && StringUtils.hasText(password)) {
            contextAttributes = new HashMap<>();

            // `PasswordOAuth2AuthorizedClientProvider` requires both attributes
            contextAttributes.put(OAuth2AuthorizationContext.USERNAME_ATTRIBUTE_NAME, username);
            contextAttributes.put(OAuth2AuthorizationContext.PASSWORD_ATTRIBUTE_NAME, password);
        }
        return contextAttributes;
    };
}

The DefaultOAuth2AuthorizedClientManager is designed to be used within the context of a HttpServletRequest. When operating outside of a HttpServletRequest context, use AuthorizedClientServiceOAuth2AuthorizedClientManager instead.

A service application is a common use case for when to use an AuthorizedClientServiceOAuth2AuthorizedClientManager. Service applications often run in the background, without any user interaction, and typically run under a system-level account instead of a user account. An OAuth 2.0 Client configured with the client_credentials grant type can be considered a type of service application.

The following code shows an example of how to configure an AuthorizedClientServiceOAuth2AuthorizedClientManager that provides support for the client_credentials grant type:

@Bean
public OAuth2AuthorizedClientManager authorizedClientManager(
        ClientRegistrationRepository clientRegistrationRepository,
        OAuth2AuthorizedClientService authorizedClientService) {

    OAuth2AuthorizedClientProvider authorizedClientProvider =
            OAuth2AuthorizedClientProviderBuilder.builder()
                    .clientCredentials()
                    .build();

    AuthorizedClientServiceOAuth2AuthorizedClientManager authorizedClientManager =
            new AuthorizedClientServiceOAuth2AuthorizedClientManager(
                    clientRegistrationRepository, authorizedClientService);
    authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);

    return authorizedClientManager;
}

12.2.2. Authorization Grant Support

Authorization Code
Please refer to the OAuth 2.0 Authorization Framework for further details on the Authorization Code grant.
Obtaining Authorization
Please refer to the Authorization Request/Response protocol flow for the Authorization Code grant.
Initiating the Authorization Request

The OAuth2AuthorizationRequestRedirectFilter uses an OAuth2AuthorizationRequestResolver to resolve an OAuth2AuthorizationRequest and initiate the Authorization Code grant flow by redirecting the end-user’s user-agent to the Authorization Server’s Authorization Endpoint.

The primary role of the OAuth2AuthorizationRequestResolver is to resolve an OAuth2AuthorizationRequest from the provided web request. The default implementation DefaultOAuth2AuthorizationRequestResolver matches on the (default) path /oauth2/authorization/{registrationId} extracting the registrationId and using it to build the OAuth2AuthorizationRequest for the associated ClientRegistration.

Given the following Spring Boot 2.x properties for an OAuth 2.0 Client registration:

spring:
  security:
    oauth2:
      client:
        registration:
          okta:
            client-id: okta-client-id
            client-secret: okta-client-secret
            authorization-grant-type: authorization_code
            redirect-uri: "{baseUrl}/authorized/okta"
            scope: read, write
        provider:
          okta:
            authorization-uri: https://dev-1234.oktapreview.com/oauth2/v1/authorize
            token-uri: https://dev-1234.oktapreview.com/oauth2/v1/token

A request with the base path /oauth2/authorization/okta will initiate the Authorization Request redirect by the OAuth2AuthorizationRequestRedirectFilter and ultimately start the Authorization Code grant flow.

The AuthorizationCodeOAuth2AuthorizedClientProvider is an implementation of OAuth2AuthorizedClientProvider for the Authorization Code grant, which also initiates the Authorization Request redirect by the OAuth2AuthorizationRequestRedirectFilter.

If the OAuth 2.0 Client is a Public Client, then configure the OAuth 2.0 Client registration as follows:

spring:
  security:
    oauth2:
      client:
        registration:
          okta:
            client-id: okta-client-id
            client-authentication-method: none
            authorization-grant-type: authorization_code
            redirect-uri: "{baseUrl}/authorized/okta"
            ...

Public Clients are supported using Proof Key for Code Exchange (PKCE). If the client is running in an untrusted environment (eg. native application or web browser-based application) and therefore incapable of maintaining the confidentiality of it’s credentials, PKCE will automatically be used when the following conditions are true:

  1. client-secret is omitted (or empty)

  2. client-authentication-method is set to "none" (ClientAuthenticationMethod.NONE)

The DefaultOAuth2AuthorizationRequestResolver also supports URI template variables for the redirect-uri using UriComponentsBuilder.

The following configuration uses all the supported URI template variables:

spring:
  security:
    oauth2:
      client:
        registration:
          okta:
            ...
            redirect-uri: "{baseScheme}://{baseHost}{basePort}{basePath}/authorized/{registrationId}"
            ...
{baseUrl} resolves to {baseScheme}://{baseHost}{basePort}{basePath}

Configuring the redirect-uri with URI template variables is especially useful when the OAuth 2.0 Client is running behind a Proxy Server. This ensures that the X-Forwarded-* headers are used when expanding the redirect-uri.

Customizing the Authorization Request

One of the primary use cases an OAuth2AuthorizationRequestResolver can realize is the ability to customize the Authorization Request with additional parameters above the standard parameters defined in the OAuth 2.0 Authorization Framework.

For example, OpenID Connect defines additional OAuth 2.0 request parameters for the Authorization Code Flow extending from the standard parameters defined in the OAuth 2.0 Authorization Framework. One of those extended parameters is the prompt parameter.

OPTIONAL. Space delimited, case sensitive list of ASCII string values that specifies whether the Authorization Server prompts the End-User for reauthentication and consent. The defined values are: none, login, consent, select_account

The following example shows how to configure the DefaultOAuth2AuthorizationRequestResolver with a Consumer<OAuth2AuthorizationRequest.Builder> that customizes the Authorization Request for oauth2Login(), by including the request parameter prompt=consent.

@EnableWebSecurity
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private ClientRegistrationRepository clientRegistrationRepository;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .oauth2Login(oauth2 -> oauth2
                .authorizationEndpoint(authorization -> authorization
                    .authorizationRequestResolver(
                        authorizationRequestResolver(this.clientRegistrationRepository)
                    )
                )
            );
    }

    private OAuth2AuthorizationRequestResolver authorizationRequestResolver(
            ClientRegistrationRepository clientRegistrationRepository) {

        DefaultOAuth2AuthorizationRequestResolver authorizationRequestResolver =
                new DefaultOAuth2AuthorizationRequestResolver(
                        clientRegistrationRepository, "/oauth2/authorization");
        authorizationRequestResolver.setAuthorizationRequestCustomizer(
                authorizationRequestCustomizer());

        return  authorizationRequestResolver;
    }

    private Consumer<OAuth2AuthorizationRequest.Builder> authorizationRequestCustomizer() {
        return customizer -> customizer
                    .additionalParameters(params -> params.put("prompt", "consent"));
    }
}

For the simple use case, where the additional request parameter is always the same for a specific provider, it may be added directly in the authorization-uri property.

For example, if the value for the request parameter prompt is always consent for the provider okta, than simply configure as follows:

spring:
  security:
    oauth2:
      client:
        provider:
          okta:
            authorization-uri: https://dev-1234.oktapreview.com/oauth2/v1/authorize?prompt=consent

The preceding example shows the common use case of adding a custom parameter on top of the standard parameters. Alternatively, if your requirements are more advanced, you can take full control in building the Authorization Request URI by simply overriding the OAuth2AuthorizationRequest.authorizationRequestUri property.

OAuth2AuthorizationRequest.Builder.build() constructs the OAuth2AuthorizationRequest.authorizationRequestUri, which represents the Authorization Request URI including all query parameters using the application/x-www-form-urlencoded format.

The following example shows a variation of authorizationRequestCustomizer() from the preceding example, and instead overrides the OAuth2AuthorizationRequest.authorizationRequestUri property.

private Consumer<OAuth2AuthorizationRequest.Builder> authorizationRequestCustomizer() {
    return customizer -> customizer
                .authorizationRequestUri(uriBuilder -> uriBuilder
                    .queryParam("prompt", "consent").build());
}
Storing the Authorization Request

The AuthorizationRequestRepository is responsible for the persistence of the OAuth2AuthorizationRequest from the time the Authorization Request is initiated to the time the Authorization Response is received (the callback).

The OAuth2AuthorizationRequest is used to correlate and validate the Authorization Response.

The default implementation of AuthorizationRequestRepository is HttpSessionOAuth2AuthorizationRequestRepository, which stores the OAuth2AuthorizationRequest in the HttpSession.

If you have a custom implementation of AuthorizationRequestRepository, you may configure it as shown in the following example:

Example 94. AuthorizationRequestRepository Configuration
Java
@EnableWebSecurity
public class OAuth2ClientSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Client(oauth2 -> oauth2
                .authorizationCodeGrant(codeGrant -> codeGrant
                    .authorizationRequestRepository(this.authorizationRequestRepository())
                    ...
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class OAuth2ClientSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Client {
                authorizationCodeGrant {
                    authorizationRequestRepository = authorizationRequestRepository()
                }
            }
        }
    }
}
Xml
<http>
    <oauth2-client>
        <authorization-code-grant authorization-request-repository-ref="authorizationRequestRepository"/>
    </oauth2-client>
</http>
Requesting an Access Token
Please refer to the Access Token Request/Response protocol flow for the Authorization Code grant.

The default implementation of OAuth2AccessTokenResponseClient for the Authorization Code grant is DefaultAuthorizationCodeTokenResponseClient, which uses a RestOperations for exchanging an authorization code for an access token at the Authorization Server’s Token Endpoint.

The DefaultAuthorizationCodeTokenResponseClient is quite flexible as it allows you to customize the pre-processing of the Token Request and/or post-handling of the Token Response.

Customizing the Access Token Request

If you need to customize the pre-processing of the Token Request, you can provide DefaultAuthorizationCodeTokenResponseClient.setRequestEntityConverter() with a custom Converter<OAuth2AuthorizationCodeGrantRequest, RequestEntity<?>>. The default implementation OAuth2AuthorizationCodeGrantRequestEntityConverter builds a RequestEntity representation of a standard OAuth 2.0 Access Token Request. However, providing a custom Converter, would allow you to extend the standard Token Request and add custom parameter(s).

The custom Converter must return a valid RequestEntity representation of an OAuth 2.0 Access Token Request that is understood by the intended OAuth 2.0 Provider.
Customizing the Access Token Response

On the other end, if you need to customize the post-handling of the Token Response, you will need to provide DefaultAuthorizationCodeTokenResponseClient.setRestOperations() with a custom configured RestOperations. The default RestOperations is configured as follows:

RestTemplate restTemplate = new RestTemplate(Arrays.asList(
        new FormHttpMessageConverter(),
        new OAuth2AccessTokenResponseHttpMessageConverter()));

restTemplate.setErrorHandler(new OAuth2ErrorResponseErrorHandler());
Spring MVC FormHttpMessageConverter is required as it’s used when sending the OAuth 2.0 Access Token Request.

OAuth2AccessTokenResponseHttpMessageConverter is a HttpMessageConverter for an OAuth 2.0 Access Token Response. You can provide OAuth2AccessTokenResponseHttpMessageConverter.setTokenResponseConverter() with a custom Converter<Map<String, String>, OAuth2AccessTokenResponse> that is used for converting the OAuth 2.0 Access Token Response parameters to an OAuth2AccessTokenResponse.

OAuth2ErrorResponseErrorHandler is a ResponseErrorHandler that can handle an OAuth 2.0 Error, eg. 400 Bad Request. It uses an OAuth2ErrorHttpMessageConverter for converting the OAuth 2.0 Error parameters to an OAuth2Error.

Whether you customize DefaultAuthorizationCodeTokenResponseClient or provide your own implementation of OAuth2AccessTokenResponseClient, you’ll need to configure it as shown in the following example:

Example 95. Access Token Response Configuration
Java
@EnableWebSecurity
public class OAuth2ClientSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .oauth2Client(oauth2 -> oauth2
                .authorizationCodeGrant(codeGrant -> codeGrant
                    .accessTokenResponseClient(this.accessTokenResponseClient())
                    ...
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class OAuth2ClientSecurityConfig : WebSecurityConfigurerAdapter() {

    override fun configure(http: HttpSecurity) {
        http {
            oauth2Client {
                authorizationCodeGrant {
                    accessTokenResponseClient = accessTokenResponseClient()
                }
            }
        }
    }
}
Xml
<http>
    <oauth2-client>
        <authorization-code-grant access-token-response-client-ref="accessTokenResponseClient"/>
    </oauth2-client>
</http>
Refresh Token
Please refer to the OAuth 2.0 Authorization Framework for further details on the Refresh Token.
Refreshing an Access Token
Please refer to the Access Token Request/Response protocol flow for the Refresh Token grant.

The default implementation of OAuth2AccessTokenResponseClient for the Refresh Token grant is DefaultRefreshTokenTokenResponseClient, which uses a RestOperations when refreshing an access token at the Authorization Server’s Token Endpoint.

The DefaultRefreshTokenTokenResponseClient is quite flexible as it allows you to customize the pre-processing of the Token Request and/or post-handling of the Token Response.

Customizing the Access Token Request

If you need to customize the pre-processing of the Token Request, you can provide DefaultRefreshTokenTokenResponseClient.setRequestEntityConverter() with a custom Converter<OAuth2RefreshTokenGrantRequest, RequestEntity<?>>. The default implementation OAuth2RefreshTokenGrantRequestEntityConverter builds a RequestEntity representation of a standard OAuth 2.0 Access Token Request. However, providing a custom Converter, would allow you to extend the standard Token Request and add custom parameter(s).

The custom Converter must return a valid RequestEntity representation of an OAuth 2.0 Access Token Request that is understood by the intended OAuth 2.0 Provider.
Customizing the Access Token Response

On the other end, if you need to customize the post-handling of the Token Response, you will need to provide DefaultRefreshTokenTokenResponseClient.setRestOperations() with a custom configured RestOperations. The default RestOperations is configured as follows:

RestTemplate restTemplate = new RestTemplate(Arrays.asList(
        new FormHttpMessageConverter(),
        new OAuth2AccessTokenResponseHttpMessageConverter()));

restTemplate.setErrorHandler(new OAuth2ErrorResponseErrorHandler());
Spring MVC FormHttpMessageConverter is required as it’s used when sending the OAuth 2.0 Access Token Request.

OAuth2AccessTokenResponseHttpMessageConverter is a HttpMessageConverter for an OAuth 2.0 Access Token Response. You can provide OAuth2AccessTokenResponseHttpMessageConverter.setTokenResponseConverter() with a custom Converter<Map<String, String>, OAuth2AccessTokenResponse> that is used for converting the OAuth 2.0 Access Token Response parameters to an OAuth2AccessTokenResponse.

OAuth2ErrorResponseErrorHandler is a ResponseErrorHandler that can handle an OAuth 2.0 Error, eg. 400 Bad Request. It uses an OAuth2ErrorHttpMessageConverter for converting the OAuth 2.0 Error parameters to an OAuth2Error.

Whether you customize DefaultRefreshTokenTokenResponseClient or provide your own implementation of OAuth2AccessTokenResponseClient, you’ll need to configure it as shown in the following example:

// Customize
OAuth2AccessTokenResponseClient<OAuth2RefreshTokenGrantRequest> refreshTokenTokenResponseClient = ...

OAuth2AuthorizedClientProvider authorizedClientProvider =
        OAuth2AuthorizedClientProviderBuilder.builder()
                .authorizationCode()
                .refreshToken(configurer -> configurer.accessTokenResponseClient(refreshTokenTokenResponseClient))
                .build();

...

authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);
OAuth2AuthorizedClientProviderBuilder.builder().refreshToken() configures a RefreshTokenOAuth2AuthorizedClientProvider, which is an implementation of an OAuth2AuthorizedClientProvider for the Refresh Token grant.

The OAuth2RefreshToken may optionally be returned in the Access Token Response for the authorization_code and password grant types. If the OAuth2AuthorizedClient.getRefreshToken() is available and the OAuth2AuthorizedClient.getAccessToken() is expired, it will automatically be refreshed by the RefreshTokenOAuth2AuthorizedClientProvider.

Client Credentials
Please refer to the OAuth 2.0 Authorization Framework for further details on the Client Credentials grant.
Requesting an Access Token
Please refer to the Access Token Request/Response protocol flow for the Client Credentials grant.

The default implementation of OAuth2AccessTokenResponseClient for the Client Credentials grant is DefaultClientCredentialsTokenResponseClient, which uses a RestOperations when requesting an access token at the Authorization Server’s Token Endpoint.

The DefaultClientCredentialsTokenResponseClient is quite flexible as it allows you to customize the pre-processing of the Token Request and/or post-handling of the Token Response.

Customizing the Access Token Request

If you need to customize the pre-processing of the Token Request, you can provide DefaultClientCredentialsTokenResponseClient.setRequestEntityConverter() with a custom Converter<OAuth2ClientCredentialsGrantRequest, RequestEntity<?>>. The default implementation OAuth2ClientCredentialsGrantRequestEntityConverter builds a RequestEntity representation of a standard OAuth 2.0 Access Token Request. However, providing a custom Converter, would allow you to extend the standard Token Request and add custom parameter(s).

The custom Converter must return a valid RequestEntity representation of an OAuth 2.0 Access Token Request that is understood by the intended OAuth 2.0 Provider.
Customizing the Access Token Response

On the other end, if you need to customize the post-handling of the Token Response, you will need to provide DefaultClientCredentialsTokenResponseClient.setRestOperations() with a custom configured RestOperations. The default RestOperations is configured as follows:

RestTemplate restTemplate = new RestTemplate(Arrays.asList(
        new FormHttpMessageConverter(),
        new OAuth2AccessTokenResponseHttpMessageConverter()));

restTemplate.setErrorHandler(new OAuth2ErrorResponseErrorHandler());
Spring MVC FormHttpMessageConverter is required as it’s used when sending the OAuth 2.0 Access Token Request.

OAuth2AccessTokenResponseHttpMessageConverter is a HttpMessageConverter for an OAuth 2.0 Access Token Response. You can provide OAuth2AccessTokenResponseHttpMessageConverter.setTokenResponseConverter() with a custom Converter<Map<String, String>, OAuth2AccessTokenResponse> that is used for converting the OAuth 2.0 Access Token Response parameters to an OAuth2AccessTokenResponse.

OAuth2ErrorResponseErrorHandler is a ResponseErrorHandler that can handle an OAuth 2.0 Error, eg. 400 Bad Request. It uses an OAuth2ErrorHttpMessageConverter for converting the OAuth 2.0 Error parameters to an OAuth2Error.

Whether you customize DefaultClientCredentialsTokenResponseClient or provide your own implementation of OAuth2AccessTokenResponseClient, you’ll need to configure it as shown in the following example:

// Customize
OAuth2AccessTokenResponseClient<OAuth2ClientCredentialsGrantRequest> clientCredentialsTokenResponseClient = ...

OAuth2AuthorizedClientProvider authorizedClientProvider =
        OAuth2AuthorizedClientProviderBuilder.builder()
                .clientCredentials(configurer -> configurer.accessTokenResponseClient(clientCredentialsTokenResponseClient))
                .build();

...

authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);
OAuth2AuthorizedClientProviderBuilder.builder().clientCredentials() configures a ClientCredentialsOAuth2AuthorizedClientProvider, which is an implementation of an OAuth2AuthorizedClientProvider for the Client Credentials grant.
Using the Access Token

Given the following Spring Boot 2.x properties for an OAuth 2.0 Client registration:

spring:
  security:
    oauth2:
      client:
        registration:
          okta:
            client-id: okta-client-id
            client-secret: okta-client-secret
            authorization-grant-type: client_credentials
            scope: read, write
        provider:
          okta:
            token-uri: https://dev-1234.oktapreview.com/oauth2/v1/token

…​and the OAuth2AuthorizedClientManager @Bean:

@Bean
public OAuth2AuthorizedClientManager authorizedClientManager(
        ClientRegistrationRepository clientRegistrationRepository,
        OAuth2AuthorizedClientRepository authorizedClientRepository) {

    OAuth2AuthorizedClientProvider authorizedClientProvider =
            OAuth2AuthorizedClientProviderBuilder.builder()
                    .clientCredentials()
                    .build();

    DefaultOAuth2AuthorizedClientManager authorizedClientManager =
            new DefaultOAuth2AuthorizedClientManager(
                    clientRegistrationRepository, authorizedClientRepository);
    authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);

    return authorizedClientManager;
}

You may obtain the OAuth2AccessToken as follows:

@Controller
public class OAuth2ClientController {

    @Autowired
    private OAuth2AuthorizedClientManager authorizedClientManager;

    @GetMapping("/")
    public String index(Authentication authentication,
                        HttpServletRequest servletRequest,
                        HttpServletResponse servletResponse) {

        OAuth2AuthorizeRequest authorizeRequest = OAuth2AuthorizeRequest.withClientRegistrationId("okta")
                .principal(authentication)
                .attributes(attrs -> {
                    attrs.put(HttpServletRequest.class.getName(), servletRequest);
                    attrs.put(HttpServletResponse.class.getName(), servletResponse);
                })
                .build();
        OAuth2AuthorizedClient authorizedClient = this.authorizedClientManager.authorize(authorizeRequest);

        OAuth2AccessToken accessToken = authorizedClient.getAccessToken();

        ...

        return "index";
    }
}
HttpServletRequest and HttpServletResponse are both OPTIONAL attributes. If not provided, it will default to ServletRequestAttributes using RequestContextHolder.getRequestAttributes().
Resource Owner Password Credentials
Please refer to the OAuth 2.0 Authorization Framework for further details on the Resource Owner Password Credentials grant.
Requesting an Access Token
Please refer to the Access Token Request/Response protocol flow for the Resource Owner Password Credentials grant.

The default implementation of OAuth2AccessTokenResponseClient for the Resource Owner Password Credentials grant is DefaultPasswordTokenResponseClient, which uses a RestOperations when requesting an access token at the Authorization Server’s Token Endpoint.

The DefaultPasswordTokenResponseClient is quite flexible as it allows you to customize the pre-processing of the Token Request and/or post-handling of the Token Response.

Customizing the Access Token Request

If you need to customize the pre-processing of the Token Request, you can provide DefaultPasswordTokenResponseClient.setRequestEntityConverter() with a custom Converter<OAuth2PasswordGrantRequest, RequestEntity<?>>. The default implementation OAuth2PasswordGrantRequestEntityConverter builds a RequestEntity representation of a standard OAuth 2.0 Access Token Request. However, providing a custom Converter, would allow you to extend the standard Token Request and add custom parameter(s).

The custom Converter must return a valid RequestEntity representation of an OAuth 2.0 Access Token Request that is understood by the intended OAuth 2.0 Provider.
Customizing the Access Token Response

On the other end, if you need to customize the post-handling of the Token Response, you will need to provide DefaultPasswordTokenResponseClient.setRestOperations() with a custom configured RestOperations. The default RestOperations is configured as follows:

RestTemplate restTemplate = new RestTemplate(Arrays.asList(
        new FormHttpMessageConverter(),
        new OAuth2AccessTokenResponseHttpMessageConverter()));

restTemplate.setErrorHandler(new OAuth2ErrorResponseErrorHandler());
Spring MVC FormHttpMessageConverter is required as it’s used when sending the OAuth 2.0 Access Token Request.

OAuth2AccessTokenResponseHttpMessageConverter is a HttpMessageConverter for an OAuth 2.0 Access Token Response. You can provide OAuth2AccessTokenResponseHttpMessageConverter.setTokenResponseConverter() with a custom Converter<Map<String, String>, OAuth2AccessTokenResponse> that is used for converting the OAuth 2.0 Access Token Response parameters to an OAuth2AccessTokenResponse.

OAuth2ErrorResponseErrorHandler is a ResponseErrorHandler that can handle an OAuth 2.0 Error, eg. 400 Bad Request. It uses an OAuth2ErrorHttpMessageConverter for converting the OAuth 2.0 Error parameters to an OAuth2Error.

Whether you customize DefaultPasswordTokenResponseClient or provide your own implementation of OAuth2AccessTokenResponseClient, you’ll need to configure it as shown in the following example:

// Customize
OAuth2AccessTokenResponseClient<OAuth2PasswordGrantRequest> passwordTokenResponseClient = ...

OAuth2AuthorizedClientProvider authorizedClientProvider =
        OAuth2AuthorizedClientProviderBuilder.builder()
                .password(configurer -> configurer.accessTokenResponseClient(passwordTokenResponseClient))
                .refreshToken()
                .build();

...

authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);
OAuth2AuthorizedClientProviderBuilder.builder().password() configures a PasswordOAuth2AuthorizedClientProvider, which is an implementation of an OAuth2AuthorizedClientProvider for the Resource Owner Password Credentials grant.
Using the Access Token

Given the following Spring Boot 2.x properties for an OAuth 2.0 Client registration:

spring:
  security:
    oauth2:
      client:
        registration:
          okta:
            client-id: okta-client-id
            client-secret: okta-client-secret
            authorization-grant-type: password
            scope: read, write
        provider:
          okta:
            token-uri: https://dev-1234.oktapreview.com/oauth2/v1/token

…​and the OAuth2AuthorizedClientManager @Bean:

@Bean
public OAuth2AuthorizedClientManager authorizedClientManager(
        ClientRegistrationRepository clientRegistrationRepository,
        OAuth2AuthorizedClientRepository authorizedClientRepository) {

    OAuth2AuthorizedClientProvider authorizedClientProvider =
            OAuth2AuthorizedClientProviderBuilder.builder()
                    .password()
                    .refreshToken()
                    .build();

    DefaultOAuth2AuthorizedClientManager authorizedClientManager =
            new DefaultOAuth2AuthorizedClientManager(
                    clientRegistrationRepository, authorizedClientRepository);
    authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);

    // Assuming the `username` and `password` are supplied as `HttpServletRequest` parameters,
    // map the `HttpServletRequest` parameters to `OAuth2AuthorizationContext.getAttributes()`
    authorizedClientManager.setContextAttributesMapper(contextAttributesMapper());

    return authorizedClientManager;
}

private Function<OAuth2AuthorizeRequest, Map<String, Object>> contextAttributesMapper() {
    return authorizeRequest -> {
        Map<String, Object> contextAttributes = Collections.emptyMap();
        HttpServletRequest servletRequest = authorizeRequest.getAttribute(HttpServletRequest.class.getName());
        String username = servletRequest.getParameter(OAuth2ParameterNames.USERNAME);
        String password = servletRequest.getParameter(OAuth2ParameterNames.PASSWORD);
        if (StringUtils.hasText(username) && StringUtils.hasText(password)) {
            contextAttributes = new HashMap<>();

            // `PasswordOAuth2AuthorizedClientProvider` requires both attributes
            contextAttributes.put(OAuth2AuthorizationContext.USERNAME_ATTRIBUTE_NAME, username);
            contextAttributes.put(OAuth2AuthorizationContext.PASSWORD_ATTRIBUTE_NAME, password);
        }
        return contextAttributes;
    };
}

You may obtain the OAuth2AccessToken as follows:

@Controller
public class OAuth2ClientController {

    @Autowired
    private OAuth2AuthorizedClientManager authorizedClientManager;

    @GetMapping("/")
    public String index(Authentication authentication,
                        HttpServletRequest servletRequest,
                        HttpServletResponse servletResponse) {

        OAuth2AuthorizeRequest authorizeRequest = OAuth2AuthorizeRequest.withClientRegistrationId("okta")
                .principal(authentication)
                .attributes(attrs -> {
                    attrs.put(HttpServletRequest.class.getName(), servletRequest);
                    attrs.put(HttpServletResponse.class.getName(), servletResponse);
                })
                .build();
        OAuth2AuthorizedClient authorizedClient = this.authorizedClientManager.authorize(authorizeRequest);

        OAuth2AccessToken accessToken = authorizedClient.getAccessToken();

        ...

        return "index";
    }
}
HttpServletRequest and HttpServletResponse are both OPTIONAL attributes. If not provided, it will default to ServletRequestAttributes using RequestContextHolder.getRequestAttributes().

12.2.3. Additional Features

Resolving an Authorized Client

The @RegisteredOAuth2AuthorizedClient annotation provides the capability of resolving a method parameter to an argument value of type OAuth2AuthorizedClient. This is a convenient alternative compared to accessing the OAuth2AuthorizedClient using the OAuth2AuthorizedClientManager or OAuth2AuthorizedClientService.

@Controller
public class OAuth2ClientController {

    @GetMapping("/")
    public String index(@RegisteredOAuth2AuthorizedClient("okta") OAuth2AuthorizedClient authorizedClient) {
        OAuth2AccessToken accessToken = authorizedClient.getAccessToken();

        ...

        return "index";
    }
}

The @RegisteredOAuth2AuthorizedClient annotation is handled by OAuth2AuthorizedClientArgumentResolver, which directly uses an OAuth2AuthorizedClientManager and therefore inherits it’s capabilities.

12.2.4. WebClient integration for Servlet Environments

The OAuth 2.0 Client support integrates with WebClient using an ExchangeFilterFunction.

The ServletOAuth2AuthorizedClientExchangeFilterFunction provides a simple mechanism for requesting protected resources by using an OAuth2AuthorizedClient and including the associated OAuth2AccessToken as a Bearer Token. It directly uses an OAuth2AuthorizedClientManager and therefore inherits the following capabilities:

  • An OAuth2AccessToken will be requested if the client has not yet been authorized.

    • authorization_code - triggers the Authorization Request redirect to initiate the flow

    • client_credentials - the access token is obtained directly from the Token Endpoint

    • password - the access token is obtained directly from the Token Endpoint

  • If the OAuth2AccessToken is expired, it will be refreshed (or renewed) if an OAuth2AuthorizedClientProvider is available to perform the authorization

The following code shows an example of how to configure WebClient with OAuth 2.0 Client support:

@Bean
WebClient webClient(OAuth2AuthorizedClientManager authorizedClientManager) {
    ServletOAuth2AuthorizedClientExchangeFilterFunction oauth2Client =
            new ServletOAuth2AuthorizedClientExchangeFilterFunction(authorizedClientManager);
    return WebClient.builder()
            .apply(oauth2Client.oauth2Configuration())
            .build();
}
Providing the Authorized Client

The ServletOAuth2AuthorizedClientExchangeFilterFunction determines the client to use (for a request) by resolving the OAuth2AuthorizedClient from the ClientRequest.attributes() (request attributes).

The following code shows how to set an OAuth2AuthorizedClient as a request attribute:

@GetMapping("/")
public String index(@RegisteredOAuth2AuthorizedClient("okta") OAuth2AuthorizedClient authorizedClient) {
    String resourceUri = ...

    String body = webClient
            .get()
            .uri(resourceUri)
            .attributes(oauth2AuthorizedClient(authorizedClient))   (1)
            .retrieve()
            .bodyToMono(String.class)
            .block();

    ...

    return "index";
}
1 oauth2AuthorizedClient() is a static method in ServletOAuth2AuthorizedClientExchangeFilterFunction.

The following code shows how to set the ClientRegistration.getRegistrationId() as a request attribute:

@GetMapping("/")
public String index() {
    String resourceUri = ...

    String body = webClient
            .get()
            .uri(resourceUri)
            .attributes(clientRegistrationId("okta"))   (1)
            .retrieve()
            .bodyToMono(String.class)
            .block();

    ...

    return "index";
}
1 clientRegistrationId() is a static method in ServletOAuth2AuthorizedClientExchangeFilterFunction.
Defaulting the Authorized Client

If neither OAuth2AuthorizedClient or ClientRegistration.getRegistrationId() is provided as a request attribute, the ServletOAuth2AuthorizedClientExchangeFilterFunction can determine the default client to use depending on it’s configuration.

If setDefaultOAuth2AuthorizedClient(true) is configured and the user has authenticated using HttpSecurity.oauth2Login(), the OAuth2AccessToken associated with the current OAuth2AuthenticationToken is used.

The following code shows the specific configuration:

@Bean
WebClient webClient(OAuth2AuthorizedClientManager authorizedClientManager) {
    ServletOAuth2AuthorizedClientExchangeFilterFunction oauth2Client =
            new ServletOAuth2AuthorizedClientExchangeFilterFunction(authorizedClientManager);
    oauth2Client.setDefaultOAuth2AuthorizedClient(true);
    return WebClient.builder()
            .apply(oauth2Client.oauth2Configuration())
            .build();
}
It is recommended to be cautious with this feature since all HTTP requests will receive the access token.

Alternatively, if setDefaultClientRegistrationId("okta") is configured with a valid ClientRegistration, the OAuth2AccessToken associated with the OAuth2AuthorizedClient is used.

The following code shows the specific configuration:

@Bean
WebClient webClient(OAuth2AuthorizedClientManager authorizedClientManager) {
    ServletOAuth2AuthorizedClientExchangeFilterFunction oauth2Client =
            new ServletOAuth2AuthorizedClientExchangeFilterFunction(authorizedClientManager);
    oauth2Client.setDefaultClientRegistrationId("okta");
    return WebClient.builder()
            .apply(oauth2Client.oauth2Configuration())
            .build();
}
It is recommended to be cautious with this feature since all HTTP requests will receive the access token.

12.3. OAuth 2.0 Resource Server

Spring Security supports protecting endpoints using two forms of OAuth 2.0 Bearer Tokens:

  • JWT

  • Opaque Tokens

This is handy in circumstances where an application has delegated its authority management to an authorization server (for example, Okta or Ping Identity). This authorization server can be consulted by resource servers to authorize requests.

Working samples for both JWTs and Opaque Tokens are available in the Spring Security repository.

12.3.1. Dependencies

Most Resource Server support is collected into spring-security-oauth2-resource-server. However, the support for decoding and verifying JWTs is in spring-security-oauth2-jose, meaning that both are necessary in order to have a working resource server that supports JWT-encoded Bearer Tokens.

12.3.2. Minimal Configuration for JWTs

When using Spring Boot, configuring an application as a resource server consists of two basic steps. First, include the needed dependencies and second, indicate the location of the authorization server.

Specifying the Authorization Server

In a Spring Boot application, to specify which authorization server to use, simply do:

spring:
  security:
    oauth2:
      resourceserver:
        jwt:
          issuer-uri: https://idp.example.com/issuer

Where https://idp.example.com/issuer is the value contained in the iss claim for JWT tokens that the authorization server will issue. Resource Server will use this property to further self-configure, discover the authorization server’s public keys, and subsequently validate incoming JWTs.

To use the issuer-uri property, it must also be true that one of https://idp.example.com/issuer/.well-known/openid-configuration, https://idp.example.com/.well-known/openid-configuration/issuer, or https://idp.example.com/.well-known/oauth-authorization-server/issuer is a supported endpoint for the authorization server. This endpoint is referred to as a Provider Configuration endpoint or a Authorization Server Metadata endpoint.

And that’s it!

Startup Expectations

When this property and these dependencies are used, Resource Server will automatically configure itself to validate JWT-encoded Bearer Tokens.

It achieves this through a deterministic startup process:

  1. Hit the Provider Configuration or Authorization Server Metadata endpoint, processing the response for the jwks_url property

  2. Configure the validation strategy to query jwks_url for valid public keys

  3. Configure the validation strategy to validate each JWTs iss claim against https://idp.example.com.

A consequence of this process is that the authorization server must be up and receiving requests in order for Resource Server to successfully start up.

If the authorization server is down when Resource Server queries it (given appropriate timeouts), then startup will fail.
Runtime Expectations

Once the application is started up, Resource Server will attempt to process any request containing an Authorization: Bearer header:

GET / HTTP/1.1
Authorization: Bearer some-token-value # Resource Server will process this

So long as this scheme is indicated, Resource Server will attempt to process the request according to the Bearer Token specification.

Given a well-formed JWT, Resource Server will:

  1. Validate its signature against a public key obtained from the jwks_url endpoint during startup and matched against the JWT

  2. Validate the JWT’s exp and nbf timestamps and the JWT’s iss claim, and

  3. Map each scope to an authority with the prefix SCOPE_.

As the authorization server makes available new keys, Spring Security will automatically rotate the keys used to validate JWTs.

The resulting Authentication#getPrincipal, by default, is a Spring Security Jwt object, and Authentication#getName maps to the JWT’s sub property, if one is present.

From here, consider jumping to:

12.3.3. Specifying the Authorization Server JWK Set Uri Directly

If the authorization server doesn’t support any configuration endpoints, or if Resource Server must be able to start up independently from the authorization server, then the jwk-set-uri can be supplied as well:

spring:
  security:
    oauth2:
      resourceserver:
        jwt:
          issuer-uri: https://idp.example.com
          jwk-set-uri: https://idp.example.com/.well-known/jwks.json
The JWK Set uri is not standardized, but can typically be found in the authorization server’s documentation

Consequently, Resource Server will not ping the authorization server at startup. We still specify the issuer-uri so that Resource Server still validates the iss claim on incoming JWTs.

This property can also be supplied directly on the DSL.

12.3.4. Overriding or Replacing Boot Auto Configuration

There are two @Bean s that Spring Boot generates on Resource Server’s behalf.

The first is a WebSecurityConfigurerAdapter that configures the app as a resource server. When including spring-security-oauth2-jose, this WebSecurityConfigurerAdapter looks like:

Example 96. Default JWT Configuration
Java
protected void configure(HttpSecurity http) {
    http
        .authorizeRequests(authorize -> authorize
            .anyRequest().authenticated()
        )
        .oauth2ResourceServer(OAuth2ResourceServerConfigurer::jwt);
}
Kotlin
fun configure(http: HttpSecurity) {
    http {
        authorizeRequests {
            authorize(anyRequest, authenticated)
        }
        oauth2ResourceServer {
            jwt { }
        }
    }
}

If the application doesn’t expose a WebSecurityConfigurerAdapter bean, then Spring Boot will expose the above default one.

Replacing this is as simple as exposing the bean within the application:

Example 97. Custom JWT Configuration
Java
@EnableWebSecurity
public class MyCustomSecurityConfiguration extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorize -> authorize
                .mvcMatchers("/messages/**").hasAuthority("SCOPE_message:read")
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(oauth2 -> oauth2
                .jwt(jwt -> jwt
                    .jwtAuthenticationConverter(myConverter())
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class MyCustomSecurityConfiguration : WebSecurityConfigurerAdapter() {
    override fun configure(http: HttpSecurity) {
        http {
            authorizeRequests {
                authorize("/messages/**", hasAuthority("SCOPE_message:read"))
                authorize(anyRequest, authenticated)
            }
            oauth2ResourceServer {
                jwt {
                    jwtAuthenticationConverter = myConverter()
                }
            }
        }
    }
}

The above requires the scope of message:read for any URL that starts with /messages/.

Methods on the oauth2ResourceServer DSL will also override or replace auto configuration.

For example, the second @Bean Spring Boot creates is a JwtDecoder, which decodes String tokens into validated instances of Jwt:

Example 98. JWT Decoder
@Bean
public JwtDecoder jwtDecoder() {
    return JwtDecoders.fromIssuerLocation(issuerUri);
}
Calling JwtDecoders#fromIssuerLocation is what invokes the Provider Configuration or Authorization Server Metadata endpoint in order to derive the JWK Set Uri.

If the application doesn’t expose a JwtDecoder bean, then Spring Boot will expose the above default one.

And its configuration can be overridden using jwkSetUri() or replaced using decoder().

Or, if you’re not using Spring Boot at all, then both of these components - the filter chain and a JwtDecoder can be specified in XML.

The filter chain is specified like so:

Example 99. Default JWT Configuration
Xml
<http>
    <intercept-uri pattern="/**" access="authenticated"/>
    <oauth2-resource-server>
        <jwt decoder-ref="jwtDecoder"/>
    </oauth2-resource-server>
</http>

And the JwtDecoder like so:

Example 100. JWT Decoder
Xml
<bean id="jwtDecoder"
        class="org.springframework.security.oauth2.jwt.JwtDecoders"
        factory-method="fromIssuerLocation">
    <constructor-arg value="${spring.security.oauth2.resourceserver.jwt.jwk-set-uri}"/>
</bean>
Using jwkSetUri()

An authorization server’s JWK Set Uri can be configured as a configuration property or it can be supplied in the DSL:

Example 101. JWK Set Uri Configuration
Java
@EnableWebSecurity
public class DirectlyConfiguredJwkSetUri extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(oauth2 -> oauth2
                .jwt(jwt -> jwt
                    .jwkSetUri("https://idp.example.com/.well-known/jwks.json")
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class DirectlyConfiguredJwkSetUri : WebSecurityConfigurerAdapter() {
    override fun configure(http: HttpSecurity) {
        http {
            authorizeRequests {
                authorize(anyRequest, authenticated)
            }
            oauth2ResourceServer {
                jwt {
                    jwkSetUri = "https://idp.example.com/.well-known/jwks.json"
                }
            }
        }
    }
}
Xml
<http>
    <intercept-uri pattern="/**" access="authenticated"/>
    <oauth2-resource-server>
        <jwt jwk-set-uri="https://idp.example.com/.well-known/jwks.json"/>
    </oauth2-resource-server>
</http>

Using jwkSetUri() takes precedence over any configuration property.

Using decoder()

More powerful than jwkSetUri() is decoder(), which will completely replace any Boot auto configuration of JwtDecoder:

Example 102. JWT Decoder Configuration
Java
@EnableWebSecurity
public class DirectlyConfiguredJwtDecoder extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(oauth2 -> oauth2
                .jwt(jwt -> jwt
                    .decoder(myCustomDecoder())
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class DirectlyConfiguredJwtDecoder : WebSecurityConfigurerAdapter() {
    override fun configure(http: HttpSecurity) {
        http {
            authorizeRequests {
                authorize(anyRequest, authenticated)
            }
            oauth2ResourceServer {
                jwt {
                    jwtDecoder = myCustomDecoder()
                }
            }
        }
    }
}
Xml
<http>
    <intercept-uri pattern="/**" access="authenticated"/>
    <oauth2-resource-server>
        <jwt decoder-ref="myCustomDecoder"/>
    </oauth2-resource-server>
</http>

This is handy when deeper configuration, like validation, mapping, or request timeouts, is necessary.

Exposing a JwtDecoder @Bean

Or, exposing a JwtDecoder @Bean has the same effect as decoder():

@Bean
public JwtDecoder jwtDecoder() {
    return NimbusJwtDecoder.withJwkSetUri(jwkSetUri).build();
}

12.3.5. Configuring Trusted Algorithms

By default, NimbusJwtDecoder, and hence Resource Server, will only trust and verify tokens using RS256.

You can customize this via Spring Boot, the NimbusJwtDecoder builder, or from the JWK Set response.

Via Spring Boot

The simplest way to set the algorithm is as a property:

spring:
  security:
    oauth2:
      resourceserver:
        jwt:
          jws-algorithm: RS512
          jwk-set-uri: https://idp.example.org/.well-known/jwks.json
Using a Builder

For greater power, though, we can use a builder that ships with NimbusJwtDecoder:

@Bean
JwtDecoder jwtDecoder() {
    return NimbusJwtDecoder.fromJwkSetUri(this.jwkSetUri)
            .jwsAlgorithm(RS512).build();
}

Calling jwsAlgorithm more than once will configure NimbusJwtDecoder to trust more than one algorithm, like so:

@Bean
JwtDecoder jwtDecoder() {
    return NimbusJwtDecoder.fromJwkSetUri(this.jwkSetUri)
            .jwsAlgorithm(RS512).jwsAlgorithm(EC512).build();
}

Or, you can call jwsAlgorithms:

@Bean
JwtDecoder jwtDecoder() {
    return NimbusJwtDecoder.fromJwkSetUri(this.jwkSetUri)
            .jwsAlgorithms(algorithms -> {
                    algorithms.add(RS512);
                    algorithms.add(EC512);
            }).build();
}
From JWK Set response

Since Spring Security’s JWT support is based off of Nimbus, you can use all it’s great features as well.

For example, Nimbus has a JWSKeySelector implementation that will select the set of algorithms based on the JWK Set URI response. You can use it to generate a NimbusJwtDecoder like so:

@Bean
public JwtDecoder jwtDecoder() {
    // makes a request to the JWK Set endpoint
    JWSKeySelector<SecurityContext> jwsKeySelector =
            JWSAlgorithmFamilyJWSKeySelector.fromJWKSetURL(this.jwkSetUrl);

    DefaultJWTProcessor<SecurityContext> jwtProcessor =
            new DefaultJWTProcessor<>();
    jwtProcessor.setJWSKeySelector(jwsKeySelector);

    return new NimbusJwtDecoder(jwtProcessor);
}

12.3.6. Trusting a Single Asymmetric Key

Simpler than backing a Resource Server with a JWK Set endpoint is to hard-code an RSA public key. The public key can be provided via Spring Boot or by Using a Builder.

Via Spring Boot

Specifying a key via Spring Boot is quite simple. The key’s location can be specified like so:

spring:
  security:
    oauth2:
      resourceserver:
        jwt:
          public-key-location: classpath:my-key.pub

Or, to allow for a more sophisticated lookup, you can post-process the RsaKeyConversionServicePostProcessor:

@Bean
BeanFactoryPostProcessor conversionServiceCustomizer() {
    return beanFactory ->
        beanFactory.getBean(RsaKeyConversionServicePostProcessor.class)
                .setResourceLoader(new CustomResourceLoader());
}

Specify your key’s location:

key.location: hfds://my-key.pub

And then autowire the value:

@Value("${key.location}")
RSAPublicKey key;
Using a Builder

To wire an RSAPublicKey directly, you can simply use the appropriate NimbusJwtDecoder builder, like so:

@Bean
public JwtDecoder jwtDecoder() {
    return NimbusJwtDecoder.withPublicKey(this.key).build();
}

12.3.7. Trusting a Single Symmetric Key

Using a single symmetric key is also simple. You can simply load in your SecretKey and use the appropriate NimbusJwtDecoder builder, like so:

@Bean
public JwtDecoder jwtDecoder() {
    return NimbusJwtDecoder.withSecretKey(this.key).build();
}

12.3.8. Configuring Authorization

A JWT that is issued from an OAuth 2.0 Authorization Server will typically either have a scope or scp attribute, indicating the scopes (or authorities) it’s been granted, for example:

{ …​, "scope" : "messages contacts"}

When this is the case, Resource Server will attempt to coerce these scopes into a list of granted authorities, prefixing each scope with the string "SCOPE_".

This means that to protect an endpoint or method with a scope derived from a JWT, the corresponding expressions should include this prefix:

Example 103. Authorization Configuration
Java
@EnableWebSecurity
public class DirectlyConfiguredJwkSetUri extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorize -> authorize
                .mvcMatchers("/contacts/**").hasAuthority("SCOPE_contacts")
                .mvcMatchers("/messages/**").hasAuthority("SCOPE_messages")
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(OAuth2ResourceServerConfigurer::jwt);
    }
}
Kotlin
@EnableWebSecurity
class DirectlyConfiguredJwkSetUri : WebSecurityConfigurerAdapter() {
    override fun configure(http: HttpSecurity) {
        http {
            authorizeRequests {
                authorize("/contacts/**", hasAuthority("SCOPE_contacts"))
                authorize("/messages/**", hasAuthority("SCOPE_messages"))
                authorize(anyRequest, authenticated)
            }
            oauth2ResourceServer {
                jwt { }
            }
        }
    }
}
Xml
<http>
    <intercept-uri pattern="/contacts/**" access="hasAuthority('SCOPE_contacts')"/>
    <intercept-uri pattern="/messages/**" access="hasAuthority('SCOPE_messages')"/>
    <oauth2-resource-server>
        <jwt jwk-set-uri="https://idp.example.org/.well-known/jwks.json"/>
    </oauth2-resource-server>
</http>

Or similarly with method security:

@PreAuthorize("hasAuthority('SCOPE_messages')")
public List<Message> getMessages(...) {}
Extracting Authorities Manually

However, there are a number of circumstances where this default is insufficient. For example, some authorization servers don’t use the scope attribute, but instead have their own custom attribute. Or, at other times, the resource server may need to adapt the attribute or a composition of attributes into internalized authorities.

To this end, the DSL exposes jwtAuthenticationConverter(), which is responsible for converting a Jwt into an Authentication.

As part of its configuration, we can supply a subsidiary converter to go from Jwt to a Collection of granted authorities. Let’s say that that your authorization server communicates authorities in a custom claim called authorities. In that case, you can configure the claim that JwtAuthenticationConverter should inspect, like so:

Example 104. Authorities Claim Configuration
Java
@EnableWebSecurity
public class CustomAuthoritiesClaimName extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(oauth2 -> oauth2
                .jwt(jwt -> jwt
                    .jwtAuthenticationConverter(jwtAuthenticationConverter())
                )
            );
    }
}

JwtAuthenticationConverter jwtAuthenticationConverter() {
    JwtGrantedAuthoritiesConverter grantedAuthoritiesConverter = new JwtGrantedAuthoritiesConverter();
    grantedAuthoritiesConverter.setAuthoritiesClaimName("authorities");

    JwtAuthenticationConverter authenticationConverter = new JwtAuthenticationConverter();
    jwtAuthenticationConverter.setJwtGrantedAuthoritiesConverter(authoritiesConverter);
    return jwtAuthenticationConverter;
}
Xml
<http>
    <intercept-uri pattern="/contacts/**" access="hasAuthority('SCOPE_contacts')"/>
    <intercept-uri pattern="/messages/**" access="hasAuthority('SCOPE_messages')"/>
    <oauth2-resource-server>
        <jwt jwk-set-uri="https://idp.example.org/.well-known/jwks.json"
                jwt-authentication-converter-ref="jwtAuthenticationConverter"/>
    </oauth2-resource-server>
</http>

<bean id="jwtAuthenticationConverter"
        class="org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationConverter">
    <property name="jwtGrantedAuthoritiesConverter" ref="jwtGrantedAuthoritiesConverter"/>
</bean>

<bean id="jwtGrantedAuthoritiesConverter"
        class="org.springframework.security.oauth2.server.resource.authentication.JwtGrantedAuthoritiesConverter">
    <property name="authoritiesClaimName" value="authorities"/>
</bean>

You can also configure the authority prefix to be different as well. Instead of prefixing each authority with SCOPE_, you can change it to ROLE_ like so:

Example 105. Authorities Prefix Configuration
Java
JwtAuthenticationConverter jwtAuthenticationConverter() {
    JwtGrantedAuthoritiesConverter grantedAuthoritiesConverter = new JwtGrantedAuthoritiesConverter();
    grantedAuthoritiesConverter.setAuthorityPrefix("ROLE_");

    JwtAuthenticationConverter authenticationConverter = new JwtAuthenticationConverter();
    jwtAuthenticationConverter.setJwtGrantedAuthoritiesConverter(authoritiesConverter);
    return jwtAuthenticationConverter;
}
Xml
<http>
    <intercept-uri pattern="/contacts/**" access="hasAuthority('SCOPE_contacts')"/>
    <intercept-uri pattern="/messages/**" access="hasAuthority('SCOPE_messages')"/>
    <oauth2-resource-server>
        <jwt jwk-set-uri="https://idp.example.org/.well-known/jwks.json"
                jwt-authentication-converter-ref="jwtAuthenticationConverter"/>
    </oauth2-resource-server>
</http>

<bean id="jwtAuthenticationConverter"
        class="org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationConverter">
    <property name="jwtGrantedAuthoritiesConverter" ref="jwtGrantedAuthoritiesConverter"/>
</bean>

<bean id="jwtGrantedAuthoritiesConverter"
        class="org.springframework.security.oauth2.server.resource.authentication.JwtGrantedAuthoritiesConverter">
    <property name="authorityPrefix" value="ROLE_"/>
</bean>

Or, you can remove the prefix altogether by calling JwtGrantedAuthoritiesConverter#setAuthorityPrefix("").

For more flexibility, the DSL supports entirely replacing the converter with any class that implements Converter<Jwt, AbstractAuthenticationToken>:

static class CustomAuthenticationConverter implements Converter<Jwt, AbstractAuthenticationToken> {
    public AbstractAuthenticationToken convert(Jwt jwt) {
        return new CustomAuthenticationToken(jwt);
    }
}

12.3.9. Configuring Validation

Using minimal Spring Boot configuration, indicating the authorization server’s issuer uri, Resource Server will default to verifying the iss claim as well as the exp and nbf timestamp claims.

In circumstances where validation needs to be customized, Resource Server ships with two standard validators and also accepts custom OAuth2TokenValidator instances.

Customizing Timestamp Validation

JWT’s typically have a window of validity, with the start of the window indicated in the nbf claim and the end indicated in the exp claim.

However, every server can experience clock drift, which can cause tokens to appear expired to one server, but not to another. This can cause some implementation heartburn as the number of collaborating servers increases in a distributed system.

Resource Server uses JwtTimestampValidator to verify a token’s validity window, and it can be configured with a clockSkew to alleviate the above problem:

@Bean
JwtDecoder jwtDecoder() {
     NimbusJwtDecoder jwtDecoder = (NimbusJwtDecoder)
             JwtDecoders.fromIssuerLocation(issuerUri);

     OAuth2TokenValidator<Jwt> withClockSkew = new DelegatingOAuth2TokenValidator<>(
            new JwtTimestampValidator(Duration.ofSeconds(60)),
            new IssuerValidator(issuerUri));

     jwtDecoder.setJwtValidator(withClockSkew);

     return jwtDecoder;
}
By default, Resource Server configures a clock skew of 30 seconds.
Configuring a Custom Validator

Adding a check for the aud claim is simple with the OAuth2TokenValidator API:

OAuth2TokenValidator<Jwt> audienceValidator() {
    return new JwtClaimValidator<List<String>>(AUD, aud -> aud.contains("messaging"));
}

Or, for more control you can implement your own OAuth2TokenValidator:

static class AudienceValidator implements OAuth2TokenValidator<Jwt> {
    OAuth2Error error = new OAuth2Error("custom_code", "Custom error message", null);

    @Override
    public OAuth2TokenValidatorResult validate(Jwt jwt) {
        if (jwt.getAudience().contains("messaging")) {
            return OAuth2TokenValidatorResult.success();
        } else {
            return OAuth2TokenValidatorResult.failure(error);
        }
    }
}

// ...

OAuth2TokenValidator<Jwt> audienceValidator() {
    return new AudienceValidator();
}

Then, to add into a resource server, it’s a matter of specifying the JwtDecoder instance:

@Bean
JwtDecoder jwtDecoder() {
    NimbusJwtDecoder jwtDecoder = (NimbusJwtDecoder)
        JwtDecoders.fromIssuerLocation(issuerUri);

    OAuth2TokenValidator<Jwt> audienceValidator = audienceValidator();
    OAuth2TokenValidator<Jwt> withIssuer = JwtValidators.createDefaultWithIssuer(issuerUri);
    OAuth2TokenValidator<Jwt> withAudience = new DelegatingOAuth2TokenValidator<>(withIssuer, audienceValidator);

    jwtDecoder.setJwtValidator(withAudience);

    return jwtDecoder;
}

12.3.10. Configuring Claim Set Mapping

Spring Security uses the Nimbus library for parsing JWTs and validating their signatures. Consequently, Spring Security is subject to Nimbus’s interpretation of each field value and how to coerce each into a Java type.

For example, because Nimbus remains Java 7 compatible, it doesn’t use Instant to represent timestamp fields.

And it’s entirely possible to use a different library or for JWT processing, which may make its own coercion decisions that need adjustment.

Or, quite simply, a resource server may want to add or remove claims from a JWT for domain-specific reasons.

For these purposes, Resource Server supports mapping the JWT claim set with MappedJwtClaimSetConverter.

Customizing the Conversion of a Single Claim

By default, MappedJwtClaimSetConverter will attempt to coerce claims into the following types:

Claim

Java Type

aud

Collection<String>

exp

Instant

iat

Instant

iss

String

jti

String

nbf

Instant

sub

String

An individual claim’s conversion strategy can be configured using MappedJwtClaimSetConverter.withDefaults:

@Bean
JwtDecoder jwtDecoder() {
    NimbusJwtDecoder jwtDecoder = NimbusJwtDecoder.withJwkSetUri(jwkSetUri).build();

    MappedJwtClaimSetConverter converter = MappedJwtClaimSetConverter
            .withDefaults(Collections.singletonMap("sub", this::lookupUserIdBySub));
    jwtDecoder.setClaimSetConverter(converter);

    return jwtDecoder;
}

This will keep all the defaults, except it will override the default claim converter for sub.

Adding a Claim

MappedJwtClaimSetConverter can also be used to add a custom claim, for example, to adapt to an existing system:

MappedJwtClaimSetConverter.withDefaults(Collections.singletonMap("custom", custom -> "value"));
Removing a Claim

And removing a claim is also simple, using the same API:

MappedJwtClaimSetConverter.withDefaults(Collections.singletonMap("legacyclaim", legacy -> null));
Renaming a Claim

In more sophisticated scenarios, like consulting multiple claims at once or renaming a claim, Resource Server accepts any class that implements Converter<Map<String, Object>, Map<String,Object>>:

public class UsernameSubClaimAdapter implements Converter<Map<String, Object>, Map<String, Object>> {
    private final MappedJwtClaimSetConverter delegate =
            MappedJwtClaimSetConverter.withDefaults(Collections.emptyMap());

    public Map<String, Object> convert(Map<String, Object> claims) {
        Map<String, Object> convertedClaims = this.delegate.convert(claims);

        String username = (String) convertedClaims.get("user_name");
        convertedClaims.put("sub", username);

        return convertedClaims;
    }
}

And then, the instance can be supplied like normal:

@Bean
JwtDecoder jwtDecoder() {
    NimbusJwtDecoder jwtDecoder = NimbusJwtDecoder.withJwkSetUri(jwkSetUri).build();
    jwtDecoder.setClaimSetConverter(new UsernameSubClaimAdapter());
    return jwtDecoder;
}

12.3.11. Configuring Timeouts

By default, Resource Server uses connection and socket timeouts of 30 seconds each for coordinating with the authorization server.

This may be too short in some scenarios. Further, it doesn’t take into account more sophisticated patterns like back-off and discovery.

To adjust the way in which Resource Server connects to the authorization server, NimbusJwtDecoder accepts an instance of RestOperations:

@Bean
public JwtDecoder jwtDecoder(RestTemplateBuilder builder) {
    RestOperations rest = builder
            .setConnectionTimeout(60000)
            .setReadTimeout(60000)
            .build();

    NimbusJwtDecoder jwtDecoder = NimbusJwtDecoder.withJwkSetUri(jwkSetUri).restOperations(rest).build();
    return jwtDecoder;
}

12.3.12. Minimal Configuration for Introspection

Typically, an opaque token can be verified via an OAuth 2.0 Introspection Endpoint, hosted by the authorization server. This can be handy when revocation is a requirement.

When using Spring Boot, configuring an application as a resource server that uses introspection consists of two basic steps. First, include the needed dependencies and second, indicate the introspection endpoint details.

Specifying the Authorization Server

To specify where the introspection endpoint is, simply do:

security:
  oauth2:
    resourceserver:
      opaque-token:
        introspection-uri: https://idp.example.com/introspect
        client-id: client
        client-secret: secret

Where https://idp.example.com/introspect is the introspection endpoint hosted by your authorization server and client-id and client-secret are the credentials needed to hit that endpoint.

Resource Server will use these properties to further self-configure and subsequently validate incoming JWTs.

When using introspection, the authorization server’s word is the law. If the authorization server responses that the token is valid, then it is.

And that’s it!

Startup Expectations

When this property and these dependencies are used, Resource Server will automatically configure itself to validate Opaque Bearer Tokens.

This startup process is quite a bit simpler than for JWTs since no endpoints need to be discovered and no additional validation rules get added.

Runtime Expectations

Once the application is started up, Resource Server will attempt to process any request containing an Authorization: Bearer header:

GET / HTTP/1.1
Authorization: Bearer some-token-value # Resource Server will process this

So long as this scheme is indicated, Resource Server will attempt to process the request according to the Bearer Token specification.

Given an Opaque Token, Resource Server will

  1. Query the provided introspection endpoint using the provided credentials and the token

  2. Inspect the response for an { 'active' : true } attribute

  3. Map each scope to an authority with the prefix SCOPE_

The resulting Authentication#getPrincipal, by default, is a Spring Security OAuth2AuthenticatedPrincipal object, and Authentication#getName maps to the token’s sub property, if one is present.

From here, you may want to jump to:

12.3.13. Looking Up Attributes Post-Authentication

Once a token is authenticated, an instance of BearerTokenAuthentication is set in the SecurityContext.

This means that it’s available in @Controller methods when using @EnableWebMvc in your configuration:

@GetMapping("/foo")
public String foo(BearerTokenAuthentication authentication) {
    return authentication.getTokenAttributes().get("sub") + " is the subject";
}

Since BearerTokenAuthentication holds an OAuth2AuthenticatedPrincipal, that also means that it’s available to controller methods, too:

@GetMapping("/foo")
public String foo(@AuthenticationPrincipal OAuth2AuthenticatedPrincipal principal) {
    return principal.getAttribute("sub") + " is the subject";
}
Looking Up Attributes Via SpEL

Of course, this also means that attributes can be accessed via SpEL.

For example, if using @EnableGlobalMethodSecurity so that you can use @PreAuthorize annotations, you can do:

@PreAuthorize("principal?.attributes['sub'] == 'foo'")
public String forFoosEyesOnly() {
    return "foo";
}

12.3.14. Overriding or Replacing Boot Auto Configuration

There are two @Bean s that Spring Boot generates on Resource Server’s behalf.

The first is a WebSecurityConfigurerAdapter that configures the app as a resource server. When use Opaque Token, this WebSecurityConfigurerAdapter looks like:

Example 106. Default Opaque Token Configuration
Java
protected void configure(HttpSecurity http) {
    http
        .authorizeRequests(authorize -> authorize
            .anyRequest().authenticated()
        )
        .oauth2ResourceServer(OAuth2ResourceServerConfigurer::opaqueToken);
}
Kotlin
override fun configure(http: HttpSecurity) {
    http {
        authorizeRequests {
            authorize(anyRequest, authenticated)
        }
        oauth2ResourceServer {
            opaqueToken { }
        }
    }
}

If the application doesn’t expose a WebSecurityConfigurerAdapter bean, then Spring Boot will expose the above default one.

Replacing this is as simple as exposing the bean within the application:

Example 107. Custom Opaque Token Configuration
Java
@EnableWebSecurity
public class MyCustomSecurityConfiguration extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorize -> authorize
                .mvcMatchers("/messages/**").hasAuthority("SCOPE_message:read")
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(oauth2 -> oauth2
                .opaqueToken(opaqueToken -> opaqueToken
                    .introspector(myIntrospector())
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class MyCustomSecurityConfiguration : WebSecurityConfigurerAdapter() {
    override fun configure(http: HttpSecurity) {
        http {
            authorizeRequests {
                authorize("/messages/**", hasAuthority("SCOPE_message:read"))
                authorize(anyRequest, authenticated)
            }
            oauth2ResourceServer {
                opaqueToken {
                    introspector = myIntrospector()
                }
            }
        }
    }
}

The above requires the scope of message:read for any URL that starts with /messages/.

Methods on the oauth2ResourceServer DSL will also override or replace auto configuration.

For example, the second @Bean Spring Boot creates is an OpaqueTokenIntrospector, which decodes String tokens into validated instances of OAuth2AuthenticatedPrincipal:

@Bean
public OpaqueTokenIntrospector introspector() {
    return new NimbusOpaqueTokenIntrospector(introspectionUri, clientId, clientSecret);
}

If the application doesn’t expose a OpaqueTokenIntrospector bean, then Spring Boot will expose the above default one.

And its configuration can be overridden using introspectionUri() and introspectionClientCredentials() or replaced using introspector().

Or, if you’re not using Spring Boot at all, then both of these components - the filter chain and a OpaqueTokenIntrospector can be specified in XML.

The filter chain is specified like so:

Example 108. Default Opaque Token Configuration
Xml
<http>
    <intercept-uri pattern="/**" access="authenticated"/>
    <oauth2-resource-server>
        <opaque-token introspector-ref="opaqueTokenIntrospector"/>
    </oauth2-resource-server>
</http>

And the OpaqueTokenIntrospector like so:

Example 109. Opaque Token Introspector
Xml
<bean id="opaqueTokenIntrospector"
        class="org.springframework.security.oauth2.server.resource.introspection.NimbusOpaqueTokenIntrospector">
    <constructor-arg value="${spring.security.oauth2.resourceserver.opaquetoken.introspection_uri}"/>
    <constructor-arg value="${spring.security.oauth2.resourceserver.opaquetoken.client_id}"/>
    <constructor-arg value="${spring.security.oauth2.resourceserver.opaquetoken.client_secret}"/>
</bean>
Using introspectionUri()

An authorization server’s Introspection Uri can be configured as a configuration property or it can be supplied in the DSL:

Example 110. Introspection URI Configuration
Java
@EnableWebSecurity
public class DirectlyConfiguredIntrospectionUri extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(oauth2 -> oauth2
                .opaqueToken(opaqueToken -> opaqueToken
                    .introspectionUri("https://idp.example.com/introspect")
                    .introspectionClientCredentials("client", "secret")
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class DirectlyConfiguredIntrospectionUri : WebSecurityConfigurerAdapter() {
    override fun configure(http: HttpSecurity) {
        http {
            authorizeRequests {
                authorize(anyRequest, authenticated)
            }
            oauth2ResourceServer {
                opaqueToken {
                    introspectionUri = "https://idp.example.com/introspect"
                    introspectionClientCredentials("client", "secret")
                }
            }
        }
    }
}
Xml
<bean id="opaqueTokenIntrospector"
        class="org.springframework.security.oauth2.server.resource.introspection.NimbusOpaqueTokenIntrospector">
    <constructor-arg value="https://idp.example.com/introspect"/>
    <constructor-arg value="client"/>
    <constructor-arg value="secret"/>
</bean>

Using introspectionUri() takes precedence over any configuration property.

Using introspector()

More powerful than introspectionUri() is introspector(), which will completely replace any Boot auto configuration of OpaqueTokenIntrospector:

Example 111. Introspector Configuration
Java
@EnableWebSecurity
public class DirectlyConfiguredIntrospector extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(oauth2 -> oauth2
                .opaqueToken(opaqueToken -> opaqueToken
                    .introspector(myCustomIntrospector())
                )
            );
    }
}
Kotlin
@EnableWebSecurity
class DirectlyConfiguredIntrospector : WebSecurityConfigurerAdapter() {
    override fun configure(http: HttpSecurity) {
        http {
            authorizeRequests {
                authorize(anyRequest, authenticated)
            }
            oauth2ResourceServer {
                opaqueToken {
                    introspector = myCustomIntrospector()
                }
            }
        }
    }
}
Xml
<http>
    <intercept-uri pattern="/**" access="authenticated"/>
    <oauth2-resource-server>
        <opaque-token introspector-ref="myCustomIntrospector"/>
    </oauth2-resource-server>
</http>

This is handy when deeper configuration, like authority mapping, JWT revocation, or request timeouts, is necessary.

Exposing a OpaqueTokenIntrospector @Bean

Or, exposing a OpaqueTokenIntrospector @Bean has the same effect as introspector():

@Bean
public OpaqueTokenIntrospector introspector() {
    return new NimbusOpaqueTokenIntrospector(introspectionUri, clientId, clientSecret);
}

12.3.15. Configuring Authorization

An OAuth 2.0 Introspection endpoint will typically return a scope attribute, indicating the scopes (or authorities) it’s been granted, for example:

{ …​, "scope" : "messages contacts"}

When this is the case, Resource Server will attempt to coerce these scopes into a list of granted authorities, prefixing each scope with the string "SCOPE_".

This means that to protect an endpoint or method with a scope derived from an Opaque Token, the corresponding expressions should include this prefix:

Example 112. Authorization Opaque Token Configuration
Java
@EnableWebSecurity
public class MappedAuthorities extends WebSecurityConfigurerAdapter {
    protected void configure(HttpSecurity http) {
        http
            .authorizeRequests(authorizeRequests -> authorizeRequests
                .mvcMatchers("/contacts/**").hasAuthority("SCOPE_contacts")
                .mvcMatchers("/messages/**").hasAuthority("SCOPE_messages")
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(OAuth2ResourceServerConfigurer::opaqueToken);
    }
}
Xml
<http>
    <intercept-uri pattern="/contacts/**" access="hasAuthority('SCOPE_contacts')"/>
    <intercept-uri pattern="/messages/**" access="hasAuthority('SCOPE_messages')"/>
    <oauth2-resource-server>
        <opaque-token introspector-ref="opaqueTokenIntrospector"/>
    </oauth2-resource-server>
</http>

Or similarly with method security:

@PreAuthorize("hasAuthority('SCOPE_messages')")
public List<Message> getMessages(...) {}
Extracting Authorities Manually

By default, Opaque Token support will extract the scope claim from an introspection response and parse it into individual GrantedAuthority instances.

For example, if the introspection response were:

{
    "active" : true,
    "scope" : "message:read message:write"
}

Then Resource Server would generate an Authentication with two authorities, one for message:read and the other for message:write.

This can, of course, be customized using a custom OpaqueTokenIntrospector that takes a look at the attribute set and converts in its own way:

public class CustomAuthoritiesOpaqueTokenIntrospector implements OpaqueTokenIntrospector {
    private OpaqueTokenIntrospector delegate =
            new NimbusOpaqueTokenIntrospector("https://idp.example.org/introspect", "client", "secret");

    public OAuth2AuthenticatedPrincipal introspect(String token) {
        OAuth2AuthenticatedPrincipal principal = this.delegate.introspect(token);
        return new DefaultOAuth2AuthenticatedPrincipal(
                principal.getName(), principal.getAttributes(), extractAuthorities(principal));
    }

    private Collection<GrantedAuthority> extractAuthorities(OAuth2AuthenticatedPrincipal principal) {
        List<String> scopes = principal.getAttribute(OAuth2IntrospectionClaimNames.SCOPE);
        return scopes.stream()
                .map(SimpleGrantedAuthority::new)
                .collect(Collectors.toList());
    }
}

Thereafter, this custom introspector can be configured simply by exposing it as a @Bean:

@Bean
public OpaqueTokenIntrospector introspector() {
    return new CustomAuthoritiesOpaqueTokenIntrospector();
}

12.3.16. Configuring Timeouts

By default, Resource Server uses connection and socket timeouts of 30 seconds each for coordinating with the authorization server.

This may be too short in some scenarios. Further, it doesn’t take into account more sophisticated patterns like back-off and discovery.

To adjust the way in which Resource Server connects to the authorization server, NimbusOpaqueTokenIntrospector accepts an instance of RestOperations:

@Bean
public OpaqueTokenIntrospector introspector(RestTemplateBuilder builder) {
    RestOperations rest = builder
            .basicAuthentication(clientId, clientSecret)
            .setConnectionTimeout(60000)
            .setReadTimeout(60000)
            .build();

    return new NimbusOpaqueTokenIntrospector(introspectionUri, rest);
}

12.3.17. Using Introspection with JWTs

A common question is whether or not introspection is compatible with JWTs. Spring Security’s Opaque Token support has been designed to not care about the format of the token — it will gladly pass any token to the introspection endpoint provided.

So, let’s say that you’ve got a requirement that requires you to check with the authorization server on each request, in case the JWT has been revoked.

Even though you are using the JWT format for the token, your validation method is introspection, meaning you’d want to do:

spring:
  security:
    oauth2:
      resourceserver:
        opaque-token:
          introspection-uri: https://idp.example.org/introspection
          client-id: client
          client-secret: secret

In this case, the resulting Authentication would be BearerTokenAuthentication. Any attributes in the corresponding OAuth2AuthenticatedPrincipal would be whatever was returned by the introspection endpoint.

But, let’s say that, oddly enough, the introspection endpoint only returns whether or not the token is active. Now what?

In this case, you can create a custom OpaqueTokenIntrospector that still hits the endpoint, but then updates the returned principal to have the JWTs claims as the attributes:

public class JwtOpaqueTokenIntrospector implements OpaqueTokenIntrospector {
    private OpaqueTokenIntrospector delegate =
            new NimbusOpaqueTokenIntrospector("https://idp.example.org/introspect", "client", "secret");
    private JwtDecoder jwtDecoder = new NimbusJwtDecoder(new ParseOnlyJWTProcessor());

    public OAuth2AuthenticatedPrincipal introspect(String token) {
        OAuth2AuthenticatedPrincipal principal = this.delegate.introspect(token);
        try {
            Jwt jwt = this.jwtDecoder.decode(token);
            return new DefaultOAuth2AuthenticatedPrincipal(jwt.getClaims(), NO_AUTHORITIES);
        } catch (JwtException e) {
            throw new OAuth2IntrospectionException(e);
        }
    }

    private static class ParseOnlyJWTProcessor extends DefaultJWTProcessor<SecurityContext> {
        JWTClaimsSet process(SignedJWT jwt, SecurityContext context)
                throws JOSEException {
            return jwt.getJWTClaimSet();
        }
    }
}

Thereafter, this custom introspector can be configured simply by exposing it as a @Bean:

@Bean
public OpaqueTokenIntrospector introspector() {
    return new JwtOpaqueTokenIntropsector();
}

12.3.18. Calling a /userinfo Endpoint

Generally speaking, a Resource Server doesn’t care about the underlying user, but instead about the authorities that have been granted.

That said, at times it can be valuable to tie the authorization statement back to a user.

If an application is also using spring-security-oauth2-client, having set up the appropriate ClientRegistrationRepository, then this is quite simple with a custom OpaqueTokenIntrospector. This implementation below does three things:

  • Delegates to the introspection endpoint, to affirm the token’s validity

  • Looks up the appropriate client registration associated with the /userinfo endpoint

  • Invokes and returns the response from the /userinfo endpoint

public class UserInfoOpaqueTokenIntrospector implements OpaqueTokenIntrospector {
    private final OpaqueTokenIntrospector delegate =
            new NimbusOpaqueTokenIntrospector("https://idp.example.org/introspect", "client", "secret");
    private final OAuth2UserService oauth2UserService = new DefaultOAuth2UserService();

    private final ClientRegistrationRepository repository;

    // ... constructor

    @Override
    public OAuth2AuthenticatedPrincipal introspect(String token) {
        OAuth2AuthenticatedPrincipal authorized = this.delegate.introspect(token);
        Instant issuedAt = authorized.getAttribute(ISSUED_AT);
        Instant expiresAt = authorized.getAttribute(EXPIRES_AT);
        ClientRegistration clientRegistration = this.repository.findByRegistrationId("registration-id");
        OAuth2AccessToken token = new OAuth2AccessToken(BEARER, token, issuedAt, expiresAt);
        OAuth2UserRequest oauth2UserRequest = new OAuth2UserRequest(clientRegistration, token);
        return this.oauth2UserService.loadUser(oauth2UserRequest);
    }
}

If you aren’t using spring-security-oauth2-client, it’s still quite simple. You will simply need to invoke the /userinfo with your own instance of WebClient:

public class UserInfoOpaqueTokenIntrospector implements OpaqueTokenIntrospector {
    private final OpaqueTokenIntrospector delegate =
            new NimbusOpaqueTokenIntrospector("https://idp.example.org/introspect", "client", "secret");
    private final WebClient rest = WebClient.create();

    @Override
    public OAuth2AuthenticatedPrincipal introspect(String token) {
        OAuth2AuthenticatedPrincipal authorized = this.delegate.introspect(token);
        return makeUserInfoRequest(authorized);
    }
}

Either way, having created your OpaqueTokenIntrospector, you should publish it as a @Bean to override the defaults:

@Bean
OpaqueTokenIntrospector introspector() {
    return new UserInfoOpaqueTokenIntrospector(...);
}

12.3.19. Supporting both JWT and Opaque Token

In some cases, you may have a need to access both kinds of tokens. For example, you may support more than one tenant where one tenant issues JWTs and the other issues opaque tokens.

If this decision must be made at request-time, then you can use an AuthenticationManagerResolver to achieve it, like so:

@Bean
AuthenticationManagerResolver<HttpServletRequest> tokenAuthenticationManagerResolver() {
    BearerTokenResolver bearerToken = new DefaultBearerTokenResolver();
    JwtAuthenticationProvider jwt = jwt();
    OpaqueTokenAuthenticationProvider opaqueToken = opaqueToken();

    return request -> {
        if (useJwt(request)) {
            return jwt::authenticate;
        } else {
            return opaqueToken::authenticate;
        }
    }
}
The implementation of useJwt(HttpServletRequest) will likely depend on custom request material like the path.

And then specify this AuthenticationManagerResolver in the DSL:

Example 113. Authentication Manager Resolver
Java
http
    .authorizeRequests(authorize -> authorize
        .anyRequest().authenticated()
    )
    .oauth2ResourceServer(oauth2 -> oauth2
        .authenticationManagerResolver(this.tokenAuthenticationManagerResolver)
    );
Xml
<http>
    <oauth2-resource-server authentication-manager-resolver-ref="tokenAuthenticationManagerResolver"/>
</http>

12.3.20. Multi-tenancy

A resource server is considered multi-tenant when there are multiple strategies for verifying a bearer token, keyed by some tenant identifier.

For example, your resource server may accept bearer tokens from two different authorization servers. Or, your authorization server may represent a multiplicity of issuers.

In each case, there are two things that need to be done and trade-offs associated with how you choose to do them:

  1. Resolve the tenant

  2. Propagate the tenant

Resolving the Tenant By Claim

One way to differentiate tenants is by the issuer claim. Since the issuer claim accompanies signed JWTs, this can be done with the JwtIssuerAuthenticationManagerResolver, like so:

Example 114. Multitenancy Tenant by JWT Claim
Java
JwtIssuerAuthenticationManagerResolver authenticationManagerResolver = new JwtIssuerAuthenticationManagerResolver
    ("https://idp.example.org/issuerOne", "https://idp.example.org/issuerTwo");

http
    .authorizeRequests(authorize -> authorize
        .anyRequest().authenticated()
    )
    .oauth2ResourceServer(oauth2 -> oauth2
        .authenticationManagerResolver(authenticationManagerResolver)
    );
Xml
<http>
    <oauth2-resource-server authentication-manager-resolver-ref="authenticationManagerResolver"/>
</http>

<bean id="authenticationManagerResolver"
        class="org.springframework.security.oauth2.server.resource.authentication.JwtIssuerAuthenticationManagerResolver">
    <constructor-arg>
        <list>
            <value>https://idp.example.org/issuerOne</value>
            <value>https://idp.example.org/issuerTwo</value>
        </list>
    </constructor-arg>
</bean>

This is nice because the issuer endpoints are loaded lazily. In fact, the corresponding JwtAuthenticationProvider is instantiated only when the first request with the corresponding issuer is sent. This allows for an application startup that is independent from those authorization servers being up and available.

Dynamic Tenants

Of course, you may not want to restart the application each time a new tenant is added. In this case, you can configure the JwtIssuerAuthenticationManagerResolver with a repository of AuthenticationManager instances, which you can edit at runtime, like so:

private void addManager(Map<String, AuthenticationManager> authenticationManagers, String issuer) {
    JwtAuthenticationProvider authenticationProvider = new JwtAuthenticationProvider
            (JwtDecoders.fromIssuerLocation(issuer));
    authenticationManagers.put(issuer, authenticationProvider::authenticate);
}

// ...

JwtIssuerAuthenticationManagerResolver authenticationManagerResolver =
        new JwtIssuerAuthenticationManagerResolver(authenticationManagers::get);

http
    .authorizeRequests(authorize -> authorize
        .anyRequest().authenticated()
    )
    .oauth2ResourceServer(oauth2 -> oauth2
        .authenticationManagerResolver(authenticationManagerResolver)
    );

In this case, you construct JwtIssuerAuthenticationManagerResolver with a strategy for obtaining the AuthenticationManager given the issuer. This approach allows us to add and remove elements from the repository (shown as a Map in the snippet) at runtime.

It would be unsafe to simply take any issuer and construct an AuthenticationManager from it. The issuer should be one that the code can verify from a trusted source like a whitelist.
Parsing the Claim Only Once

You may have observed that this strategy, while simple, comes with the trade-off that the JWT is parsed once by the AuthenticationManagerResolver and then again by the JwtDecoder later on in the request.

This extra parsing can be alleviated by configuring the JwtDecoder directly with a JWTClaimSetAwareJWSKeySelector from Nimbus:

@Component
public class TenantJWSKeySelector
    implements JWTClaimSetAwareJWSKeySelector<SecurityContext> {

    private final TenantRepository tenants; (1)
    private final Map<String, JWSKeySelector<SecurityContext>> selectors = new ConcurrentHashMap<>(); (2)

    public TenantJWSKeySelector(TenantRepository tenants) {
        this.tenants = tenants;
    }

    @Override
    public List<? extends Key> selectKeys(JWSHeader jwsHeader, JWTClaimsSet jwtClaimsSet, SecurityContext securityContext)
            throws KeySourceException {
        return this.selectors.computeIfAbsent(toTenant(jwtClaimsSet), this::fromTenant)
                .selectJWSKeys(jwsHeader, securityContext);
    }

    private String toTenant(JWTClaimsSet claimSet) {
        return (String) claimSet.getClaim("iss");
    }

    private JWSKeySelector<SecurityContext> fromTenant(String tenant) {
        return Optional.ofNullable(this.tenantRepository.findById(tenant)) (3)
                .map(t -> t.getAttrbute("jwks_uri"))
                .map(this::fromUri)
                .orElseThrow(() -> new IllegalArgumentException("unknown tenant"));
    }

    private JWSKeySelector<SecurityContext> fromUri(String uri) {
        try {
            return JWSAlgorithmFamilyJWSKeySelector.fromJWKSetURL(new URL(uri)); (4)
        } catch (Exception e) {
            throw new IllegalArgumentException(e);
        }
    }
}
1 A hypothetical source for tenant information
2 A cache for `JWKKeySelector`s, keyed by tenant identifier
3 Looking up the tenant is more secure than simply calculating the JWK Set endpoint on the fly - the lookup acts as a tenant whitelist
4 Create a JWSKeySelector via the types of keys that come back from the JWK Set endpoint - the lazy lookup here means that you don’t need to configure all tenants at startup

The above key selector is a composition of many key selectors. It chooses which key selector to use based on the iss claim in the JWT.

To use this approach, make sure that the authorization server is configured to include the claim set as part of the token’s signature. Without this, you have no guarantee that the issuer hasn’t been altered by a bad actor.

Next, we can construct a JWTProcessor:

@Bean
JWTProcessor jwtProcessor(JWTClaimSetJWSKeySelector keySelector) {
    ConfigurableJWTProcessor<SecurityContext> jwtProcessor =
            new DefaultJWTProcessor();
    jwtProcessor.setJWTClaimSetJWSKeySelector(keySelector);
    return jwtProcessor;
}

As you are already seeing, the trade-off for moving tenant-awareness down to this level is more configuration. We have just a bit more.

Next, we still want to make sure you are validating the issuer. But, since the issuer may be different per JWT, then you’ll need a tenant-aware validator, too:

@Component
public class TenantJwtIssuerValidator implements OAuth2TokenValidator<Jwt> {
    private final TenantRepository tenants;
    private final Map<String, JwtIssuerValidator> validators = new ConcurrentHashMap<>();

    public TenantJwtIssuerValidator(TenantRepository tenants) {
        this.tenants = tenants;
    }

    @Override
    public OAuth2TokenValidatorResult validate(Jwt token) {
        return this.validators.computeIfAbsent(toTenant(token), this::fromTenant)
                .validate(token);
    }

    private String toTenant(Jwt jwt) {
        return jwt.getIssuer();
    }

    private JwtIssuerValidator fromTenant(String tenant) {
        return Optional.ofNullable(this.tenants.findById(tenant))
                .map(t -> t.getAttribute("issuer"))
                .map(JwtIssuerValidator::new)
                .orElseThrow(() -> new IllegalArgumentException("unknown tenant"));
    }
}

Now that we have a tenant-aware processor and a tenant-aware validator, we can proceed with creating our JwtDecoder:

@Bean
JwtDecoder jwtDecoder(JWTProcessor jwtProcessor, OAuth2TokenValidator<Jwt> jwtValidator) {
    NimbusJwtDecoder decoder = new NimbusJwtDecoder(processor);
    OAuth2TokenValidator<Jwt> validator = new DelegatingOAuth2TokenValidator<>
            (JwtValidators.createDefault(), this.jwtValidator);
    decoder.setJwtValidator(validator);
    return decoder;
}

We’ve finished talking about resolving the tenant.

If you’ve chosen to resolve the tenant by something other than a JWT claim, then you’ll need to make sure you address your downstream resource servers in the same way. For example, if you are resolving it by subdomain, you may need to address the downstream resource server using the same subdomain.

However, if you resolve it by a claim in the bearer token, read on to learn about Spring Security’s support for bearer token propagation.

12.3.21. Bearer Token Resolution

By default, Resource Server looks for a bearer token in the Authorization header. This, however, can be customized in a couple of ways.

Reading the Bearer Token from a Custom Header

For example, you may have a need to read the bearer token from a custom header. To achieve this, you can wire a HeaderBearerTokenResolver instance into the DSL, as you can see in the following example:

Example 115. Custom Bearer Token Header
Java
http
    .oauth2ResourceServer(oauth2 -> oauth2
        .bearerTokenResolver(new HeaderBearerTokenResolver("x-goog-iap-jwt-assertion"))
    );
Xml
<http>
    <oauth2-resource-server bearer-token-resolver-ref="bearerTokenResolver"/>
</http>

<bean id="bearerTokenResolver"
        class="org.springframework.security.oauth2.server.resource.web.HeaderBearerTokenResolver">
    <constructor-arg value="x-goog-iap-jwt-assertion"/>
</bean>
Reading the Bearer Token from a Form Parameter

Or, you may wish to read the token from a form parameter, which you can do by configuring the DefaultBearerTokenResolver, as you can see below:

Example 116. Form Parameter Bearer Token
Java
DefaultBearerTokenResolver resolver = new DefaultBearerTokenResolver();
resolver.setAllowFormEncodedBodyParameter(true);
http
    .oauth2ResourceServer(oauth2 -> oauth2
        .bearerTokenResolver(resolver)
    );
Xml
<http>
    <oauth2-resource-server bearer-token-resolver-ref="bearerTokenResolver"/>
</http>

<bean id="bearerTokenResolver"
        class="org.springframework.security.oauth2.server.resource.web.HeaderBearerTokenResolver">
    <property name="allowFormEncodedBodyParameter" value="true"/>
</bean>

12.3.22. Bearer Token Propagation

Now that you’re resource server has validated the token, it might be handy to pass it to downstream services. This is quite simple with ServletBearerExchangeFilterFunction, which you can see in the following example:

@Bean
public WebClient rest() {
    return WebClient.builder()
            .filter(new ServletBearerExchangeFilterFunction())
            .build();
}

When the above WebClient is used to perform requests, Spring Security will look up the current Authentication and extract any AbstractOAuth2Token credential. Then, it will propagate that token in the Authorization header.

For example:

this.rest.get()
        .uri("https://other-service.example.com/endpoint")
        .retrieve()
        .bodyToMono(String.class)
        .block()

Will invoke the https://other-service.example.com/endpoint, adding the bearer token Authorization header for you.

In places where you need to override this behavior, it’s a simple matter of supplying the header yourself, like so:

this.rest.get()
        .uri("https://other-service.example.com/endpoint")
        .headers(headers -> headers.setBearerAuth(overridingToken))
        .retrieve()
        .bodyToMono(String.class)
        .block()

In this case, the filter will fall back and simply forward the request onto the rest of the web filter chain.

Unlike the OAuth 2.0 Client filter function, this filter function makes no attempt to renew the token, should it be expired. To obtain this level of support, please use the OAuth 2.0 Client filter.
RestTemplate support

There is no RestTemplate equivalent for ServletBearerExchangeFilterFunction at the moment, but you can propagate the request’s bearer token quite simply with your own interceptor:

@Bean
RestTemplate rest() {
    RestTemplate rest = new RestTemplate();
    rest.getInterceptors().add((request, body, execution) -> {
        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        if (authentication == null) {
            return execution.execute(request, body);
        }

        if (!(authentication.getCredentials() instanceof AbstractOAuth2Token)) {
            return execution.execute(request, body);
        }

        AbstractOAuth2Token token = (AbstractOAuth2Token) authentication.getCredentials();
        request.getHeaders().setBearerAuth(token.getTokenValue());
        return execution.execute(request, body);
    });
    return rest;
}
Unlike the OAuth 2.0 Authorized Client Manager, this filter interceptor makes no attempt to renew the token, should it be expired. To obtain this level of support, please create an interceptor using the OAuth 2.0 Authorized Client Manager.

12.3.23. Bearer Token Failure

A bearer token may be invalid for a number of reasons. For example, the token may no longer be active.

In these circumstances, Resource Server throws an InvalidBearerTokenException. Like other exceptions, this results in an OAuth 2.0 Bearer Token error response:

HTTP/1.1 401 Unauthorized
WWW-Authenticate: Bearer error_code="invalid_token", error_description="Unsupported algorithm of none", error_uri="https://tools.ietf.org/html/rfc6750#section-3.1"

Additionally, it is published as an AuthenticationFailureBadCredentialsEvent, which you can listen for in your application like so:

@Component
public class FailureEvents {
    @EventListener
    public void onFailure(AuthenticationFailureEvent failure) {
        if (badCredentials.getAuthentication() instanceof BearerTokenAuthenticationToken) {
            // ... handle
        }
    }
}

13. SAML2

13.1. SAML 2.0 Login

The SAML 2.0 Login, saml2Login(), feature provides an application with the capability to have users log in to the application by using their existing account at an SAML 2.0 Identity Provider (Okta, ADFS, etc).

SAML 2.0 Login is implemented by using the Web Browser SSO Profile, as specified in SAML 2 Profiles. Our implementation is currently limited to a simple authentication scheme.

13.1.1. SAML 2 Support in Spring Security

SAML 2 Service Provider, SP a.k.a. a relying party, support existed as an independent project since 2009. The 1.0.x branch is still in use, including in the Cloud Foundry User Account and Authentication Server that also created a SAML 2.0 Identity Provider implementation based on the SP implementation.

In 2018 we experimented with creating an updated implementation of both a Service Provider and Identity Provider as a standalone library. After careful, and lengthy, deliberation we, the Spring Security team, decided to discontinue that effort. While this effort created a replacement for that standalone 1.0.x library we didn’t feel that we should build a library on top of another library.

Instead we opted to provide framework support for SAML 2 authentication as part of core Spring Security instead.

13.1.2. Saml 2 Login - High Level Concepts

saml2Login() is aimed to support a fraction of the SAML 2 feature set with a focus on authentication being a Service Provider, SP, a relying party, receiving XML assertions from an Identity Provider, aka an asserting party.

A SAML 2 login, or authentication, is the concept that the SP receives and validates an XML message called an assertion from an IDP.

There are currently two supported authentication flows

  1. IDP Initiated flow - example: You login in directly to Okta, and then select a web application to be authenticated for. Okta, the IDP, sends an assertion to the web application, the SP.

  2. SP Initiated flow - example: You access a web application, a SP, the application sends an authentication request to the IDP requesting an assertion. Upon successful authentication on the IDP, the IDP sends an assertion to the SP.

13.1.3. Saml 2 Login - Current Feature Set

  1. Service Provider (SP/Relying Party) is identified by entityId = {baseUrl}/saml2/service-provider-metadata/{registrationId}

  2. Receive assertion embedded in a SAML response via Http-POST or Http-Redirect at {baseUrl}/login/saml2/sso/{registrationId}

  3. Requires the assertion to be signed, unless the response is signed

  4. Supports encrypted assertions

  5. Supports encrypted NameId elements

  6. Allows for extraction of assertion attributes into authorities using a Converter<Assertion, Collection<? extends GrantedAuthority>>

  7. Allows mapping and white listing of authorities using a GrantedAuthoritiesMapper

  8. Public keys in java.security.cert.X509Certificate format.

  9. SP Initiated Authentication via an AuthNRequest

Saml 2 Login - Not Yet Supported
  1. Mappings assertion conditions and attributes to session features (timeout, tracking, etc)

  2. Single logout

  3. Dynamic metadata generation

  4. Receiving and validating standalone assertion (not wrapped in a response object)

13.1.4. Saml 2 Login - Introduction to Java Configuration

To add saml2Login() to a Spring Security filter chain, the minimal Java configuration requires a configuration repository, the RelyingPartyRegistrationRepository, that contains the SAML configuration and the invocation of the HttpSecurity.saml2Login() method:

@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Bean
    public RelyingPartyRegistrationRepository relyingPartyRegistrationRepository() {
        //SAML configuration
        //Mapping this application to one or more Identity Providers
        return new InMemoryRelyingPartyRegistrationRepository(...);
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .saml2Login(withDefaults())
        ;
    }
}

The bean declaration is a convenient, but optional, approach. You can directly wire up the repository using a method call

@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .saml2Login(saml2 -> saml2
                .relyingPartyRegistrationRepository(...)
            )
        ;
    }
}
RelyingPartyRegistration

The RelyingPartyRegistration object represents the mapping between this application, the SP, and the asserting party, the IDP.

URI Patterns

URI patterns are frequenty used to automatically generate URIs based on an incoming request. The URI patterns in saml2Login can contain the following variables

  • baseUrl

  • registrationId

  • baseScheme

  • baseHost

  • basePort

For example: {baseUrl}/login/saml2/sso/{registrationId}

Relying Party
  • registrationId - (required) a unique identifer for this configuration mapping. This identifier may be used in URI paths, so care should be taken that no URI encoding is required.

  • localEntityIdTemplate - (optional) A URI pattern that creates an entity ID for this application based on the incoming request. The default is {baseUrl}/saml2/service-provider-metadata/{registrationId} and for a small sample application it would look like

http://localhost:8080/saml2/service-provider-metadata/my-test-configuration

There is no requirement that this configuration option is a pattern, it can be a fixed URI value.

  • assertionConsumerServiceUrlTemplate - (optional) A URI pattern that denotes the assertion consumer service URI to be sent with any AuthNRequest from the SP to the IDP during the SP initiated flow. While this can be a pattern the actual URI must resolve to the ACS endpoint on the SP. The default value is {baseUrl}/login/saml2/sso/{registrationId} and maps directly to the Saml2WebSsoAuthenticationFilter endpoint

  • credentials - A list of credentials, private keys and x509 certificates, used for message signing, verification, encryption and decryption. This list can contain redundant credentials to allow for easy rotation of credentials. For example

    • [0] - X509Certificate{VERIFICATION,ENCRYPTION} - The IDP’s first public key used for verification and encryption.

    • [1] - X509Certificate/{VERIFICATION,ENCRYPTION} - The IDP’s second verification key used for verification. Encryption is always done using the first ENCRYPTION key in the list.

    • [2] - PrivateKey/X509Certificate{SIGNING,DECRYPTION} - The SP’s first signing and decryption credential.

    • [3] - PrivateKey/X509Certificate{SIGNING,DECRYPTION} - The SP’s second decryption credential. Signing is always done using the first SIGNING key in the list.

  • ProviderDetails#entityId - (required) the entity ID of the Identity Provider. Always a fixed URI value or string, no patterns allowed.

  • ProviderDetails#webSsoUrl - (required) a fixed URI value for the IDP Single Sign On endpoint where the SP sends the AuthNRequest messages.

  • ProviderDetails#signAuthNRequest - A boolean indicating whether or not to sign the AuthNRequest with the SP’s private key, defaults to true

  • ProviderDetails#binding - A Saml2MessageBinding indicating what kind of binding to use for the AuthNRequest, whether that be REDIRECT or POST, defaults to REDIRECT

When an incoming message is received, signatures are always required, the system will first attempt to validate the signature using the certificate at index [0] and only move to the second credential if the first one fails.

In a similar fashion, the SP configured private keys are used for decryption and attempted in the same order. The first SP credential (type=SIGNING) will be used when messages to the IDP are signed.

Duplicated Relying Party Configurations

In the use case where an application uses multiple identity providers it becomes obvious that some configuration is duplicated between two RelyingPartyRegistration objects

  • localEntityIdTemplate

  • credentials (all SP credentials, IDP credentials change)

  • assertionConsumerServiceUrlTemplate

While there is some drawback in duplicating configuration values the back end configuration repository does not need to replicate this data storage model.

There is a benefit that comes with this setup. Credentials may be more easily rotated for some identity providers vs others. This object model can ensure that there is no disruption when configuration is changed in a multi IDP use case and you’re not able to rotate credentials on all the identity providers.

Service Provider Metadata

The Spring Security SAML 2 implementation does not yet provide an endpoint for downloading SP metadata in XML format. The minimal pieces that are exchanged

  • entity ID - defaults to {baseUrl}/saml2/service-provider-metadata/{registrationId} Other known configuration names that also use this same value

    • Audience Restriction

  • single signon URL - defaults to {baseUrl}/login/saml2/sso/{registrationId} Other known configuration names that also use this same value

    • Recipient URL

    • Destination URL

    • Assertion Consumer Service URL

  • X509Certificate - the certificate that you configure as part of your {SIGNING,DECRYPTION} credentials must be shared with the Identity Provider

Authentication Requests - SP Initiated Flow

To initiate an authentication from the web application, you can redirect to:

{baseUrl}/saml2/authenticate/{registrationId}

This endpoint will generate an AuthNRequest either as a Redirect or POST depending on your RelyingPartyRegistration.

Customizing the AuthNRequest

To adjust the AuthNRequest, you can publish an instance of Saml2AuthenticationRequestFactory.

For example, if you wanted to configure the AuthNRequest to request the IDP to send the SAML Assertion by REDIRECT, you could do:

@Bean
public Saml2AuthenticationRequestFactory authenticationRequestFactory() {
    OpenSamlAuthenticationRequestFactory authenticationRequestFactory =
        new OpenSamlAuthenticationRequestFactory();
    authenticationRequestFactory.setProtocolBinding("urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect");
    return authenticationRequestFactory;
}
Delegating to an AuthenticationRequestFactory

Or, in circumstances where you need more control over what is sent as parameters to the AuthenticationRequestFactory, you can use delegation:

@Component
public class IssuerSaml2AuthenticationRequestFactory implements Saml2AuthenticationRequestFactory {
    private OpenSamlAuthenticationRequestFactory delegate = new OpenSamlAuthenticationRequestFactory();

    @Override
    public String createAuthenticationRequest(Saml2AuthenticationRequest request) {
        return this.delegate.createAuthenticationRequest(request);
    }

    @Override
    public Saml2PostAuthenticationRequest createPostAuthenticationRequest
        (Saml2AuthenticationRequestContext context) {

        String issuer = // ... calculate issuer

        Saml2AuthenticationRequestContext customIssuer = Saml2AuthenticationRequestContext.builder()
                .assertionConsumerServiceUrl(context.getAssertionConsumerServiceUrl())
                .issuer(issuer)
                .relayState(context.getRelayState())
                .relyingPartyRegistration(context.getRelyingPartyRegistration())
                .build();

        return this.delegate.createPostAuthenticationRequest(customIssuer);
    }

    @Override
    public Saml2RedirectAuthenticationRequest createRedirectAuthenticationRequest
        (Saml2AuthenticationRequestContext context) {

        throw new UnsupportedOperationException("unsupported");
    }
}

13.1.5. Customizing Authentication Logic

By default Spring Security configures the OpenSamlAuthenticationProvider to validate and parse the SAML 2 response and assertions that are received. This provider has three configuration options

  1. An authorities extractor - extract group information from the assertion

  2. An authorities mapper - map extracted group information to internal authorities

  3. Response time validation duration - the built in tolerances for timestamp validation should be used when there may be a time synchronization issue.

One customization strategy is to use an ObjectPostProcessor, which allows you to modify the objects created by the implementation. Another option is to override the authentication manager for the filter that intercepts the SAMLResponse.

OpenSamlAuthenticationProvider ObjectPostProcessor
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        ObjectPostProcessor<OpenSamlAuthenticationProvider> processor = new ObjectPostProcessor<>() {
            @Override
            public <O extends OpenSamlAuthenticationProvider> O postProcess(O provider) {
                provider.setResponseTimeValidationSkew(RESPONSE_TIME_VALIDATION_SKEW);
                provider.setAuthoritiesMapper(AUTHORITIES_MAPPER);
                provider.setAuthoritiesExtractor(AUTHORITIES_EXTRACTOR);
                return provider;
            }
        };

        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .saml2Login(saml2 -> saml2
               .addObjectPostProcessor(processor)
            )
        ;
    }
}
Configure OpenSamlAuthenticationProvider as an Authentication Manager

We can leverage the same method, authenticationManager, to override and customize the default OpenSamlAuthenticationProvider.

@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        OpenSamlAuthenticationProvider authProvider = new OpenSamlAuthenticationProvider();
        authProvider.setResponseTimeValidationSkew(RESPONSE_TIME_VALIDATION_SKEW);
        authProvider.setAuthoritiesMapper(AUTHORITIES_MAPPER);
        authProvider.setAuthoritiesExtractor(AUTHORITIES_EXTRACTOR);
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .saml2Login(saml2 -> saml2
                .authenticationManager(new ProviderManager(asList(authProvider)))
            )
        ;
    }
}
Custom Authentication Manager

The authentication manager for the security filter can also be overwritten, using your own custom AuthenticationManager implementation. This authentication manager should expect a Saml2AuthenticationToken object containing the SAML 2 Response XML data.

@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        AuthenticationManager authenticationManager = new MySaml2AuthenticationManager(...);
        http
            .authorizeRequests(authorize -> authorize
                .anyRequest().authenticated()
            )
            .saml2Login(saml2 -> saml2
                .authenticationManager(authenticationManager)
            )
        ;
    }
}

13.1.6. Spring Boot 2.x Sample

We are currently working with the Spring Boot team on the Auto Configuration for Spring Security SAML Login. In the meantime, we have provided a Spring Boot sample that supports a Yaml configuration.

To run the sample, follow these three steps

  1. Launch the Spring Boot application

    • ./gradlew :spring-security-samples-boot-saml2login:bootRun

  2. Open a browser

  3. This will take you to an identity provider, log in using:

    • User: user

    • Password: password

Multiple Identity Provider Sample

It’s very simple to use multiple providers, but there are some defaults that may trip you up if you don’t pay attention. In our SAML configuration of RelyingPartyRegistration objects, we default an SP entity ID to {baseUrl}/saml2/service-provider-metadata/{registrationId}

That means in our two provider configuration, our system would look like

registration-1 (Identity Provider 1) - Our local SP Entity ID is:
http://localhost:8080/saml2/service-provider-metadata/registration-1

registration-2 (Identity Provider 2) - Our local SP Entity ID is:
http://localhost:8080/saml2/service-provider-metadata/registration-2

In this configuration, illustrated in the sample below, to the outside world, we have actually created two virtual Service Provider identities hosted within the same application.

spring:
  security:
    saml2:
      login:
        relying-parties:
          - entity-id: &idp-entity-id https://simplesaml-for-spring-saml.cfapps.io/saml2/idp/metadata.php
            registration-id: simplesamlphp
            web-sso-url: &idp-sso-url https://simplesaml-for-spring-saml.cfapps.io/saml2/idp/SSOService.php
            signing-credentials: &service-provider-credentials
              - private-key: |
                  -----BEGIN PRIVATE KEY-----
                  MIICeAIBADANBgkqhkiG9w0BAQEFAASCAmIwggJeAgEAAoGBANG7v8QjQGU3MwQE
                  ...................SHORTENED FOR READ ABILITY...................
                  INrtuLp4YHbgk1mi
                  -----END PRIVATE KEY-----
                certificate: |
                  -----BEGIN CERTIFICATE-----
                  MIICgTCCAeoCCQCuVzyqFgMSyDANBgkqhkiG9w0BAQsFADCBhDELMAkGA1UEBhMC
                  ...................SHORTENED FOR READ ABILITY...................
                  RZ/nbTJ7VTeZOSyRoVn5XHhpuJ0B
                  -----END CERTIFICATE-----
            verification-credentials: &idp-certificates
              - |
                -----BEGIN CERTIFICATE-----
                MIIEEzCCAvugAwIBAgIJAIc1qzLrv+5nMA0GCSqGSIb3DQEBCwUAMIGfMQswCQYD
                ...................SHORTENED FOR READ ABILITY...................
                lx13Y1YlQ4/tlpgTgfIJxKV6nyPiLoK0nywbMd+vpAirDt2Oc+hk
                -----END CERTIFICATE-----
          - entity-id: *idp-entity-id
            registration-id: simplesamlphp2
            web-sso-url: *idp-sso-url
            signing-credentials: *service-provider-credentials
            verification-credentials: *idp-certificates

If this is not desirable, you can manually override the local SP entity ID by using the

localEntityIdTemplate = {baseUrl}/saml2/service-provider-metadata

If we change our local SP entity ID to this value, it is still important that we give out the correct single sign on URL (the assertion consumer service URL) for each registered identity provider based on the registration Id. {baseUrl}/login/saml2/sso/{registrationId}

14. Protection Against Exploits

14.1. Cross Site Request Forgery (CSRF) for Servlet Environments

This section discusses Spring Security’s Cross Site Request Forgery (CSRF) support for servlet environments.

14.1.1. Using Spring Security CSRF Protection

The steps to using Spring Security’s CSRF protection are outlined below:

Use proper HTTP verbs

The first step to protecting against CSRF attacks is to ensure your website uses proper HTTP verbs. This is covered in detail in Safe Methods Must be Idempotent.

Configure CSRF Protection

The next step is to configure Spring Security’s CSRF protection within your application. Spring Security’s CSRF protection is enabled by default, but you may need to customize the configuration. Below are a few common customizations.

Custom CsrfTokenRepository

By default Spring Security stores the expected CSRF token in the HttpSession using HttpSessionCsrfTokenRepository. There can be cases where users will want to configure a custom CsrfTokenRepository. For example, it might be desirable to persist the CsrfToken in a cookie to support a JavaScript based application.

By default the CookieCsrfTokenRepository will write to a cookie named XSRF-TOKEN and read it from a header named X-XSRF-TOKEN or the HTTP parameter _csrf. These defaults come from AngularJS

You can configure CookieCsrfTokenRepository in XML using the following:

Example 117. Store CSRF Token in a Cookie with XML Configuration
<http>
    <!-- ... -->
    <csrf token-repository-ref="tokenRepository"/>
</http>
<b:bean id="tokenRepository"
    class="org.springframework.security.web.csrf.CookieCsrfTokenRepository"
    p:cookieHttpOnly="false"/>

The sample explicitly sets cookieHttpOnly=false. This is necessary to allow JavaScript (i.e. AngularJS) to read it. If you do not need the ability to read the cookie with JavaScript directly, it is recommended to omit cookieHttpOnly=false to improve security.

You can configure CookieCsrfTokenRepository in Java Configuration using:

Example 118. Store CSRF Token in a Cookie with Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
        WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            .csrf(csrf -> csrf
                .csrfTokenRepository(CookieCsrfTokenRepository.withHttpOnlyFalse())
            );
    }
}

The sample explicitly sets cookieHttpOnly=false. This is necessary to allow JavaScript (i.e. AngularJS) to read it. If you do not need the ability to read the cookie with JavaScript directly, it is recommended to omit cookieHttpOnly=false (by using new CookieCsrfTokenRepository() instead) to improve security.

Disable CSRF Protection

CSRF protection is enabled by default. However, it is simple to disable CSRF protection if it makes sense for your application.

The XML configuration below will disable CSRF protection.

Example 119. Disable CSRF XML Configuration
<http>
    <!-- ... -->
    <csrf disabled="true"/>
</http>

The Java configuration below will disable CSRF protection.

Example 120. Disable CSRF Java Configuration
@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
        WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            .csrf(csrf -> csrf.disable());
    }
}
Include the CSRF Token

In order for the synchronizer token pattern to protect against CSRF attacks, we must include the actual CSRF token in the HTTP request. This must be included in a part of the request (i.e. form parameter, HTTP header, etc) that is not automatically included in the HTTP request by the browser.

Spring Security’s CsrfFilter exposes a CsrfToken as an HttpServletRequest attribute named _csrf. This means that any view technology can access the CsrfToken to expose the expected token as either a form or meta tag. Fortunately, there are integrations listed below that make including the token in form and ajax requests even easier.

Form URL Encoded

In order to post an HTML form the CSRF token must be included in the form as a hidden input. For example, the rendered HTML might look like:

Example 121. CSRF Token HTML
<input type="hidden"
    name="_csrf"
    value="4bfd1575-3ad1-4d21-96c7-4ef2d9f86721"/>

Next we will discuss various ways of including the CSRF token in a form as a hidden input.

Automatic CSRF Token Inclusion

Spring Security’s CSRF support provides integration with Spring’s RequestDataValueProcessor via its CsrfRequestDataValueProcessor. This means that if you leverage Spring’s form tag library, Thymeleaf, or any other view technology that integrates with RequestDataValueProcessor, then forms that have an unsafe HTTP method (i.e. post) will automatically include the actual CSRF token.

csrfInput Tag

If you are using JSPs, then you can use Spring’s form tag library. However, if that is not an option, you can also easily include the token with the csrfInput tag.

CsrfToken Request Attribute

If the other options for including the actual CSRF token in the request do not work, you can take advantage of the fact that the CsrfToken is exposed as an HttpServletRequest attribute named _csrf.

An example of doing this with a JSP is shown below:

Example 122. CSRF Token in Form with Request Attribute
<c:url var="logoutUrl" value="/logout"/>
<form action="${logoutUrl}"
    method="post">
<input type="submit"
    value="Log out" />
<input type="hidden"
    name="${_csrf.parameterName}"
    value="${_csrf.token}"/>
</form>
Ajax and JSON Requests

If you are using JSON, then it is not possible to submit the CSRF token within an HTTP parameter. Instead you can submit the token within a HTTP header.

In the following sections we will discuss various ways of including the CSRF token as an HTTP request header in JavaScript based applications.

Automatic Inclusion

Spring Security can easily be configured to store the expected CSRF token in a cookie. By storing the expected CSRF in a cookie, JavaScript frameworks like AngularJS will automatically include the actual CSRF token in the HTTP request headers.

Meta tags

An alternative pattern to exposing the CSRF in a cookie is to include the CSRF token within your meta tags. The HTML might look something like this:

Example 123. CSRF meta tag HTML
<html>
<head>
    <meta name="_csrf" content="4bfd1575-3ad1-4d21-96c7-4ef2d9f86721"/>
    <meta name="_csrf_header" content="X-CSRF-TOKEN"/>
    <!-- ... -->
</head>
<!-- ... -->

Once the meta tags contained the CSRF token, the JavaScript code would read the meta tags and include the CSRF token as a header. If you were using jQuery, this could be done with the following:

Example 124. AJAX send CSRF Token
$(function () {
    var token = $("meta[name='_csrf']").attr("content");
    var header = $("meta[name='_csrf_header']").attr("content");
    $(document).ajaxSend(function(e, xhr, options) {
        xhr.setRequestHeader(header, token);
    });
});
csrfMeta tag

If you are using JSPs a simple way to write the CSRF token to the meta tags is by leveraging the csrfMeta tag.

CsrfToken Request Attribute

If the other options for including the actual CSRF token in the request do not work, you can take advantage of the fact that the CsrfToken is exposed as an HttpServletRequest attribute named _csrf. An example of doing this with a JSP is shown below:

Example 125. CSRF meta tag JSP
<html>
<head>
    <meta name="_csrf" content="${_csrf.token}"/>
    <!-- default header name is X-CSRF-TOKEN -->
    <meta name="_csrf_header" content="${_csrf.headerName}"/>
    <!-- ... -->
</head>
<!-- ... -->

14.1.2. CSRF Considerations

There are a few special considerations to consider when implementing protection against CSRF attacks. This section discusses those considerations as it pertains to servlet environments. Refer to CSRF Considerations for a more general discussion.

Logging In

It is important to require CSRF for log in requests to protect against forging log in attempts. Spring Security’s servlet support does this out of the box.

Logging Out

It is important to require CSRF for log out requests to protect against forging log out attempts. If CSRF protection is enabled (default), Spring Security’s LogoutFilter to only process HTTP POST. This ensures that log out requires a CSRF token and that a malicious user cannot forcibly log out your users.

The easiest approach is to use a form to log out. If you really want a link, you can use JavaScript to have the link perform a POST (i.e. maybe on a hidden form). For browsers with JavaScript that is disabled, you can optionally have the link take the user to a log out confirmation page that will perform the POST.

If you really want to use HTTP GET with logout you can do so, but remember this is generally not recommended. For example, the following Java Configuration will perform logout with the URL /logout is requested with any HTTP method:

Example 126. Log out with HTTP GET
@EnableWebSecurity
public class WebSecurityConfig extends
        WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            .logout(logout -> logout
                .logoutRequestMatcher(new AntPathRequestMatcher("/logout"))
            );
    }
}
CSRF and Session Timeouts

By default Spring Security stores the CSRF token in the HttpSession. This can lead to a situation where the session expires which means there is not an expected CSRF token to validate against.

We’ve already discussed general solutions to session timeouts. This section discusses the specifics of CSRF timeouts as it pertains to the servlet support.

It is simple to change storage of the expected CSRF token to be in a cookie. For details, refer to the Custom CsrfTokenRepository section.

If a token does expire, you might want to customize how it is handled by specifying a custom AccessDeniedHandler. The custom AccessDeniedHandler can process the InvalidCsrfTokenException any way you like. For an example of how to customize the AccessDeniedHandler refer to the provided links for both xml and Java configuration.

Multipart (file upload)

We have already discussed how protecting multipart requests (file uploads) from CSRF attacks causes a chicken and the egg problem. This section discusses how to implement placing the CSRF token in the body and url within a servlet application.

More information about using multipart forms with Spring can be found within the 1.1.11. Multipart Resolver section of the Spring reference and the MultipartFilter javadoc.

Place CSRF Token in the Body

We have already discussed the tradeoffs of placing the CSRF token in the body. In this section we will discuss how to configure Spring Security to read the CSRF from the body.

In order to read the CSRF token from the body, the MultipartFilter is specified before the Spring Security filter. Specifying the MultipartFilter before the Spring Security filter means that there is no authorization for invoking the MultipartFilter which means anyone can place temporary files on your server. However, only authorized users will be able to submit a File that is processed by your application. In general, this is the recommended approach because the temporary file upload should have a negligible impact on most servers.

To ensure MultipartFilter is specified before the Spring Security filter with java configuration, users can override beforeSpringSecurityFilterChain as shown below:

Example 127. Initializer MultipartFilter
public class SecurityApplicationInitializer extends AbstractSecurityWebApplicationInitializer {

    @Override
    protected void beforeSpringSecurityFilterChain(ServletContext servletContext) {
        insertFilters(servletContext, new MultipartFilter());
    }
}

To ensure MultipartFilter is specified before the Spring Security filter with XML configuration, users can ensure the <filter-mapping> element of the MultipartFilter is placed before the springSecurityFilterChain within the web.xml as shown below:

Example 128. web.xml - MultipartFilter
<filter>
    <filter-name>MultipartFilter</filter-name>
    <filter-class>org.springframework.web.multipart.support.MultipartFilter</filter-class>
</filter>
<filter>
    <filter-name>springSecurityFilterChain</filter-name>
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
    <filter-name>MultipartFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
    <filter-name>springSecurityFilterChain</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
Include CSRF Token in URL

If allowing unauthorized users to upload temporary files is not acceptable, an alternative is to place the MultipartFilter after the Spring Security filter and include the CSRF as a query parameter in the action attribute of the form. Since the CsrfToken is exposed as an HttpServletRequest request attribute, we can use that to create an action with the CSRF token in it. An example with a jsp is shown below

Example 129. CSRF Token in Action
<form method="post"
    action="./upload?${_csrf.parameterName}=${_csrf.token}"
    enctype="multipart/form-data">
HiddenHttpMethodFilter

We have already discussed the trade-offs of placing the CSRF token in the body.

In Spring’s Servlet support, overriding the HTTP method is done using HiddenHttpMethodFilter. More information can be found in HTTP Method Conversion section of the reference documentation.

14.2. Security HTTP Response Headers

Security HTTP Response Headers can be used to increase the security of web applications. This section is dedicated to servlet based support for Security HTTP Response Headers.

14.2.1. Default Security Headers

Spring Security provides a default set of Security HTTP Response Headers to provide secure defaults. While each of these headers are considered best practice, it should be noted that not all clients utilize the headers, so additional testing is encouraged.

You can customize specific headers. For example, assume that you want the defaults except you wish to specify SAMEORIGIN for X-Frame-Options.

You can easily do this with the following Java Configuration:

Example 130. Customize Default Security Headers with Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
        WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            // ...
            .headers(headers -> headers
                .frameOptions(frameOptions -> frameOptions
                    .sameOrigin()
                )
            );
    }
}

Alternatively, if you are using Spring Security XML Configuration, you can use the following:

Example 131. Customize Default Security Headers with XML Configuration
<http>
    <!-- ... -->

    <headers>
        <frame-options policy="SAMEORIGIN" />
    </headers>
</http>

If you do not want the defaults to be added and want explicit control over what should be used, you can disable the defaults. An example for both Java and XML based configuration is provided below:

If you are using Spring Security’s Java Configuration the following will only add Cache Control.

@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                // do not use any default headers unless explicitly listed
                .defaultsDisabled()
                .cacheControl(withDefaults())
            );
    }
}

The following XML will only add Cache Control.

<http>
    <!-- ... -->

    <headers defaults-disabled="true">
        <cache-control/>
    </headers>
</http>

If necessary, you can disable all of the HTTP Security response headers with the following Java Configuration:

@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers.disable());
    }
}

If necessary, you can disable all of the HTTP Security response headers with the following XML configuration below:

<http>
    <!-- ... -->

    <headers disabled="true" />
</http>

14.2.2. Cache Control

Spring Security includes Cache Control headers by default.

However, if you actually want to cache specific responses, your application can selectively invoke HttpServletResponse.setHeader(String,String) to override the header set by Spring Security. This is useful to ensure things like CSS, JavaScript, and images are properly cached.

When using Spring Web MVC, this is typically done within your configuration. Details on how to do this can be found in the Static Resources portion of the Spring Reference documentation

If necessary, you can also disable Spring Security’s cache control HTTP response headers.

Example 132. Cache Control Disabled with Java Configuration
@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            // ...
            .headers(headers -> headers
                .cacheControl(cache -> cache.disable())
            );
    }
}

Similarly, you can use the <cache-control> element to disable it:

Example 133. Cache Control Disabled with XML
<http>
    <!-- ... -->

    <headers>
        <cache-control disabled="true"/>
    </headers>
</http>

14.2.3. Content Type Options

Spring Security includes Content-Type headers by default. However, you can disable it in Java Configuration with:

Example 134. Content Type Options Disabled with Java Configuration
@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
        WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            // ...
            .headers(headers -> headers
                .contentTypeOptions(contentTypeOptions -> contentTypeOptions.disable())
            );
    }
}

Similarly, you can use the <content-type-options> element to disable it:

Example 135. Content Type Options Disabled with XML
<http>
    <!-- ... -->

    <headers>
        <content-type-options disabled="true"/>
    </headers>
</http>

14.2.4. HTTP Strict Transport Security (HSTS)

Spring Security provides the Strict Transport Security header by default. However, you can customize the results explicitly. For example, the following is an example of explicitly providing HSTS with Java Configuration:

Example 136. Strict Transport Security with Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .httpStrictTransportSecurity(hsts -> hsts
                    .includeSubDomains(true)
                    .preload(true)
                    .maxAgeInSeconds(31536000)
                )
            );
    }
}

Similarly, you can explicitly provide HSTS with XML configuration using the <hsts> element as shown below:

Example 137. Strict Transport Security with XML Configuration
<http>
    <!-- ... -->

    <headers>
        <hsts
            include-subdomains="true"
            max-age-seconds="31536000"
            preload="true" />
    </headers>
</http>

14.2.5. HTTP Public Key Pinning (HPKP)

For passivity reasons, Spring Security provides servlet support for HTTP Public Key Pinning but it is no longer recommended.

You can enable HPKP headers with Java Configuration:

Example 138. HTTP Public Key Pinning with Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .httpPublicKeyPinning(hpkp -> hpkp
                    .includeSubDomains(true)
                    .reportUri("https://example.net/pkp-report")
                    .addSha256Pins("d6qzRu9zOECb90Uez27xWltNsj0e1Md7GkYYkVoZWmM=", "E9CZ9INDbd+2eRQozYqqbQ2yXLVKB9+xcprMF+44U1g=")
                )
            );
    }
}

Similarly you can enable HPKP headers using the <hpkp> element as shown below:

Example 139. HTTP Public Key Pinning with XML Configuration
<http>
    <!-- ... -->

    <headers>
        <hpkp
            include-subdomains="true"
            report-uri="https://example.net/pkp-report">
            <pins>
                <pin algorithm="sha256">d6qzRu9zOECb90Uez27xWltNsj0e1Md7GkYYkVoZWmM=</pin>
                <pin algorithm="sha256">E9CZ9INDbd+2eRQozYqqbQ2yXLVKB9+xcprMF+44U1g=</pin>
            </pins>
        </hpkp>
    </headers>
</http>

14.2.6. X-Frame-Options

By default, Spring Security disables rendering within an iframe using X-Frame-Options.

You can customize frame options to use the same origin within Java Configuration using the following:

Example 140. X-Frame-Options: SAMEORIGIN with Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .frameOptions(frameOptions -> frameOptions
                    .sameOrigin()
                )
            );
    }
}

Alternatively, you can use frame-options element within XML configuration:

Example 141. X-Frame-Options: SAMEORIGIN with XML Configuration
<http>
    <!-- ... -->

    <headers>
        <frame-options
        policy="SAMEORIGIN" />
    </headers>
</http>

14.2.7. X-XSS-Protection

By default, Spring Security instructs browsers to block reflected XSS attacks using the <<headers-xss-protection,X-XSS-Protection header>. However, you can change this default. For example, the following Java Configuration specifies that Spring Security should no longer instruct browsers to block the content:

Example 142. X-XSS-Protection Customization with Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .xssProtection(xss -> xss
                    .block(false)
                )
            );
    }
}

Similarly, the following XML configuration specifies that Spring Security should no longer instruct browsers to block the content:

Example 143. X-XSS-Protection Customization with XML Configuration
<http>
    <!-- ... -->

    <headers>
        <xss-protection block="false"/>
    </headers>
</http>

14.2.8. Content Security Policy (CSP)

Spring Security does not add Content Security Policy by default, because a reasonable default is impossible to know without context of the application. The web application author must declare the security policy(s) to enforce and/or monitor for the protected resources.

For example, given the following security policy:

Example 144. Content Security Policy Example
Content-Security-Policy: script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/

You can enable the CSP header using Java configuration as shown below:

Example 145. Content Security Policy Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            // ...
            .headers(headers -> headers
                .contentSecurityPolicy(csp -> csp
                    .policyDirectives("script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/")
                )
            );
    }
}

The same can be done using XML configuration with the <content-security-policy> element as shown below:

Example 146. Content Security Policy Java Configuration
<http>
    <!-- ... -->

    <headers>
        <content-security-policy
            policy-directives="script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/" />
    </headers>
</http>

To enable the CSP report-only header, provide the following Java configuration:

Example 147. Content Security Policy Report Only Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
        WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .contentSecurityPolicy(csp -> csp
                    .policyDirectives("script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/")
                    .reportOnly()
                )
            );
    }
}

The same can be achieved with XML configuration using:

Example 148. Content Security Policy XML Configuration
<http>
    <!-- ... -->

    <headers>
        <content-security-policy
            policy-directives="script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/"
            report-only="true" />
    </headers>
</http>

14.2.9. Referrer Policy

Spring Security does not add Referrer Policy headers by default. You can enable the Referrer Policy header using Java configuration as shown below:

Example 149. Referrer Policy Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            // ...
            .headers(headers -> headers
                .referrerPolicy(referrer -> referrer
                    .policy(ReferrerPolicy.SAME_ORIGIN)
                )
            );
    }
}

You can enable the Referrer-Policy header using XML configuration with the <referrer-policy> element as shown below:

Example 150. Referrer Policy XML Configuration
<http>
    <!-- ... -->

    <headers>
        <referrer-policy policy="same-origin" />
    </headers>
</http>

14.2.10. Feature Policy

Spring Security does not add Feature Policy headers by default. The following Feature-Policy header:

Example 151. Feature-Policy Example
Feature-Policy: geolocation 'self'

can enable the Feature Policy header using Java configuration as shown below:

Example 152. Feature-Policy Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .featurePolicy("geolocation 'self'")
            );
    }
}

Alternatively, you can enable the Feature-Policy header using XML configuration with the <feature-policy> element as shown below:

Example 153. Feature-Policy XML Configuration
<http>
    <!-- ... -->

    <headers>
        <feature-policy policy-directives="geolocation 'self'" />
    </headers>
</http>

14.2.11. Clear Site Data

Spring Security does not add Clear-Site-Data headers by default. The following Clear-Site-Data header:

Example 154. Clear-Site-Data Example
Clear-Site-Data: "cache", "cookies"

can be sent on log out with the following configuration:

Example 155. Clear-Site-Data Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .logout()
                .addLogoutHandler(new HeaderWriterLogoutHandler(new ClearSiteDataHeaderWriter(CACHE, COOKIES)));
    }
}

14.2.12. Custom Headers

Spring Security has mechanisms to make it convenient to add the more common security headers to your application. However, it also provides hooks to enable adding custom headers.

Static Headers

There may be times you wish to inject custom security headers into your application that are not supported out of the box. For example, given the following custom security header:

X-Custom-Security-Header: header-value

The headers could be added to the response using Java Configuration as shown in the following:

Example 156. StaticHeadersWriter Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .addHeaderWriter(new StaticHeadersWriter("X-Custom-Security-Header","header-value"))
            );
    }
}

When using the XML namespace, these headers can be added to the response using the <header> element as shown below:

Example 157. StaticHeadersWriter XML Configuration
<http>
    <!-- ... -->

    <headers>
        <header name="X-Custom-Security-Header" value="header-value"/>
    </headers>
</http>
Headers Writer

When the namespace or Java configuration does not support the headers you want, you can create a custom HeadersWriter instance or even provide a custom implementation of the HeadersWriter.

Let’s take a look at an example of using an custom instance of XFrameOptionsHeaderWriter. If you wanted to explicitly configure X-Frame-Options it could be done with the following Java Configuration:

Example 158. Headers Writer Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .addHeaderWriter(new XFrameOptionsHeaderWriter(XFrameOptionsMode.SAMEORIGIN))
            );
    }
}

Alternatively, we could use the ref attribute for XML based configuration:

Example 159. Headers Writer XML Configuration
<http>
    <!-- ... -->

    <headers>
        <header ref="frameOptionsWriter"/>
    </headers>
</http>
<!-- Requires the c-namespace.
See https://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#beans-c-namespace
-->
<beans:bean id="frameOptionsWriter"
    class="org.springframework.security.web.header.writers.frameoptions.XFrameOptionsHeaderWriter"
    c:frameOptionsMode="SAMEORIGIN"/>
DelegatingRequestMatcherHeaderWriter

At times you may want to only write a header for certain requests. For example, perhaps you want to only protect your log in page from being framed. You could use the DelegatingRequestMatcherHeaderWriter to do so.

An example of using DelegatingRequestMatcherHeaderWriter in Java Configuration can be seen below:

Example 160. DelegatingRequestMatcherHeaderWriter Java Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        RequestMatcher matcher = new AntPathRequestMatcher("/login");
        DelegatingRequestMatcherHeaderWriter headerWriter =
            new DelegatingRequestMatcherHeaderWriter(matcher,new XFrameOptionsHeaderWriter());
        http
            // ...
            .headers(headers -> headers
                .frameOptions(frameOptions -> frameOptions.disable())
                .addHeaderWriter(headerWriter)
            );
    }
}

The same can be achieved with XML based configuration:

Example 161. DelegatingRequestMatcherHeaderWriter XML Configuration
<http>
    <!-- ... -->

    <headers>
        <frame-options disabled="true"/>
        <header ref="headerWriter"/>
    </headers>
</http>

<beans:bean id="headerWriter"
    class="org.springframework.security.web.header.writers.DelegatingRequestMatcherHeaderWriter">
    <beans:constructor-arg>
        <bean class="org.springframework.security.web.util.matcher.AntPathRequestMatcher"
            c:pattern="/login"/>
    </beans:constructor-arg>
    <beans:constructor-arg>
        <beans:bean
            class="org.springframework.security.web.header.writers.frameoptions.XFrameOptionsHeaderWriter"/>
    </beans:constructor-arg>
</beans:bean>

14.3. HTTP

All HTTP based communication should be protected using TLS.

Below you can find details around Servlet specific features that assist with HTTPS usage.

14.3.1. Redirect to HTTPS

If a client makes a request using HTTP rather than HTTPS, Spring Security can be configured to redirect to HTTPS.

For example, the following Java configuration will redirect any HTTP requests to HTTPS:

Example 162. Redirect to HTTPS with Java Configuration
@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends
        WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) {
        http
            // ...
            .requiresChannel(channel -> channel
                .anyRequest().requiresSecure()
            );
    }
}

The following XML configuration will redirect all HTTP requests to HTTPS

Example 163. Redirect to HTTPS with XML Configuration
<http>
    <intercept-url pattern="/**" access="ROLE_USER" requires-channel="https"/>
...
</http>

14.3.2. Strict Transport Security

Spring Security provides support for Strict Transport Security and enables it by default.

14.3.3. Proxy Server Configuration

14.4. HttpFirewall

Spring Security has several areas where patterns you have defined are tested against incoming requests in order to decide how the request should be handled. This occurs when the FilterChainProxy decides which filter chain a request should be passed through and also when the FilterSecurityInterceptor decides which security constraints apply to a request. It’s important to understand what the mechanism is and what URL value is used when testing against the patterns that you define.

The Servlet Specification defines several properties for the HttpServletRequest which are accessible via getter methods, and which we might want to match against. These are the contextPath, servletPath, pathInfo and queryString. Spring Security is only interested in securing paths within the application, so the contextPath is ignored. Unfortunately, the servlet spec does not define exactly what the values of servletPath and pathInfo will contain for a particular request URI. For example, each path segment of a URL may contain parameters, as defined in RFC 2396 [5]. The Specification does not clearly state whether these should be included in the servletPath and pathInfo values and the behaviour varies between different servlet containers. There is a danger that when an application is deployed in a container which does not strip path parameters from these values, an attacker could add them to the requested URL in order to cause a pattern match to succeed or fail unexpectedly. [6]. Other variations in the incoming URL are also possible. For example, it could contain path-traversal sequences (like /../) or multiple forward slashes (//) which could also cause pattern-matches to fail. Some containers normalize these out before performing the servlet mapping, but others don’t. To protect against issues like these, FilterChainProxy uses an HttpFirewall strategy to check and wrap the request. Un-normalized requests are automatically rejected by default, and path parameters and duplicate slashes are removed for matching purposes. [7]. It is therefore essential that a FilterChainProxy is used to manage the security filter chain. Note that the servletPath and pathInfo values are decoded by the container, so your application should not have any valid paths which contain semi-colons, as these parts will be removed for matching purposes.

As mentioned above, the default strategy is to use Ant-style paths for matching and this is likely to be the best choice for most users. The strategy is implemented in the class AntPathRequestMatcher which uses Spring’s AntPathMatcher to perform a case-insensitive match of the pattern against the concatenated servletPath and pathInfo, ignoring the queryString.

If for some reason, you need a more powerful matching strategy, you can use regular expressions. The strategy implementation is then RegexRequestMatcher. See the Javadoc for this class for more information.

In practice we recommend that you use method security at your service layer, to control access to your application, and do not rely entirely on the use of security constraints defined at the web-application level. URLs change and it is difficult to take account of all the possible URLs that an application might support and how requests might be manipulated. You should try and restrict yourself to using a few simple ant paths which are simple to understand. Always try to use a "deny-by-default" approach where you have a catch-all wildcard ( / or ) defined last and denying access.

Security defined at the service layer is much more robust and harder to bypass, so you should always take advantage of Spring Security’s method security options.

The HttpFirewall also prevents HTTP Response Splitting by rejecting new line characters in the HTTP Response headers.

By default the StrictHttpFirewall is used. This implementation rejects requests that appear to be malicious. If it is too strict for your needs, then you can customize what types of requests are rejected. However, it is important that you do so knowing that this can open your application up to attacks. For example, if you wish to leverage Spring MVC’s Matrix Variables, the following configuration could be used:

Example 164. Allow Matrix Variables
Java
@Bean
public StrictHttpFirewall httpFirewall() {
    StrictHttpFirewall firewall = new StrictHttpFirewall();
    firewall.setAllowSemicolon(true);
    return firewall;
}
XML
<b:bean id="httpFirewall"
    class="org.springframework.security.web.firewall.StrictHttpFirewall"
    p:allowSemicolon="true"/>

<http-firewall ref="httpFirewall"/>
Kotlin
@Bean
fun httpFirewall(): StrictHttpFirewall {
    val firewall = StrictHttpFirewall()
    firewall.setAllowSemicolon(true)
    return firewall
}

The StrictHttpFirewall provides an allowed list of valid HTTP methods that are allowed to protect against Cross Site Tracing (XST) and HTTP Verb Tampering. The default valid methods are "DELETE", "GET", "HEAD", "OPTIONS", "PATCH", "POST", and "PUT". If your application needs to modify the valid methods, you can configure a custom StrictHttpFirewall bean. For example, the following will only allow HTTP "GET" and "POST" methods:

Example 165. Allow Only GET & POST
Java
@Bean
public StrictHttpFirewall httpFirewall() {
    StrictHttpFirewall firewall = new StrictHttpFirewall();
    firewall.setAllowedHttpMethods(Arrays.asList("GET", "POST"));
    return firewall;
}
XML
<b:bean id="httpFirewall"
      class="org.springframework.security.web.firewall.StrictHttpFirewall"
      p:allowedHttpMethods="GET,HEAD"/>

<http-firewall ref="httpFirewall"/>
Kotlin
@Bean
fun httpFirewall(): StrictHttpFirewall {
    val firewall = StrictHttpFirewall()
    firewall.setAllowedHttpMethods(listOf("GET", "POST"))
    return firewall
}

If you are using new MockHttpServletRequest() it currently creates an HTTP method as an empty String "". This is an invalid HTTP method and will be rejected by Spring Security. You can resolve this by replacing it with new MockHttpServletRequest("GET", ""). See SPR_16851 for an issue requesting to improve this.

If you must allow any HTTP method (not recommended), you can use StrictHttpFirewall.setUnsafeAllowAnyHttpMethod(true). This will disable validation of the HTTP method entirely.

15. Integrations

15.1. Servlet API integration

This section describes how Spring Security is integrated with the Servlet API. The servletapi-xml sample application demonstrates the usage of each of these methods.

15.1.1. Servlet 2.5+ Integration

HttpServletRequest.getRemoteUser()

The HttpServletRequest.getRemoteUser() will return the result of SecurityContextHolder.getContext().getAuthentication().getName() which is typically the current username. This can be useful if you want to display the current username in your application. Additionally, checking if this is null can be used to indicate if a user has authenticated or is anonymous. Knowing if the user is authenticated or not can be useful for determining if certain UI elements should be shown or not (i.e. a log out link should only be displayed if the user is authenticated).

HttpServletRequest.getUserPrincipal()

The HttpServletRequest.getUserPrincipal() will return the result of SecurityContextHolder.getContext().getAuthentication(). This means it is an Authentication which is typically an instance of UsernamePasswordAuthenticationToken when using username and password based authentication. This can be useful if you need additional information about your user. For example, you might have created a custom UserDetailsService that returns a custom UserDetails containing a first and last name for your user. You could obtain this information with the following:

Authentication auth = httpServletRequest.getUserPrincipal();
// assume integrated custom UserDetails called MyCustomUserDetails
// by default, typically instance of UserDetails
MyCustomUserDetails userDetails = (MyCustomUserDetails) auth.getPrincipal();
String firstName = userDetails.getFirstName();
String lastName = userDetails.getLastName();

It should be noted that it is typically bad practice to perform so much logic throughout your application. Instead, one should centralize it to reduce any coupling of Spring Security and the Servlet API’s.

HttpServletRequest.isUserInRole(String)

The HttpServletRequest.isUserInRole(String) will determine if SecurityContextHolder.getContext().getAuthentication().getAuthorities() contains a GrantedAuthority with the role passed into isUserInRole(String). Typically users should not pass in the "ROLE_" prefix into this method since it is added automatically. For example, if you want to determine if the current user has the authority "ROLE_ADMIN", you could use the following:

boolean isAdmin = httpServletRequest.isUserInRole("ADMIN");

This might be useful to determine if certain UI components should be displayed. For example, you might display admin links only if the current user is an admin.

15.1.2. Servlet 3+ Integration

The following section describes the Servlet 3 methods that Spring Security integrates with.

HttpServletRequest.authenticate(HttpServletRequest,HttpServletResponse)

The HttpServletRequest.authenticate(HttpServletRequest,HttpServletResponse) method can be used to ensure that a user is authenticated. If they are not authenticated, the configured AuthenticationEntryPoint will be used to request the user to authenticate (i.e. redirect to the login page).

HttpServletRequest.login(String,String)

The HttpServletRequest.login(String,String) method can be used to authenticate the user with the current AuthenticationManager. For example, the following would attempt to authenticate with the username "user" and password "password":

try {
httpServletRequest.login("user","password");
} catch(ServletException e) {
// fail to authenticate
}

It is not necessary to catch the ServletException if you want Spring Security to process the failed authentication attempt.

HttpServletRequest.logout()

The HttpServletRequest.logout() method can be used to log the current user out.

Typically this means that the SecurityContextHolder will be cleared out, the HttpSession will be invalidated, any "Remember Me" authentication will be cleaned up, etc. However, the configured LogoutHandler implementations will vary depending on your Spring Security configuration. It is important to note that after HttpServletRequest.logout() has been invoked, you are still in charge of writing a response out. Typically this would involve a redirect to the welcome page.

AsyncContext.start(Runnable)

The AsyncContext.start(Runnable) method that ensures your credentials will be propagated to the new Thread. Using Spring Security’s concurrency support, Spring Security overrides the AsyncContext.start(Runnable) to ensure that the current SecurityContext is used when processing the Runnable. For example, the following would output the current user’s Authentication:

final AsyncContext async = httpServletRequest.startAsync();
async.start(new Runnable() {
    public void run() {
        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        try {
            final HttpServletResponse asyncResponse = (HttpServletResponse) async.getResponse();
            asyncResponse.setStatus(HttpServletResponse.SC_OK);
            asyncResponse.getWriter().write(String.valueOf(authentication));
            async.complete();
        } catch(Exception e) {
            throw new RuntimeException(e);
        }
    }
});
Async Servlet Support

If you are using Java Based configuration, you are ready to go. If you are using XML configuration, there are a few updates that are necessary. The first step is to ensure you have updated your web.xml to use at least the 3.0 schema as shown below:

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee https://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">

</web-app>

Next you need to ensure that your springSecurityFilterChain is setup for processing asynchronous requests.

<filter>
<filter-name>springSecurityFilterChain</filter-name>
<filter-class>
    org.springframework.web.filter.DelegatingFilterProxy
</filter-class>
<async-supported>true</async-supported>
</filter>
<filter-mapping>
<filter-name>springSecurityFilterChain</filter-name>
<url-pattern>/*</url-pattern>
<dispatcher>REQUEST</dispatcher>
<dispatcher>ASYNC</dispatcher>
</filter-mapping>

That’s it! Now Spring Security will ensure that your SecurityContext is propagated on asynchronous requests too.

So how does it work? If you are not really interested, feel free to skip the remainder of this section, otherwise read on. Most of this is built into the Servlet specification, but there is a little bit of tweaking that Spring Security does to ensure things work with asynchronous requests properly. Prior to Spring Security 3.2, the SecurityContext from the SecurityContextHolder was automatically saved as soon as the HttpServletResponse was committed. This can cause issues in an Async environment. For example, consider the following:

httpServletRequest.startAsync();
new Thread("AsyncThread") {
    @Override
    public void run() {
        try {
            // Do work
            TimeUnit.SECONDS.sleep(1);

            // Write to and commit the httpServletResponse
            httpServletResponse.getOutputStream().flush();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}.start();

The issue is that this Thread is not known to Spring Security, so the SecurityContext is not propagated to it. This means when we commit the HttpServletResponse there is no SecurityContext. When Spring Security automatically saved the SecurityContext on committing the HttpServletResponse it would lose our logged in user.

Since version 3.2, Spring Security is smart enough to no longer automatically save the SecurityContext on committing the HttpServletResponse as soon as HttpServletRequest.startAsync() is invoked.

15.1.3. Servlet 3.1+ Integration

The following section describes the Servlet 3.1 methods that Spring Security integrates with.

HttpServletRequest#changeSessionId()

The HttpServletRequest.changeSessionId() is the default method for protecting against Session Fixation attacks in Servlet 3.1 and higher.

15.2. Spring Data Integration

Spring Security provides Spring Data integration that allows referring to the current user within your queries. It is not only useful but necessary to include the user in the queries to support paged results since filtering the results afterwards would not scale.

15.2.1. Spring Data & Spring Security Configuration

To use this support, add org.springframework.security:spring-security-data dependency and provide a bean of type SecurityEvaluationContextExtension. In Java Configuration, this would look like:

@Bean
public SecurityEvaluationContextExtension securityEvaluationContextExtension() {
    return new SecurityEvaluationContextExtension();
}

In XML Configuration, this would look like:

<bean class="org.springframework.security.data.repository.query.SecurityEvaluationContextExtension"/>

15.2.2. Security Expressions within @Query

Now Spring Security can be used within your queries. For example:

@Repository
public interface MessageRepository extends PagingAndSortingRepository<Message,Long> {
    @Query("select m from Message m where m.to.id = ?#{ principal?.id }")
    Page<Message> findInbox(Pageable pageable);
}

This checks to see if the Authentication.getPrincipal().getId() is equal to the recipient of the Message. Note that this example assumes you have customized the principal to be an Object that has an id property. By exposing the SecurityEvaluationContextExtension bean, all of the Common Security Expressions are available within the Query.

15.3. Concurrency Support

In most environments, Security is stored on a per Thread basis. This means that when work is done on a new Thread, the SecurityContext is lost. Spring Security provides some infrastructure to help make this much easier for users. Spring Security provides low level abstractions for working with Spring Security in multi-threaded environments. In fact, this is what Spring Security builds on to integration with AsyncContext.start(Runnable) and Spring MVC Async Integration.

15.3.1. DelegatingSecurityContextRunnable

One of the most fundamental building blocks within Spring Security’s concurrency support is the DelegatingSecurityContextRunnable. It wraps a delegate Runnable in order to initialize the SecurityContextHolder with a specified SecurityContext for the delegate. It then invokes the delegate Runnable ensuring to clear the SecurityContextHolder afterwards. The DelegatingSecurityContextRunnable looks something like this:

public void run() {
try {
    SecurityContextHolder.setContext(securityContext);
    delegate.run();
} finally {
    SecurityContextHolder.clearContext();
}
}

While very simple, it makes it seamless to transfer the SecurityContext from one Thread to another. This is important since, in most cases, the SecurityContextHolder acts on a per Thread basis. For example, you might have used Spring Security’s <global-method-security> support to secure one of your services. You can now easily transfer the SecurityContext of the current Thread to the Thread that invokes the secured service. An example of how you might do this can be found below:

Runnable originalRunnable = new Runnable() {
public void run() {
    // invoke secured service
}
};

SecurityContext context = SecurityContextHolder.getContext();
DelegatingSecurityContextRunnable wrappedRunnable =
    new DelegatingSecurityContextRunnable(originalRunnable, context);

new Thread(wrappedRunnable).start();

The code above performs the following steps:

  • Creates a Runnable that will be invoking our secured service. Notice that it is not aware of Spring Security

  • Obtains the SecurityContext that we wish to use from the SecurityContextHolder and initializes the DelegatingSecurityContextRunnable

  • Use the DelegatingSecurityContextRunnable to create a Thread

  • Start the Thread we created

Since it is quite common to create a DelegatingSecurityContextRunnable with the SecurityContext from the SecurityContextHolder there is a shortcut constructor for it. The following code is the same as the code above:

Runnable originalRunnable = new Runnable() {
public void run() {
    // invoke secured service
}
};

DelegatingSecurityContextRunnable wrappedRunnable =
    new DelegatingSecurityContextRunnable(originalRunnable);

new Thread(wrappedRunnable).start();

The code we have is simple to use, but it still requires knowledge that we are using Spring Security. In the next section we will take a look at how we can utilize DelegatingSecurityContextExecutor to hide the fact that we are using Spring Security.

15.3.2. DelegatingSecurityContextExecutor

In the previous section we found that it was easy to use the DelegatingSecurityContextRunnable, but it was not ideal since we had to be aware of Spring Security in order to use it. Let’s take a look at how DelegatingSecurityContextExecutor can shield our code from any knowledge that we are using Spring Security.

The design of DelegatingSecurityContextExecutor is very similar to that of DelegatingSecurityContextRunnable except it accepts a delegate Executor instead of a delegate Runnable. You can see an example of how it might be used below:

SecurityContext context = SecurityContextHolder.createEmptyContext();
Authentication authentication =
    new UsernamePasswordAuthenticationToken("user","doesnotmatter", AuthorityUtils.createAuthorityList("ROLE_USER"));
context.setAuthentication(authentication);

SimpleAsyncTaskExecutor delegateExecutor =
    new SimpleAsyncTaskExecutor();
DelegatingSecurityContextExecutor executor =
    new DelegatingSecurityContextExecutor(delegateExecutor, context);

Runnable originalRunnable = new Runnable() {
public void run() {
    // invoke secured service
}
};

executor.execute(originalRunnable);

The code performs the following steps:

  • Creates the SecurityContext to be used for our DelegatingSecurityContextExecutor. Note that in this example we simply create the SecurityContext by hand. However, it does not matter where or how we get the SecurityContext (i.e. we could obtain it from the SecurityContextHolder if we wanted).

  • Creates a delegateExecutor that is in charge of executing submitted Runnables

  • Finally we create a DelegatingSecurityContextExecutor which is in charge of wrapping any Runnable that is passed into the execute method with a DelegatingSecurityContextRunnable. It then passes the wrapped Runnable to the delegateExecutor. In this instance, the same SecurityContext will be used for every Runnable submitted to our DelegatingSecurityContextExecutor. This is nice if we are running background tasks that need to be run by a user with elevated privileges.

  • At this point you may be asking yourself "How does this shield my code of any knowledge of Spring Security?" Instead of creating the SecurityContext and the DelegatingSecurityContextExecutor in our own code, we can inject an already initialized instance of DelegatingSecurityContextExecutor.

@Autowired
private Executor executor; // becomes an instance of our DelegatingSecurityContextExecutor

public void submitRunnable() {
Runnable originalRunnable = new Runnable() {
    public void run() {
    // invoke secured service
    }
};
executor.execute(originalRunnable);
}

Now our code is unaware that the SecurityContext is being propagated to the Thread, then the originalRunnable is executed, and then the SecurityContextHolder is cleared out. In this example, the same user is being used to execute each Thread. What if we wanted to use the user from SecurityContextHolder at the time we invoked executor.execute(Runnable) (i.e. the currently logged in user) to process originalRunnable? This can be done by removing the SecurityContext argument from our DelegatingSecurityContextExecutor constructor. For example:

SimpleAsyncTaskExecutor delegateExecutor = new SimpleAsyncTaskExecutor();
DelegatingSecurityContextExecutor executor =
    new DelegatingSecurityContextExecutor(delegateExecutor);

Now anytime executor.execute(Runnable) is executed the SecurityContext is first obtained by the SecurityContextHolder and then that SecurityContext is used to create our DelegatingSecurityContextRunnable. This means that we are executing our Runnable with the same user that was used to invoke the executor.execute(Runnable) code.

15.3.3. Spring Security Concurrency Classes

Refer to the Javadoc for additional integrations with both the Java concurrent APIs and the Spring Task abstractions. They are quite self-explanatory once you understand the previous code.

  • DelegatingSecurityContextCallable

  • DelegatingSecurityContextExecutor

  • DelegatingSecurityContextExecutorService

  • DelegatingSecurityContextRunnable

  • DelegatingSecurityContextScheduledExecutorService

  • DelegatingSecurityContextSchedulingTaskExecutor

  • DelegatingSecurityContextAsyncTaskExecutor

  • DelegatingSecurityContextTaskExecutor

  • DelegatingSecurityContextTaskScheduler

15.4. Jackson Support

Spring Security provides Jackson support for persisting Spring Security related classes. This can improve the performance of serializing Spring Security related classes when working with distributed sessions (i.e. session replication, Spring Session, etc).

To use it, register the SecurityJackson2Modules.getModules(ClassLoader) with ObjectMapper (jackson-databind):

ObjectMapper mapper = new ObjectMapper();
ClassLoader loader = getClass().getClassLoader();
List<Module> modules = SecurityJackson2Modules.getModules(loader);
mapper.registerModules(modules);

// ... use ObjectMapper as normally ...
SecurityContext context = new SecurityContextImpl();
// ...
String json = mapper.writeValueAsString(context);

The following Spring Security modules provide Jackson support:

  • spring-security-core (CoreJackson2Module)

  • spring-security-web (WebJackson2Module, WebServletJackson2Module, WebServerJackson2Module)

  • spring-security-oauth2-client (OAuth2ClientJackson2Module)

  • spring-security-cas (CasJackson2Module)

15.5. Localization

Spring Security supports localization of exception messages that end users are likely to see. If your application is designed for English-speaking users, you don’t need to do anything as by default all Security messages are in English. If you need to support other locales, everything you need to know is contained in this section.

All exception messages can be localized, including messages related to authentication failures and access being denied (authorization failures). Exceptions and logging messages that are focused on developers or system deplopers (including incorrect attributes, interface contract violations, using incorrect constructors, startup time validation, debug-level logging) are not localized and instead are hard-coded in English within Spring Security’s code.

Shipping in the spring-security-core-xx.jar you will find an org.springframework.security package that in turn contains a messages.properties file, as well as localized versions for some common languages. This should be referred to by your ApplicationContext, as Spring Security classes implement Spring’s MessageSourceAware interface and expect the message resolver to be dependency injected at application context startup time. Usually all you need to do is register a bean inside your application context to refer to the messages. An example is shown below:

<bean id="messageSource"
    class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:org/springframework/security/messages"/>
</bean>

The messages.properties is named in accordance with standard resource bundles and represents the default language supported by Spring Security messages. This default file is in English.

If you wish to customize the messages.properties file, or support other languages, you should copy the file, rename it accordingly, and register it inside the above bean definition. There are not a large number of message keys inside this file, so localization should not be considered a major initiative. If you do perform localization of this file, please consider sharing your work with the community by logging a JIRA task and attaching your appropriately-named localized version of messages.properties.

Spring Security relies on Spring’s localization support in order to actually lookup the appropriate message. In order for this to work, you have to make sure that the locale from the incoming request is stored in Spring’s org.springframework.context.i18n.LocaleContextHolder. Spring MVC’s DispatcherServlet does this for your application automatically, but since Spring Security’s filters are invoked before this, the LocaleContextHolder needs to be set up to contain the correct Locale before the filters are called. You can either do this in a filter yourself (which must come before the Spring Security filters in web.xml) or you can use Spring’s RequestContextFilter. Please refer to the Spring Framework documentation for further details on using localization with Spring.

The "contacts" sample application is set up to use localized messages.

15.6. Spring MVC Integration

Spring Security provides a number of optional integrations with Spring MVC. This section covers the integration in further detail.

15.6.1. @EnableWebMvcSecurity

As of Spring Security 4.0, @EnableWebMvcSecurity is deprecated. The replacement is @EnableWebSecurity which will determine adding the Spring MVC features based upon the classpath.

To enable Spring Security integration with Spring MVC add the @EnableWebSecurity annotation to your configuration.

Spring Security provides the configuration using Spring MVC’s WebMvcConfigurer. This means that if you are using more advanced options, like integrating with WebMvcConfigurationSupport directly, then you will need to manually provide the Spring Security configuration.

15.6.2. MvcRequestMatcher

Spring Security provides deep integration with how Spring MVC matches on URLs with MvcRequestMatcher. This is helpful to ensure your Security rules match the logic used to handle your requests.

In order to use MvcRequestMatcher you must place the Spring Security Configuration in the same ApplicationContext as your DispatcherServlet. This is necessary because Spring Security’s MvcRequestMatcher expects a HandlerMappingIntrospector bean with the name of mvcHandlerMappingIntrospector to be registered by your Spring MVC configuration that is used to perform the matching.

For a web.xml this means that you should place your configuration in the DispatcherServlet.xml.

<listener>
  <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<!-- All Spring Configuration (both MVC and Security) are in /WEB-INF/spring/ -->
<context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>/WEB-INF/spring/*.xml</param-value>
</context-param>

<servlet>
  <servlet-name>spring</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <!-- Load from the ContextLoaderListener -->
  <init-param>
    <param-name>contextConfigLocation</param-name>
    <param-value></param-value>
  </init-param>
</servlet>

<servlet-mapping>
  <servlet-name>spring</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>

Below WebSecurityConfiguration in placed in the DispatcherServlets ApplicationContext.

public class SecurityInitializer extends
    AbstractAnnotationConfigDispatcherServletInitializer {

  @Override
  protected Class<?>[] getRootConfigClasses() {
    return null;
  }

  @Override
  protected Class<?>[] getServletConfigClasses() {
    return new Class[] { RootConfiguration.class,
        WebMvcConfiguration.class };
  }

  @Override
  protected String[] getServletMappings() {
    return new String[] { "/" };
  }
}

It is always recommended to provide authorization rules by matching on the HttpServletRequest and method security.

Providing authorization rules by matching on HttpServletRequest is good because it happens very early in the code path and helps reduce the attack surface. Method security ensures that if someone has bypassed the web authorization rules, that your application is still secured. This is what is known as Defence in Depth

Consider a controller that is mapped as follows:

@RequestMapping("/admin")
public String admin() {

If we wanted to restrict access to this controller method to admin users, a developer can provide authorization rules by matching on the HttpServletRequest with the following:

protected configure(HttpSecurity http) throws Exception {
    http
        .authorizeRequests(authorize -> authorize
            .antMatchers("/admin").hasRole("ADMIN")
        );
}

or in XML

<http>
    <intercept-url pattern="/admin" access="hasRole('ADMIN')"/>
</http>

With either configuration, the URL /admin will require the authenticated user to be an admin user. However, depending on our Spring MVC configuration, the URL /admin.html will also map to our admin() method. Additionally, depending on our Spring MVC configuration, the URL /admin/ will also map to our admin() method.

The problem is that our security rule is only protecting /admin. We could add additional rules for all the permutations of Spring MVC, but this would be quite verbose and tedious.

Instead, we can leverage Spring Security’s MvcRequestMatcher. The following configuration will protect the same URLs that Spring MVC will match on by using Spring MVC to match on the URL.

protected configure(HttpSecurity http) throws Exception {
    http
        .authorizeRequests(authorize -> authorize
            .mvcMatchers("/admin").hasRole("ADMIN")
        );
}

or in XML

<http request-matcher="mvc">
    <intercept-url pattern="/admin" access="hasRole('ADMIN')"/>
</http>

15.6.3. @AuthenticationPrincipal

Spring Security provides AuthenticationPrincipalArgumentResolver which can automatically resolve the current Authentication.getPrincipal() for Spring MVC arguments. By using @EnableWebSecurity you will automatically have this added to your Spring MVC configuration. If you use XML based configuration, you must add this yourself. For example:

<mvc:annotation-driven>
        <mvc:argument-resolvers>
                <bean class="org.springframework.security.web.method.annotation.AuthenticationPrincipalArgumentResolver" />
        </mvc:argument-resolvers>
</mvc:annotation-driven>

Once AuthenticationPrincipalArgumentResolver is properly configured, you can be entirely decoupled from Spring Security in your Spring MVC layer.

Consider a situation where a custom UserDetailsService that returns an Object that implements UserDetails and your own CustomUser Object. The CustomUser of the currently authenticated user could be accessed using the following code:

@RequestMapping("/messages/inbox")
public ModelAndView findMessagesForUser() {
    Authentication authentication =
    SecurityContextHolder.getContext().getAuthentication();
    CustomUser custom = (CustomUser) authentication == null ? null : authentication.getPrincipal();

    // .. find messages for this user and return them ...
}

As of Spring Security 3.2 we can resolve the argument more directly by adding an annotation. For example:

import org.springframework.security.core.annotation.AuthenticationPrincipal;

// ...

@RequestMapping("/messages/inbox")
public ModelAndView findMessagesForUser(@AuthenticationPrincipal CustomUser customUser) {

    // .. find messages for this user and return them ...
}

Sometimes it may be necessary to transform the principal in some way. For example, if CustomUser needed to be final it could not be extended. In this situation the UserDetailsService might returns an Object that implements UserDetails and provides a method named getCustomUser to access CustomUser. For example, it might look like:

public class CustomUserUserDetails extends User {
        // ...
        public CustomUser getCustomUser() {
                return customUser;
        }
}

We could then access the CustomUser using a SpEL expression that uses Authentication.getPrincipal() as the root object:

import org.springframework.security.core.annotation.AuthenticationPrincipal;

// ...

@RequestMapping("/messages/inbox")
public ModelAndView findMessagesForUser(@AuthenticationPrincipal(expression = "customUser") CustomUser customUser) {

    // .. find messages for this user and return them ...
}

We can also refer to Beans in our SpEL expressions. For example, the following could be used if we were using JPA to manage our Users and we wanted to modify and save a property on the current user.

import org.springframework.security.core.annotation.AuthenticationPrincipal;

// ...

@PutMapping("/users/self")
public ModelAndView updateName(@AuthenticationPrincipal(expression = "@jpaEntityManager.merge(#this)") CustomUser attachedCustomUser,
        @RequestParam String firstName) {

    // change the firstName on an attached instance which will be persisted to the database
    attachedCustomUser.setFirstName(firstName);

    // ...
}

We can further remove our dependency on Spring Security by making @AuthenticationPrincipal a meta annotation on our own annotation. Below we demonstrate how we could do this on an annotation named @CurrentUser.

It is important to realize that in order to remove the dependency on Spring Security, it is the consuming application that would create @CurrentUser. This step is not strictly required, but assists in isolating your dependency to Spring Security to a more central location.
@Target({ElementType.PARAMETER, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@AuthenticationPrincipal
public @interface CurrentUser {}

Now that @CurrentUser has been specified, we can use it to signal to resolve our CustomUser of the currently authenticated user. We have also isolated our dependency on Spring Security to a single file.

@RequestMapping("/messages/inbox")
public ModelAndView findMessagesForUser(@CurrentUser CustomUser customUser) {

    // .. find messages for this user and return them ...
}

15.6.4. Spring MVC Async Integration

Spring Web MVC 3.2+ has excellent support for Asynchronous Request Processing. With no additional configuration, Spring Security will automatically setup the SecurityContext to the Thread that executes a Callable returned by your controllers. For example, the following method will automatically have its Callable executed with the SecurityContext that was available when the Callable was created:

@RequestMapping(method=RequestMethod.POST)
public Callable<String> processUpload(final MultipartFile file) {

return new Callable<String>() {
    public Object call() throws Exception {
    // ...
    return "someView";
    }
};
}
Associating SecurityContext to Callable’s

More technically speaking, Spring Security integrates with WebAsyncManager. The SecurityContext that is used to process the Callable is the SecurityContext that exists on the SecurityContextHolder at the time startCallableProcessing is invoked.

There is no automatic integration with a DeferredResult that is returned by controllers. This is because DeferredResult is processed by the users and thus there is no way of automatically integrating with it. However, you can still use Concurrency Support to provide transparent integration with Spring Security.

15.6.5. Spring MVC and CSRF Integration

Automatic Token Inclusion

Spring Security will automatically include the CSRF Token within forms that use the Spring MVC form tag. For example, the following JSP:

<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page"
    xmlns:c="http://java.sun.com/jsp/jstl/core"
    xmlns:form="http://www.springframework.org/tags/form" version="2.0">
    <jsp:directive.page language="java" contentType="text/html" />
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
    <!-- ... -->

    <c:url var="logoutUrl" value="/logout"/>
    <form:form action="${logoutUrl}"
        method="post">
    <input type="submit"
        value="Log out" />
    <input type="hidden"
        name="${_csrf.parameterName}"
        value="${_csrf.token}"/>
    </form:form>

    <!-- ... -->
</html>
</jsp:root>

Will output HTML that is similar to the following:

<!-- ... -->

<form action="/context/logout" method="post">
<input type="submit" value="Log out"/>
<input type="hidden" name="_csrf" value="f81d4fae-7dec-11d0-a765-00a0c91e6bf6"/>
</form>

<!-- ... -->
Resolving the CsrfToken

Spring Security provides CsrfTokenArgumentResolver which can automatically resolve the current CsrfToken for Spring MVC arguments. By using @EnableWebSecurity you will automatically have this added to your Spring MVC configuration. If you use XML based configuration, you must add this yourself.

Once CsrfTokenArgumentResolver is properly configured, you can expose the CsrfToken to your static HTML based application.

@RestController
public class CsrfController {

    @RequestMapping("/csrf")
    public CsrfToken csrf(CsrfToken token) {
        return token;
    }
}

It is important to keep the CsrfToken a secret from other domains. This means if you are using Cross Origin Sharing (CORS), you should NOT expose the CsrfToken to any external domains.

15.7. WebSocket Security

Spring Security 4 added support for securing Spring’s WebSocket support. This section describes how to use Spring Security’s WebSocket support.

You can find a complete working sample of WebSocket security at https://github.com/spring-projects/spring-session/tree/master/samples/boot/websocket.
Direct JSR-356 Support

Spring Security does not provide direct JSR-356 support because doing so would provide little value. This is because the format is unknown, so there is little Spring can do to secure an unknown format. Additionally, JSR-356 does not provide a way to intercept messages, so security would be rather invasive.

15.7.1. WebSocket Configuration

Spring Security 4.0 has introduced authorization support for WebSockets through the Spring Messaging abstraction. To configure authorization using Java Configuration, simply extend the AbstractSecurityWebSocketMessageBrokerConfigurer and configure the MessageSecurityMetadataSourceRegistry. For example:

@Configuration
public class WebSocketSecurityConfig
      extends AbstractSecurityWebSocketMessageBrokerConfigurer { (1) (2)

    protected void configureInbound(MessageSecurityMetadataSourceRegistry messages) {
        messages
                .simpDestMatchers("/user/**").authenticated() (3)
    }
}

This will ensure that:

1 Any inbound CONNECT message requires a valid CSRF token to enforce Same Origin Policy
2 The SecurityContextHolder is populated with the user within the simpUser header attribute for any inbound request.
3 Our messages require the proper authorization. Specifically, any inbound message that starts with "/user/" will require ROLE_USER. Additional details on authorization can be found in WebSocket Authorization

Spring Security also provides XML Namespace support for securing WebSockets. A comparable XML based configuration looks like the following:

<websocket-message-broker> (1) (2)
    (3)
    <intercept-message pattern="/user/**" access="hasRole('USER')" />
</websocket-message-broker>

This will ensure that:

1 Any inbound CONNECT message requires a valid CSRF token to enforce Same Origin Policy
2 The SecurityContextHolder is populated with the user within the simpUser header attribute for any inbound request.
3 Our messages require the proper authorization. Specifically, any inbound message that starts with "/user/" will require ROLE_USER. Additional details on authorization can be found in WebSocket Authorization

15.7.2. WebSocket Authentication

WebSockets reuse the same authentication information that is found in the HTTP request when the WebSocket connection was made. This means that the Principal on the HttpServletRequest will be handed off to WebSockets. If you are using Spring Security, the Principal on the HttpServletRequest is overridden automatically.

More concretely, to ensure a user has authenticated to your WebSocket application, all that is necessary is to ensure that you setup Spring Security to authenticate your HTTP based web application.

15.7.3. WebSocket Authorization

Spring Security 4.0 has introduced authorization support for WebSockets through the Spring Messaging abstraction. To configure authorization using Java Configuration, simply extend the AbstractSecurityWebSocketMessageBrokerConfigurer and configure the MessageSecurityMetadataSourceRegistry. For example:

@Configuration
public class WebSocketSecurityConfig extends AbstractSecurityWebSocketMessageBrokerConfigurer {

    @Override
    protected void configureInbound(MessageSecurityMetadataSourceRegistry messages) {
        messages
                .nullDestMatcher().authenticated() (1)
                .simpSubscribeDestMatchers("/user/queue/errors").permitAll() (2)
                .simpDestMatchers("/app/**").hasRole("USER") (3)
                .simpSubscribeDestMatchers("/user/**", "/topic/friends/*").hasRole("USER") (4)
                .simpTypeMatchers(MESSAGE, SUBSCRIBE).denyAll() (5)
                .anyMessage().denyAll(); (6)

    }
}

This will ensure that:

1 Any message without a destination (i.e. anything other than Message type of MESSAGE or SUBSCRIBE) will require the user to be authenticated
2 Anyone can subscribe to /user/queue/errors
3 Any message that has a destination starting with "/app/" will be require the user to have the role ROLE_USER
4 Any message that starts with "/user/" or "/topic/friends/" that is of type SUBSCRIBE will require ROLE_USER
5 Any other message of type MESSAGE or SUBSCRIBE is rejected. Due to 6 we do not need this step, but it illustrates how one can match on specific message types.
6 Any other Message is rejected. This is a good idea to ensure that you do not miss any messages.

Spring Security also provides XML Namespace support for securing WebSockets. A comparable XML based configuration looks like the following:

<websocket-message-broker>
    (1)
    <intercept-message type="CONNECT" access="permitAll" />
    <intercept-message type="UNSUBSCRIBE" access="permitAll" />
    <intercept-message type="DISCONNECT" access="permitAll" />

    <intercept-message pattern="/user/queue/errors" type="SUBSCRIBE" access="permitAll" /> (2)
    <intercept-message pattern="/app/**" access="hasRole('USER')" />      (3)

    (4)
    <intercept-message pattern="/user/**" access="hasRole('USER')" />
    <intercept-message pattern="/topic/friends/*" access="hasRole('USER')" />

    (5)
    <intercept-message type="MESSAGE" access="denyAll" />
    <intercept-message type="SUBSCRIBE" access="denyAll" />

    <intercept-message pattern="/**" access="denyAll" /> (6)
</websocket-message-broker>

This will ensure that:

1 Any message of type CONNECT, UNSUBSCRIBE, or DISCONNECT will require the user to be authenticated
2 Anyone can subscribe to /user/queue/errors
3 Any message that has a destination starting with "/app/" will be require the user to have the role ROLE_USER
4 Any message that starts with "/user/" or "/topic/friends/" that is of type SUBSCRIBE will require ROLE_USER
5 Any other message of type MESSAGE or SUBSCRIBE is rejected. Due to 6 we do not need this step, but it illustrates how one can match on specific message types.
6 Any other message with a destination is rejected. This is a good idea to ensure that you do not miss any messages.
WebSocket Authorization Notes

In order to properly secure your application it is important to understand Spring’s WebSocket support.

WebSocket Authorization on Message Types

It is important to understand the distinction between SUBSCRIBE and MESSAGE types of messages and how it works within Spring.

Consider a chat application.

  • The system can send notifications MESSAGE to all users through a destination of "/topic/system/notifications"

  • Clients can receive notifications by SUBSCRIBE to the "/topic/system/notifications".

While we want clients to be able to SUBSCRIBE to "/topic/system/notifications", we do not want to enable them to send a MESSAGE to that destination. If we allowed sending a MESSAGE to "/topic/system/notifications", then clients could send a message directly to that endpoint and impersonate the system.

In general, it is common for applications to deny any MESSAGE sent to a destination that starts with the broker prefix (i.e. "/topic/" or "/queue/").

WebSocket Authorization on Destinations

It is also is important to understand how destinations are transformed.

Consider a chat application.

  • Users can send messages to a specific user by sending a message to the destination of "/app/chat".

  • The application sees the message, ensures that the "from" attribute is specified as the current user (we cannot trust the client).

  • The application then sends the message to the recipient using SimpMessageSendingOperations.convertAndSendToUser("toUser", "/queue/messages", message).

  • The message gets turned into the destination of "/queue/user/messages-<sessionid>"

With the application above, we want to allow our client to listen to "/user/queue" which is transformed into "/queue/user/messages-<sessionid>". However, we do not want the client to be able to listen to "/queue/*" because that would allow the client to see messages for every user.

In general, it is common for applications to deny any SUBSCRIBE sent to a message that starts with the broker prefix (i.e. "/topic/" or "/queue/"). Of course we may provide exceptions to account for things like

Outbound Messages

Spring contains a section titled Flow of Messages that describes how messages flow through the system. It is important to note that Spring Security only secures the clientInboundChannel. Spring Security does not attempt to secure the clientOutboundChannel.

The most important reason for this is performance. For every message that goes in, there are typically many more that go out. Instead of securing the outbound messages, we encourage securing the subscription to the endpoints.

15.7.4. Enforcing Same Origin Policy

It is important to emphasize that the browser does not enforce the Same Origin Policy for WebSocket connections. This is an extremely important consideration.

Why Same Origin?

Consider the following scenario. A user visits bank.com and authenticates to their account. The same user opens another tab in their browser and visits evil.com. The Same Origin Policy ensures that evil.com cannot read or write data to bank.com.

With WebSockets the Same Origin Policy does not apply. In fact, unless bank.com explicitly forbids it, evil.com can read and write data on behalf of the user. This means that anything the user can do over the webSocket (i.e. transfer money), evil.com can do on that users behalf.

Since SockJS tries to emulate WebSockets it also bypasses the Same Origin Policy. This means developers need to explicitly protect their applications from external domains when using SockJS.

Spring WebSocket Allowed Origin

Fortunately, since Spring 4.1.5 Spring’s WebSocket and SockJS support restricts access to the current domain. Spring Security adds an additional layer of protection to provide defence in depth.

Adding CSRF to Stomp Headers

By default Spring Security requires the CSRF token in any CONNECT message type. This ensures that only a site that has access to the CSRF token can connect. Since only the Same Origin can access the CSRF token, external domains are not allowed to make a connection.

Typically we need to include the CSRF token in an HTTP header or an HTTP parameter. However, SockJS does not allow for these options. Instead, we must include the token in the Stomp headers

Applications can obtain a CSRF token by accessing the request attribute named _csrf. For example, the following will allow accessing the CsrfToken in a JSP:

var headerName = "${_csrf.headerName}";
var token = "${_csrf.token}";

If you are using static HTML, you can expose the CsrfToken on a REST endpoint. For example, the following would expose the CsrfToken on the URL /csrf

@RestController
public class CsrfController {

    @RequestMapping("/csrf")
    public CsrfToken csrf(CsrfToken token) {
        return token;
    }
}

The JavaScript can make a REST call to the endpoint and use the response to populate the headerName and the token.

We can now include the token in our Stomp client. For example:

...
var headers = {};
headers[headerName] = token;
stompClient.connect(headers, function(frame) {
  ...

}
Disable CSRF within WebSockets

If you want to allow other domains to access your site, you can disable Spring Security’s protection. For example, in Java Configuration you can use the following:

@Configuration
public class WebSocketSecurityConfig extends AbstractSecurityWebSocketMessageBrokerConfigurer {

    ...

    @Override
    protected boolean sameOriginDisabled() {
        return true;
    }
}

15.7.5. Working with SockJS

SockJS provides fallback transports to support older browsers. When using the fallback options we need to relax a few security constraints to allow SockJS to work with Spring Security.

SockJS & frame-options

SockJS may use an transport that leverages an iframe. By default Spring Security will deny the site from being framed to prevent Clickjacking attacks. To allow SockJS frame based transports to work, we need to configure Spring Security to allow the same origin to frame the content.

You can customize X-Frame-Options with the frame-options element. For example, the following will instruct Spring Security to use "X-Frame-Options: SAMEORIGIN" which allows iframes within the same domain:

<http>
    <!-- ... -->

    <headers>
        <frame-options
          policy="SAMEORIGIN" />
    </headers>
</http>

Similarly, you can customize frame options to use the same origin within Java Configuration using the following:

@EnableWebSecurity
public class WebSecurityConfig extends
   WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // ...
            .headers(headers -> headers
                .frameOptions(frameOptions -> frameOptions
                     .sameOrigin()
                )
        );
    }
}
SockJS & Relaxing CSRF

SockJS uses a POST on the CONNECT messages for any HTTP based transport. Typically we need to include the CSRF token in an HTTP header or an HTTP parameter. However, SockJS does not allow for these options. Instead, we must include the token in the Stomp headers as described in Adding CSRF to Stomp Headers.

It also means we need to relax our CSRF protection with the web layer. Specifically, we want to disable CSRF protection for our connect URLs. We do NOT want to disable CSRF protection for every URL. Otherwise our site will be vulnerable to CSRF attacks.

We can easily achieve this by providing a CSRF RequestMatcher. Our Java Configuration makes this extremely easy. For example, if our stomp endpoint is "/chat" we can disable CSRF protection for only URLs that start with "/chat/" using the following configuration:

@Configuration
@EnableWebSecurity
public class WebSecurityConfig
    extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .csrf(csrf -> csrf
                // ignore our stomp endpoints since they are protected using Stomp headers
                .ignoringAntMatchers("/chat/**")
            )
            .headers(headers -> headers
                // allow same origin to frame our site to support iframe SockJS
                .frameOptions(frameOptions -> frameOptions
                    .sameOrigin()
                )
            )
            .authorizeRequests(authorize -> authorize
                ...
            )
            ...

If we are using XML based configuration, we can use the [email protected]. For example:

<http ...>
    <csrf request-matcher-ref="csrfMatcher"/>

    <headers>
        <frame-options policy="SAMEORIGIN"/>
    </headers>

    ...
</http>

<b:bean id="csrfMatcher"
    class="AndRequestMatcher">
    <b:constructor-arg value="#{T(org.springframework.security.web.csrf.CsrfFilter).DEFAULT_CSRF_MATCHER}"/>
    <b:constructor-arg>
        <b:bean class="org.springframework.security.web.util.matcher.NegatedRequestMatcher">
          <b:bean class="org.springframework.security.web.util.matcher.AntPathRequestMatcher">
            <b:constructor-arg value="/chat/**"/>
          </b:bean>
        </b:bean>
    </b:constructor-arg>
</b:bean>

15.8. CORS

Spring Framework provides first class support for CORS. CORS must be processed before Spring Security because the pre-flight request will not contain any cookies (i.e. the JSESSIONID). If the request does not contain any cookies and Spring Security is first, the request will determine the user is not authenticated (since there are no cookies in the request) and reject it.

The easiest way to ensure that CORS is handled first is to use the CorsFilter. Users can integrate the CorsFilter with Spring Security by providing a CorsConfigurationSource using the following:

@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // by default uses a Bean by the name of corsConfigurationSource
            .cors(withDefaults())
            ...
    }

    @Bean
    CorsConfigurationSource corsConfigurationSource() {
        CorsConfiguration configuration = new CorsConfiguration();
        configuration.setAllowedOrigins(Arrays.asList("https://example.com"));
        configuration.setAllowedMethods(Arrays.asList("GET","POST"));
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return source;
    }
}

or in XML

<http>
    <cors configuration-source-ref="corsSource"/>
    ...
</http>
<b:bean id="corsSource" class="org.springframework.web.cors.UrlBasedCorsConfigurationSource">
    ...
</b:bean>

If you are using Spring MVC’s CORS support, you can omit specifying the CorsConfigurationSource and Spring Security will leverage the CORS configuration provided to Spring MVC.

@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // if Spring MVC is on classpath and no CorsConfigurationSource is provided,
            // Spring Security will use CORS configuration provided to Spring MVC
            .cors(withDefaults())
            ...
    }
}

or in XML

<http>
    <!-- Default to Spring MVC's CORS configuration -->
    <cors />
    ...
</http>

15.9. JSP Tag Libraries

Spring Security has its own taglib which provides basic support for accessing security information and applying security constraints in JSPs.

15.9.1. Declaring the Taglib

To use any of the tags, you must have the security taglib declared in your JSP:

<%@ taglib prefix="sec" uri="http://www.springframework.org/security/tags" %>

15.9.2. The authorize Tag

This tag is used to determine whether its contents should be evaluated or not. In Spring Security 3.0, it can be used in two ways [8]. The first approach uses a web-security expression, specified in the access attribute of the tag. The expression evaluation will be delegated to the SecurityExpressionHandler<FilterInvocation> defined in the application context (you should have web expressions enabled in your <http> namespace configuration to make sure this service is available). So, for example, you might have

<sec:authorize access="hasRole('supervisor')">

This content will only be visible to users who have the "supervisor" authority in their list of <tt>GrantedAuthority</tt>s.

</sec:authorize>

When used in conjunction with Spring Security’s PermissionEvaluator, the tag can also be used to check permissions. For example:

<sec:authorize access="hasPermission(#domain,'read') or hasPermission(#domain,'write')">

This content will only be visible to users who have read or write permission to the Object found as a request attribute named "domain".

</sec:authorize>

A common requirement is to only show a particular link, if the user is actually allowed to click it. How can we determine in advance whether something will be allowed? This tag can also operate in an alternative mode which allows you to define a particular URL as an attribute. If the user is allowed to invoke that URL, then the tag body will be evaluated, otherwise it will be skipped. So you might have something like

<sec:authorize url="/admin">

This content will only be visible to users who are authorized to send requests to the "/admin" URL.

</sec:authorize>

To use this tag there must also be an instance of WebInvocationPrivilegeEvaluator in your application context. If you are using the namespace, one will automatically be registered. This is an instance of DefaultWebInvocationPrivilegeEvaluator, which creates a dummy web request for the supplied URL and invokes the security interceptor to see whether the request would succeed or fail. This allows you to delegate to the access-control setup you defined using intercept-url declarations within the <http> namespace configuration and saves having to duplicate the information (such as the required roles) within your JSPs. This approach can also be combined with a method attribute, supplying the HTTP method, for a more specific match.

The Boolean result of evaluating the tag (whether it grants or denies access) can be stored in a page context scope variable by setting the var attribute to the variable name, avoiding the need for duplicating and re-evaluating the condition at other points in the page.

Disabling Tag Authorization for Testing

Hiding a link in a page for unauthorized users doesn’t prevent them from accessing the URL. They could just type it into their browser directly, for example. As part of your testing process, you may want to reveal the hidden areas in order to check that links really are secured at the back end. If you set the system property spring.security.disableUISecurity to true, the authorize tag will still run but will not hide its contents. By default it will also surround the content with <span class="securityHiddenUI">…​</span> tags. This allows you to display "hidden" content with a particular CSS style such as a different background colour. Try running the "tutorial" sample application with this property enabled, for example.

You can also set the properties spring.security.securedUIPrefix and spring.security.securedUISuffix if you want to change surrounding text from the default span tags (or use empty strings to remove it completely).

15.9.3. The authentication Tag

This tag allows access to the current Authentication object stored in the security context. It renders a property of the object directly in the JSP. So, for example, if the principal property of the Authentication is an instance of Spring Security’s UserDetails object, then using <sec:authentication property="principal.username" /> will render the name of the current user.

Of course, it isn’t necessary to use JSP tags for this kind of thing and some people prefer to keep as little logic as possible in the view. You can access the Authentication object in your MVC controller (by calling SecurityContextHolder.getContext().getAuthentication()) and add the data directly to your model for rendering by the view.

15.9.4. The accesscontrollist Tag

This tag is only valid when used with Spring Security’s ACL module. It checks a comma-separated list of required permissions for a specified domain object. If the current user has all of those permissions, then the tag body will be evaluated. If they don’t, it will be skipped. An example might be

In general this tag should be considered deprecated. Instead use the The authorize Tag.
<sec:accesscontrollist hasPermission="1,2" domainObject="${someObject}">

This will be shown if the user has all of the permissions represented by the values "1" or "2" on the given object.

</sec:accesscontrollist>

The permissions are passed to the PermissionFactory defined in the application context, converting them to ACL Permission instances, so they may be any format which is supported by the factory - they don’t have to be integers, they could be strings like READ or WRITE. If no PermissionFactory is found, an instance of DefaultPermissionFactory will be used. The AclService from the application context will be used to load the Acl instance for the supplied object. The Acl will be invoked with the required permissions to check if all of them are granted.

This tag also supports the var attribute, in the same way as the authorize tag.

15.9.5. The csrfInput Tag

If CSRF protection is enabled, this tag inserts a hidden form field with the correct name and value for the CSRF protection token. If CSRF protection is not enabled, this tag outputs nothing.

Normally Spring Security automatically inserts a CSRF form field for any <form:form> tags you use, but if for some reason you cannot use <form:form>, csrfInput is a handy replacement.

You should place this tag within an HTML <form></form> block, where you would normally place other input fields. Do NOT place this tag within a Spring <form:form></form:form> block. Spring Security handles Spring forms automatically.

<form method="post" action="/do/something">
    <sec:csrfInput />
    Name:<br />
    <input type="text" name="name" />
    ...
</form>

15.9.6. The csrfMetaTags Tag

If CSRF protection is enabled, this tag inserts meta tags containing the CSRF protection token form field and header names and CSRF protection token value. These meta tags are useful for employing CSRF protection within JavaScript in your applications.

You should place csrfMetaTags within an HTML <head></head> block, where you would normally place other meta tags. Once you use this tag, you can access the form field name, header name, and token value easily using JavaScript. JQuery is used in this example to make the task easier.

<!DOCTYPE html>
<html>
    <head>
        <title>CSRF Protected JavaScript Page</title>
        <meta name="description" content="This is the description for this page" />
        <sec:csrfMetaTags />
        <script type="text/javascript" language="javascript">

            var csrfParameter = $("meta[name='_csrf_parameter']").attr("content");
            var csrfHeader = $("meta[name='_csrf_header']").attr("content");
            var csrfToken = $("meta[name='_csrf']").attr("content");

            // using XMLHttpRequest directly to send an x-www-form-urlencoded request
            var ajax = new XMLHttpRequest();
            ajax.open("POST", "https://www.example.org/do/something", true);
            ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded data");
            ajax.send(csrfParameter + "=" + csrfToken + "&name=John&...");

            // using XMLHttpRequest directly to send a non-x-www-form-urlencoded request
            var ajax = new XMLHttpRequest();
            ajax.open("POST", "https://www.example.org/do/something", true);
            ajax.setRequestHeader(csrfHeader, csrfToken);
            ajax.send("...");

            // using JQuery to send an x-www-form-urlencoded request
            var data = {};
            data[csrfParameter] = csrfToken;
            data["name"] = "John";
            ...
            $.ajax({
                url: "https://www.example.org/do/something",
                type: "POST",
                data: data,
                ...
            });

            // using JQuery to send a non-x-www-form-urlencoded request
            var headers = {};
            headers[csrfHeader] = csrfToken;
            $.ajax({
                url: "https://www.example.org/do/something",
                type: "POST",
                headers: headers,
                ...
            });

        <script>
    </head>
    <body>
        ...
    </body>
</html>

If CSRF protection is not enabled, csrfMetaTags outputs nothing.

16. Java Configuration

General support for Java Configuration was added to Spring Framework in Spring 3.1. Since Spring Security 3.2 there has been Spring Security Java Configuration support which enables users to easily configure Spring Security without the use of any XML.

If you are familiar with the Security Namespace Configuration then you should find quite a few similarities between it and the Security Java Configuration support.

Spring Security provides lots of sample applications which demonstrate the use of Spring Security Java Configuration.

16.1. Hello Web Security Java Configuration

The first step is to create our Spring Security Java Configuration. The configuration creates a Servlet Filter known as the springSecurityFilterChain which is responsible for all the security (protecting the application URLs, validating submitted username and passwords, redirecting to the log in form, etc) within your application. You can find the most basic example of a Spring Security Java Configuration below:

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.annotation.*;
import org.springframework.security.config.annotation.authentication.builders.*;
import org.springframework.security.config.annotation.web.configuration.*;

@EnableWebSecurity
public class WebSecurityConfig {

    @Bean
    public UserDetailsService userDetailsService() {
        InMemoryUserDetailsManager manager = new InMemoryUserDetailsManager();
        manager.createUser(User.withDefaultPasswordEncoder().username("user").password("password").roles("USER").build());
        return manager;
    }
}

There really isn’t much to this configuration, but it does a lot. You can find a summary of the features below:

16.1.1. AbstractSecurityWebApplicationInitializer

The next step is to register the springSecurityFilterChain with the war. This can be done in Java Configuration with Spring’s WebApplicationInitializer support in a Servlet 3.0+ environment. Not suprisingly, Spring Security provides a base class AbstractSecurityWebApplicationInitializer that will ensure the springSecurityFilterChain gets registered for you. The way in which we use AbstractSecurityWebApplicationInitializer differs depending on if we are already using Spring or if Spring Security is the only Spring component in our application.

16.1.2. AbstractSecurityWebApplicationInitializer without Existing Spring

If you are not using Spring or Spring MVC, you will need to pass in the WebSecurityConfig into the superclass to ensure the configuration is picked up. You can find an example below:

import org.springframework.security.web.context.*;

public class SecurityWebApplicationInitializer
    extends AbstractSecurityWebApplicationInitializer {

    public SecurityWebApplicationInitializer() {
        super(WebSecurityConfig.class);
    }
}

The SecurityWebApplicationInitializer will do the following things:

  • Automatically register the springSecurityFilterChain Filter for every URL in your application

  • Add a ContextLoaderListener that loads the WebSecurityConfig.

16.1.3. AbstractSecurityWebApplicationInitializer with Spring MVC

If we were using Spring elsewhere in our application we probably already had a WebApplicationInitializer that is loading our Spring Configuration. If we use the previous configuration we would get an error. Instead, we should register Spring Security with the existing ApplicationContext. For example, if we were using Spring MVC our SecurityWebApplicationInitializer would look something like the following:

import org.springframework.security.web.context.*;

public class SecurityWebApplicationInitializer
    extends AbstractSecurityWebApplicationInitializer {

}

This would simply only register the springSecurityFilterChain Filter for every URL in your application. After that we would ensure that WebSecurityConfig was loaded in our existing ApplicationInitializer. For example, if we were using Spring MVC it would be added in the getRootConfigClasses()

public class MvcWebApplicationInitializer extends
        AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[] { WebSecurityConfig.class };
    }

    // ... other overrides ...
}

16.2. HttpSecurity

Thus far our WebSecurityConfig only contains information about how to authenticate our users. How does Spring Security know that we want to require all users to be authenticated? How does Spring Security know we want to support form based authentication? Actually, there is a configuration class that is being invoked behind the scenes called WebSecurityConfigurerAdapter. It has a method called configure with the following default implementation:

protected void configure(HttpSecurity http) throws Exception {
    http
        .authorizeRequests(authorize -> authorize
            .anyRequest().authenticated()
        )
        .formLogin(withDefaults())
        .httpBasic(withDefaults());
}

The default configuration above:

  • Ensures that any request to our application requires the user to be authenticated

  • Allows users to authenticate with form based login

  • Allows users to authenticate with HTTP Basic authentication

You will notice that this configuration is quite similar the XML Namespace configuration:

<http>
    <intercept-url pattern="/**" access="authenticated"/>
    <form-login />
    <http-basic />
</http>

16.3. Multiple HttpSecurity

We can configure multiple HttpSecurity instances just as we can have multiple <http> blocks. The key is to extend the WebSecurityConfigurerAdapter multiple times. For example, the following is an example of having a different configuration for URL’s that start with /api/.

@EnableWebSecurity
public class MultiHttpSecurityConfig {
    @Bean                                                             (1)
    public UserDetailsService userDetailsService() throws Exception {
        // ensure the passwords are encoded properly
        UserBuilder users = User.withDefaultPasswordEncoder();
        InMemoryUserDetailsManager manager = new InMemoryUserDetailsManager();
        manager.createUser(users.username("user").password("password").roles("USER").build());
        manager.createUser(users.username("admin").password("password").roles("USER","ADMIN").build());
        return manager;
    }

    @Configuration
    @Order(1)                                                        (2)
    public static class ApiWebSecurityConfigurationAdapter extends WebSecurityConfigurerAdapter {
        protected void configure(HttpSecurity http) throws Exception {
            http
                .antMatcher("/api/**")                               (3)
                .authorizeRequests(authorize -> authorize
                    .anyRequest().hasRole("ADMIN")
                )
                .httpBasic(withDefaults());
        }
    }

    @Configuration                                                   (4)
    public static class FormLoginWebSecurityConfigurerAdapter extends WebSecurityConfigurerAdapter {

        @Override
        protected void configure(HttpSecurity http) throws Exception {
            http
                .authorizeRequests(authorize -> authorize
                    .anyRequest().authenticated()
                )
                .formLogin(withDefaults());
        }
    }
}
1 Configure Authentication as normal
2 Create an instance of WebSecurityConfigurerAdapter that contains @Order to specify which WebSecurityConfigurerAdapter should be considered first.
3 The http.antMatcher states that this HttpSecurity will only be applicable to URLs that start with /api/
4 Create another instance of WebSecurityConfigurerAdapter. If the URL does not start with /api/ this configuration will be used. This configuration is considered after ApiWebSecurityConfigurationAdapter since it has an @Order value after 1 (no @Order defaults to last).

16.4. Custom DSLs

You can provide your own custom DSLs in Spring Security. For example, you might have something that looks like this:

public class MyCustomDsl extends AbstractHttpConfigurer<MyCustomDsl, HttpSecurity> {
    private boolean flag;

    @Override
    public void init(H http) throws Exception {
        // any method that adds another configurer
        // must be done in the init method
        http.csrf().disable();
    }

    @Override
    public void configure(H http) throws Exception {
        ApplicationContext context = http.getSharedObject(ApplicationContext.class);

        // here we lookup from the ApplicationContext. You can also just create a new instance.
        MyFilter myFilter = context.getBean(MyFilter.class);
        myFilter.setFlag(flag);
        http.addFilterBefore(myFilter, UsernamePasswordAuthenticationFilter.class);
    }

    public MyCustomDsl flag(boolean value) {
        this.flag = value;
        return this;
    }

    public static MyCustomDsl customDsl() {
        return new MyCustomDsl();
    }
}
This is actually how methods like HttpSecurity.authorizeRequests() are implemented.

The custom DSL can then be used like this:

@EnableWebSecurity
public class Config extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .apply(customDsl())
                .flag(true)
                .and()
            ...;
    }
}

The code is invoked in the following order:

  • Code in `Config`s configure method is invoked

  • Code in `MyCustomDsl`s init method is invoked

  • Code in `MyCustomDsl`s configure method is invoked

If you want, you can have WebSecurityConfiguerAdapter add MyCustomDsl by default by using SpringFactories. For example, you would create a resource on the classpath named META-INF/spring.factories with the following contents:

META-INF/spring.factories
org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer = sample.MyCustomDsl

Users wishing to disable the default can do so explicitly.

@EnableWebSecurity
public class Config extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .apply(customDsl()).disable()
            ...;
    }
}

16.5. Post Processing Configured Objects

Spring Security’s Java Configuration does not expose every property of every object that it configures. This simplifies the configuration for a majority of users. Afterall, if every property was exposed, users could use standard bean configuration.

While there are good reasons to not directly expose every property, users may still need more advanced configuration options. To address this Spring Security introduces the concept of an ObjectPostProcessor which can be used to modify or replace many of the Object instances created by the Java Configuration. For example, if you wanted to configure the filterSecurityPublishAuthorizationSuccess property on FilterSecurityInterceptor you could use the following:

@Override
protected void configure(HttpSecurity http) throws Exception {
    http
        .authorizeRequests(authorize -> authorize
            .anyRequest().authenticated()
            .withObjectPostProcessor(new ObjectPostProcessor<FilterSecurityInterceptor>() {
                public <O extends FilterSecurityInterceptor> O postProcess(
                        O fsi) {
                    fsi.setPublishAuthorizationSuccess(true);
                    return fsi;
                }
            })
        );
}

17. Kotlin Configuration

Spring Security Kotlin Configuration support has been available since Spring Security 5.3. It enables users to easily configure Spring Security using a native Kotlin DSL.

Spring Security provides a sample application which demonstrates the use of Spring Security Kotlin Configuration.

17.1. HttpSecurity

How does Spring Security know that we want to require all users to be authenticated? How does Spring Security know we want to support form based authentication? There is a configuration class that is being invoked behind the scenes called WebSecurityConfigurerAdapter. It has a method called configure with the following default implementation:

fun configure(http: HttpSecurity) {
   http {
        authorizeRequests {
            authorize(anyRequest, authenticated)
        }
       formLogin { }
       httpBasic { }
    }
}

The default configuration above:

  • Ensures that any request to our application requires the user to be authenticated

  • Allows users to authenticate with form based login

  • Allows users to authenticate with HTTP Basic authentication

You will notice that this configuration is quite similar the XML Namespace configuration:

<http>
    <intercept-url pattern="/**" access="authenticated"/>
    <form-login />
    <http-basic />
</http>

17.2. Multiple HttpSecurity

We can configure multiple HttpSecurity instances just as we can have multiple <http> blocks. The key is to extend the WebSecurityConfigurerAdapter multiple times. For example, the following is an example of having a different configuration for URL’s that start with /api/.

@EnableWebSecurity
class MultiHttpSecurityConfig {
    @Bean                                                            (1)
    public fun userDetailsService(): UserDetailsService {
        val users: User.UserBuilder = User.withDefaultPasswordEncoder()
        val manager = InMemoryUserDetailsManager()
        manager.createUser(users.username("user").password("password").roles("USER").build())
        manager.createUser(users.username("admin").password("password").roles("USER","ADMIN").build())
        return manager
    }

    @Configuration
    @Order(1)                                                        (2)
    class ApiWebSecurityConfigurationAdapter: WebSecurityConfigurerAdapter() {
        override fun configure(http: HttpSecurity) {
            http {
                securityMatcher("/api/**")                           (3)
                authorizeRequests {
                    authorize(anyRequest, hasRole("ADMIN"))
                }
                httpBasic { }
            }
        }
    }

    @Configuration                                                   (4)
    class FormLoginWebSecurityConfigurerAdapter: WebSecurityConfigurerAdapter() {
        override fun configure(http: HttpSecurity) {
            http {
                authorizeRequests {
                    authorize(anyRequest, authenticated)
                }
                formLogin { }
            }
        }
    }
}
1 Configure Authentication as normal
2 Create an instance of WebSecurityConfigurerAdapter that contains @Order to specify which WebSecurityConfigurerAdapter should be considered first.
3 The http.antMatcher states that this HttpSecurity will only be applicable to URLs that start with /api/
4 Create another instance of WebSecurityConfigurerAdapter. If the URL does not start with /api/ this configuration will be used. This configuration is considered after ApiWebSecurityConfigurationAdapter since it has an @Order value after 1 (no @Order defaults to last).

18. Security Namespace Configuration

18.1. Introduction

Namespace configuration has been available since version 2.0 of the Spring Framework. It allows you to supplement the traditional Spring beans application context syntax with elements from additional XML schema. You can find more information in the Spring Reference Documentation. A namespace element can be used simply to allow a more concise way of configuring an individual bean or, more powerfully, to define an alternative configuration syntax which more closely matches the problem domain and hides the underlying complexity from the user. A simple element may conceal the fact that multiple beans and processing steps are being added to the application context. For example, adding the following element from the security namespace to an application context will start up an embedded LDAP server for testing use within the application:

<security:ldap-server />

This is much simpler than wiring up the equivalent Apache Directory Server beans. The most common alternative configuration requirements are supported by attributes on the ldap-server element and the user is isolated from worrying about which beans they need to create and what the bean property names are. [9]. Use of a good XML editor while editing the application context file should provide information on the attributes and elements that are available. We would recommend that you try out the Spring Tool Suite as it has special features for working with standard Spring namespaces.

To start using the security namespace in your application context, you need to have the spring-security-config jar on your classpath. Then all you need to do is add the schema declaration to your application context file:

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:security="http://www.springframework.org/schema/security"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/security
        https://www.springframework.org/schema/security/spring-security.xsd">
    ...
</beans>

In many of the examples you will see (and in the sample applications), we will often use "security" as the default namespace rather than "beans", which means we can omit the prefix on all the security namespace elements, making the content easier to read. You may also want to do this if you have your application context divided up into separate files and have most of your security configuration in one of them. Your security application context file would then start like this

<beans:beans xmlns="http://www.springframework.org/schema/security"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/security
        https://www.springframework.org/schema/security/spring-security.xsd">
    ...
</beans:beans>

We’ll assume this syntax is being used from now on in this chapter.

18.1.1. Design of the Namespace

The namespace is designed to capture the most common uses of the framework and provide a simplified and concise syntax for enabling them within an application. The design is based around the large-scale dependencies within the framework, and can be divided up into the following areas:

  • Web/HTTP Security - the most complex part. Sets up the filters and related service beans used to apply the framework authentication mechanisms, to secure URLs, render login and error pages and much more.

  • Business Object (Method) Security - options for securing the service layer.

  • AuthenticationManager - handles authentication requests from other parts of the framework.

  • AccessDecisionManager - provides access decisions for web and method security. A default one will be registered, but you can also choose to use a custom one, declared using normal Spring bean syntax.

  • AuthenticationProviders - mechanisms against which the authentication manager authenticates users. The namespace provides supports for several standard options and also a means of adding custom beans declared using a traditional syntax.

  • UserDetailsService - closely related to authentication providers, but often also required by other beans.

We’ll see how to configure these in the following sections.

18.2. Getting Started with Security Namespace Configuration

In this section, we’ll look at how you can build up a namespace configuration to use some of the main features of the framework. Let’s assume you initially want to get up and running as quickly as possible and add authentication support and access control to an existing web application, with a few test logins. Then we’ll look at how to change over to authenticating against a database or other security repository. In later sections we’ll introduce more advanced namespace configuration options.

18.2.1. web.xml Configuration

The first thing you need to do is add the following filter declaration to your web.xml file:

<filter>
<filter-name>springSecurityFilterChain</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>

<filter-mapping>
<filter-name>springSecurityFilterChain</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

This provides a hook into the Spring Security web infrastructure. DelegatingFilterProxy is a Spring Framework class which delegates to a filter implementation which is defined as a Spring bean in your application context. In this case, the bean is named "springSecurityFilterChain", which is an internal infrastructure bean created by the namespace to handle web security. Note that you should not use this bean name yourself. Once you’ve added this to your web.xml, you’re ready to start editing your application context file. Web security services are configured using the <http> element.

18.2.2. A Minimal <http> Configuration

All you need to enable web security to begin with is

<http>
<intercept-url pattern="/**" access="hasRole('USER')" />
<form-login />
<logout />
</http>

Which says that we want all URLs within our application to be secured, requiring the role ROLE_USER to access them, we want to log in to the application using a form with username and password, and that we want a logout URL registered which will allow us to log out of the application. <http> element is the parent for all web-related namespace functionality. The <intercept-url> element defines a pattern which is matched against the URLs of incoming requests using an ant path style syntax [10]. You can also use regular-expression matching as an alternative (see the namespace appendix for more details). The access attribute defines the access requirements for requests matching the given pattern. With the default configuration, this is typically a comma-separated list of roles, one of which a user must have to be allowed to make the request. The prefix "ROLE_" is a marker which indicates that a simple comparison with the user’s authorities should be made. In other words, a normal role-based check should be used. Access-control in Spring Security is not limited to the use of simple roles (hence the use of the prefix to differentiate between different types of security attributes). We’ll see later how the interpretation can vary [11]. In Spring Security 3.0, the attribute can also be populated with an EL expression.

You can use multiple <intercept-url> elements to define different access requirements for different sets of URLs, but they will be evaluated in the order listed and the first match will be used. So you must put the most specific matches at the top. You can also add a method attribute to limit the match to a particular HTTP method (GET, POST, PUT etc.).

To add some users, you can define a set of test data directly in the namespace:

<authentication-manager>
<authentication-provider>
    <user-service>
    <!-- Password is prefixed with {noop} to indicate to DelegatingPasswordEncoder that
    NoOpPasswordEncoder should be used. This is not safe for production, but makes reading
    in samples easier. Normally passwords should be hashed using BCrypt -->
    <user name="jimi" password="{noop}jimispassword" authorities="ROLE_USER, ROLE_ADMIN" />
    <user name="bob" password="{noop}bobspassword" authorities="ROLE_USER" />
    </user-service>
</authentication-provider>
</authentication-manager>

This is an example of a secure way of storing the same passwords. The password is prefixed with {bcrypt} to instruct DelegatingPasswordEncoder, which supports any configured PasswordEncoder for matching, that the passwords are hashed using BCrypt:

<authentication-manager>
<authentication-provider>
    <user-service>
    <user name="jimi" password="{bcrypt}$2a$10$ddEWZUl8aU0GdZPPpy7wbu82dvEw/pBpbRvDQRqA41y6mK1CoH00m"
            authorities="ROLE_USER, ROLE_ADMIN" />
    <user name="bob" password="{bcrypt}$2a$10$/elFpMBnAYYig6KRR5bvOOYeZr1ie1hSogJryg9qDlhza4oCw1Qka"
            authorities="ROLE_USER" />
    <user name="jimi" password="{noop}jimispassword" authorities="ROLE_USER, ROLE_ADMIN" />
    <user name="bob" password="{noop}bobspassword" authorities="ROLE_USER" />
    </user-service>
</authentication-provider>
</authentication-manager>

If you are familiar with pre-namespace versions of the framework, you can probably already guess roughly what’s going on here. The <http> element is responsible for creating a FilterChainProxy and the filter beans which it uses. Common problems like incorrect filter ordering are no longer an issue as the filter positions are predefined.

The <authentication-provider> element creates a DaoAuthenticationProvider bean and the <user-service> element creates an InMemoryDaoImpl. All authentication-provider elements must be children of the <authentication-manager> element, which creates a ProviderManager and registers the authentication providers with it. You can find more detailed information on the beans that are created in the namespace appendix. It’s worth cross-checking this if you want to start understanding what the important classes in the framework are and how they are used, particularly if you want to customise things later.

The configuration above defines two users, their passwords and their roles within the application (which will be used for access control). It is also possible to load user information from a standard properties file using the properties attribute on user-service. See the section on in-memory authentication for more details on the file format. Using the <authentication-provider> element means that the user information will be used by the authentication manager to process authentication requests. You can have multiple <authentication-provider> elements to define different authentication sources and each will be consulted in turn.

At this point you should be able to start up your application and you will be required to log in to proceed. Try it out, or try experimenting with the "tutorial" sample application that comes with the project.

Setting a Default Post-Login Destination

If a form login isn’t prompted by an attempt to access a protected resource, the default-target-url option comes into play. This is the URL the user will be taken to after successfully logging in, and defaults to "/". You can also configure things so that the user always ends up at this page (regardless of whether the login was "on-demand" or they explicitly chose to log in) by setting the always-use-default-target attribute to "true". This is useful if your application always requires that the user starts at a "home" page, for example:

<http pattern="/login.htm*" security="none"/>
<http use-expressions="false">
<intercept-url pattern='/**' access='ROLE_USER' />
<form-login login-page='/login.htm' default-target-url='/home.htm'
        always-use-default-target='true' />
</http>

For even more control over the destination, you can use the authentication-success-handler-ref attribute as an alternative to default-target-url. The referenced bean should be an instance of AuthenticationSuccessHandler.

18.3. Advanced Web Features

18.3.1. Adding in Your Own Filters

If you’ve used Spring Security before, you’ll know that the framework maintains a chain of filters in order to apply its services. You may want to add your own filters to the stack at particular locations or use a Spring Security filter for which there isn’t currently a namespace configuration option (CAS, for example). Or you might want to use a customized version of a standard namespace filter, such as the UsernamePasswordAuthenticationFilter which is created by the <form-login> element, taking advantage of some of the extra configuration options which are available by using the bean explicitly. How can you do this with namespace configuration, since the filter chain is not directly exposed?

The order of the filters is always strictly enforced when using the namespace. When the application context is being created, the filter beans are sorted by the namespace handling code and the standard Spring Security filters each have an alias in the namespace and a well-known position.

In previous versions, the sorting took place after the filter instances had been created, during post-processing of the application context. In version 3.0+ the sorting is now done at the bean metadata level, before the classes have been instantiated. This has implications for how you add your own filters to the stack as the entire filter list must be known during the parsing of the <http> element, so the syntax has changed slightly in 3.0.

The filters, aliases and namespace elements/attributes which create the filters are shown in Standard Filter Aliases and Ordering. The filters are listed in the order in which they occur in the filter chain.

Table 2. Standard Filter Aliases and Ordering
Alias Filter Class Namespace Element or Attribute

CHANNEL_FILTER

ChannelProcessingFilter

http/[email protected]nel

SECURITY_CONTEXT_FILTER

SecurityContextPersistenceFilter

http

CONCURRENT_SESSION_FILTER

ConcurrentSessionFilter

session-management/concurrency-control

HEADERS_FILTER

HeaderWriterFilter

http/headers

CSRF_FILTER

CsrfFilter

http/csrf

LOGOUT_FILTER

LogoutFilter

http/logout

X509_FILTER

X509AuthenticationFilter

http/x509

PRE_AUTH_FILTER

AbstractPreAuthenticatedProcessingFilter Subclasses

N/A

CAS_FILTER

CasAuthenticationFilter

N/A

FORM_LOGIN_FILTER

UsernamePasswordAuthenticationFilter

http/form-login

BASIC_AUTH_FILTER

BasicAuthenticationFilter

http/http-basic

SERVLET_API_SUPPORT_FILTER

SecurityContextHolderAwareRequestFilter

http/@servlet-api-provision

JAAS_API_SUPPORT_FILTER

JaasApiIntegrationFilter

http/@jaas-api-provision

REMEMBER_ME_FILTER

RememberMeAuthenticationFilter

http/remember-me

ANONYMOUS_FILTER

AnonymousAuthenticationFilter

http/anonymous

SESSION_MANAGEMENT_FILTER

SessionManagementFilter

session-management

EXCEPTION_TRANSLATION_FILTER

ExceptionTranslationFilter

http

FILTER_SECURITY_INTERCEPTOR

FilterSecurityInterceptor

http

SWITCH_USER_FILTER

SwitchUserFilter

N/A

You can add your own filter to the stack, using the custom-filter element and one of these names to specify the position your filter should appear at:

<http>
<custom-filter position="FORM_LOGIN_FILTER" ref="myFilter" />
</http>

<beans:bean id="myFilter" class="com.mycompany.MySpecialAuthenticationFilter"/>

You can also use the after or before attributes if you want your filter to be inserted before or after another filter in the stack. The names "FIRST" and "LAST" can be used with the position attribute to indicate that you want your filter to appear before or after the entire stack, respectively.

Avoiding filter position conflicts

If you are inserting a custom filter which may occupy the same position as one of the standard filters created by the namespace then it’s important that you don’t include the namespace versions by mistake. Remove any elements which create filters whose functionality you want to replace.

Note that you can’t replace filters which are created by the use of the <http> element itself - SecurityContextPersistenceFilter, ExceptionTranslationFilter or FilterSecurityInterceptor. Some other filters are added by default, but you can disable them. An AnonymousAuthenticationFilter is added by default and unless you have session-fixation protection disabled, a SessionManagementFilter will also be added to the filter chain.

If you’re replacing a namespace filter which requires an authentication entry point (i.e. where the authentication process is triggered by an attempt by an unauthenticated user to access to a secured resource), you will need to add a custom entry point bean too.

18.4. Method Security

From version 2.0 onwards Spring Security has improved support substantially for adding security to your service layer methods. It provides support for JSR-250 annotation security as well as the framework’s original @Secured annotation. From 3.0 you can also make use of new expression-based annotations. You can apply security to a single bean, using the intercept-methods element to decorate the bean declaration, or you can secure multiple beans across the entire service layer using the AspectJ style pointcuts.

18.5. The Default AccessDecisionManager

This section assumes you have some knowledge of the underlying architecture for access-control within Spring Security. If you don’t you can skip it and come back to it later, as this section is only really relevant for people who need to do some customization in order to use more than simple role-based security.

When you use a namespace configuration, a default instance of AccessDecisionManager is automatically registered for you and will be used for making access decisions for method invocations and web URL access, based on the access attributes you specify in your intercept-url and protect-pointcut declarations (and in annotations if you are using annotation secured methods).

The default strategy is to use an AffirmativeBased AccessDecisionManager with a RoleVoter and an AuthenticatedVoter. You can find out more about these in the chapter on authorization.

18.5.1. Customizing the AccessDecisionManager

If you need to use a more complicated access control strategy then it is easy to set an alternative for both method and web security.

For method security, you do this by setting the access-decision-manager-ref attribute on global-method-security to the id of the appropriate AccessDecisionManager bean in the application context:

<global-method-security access-decision-manager-ref="myAccessDecisionManagerBean">
...
</global-method-security>

The syntax for web security is the same, but on the http element:

<http access-decision-manager-ref="myAccessDecisionManagerBean">
...
</http>

19. Testing

This section describes the testing support provided by Spring Security.

To use the Spring Security test support, you must include spring-security-test-5.3.6.BUILD-SNAPSHOT.jar as a dependency of your project.

19.1. Testing Method Security

This section demonstrates how to use Spring Security’s Test support to test method based security. We first introduce a MessageService that requires the user to be authenticated in order to access it.

public class HelloMessageService implements MessageService {

    @PreAuthorize("authenticated")
    public String getMessage() {
        Authentication authentication = SecurityContextHolder.getContext()
            .getAuthentication();
        return "Hello " + authentication;
    }
}

The result of getMessage is a String saying "Hello" to the current Spring Security Authentication. An example of the output is displayed below.

Hello org.springframew[email protected]ca25360: Principal: [email protected]: Username: user; Password: [PROTECTED]; Enabled: true; AccountNonExpired: true; credentialsNonExpired: true; AccountNonLocked: true; Granted Authorities: ROLE_USER; Credentials: [PROTECTED]; Authenticated: true; Details: null; Granted Authorities: ROLE_USER

19.1.1. Security Test Setup

Before we can use Spring Security Test support, we must perform some setup. An example can be seen below:

@RunWith(SpringJUnit4ClassRunner.class) (1)
@ContextConfiguration (2)
public class WithMockUserTests {

This is a basic example of how to setup Spring Security Test. The highlights are:

1 @RunWith instructs the spring-test module that it should create an ApplicationContext. This is no different than using the existing Spring Test support. For additional information, refer to the Spring Reference
2 @ContextConfiguration instructs the spring-test the configuration to use to create the ApplicationContext. Since no configuration is specified, the default configuration locations will be tried. This is no different than using the existing Spring Test support. For additional information, refer to the Spring Reference
Spring Security hooks into Spring Test support using the WithSecurityContextTestExecutionListener which will ensure our tests are ran with the correct user. It does this by populating the SecurityContextHolder prior to running our tests. If you are using reactive method security, you will also need ReactorContextTestExecutionListener which populates ReactiveSecurityContextHolder. After the test is done, it will clear out the SecurityContextHolder. If you only need Spring Security related support, you can replace @ContextConfiguration with @SecurityTestExecutionListeners.

Remember we added the @PreAuthorize annotation to our HelloMessageService and so it requires an authenticated user to invoke it. If we ran the following test, we would expect the following test will pass:

@Test(expected = AuthenticationCredentialsNotFoundException.class)
public void getMessageUnauthenticated() {
    messageService.getMessage();
}

19.1.2. @WithMockUser

The question is "How could we most easily run the test as a specific user?" The answer is to use @WithMockUser. The following test will be run as a user with the username "user", the password "password", and the roles "ROLE_USER".

@Test
@WithMockUser
public void getMessageWithMockUser() {
String message = messageService.getMessage();
...
}

Specifically the following is true:

  • The user with the username "user" does not have to exist since we are mocking the user

  • The Authentication that is populated in the SecurityContext is of type UsernamePasswordAuthenticationToken

  • The principal on the Authentication is Spring Security’s User object

  • The User will have the username of "user", the password "password", and a single GrantedAuthority named "ROLE_USER" is used.

Our example is nice because we are able to leverage a lot of defaults. What if we wanted to run the test with a different username? The following test would run with the username "customUser". Again, the user does not need to actually exist.

@Test
@WithMockUser("customUsername")
public void getMessageWithMockUserCustomUsername() {
    String message = messageService.getMessage();
...
}

We can also easily customize the roles. For example, this test will be invoked with the username "admin" and the roles "ROLE_USER" and "ROLE_ADMIN".

@Test
@WithMockUser(username="admin",roles={"USER","ADMIN"})
public void getMessageWithMockUserCustomUser() {
    String message = messageService.getMessage();
    ...
}

If we do not want the value to automatically be prefixed with ROLE_ we can leverage the authorities attribute. For example, this test will be invoked with the username "admin" and the authorities "USER" and "ADMIN".

@Test
@WithMockUser(username = "admin", authorities = { "ADMIN", "USER" })
public void getMessageWithMockUserCustomAuthorities() {
    String message = messageService.getMessage();
    ...
}

Of course it can be a bit tedious placing the annotation on every test method. Instead, we can place the annotation at the class level and every test will use the specified user. For example, the following would run every test with a user with the username "admin", the password "password", and the roles "ROLE_USER" and "ROLE_ADMIN".

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
@WithMockUser(username="admin",roles={"USER","ADMIN"})
public class WithMockUserTests {

By default the SecurityContext is set during the TestExecutionListener.beforeTestMethod event. This is the equivalent of happening before JUnit’s @Before. You can change this to happen during the TestExecutionListener.beforeTestExecution event which is after JUnit’s @Before but before the test method is invoked.

@WithMockUser(setupBefore = TestExecutionEvent.TEST_EXECUTION)

19.1.3. @WithAnonymousUser

Using @WithAnonymousUser allows running as an anonymous user. This is especially convenient when you wish to run most of your tests with a specific user, but want to run a few tests as an anonymous user. For example, the following will run withMockUser1 and withMockUser2 using @WithMockUser and anonymous as an anonymous user.

@RunWith(SpringJUnit4ClassRunner.class)
@WithMockUser
public class WithUserClassLevelAuthenticationTests {

    @Test
    public void withMockUser1() {
    }

    @Test
    public void withMockUser2() {
    }

    @Test
    @WithAnonymousUser
    public void anonymous() throws Exception {
        // override default to run as anonymous user
    }
}

By default the SecurityContext is set during the TestExecutionListener.beforeTestMethod event. This is the equivalent of happening before JUnit’s @Before. You can change this to happen during the TestExecutionListener.beforeTestExecution event which is after JUnit’s @Before but before the test method is invoked.

@WithAnonymousUser(setupBefore = TestExecutionEvent.TEST_EXECUTION)

19.1.4. @WithUserDetails

While @WithMockUser is a very convenient way to get started, it may not work in all instances. For example, it is common for applications to expect that the Authentication principal be of a specific type. This is done so that the application can refer to the principal as the custom type and reduce coupling on Spring Security.

The custom principal is often times returned by a custom UserDetailsService that returns an object that implements both UserDetails and the custom type. For situations like this, it is useful to create the test user using the custom UserDetailsService. That is exactly what @WithUserDetails does.

Assuming we have a UserDetailsService exposed as a bean, the following test will be invoked with an Authentication of type UsernamePasswordAuthenticationToken and a principal that is returned from the UserDetailsService with the username of "user".

@Test
@WithUserDetails
public void getMessageWithUserDetails() {
    String message = messageService.getMessage();
    ...
}

We can also customize the username used to lookup the user from our UserDetailsService. For example, this test would be executed with a principal that is returned from the UserDetailsService with the username of "customUsername".

@Test
@WithUserDetails("customUsername")
public void getMessageWithUserDetailsCustomUsername() {
    String message = messageService.getMessage();
    ...
}

We can also provide an explicit bean name to look up the UserDetailsService. For example, this test would look up the username of "customUsername" using the UserDetailsService with the bean name "myUserDetailsService".

@Test
@WithUserDetails(value="customUsername", userDetailsServiceBeanName="myUserDetailsService")
public void getMessageWithUserDetailsServiceBeanName() {
    String message = messageService.getMessage();
    ...
}

Like @WithMockUser we can also place our annotation at the class level so that every test uses the same user. However unlike @WithMockUser, @WithUserDetails requires the user to exist.

By default the SecurityContext is set during the TestExecutionListener.beforeTestMethod event. This is the equivalent of happening before JUnit’s @Before. You can change this to happen during the TestExecutionListener.beforeTestExecution event which is after JUnit’s @Before but before the test method is invoked.

@WithUserDetails(setupBefore = TestExecutionEvent.TEST_EXECUTION)

19.1.5. @WithSecurityContext

We have seen that @WithMockUser is an excellent choice if we are not using a custom Authentication principal. Next we discovered that @WithUserDetails would allow us to use a custom UserDetailsService to create our Authentication principal but required the user to exist. We will now see an option that allows the most flexibility.

We can create our own annotation that uses the @WithSecurityContext to create any SecurityContext we want. For example, we might create an annotation named @WithMockCustomUser as shown below:

@Retention(RetentionPolicy.RUNTIME)
@WithSecurityContext(factory = WithMockCustomUserSecurityContextFactory.class)
public @interface WithMockCustomUser {

    String username() default "rob";

    String name() default "Rob Winch";
}

You can see that @WithMockCustomUser is annotated with the @WithSecurityContext annotation. This is what signals to Spring Security Test support that we intend to create a SecurityContext for the test. The @WithSecurityContext annotation requires we specify a SecurityContextFactory that will create a new SecurityContext given our @WithMockCustomUser annotation. You can find our WithMockCustomUserSecurityContextFactory implementation below:

public class WithMockCustomUserSecurityContextFactory
    implements WithSecurityContextFactory<WithMockCustomUser> {
    @Override
    public SecurityContext createSecurityContext(WithMockCustomUser customUser) {
        SecurityContext context = SecurityContextHolder.createEmptyContext();

        CustomUserDetails principal =
            new CustomUserDetails(customUser.name(), customUser.username());
        Authentication auth =
            new UsernamePasswordAuthenticationToken(principal, "password", principal.getAuthorities());
        context.setAuthentication(auth);
        return context;
    }
}

We can now annotate a test class or a test method with our new annotation and Spring Security’s WithSecurityContextTestExecutionListener will ensure that our SecurityContext is populated appropriately.

When creating your own WithSecurityContextFactory implementations, it is nice to know that they can be annotated with standard Spring annotations. For example, the WithUserDetailsSecurityContextFactory uses the @Autowired annotation to acquire the UserDetailsService:

final class WithUserDetailsSecurityContextFactory
    implements WithSecurityContextFactory<WithUserDetails> {

    private UserDetailsService userDetailsService;

    @Autowired
    public WithUserDetailsSecurityContextFactory(UserDetailsService userDetailsService) {
        this.userDetailsService = userDetailsService;
    }

    public SecurityContext createSecurityContext(WithUserDetails withUser) {
        String username = withUser.value();
        Assert.hasLength(username, "value() must be non-empty String");
        UserDetails principal = userDetailsService.loadUserByUsername(username);
        Authentication authentication = new UsernamePasswordAuthenticationToken(principal, principal.getPassword(), principal.getAuthorities());
        SecurityContext context = SecurityContextHolder.createEmptyContext();
        context.setAuthentication(authentication);
        return context;
    }
}

By default the SecurityContext is set during the TestExecutionListener.beforeTestMethod event. This is the equivalent of happening before JUnit’s @Before. You can change this to happen during the TestExecutionListener.beforeTestExecution event which is after JUnit’s @Before but before the test method is invoked.

@WithSecurityContext(setupBefore = TestExecutionEvent.TEST_EXECUTION)

19.1.6. Test Meta Annotations

If you reuse the same user within your tests often, it is not ideal to have to repeatedly specify the attributes. For example, if there are many tests related to an administrative user with the username "admin" and the roles ROLE_USER and ROLE_ADMIN you would have to write:

@WithMockUser(username="admin",roles={"USER","ADMIN"})

Rather than repeating this everywhere, we can use a meta annotation. For example, we could create a meta annotation named WithMockAdmin:

@Retention(RetentionPolicy.RUNTIME)
@WithMockUser(value="rob",roles="ADMIN")
public @interface WithMockAdmin { }

Now we can use @WithMockAdmin in the same way as the more verbose @WithMockUser.

Meta annotations work with any of the testing annotations described above. For example, this means we could create a meta annotation for @WithUserDetails("admin") as well.

19.2. Spring MVC Test Integration

Spring Security provides comprehensive integration with Spring MVC Test

19.2.1. Setting Up MockMvc and Spring Security

In order to use Spring Security with Spring MVC Test it is necessary to add the Spring Security FilterChainProxy as a Filter. It is also necessary to add Spring Security’s TestSecurityContextHolderPostProcessor to support Running as a User in Spring MVC Test with Annotations. This can be done using Spring Security’s SecurityMockMvcConfigurers.springSecurity(). For example:

Spring Security’s testing support requires spring-test-4.1.3.RELEASE or greater.
import static org.springframework.security.test.web.servlet.setup.SecurityMockMvcConfigurers.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = SecurityConfig.class)
@WebAppConfiguration
public class CsrfShowcaseTests {

    @Autowired
    private WebApplicationContext context;

    private MockMvc mvc;

    @Before
    public void setup() {
        mvc = MockMvcBuilders
                .webAppContextSetup(context)
                .apply(springSecurity()) (1)
                .build();
    }

...
1 SecurityMockMvcConfigurers.springSecurity() will perform all of the initial setup we need to integrate Spring Security with Spring MVC Test

19.2.2. SecurityMockMvcRequestPostProcessors

Spring MVC Test provides a convenient interface called a RequestPostProcessor that can be used to modify a request. Spring Security provides a number of RequestPostProcessor implementations that make testing easier. In order to use Spring Security’s RequestPostProcessor implementations ensure the following static import is used:

import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.*;
Testing with CSRF Protection

When testing any non-safe HTTP methods and using Spring Security’s CSRF protection, you must be sure to include a valid CSRF Token in the request. To specify a valid CSRF token as a request parameter using the following:

mvc
    .perform(post("/").with(csrf()))

If you like you can include CSRF token in the header instead:

mvc
    .perform(post("/").with(csrf().asHeader()))

You can also test providing an invalid CSRF token using the following:

mvc
    .perform(post("/").with(csrf().useInvalidToken()))
Running a Test as a User in Spring MVC Test

It is often desirable to run tests as a specific user. There are two simple ways of populating the user:

Running as a User in Spring MVC Test with RequestPostProcessor

There are a number of options available to associate a user to the current HttpServletRequest. For example, the following will run as a user (which does not need to exist) with the username "user", the password "password", and the role "ROLE_USER":

The support works by associating the user to the HttpServletRequest. To associate the request to the SecurityContextHolder you need to ensure that the SecurityContextPersistenceFilter is associated with the MockMvc instance. A few ways to do this are:

  • Invoking apply(springSecurity())

  • Adding Spring Security’s FilterChainProxy to MockMvc

  • Manually adding SecurityContextPersistenceFilter to the MockMvc instance may make sense when using MockMvcBuilders.standaloneSetup

mvc
    .perform(get("/").with(user("user")))

You can easily make customizations. For example, the following will run as a user (which does not need to exist) with the username "admin", the password "pass", and the roles "ROLE_USER" and "ROLE_ADMIN".

mvc
    .perform(get("/admin").with(user("admin").password("pass").roles("USER","ADMIN")))

If you have a custom UserDetails that you would like to use, you can easily specify that as well. For example, the following will use the specified UserDetails (which does not need to exist) to run with a UsernamePasswordAuthenticationToken that has a principal of the specified UserDetails:

mvc
    .perform(get("/").with(user(userDetails)))

You can run as anonymous user using the following:

mvc
    .perform(get("/").with(anonymous()))

This is especially useful if you are running with a default user and wish to execute a few requests as an anonymous user.

If you want a custom Authentication (which does not need to exist) you can do so using the following:

mvc
    .perform(get("/").with(authentication(authentication)))

You can even customize the SecurityContext using the following:

mvc
    .perform(get("/").with(securityContext(securityContext)))

We can also ensure to run as a specific user for every request by using MockMvcBuilders's default request. For example, the following will run as a user (which does not need to exist) with the username "admin", the password "password", and the role "ROLE_ADMIN":