This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Security 6.3.4!

RSocket Security

Spring Security’s RSocket support relies on a SocketAcceptorInterceptor. The main entry point into security is in PayloadSocketAcceptorInterceptor, which adapts the RSocket APIs to allow intercepting a PayloadExchange with PayloadInterceptor implementations.

The following example shows a minimal RSocket Security configuration:

Hello RSocket hellorsocket
Spring Flights

Minimal RSocket Security Configuration

You can find a minimal RSocket Security configuration below:

Java
Kotlin

@Configuration
@EnableRSocketSecurity
public class HelloRSocketSecurityConfig {

	@Bean
	public MapReactiveUserDetailsService userDetailsService() {
		UserDetails user = User.withDefaultPasswordEncoder()
			.username("user")
			.password("user")
			.roles("USER")
			.build();
		return new MapReactiveUserDetailsService(user);
	}
}

@Configuration
@EnableRSocketSecurity
open class HelloRSocketSecurityConfig {
    @Bean
    open fun userDetailsService(): MapReactiveUserDetailsService {
        val user = User.withDefaultPasswordEncoder()
            .username("user")
            .password("user")
            .roles("USER")
            .build()
        return MapReactiveUserDetailsService(user)
    }
}

This configuration enables simple authentication and sets up rsocket-authorization to require an authenticated user for any request.

Adding SecuritySocketAcceptorInterceptor

For Spring Security to work, we need to apply SecuritySocketAcceptorInterceptor to the ServerRSocketFactory. Doing so connects our PayloadSocketAcceptorInterceptor with the RSocket infrastructure.

Spring Boot registers it automatically in RSocketSecurityAutoConfiguration when you include the correct dependencies.

Or, if you are not using Boot’s auto-configuration, you can register it manually in the following way:

Java
Kotlin

@Bean
RSocketServerCustomizer springSecurityRSocketSecurity(SecuritySocketAcceptorInterceptor interceptor) {
    return (server) -> server.interceptors((registry) -> registry.forSocketAcceptor(interceptor));
}

@Bean
fun springSecurityRSocketSecurity(interceptor: SecuritySocketAcceptorInterceptor): RSocketServerCustomizer {
    return RSocketServerCustomizer { server ->
        server.interceptors { registry ->
            registry.forSocketAcceptor(interceptor)
        }
    }
}

To customize the interceptor itself, use RSocketSecurity to add authentication and authorization.

RSocket Authentication

RSocket authentication is performed with AuthenticationPayloadInterceptor, which acts as a controller to invoke a ReactiveAuthenticationManager instance.

Authentication at Setup versus Request Time

Generally, authentication can occur at setup time or at request time or both.

Authentication at setup time makes sense in a few scenarios. A common scenarios is when a single user (such as a mobile connection) uses an RSocket connection. In this case, only a single user uses the connection, so authentication can be done once at connection time.

In a scenario where the RSocket connection is shared, it makes sense to send credentials on each request. For example, a web application that connects to an RSocket server as a downstream service would make a single connection that all users use. In this case, if the RSocket server needs to perform authorization based on the web application’s users credentials, authentication for each request makes sense.

In some scenarios, authentication at both setup and for each request makes sense. Consider a web application, as described previously. If we need to restrict the connection to the web application itself, we can provide a credential with a SETUP authority at connection time. Then each user can have different authorities but not the SETUP authority. This means that individual users can make requests but not make additional connections.

Simple Authentication

Spring Security has support for the Simple Authentication Metadata Extension.

Basic Authentication evolved into Simple Authentication and is only supported for backward compatibility. See RSocketSecurity.basicAuthentication(Customizer) for setting it up.

The RSocket receiver can decode the credentials by using AuthenticationPayloadExchangeConverter, which is automatically setup by using the simpleAuthentication portion of the DSL. The following example shows an explicit configuration:

Java
Kotlin

@Bean
PayloadSocketAcceptorInterceptor rsocketInterceptor(RSocketSecurity rsocket) {
	rsocket
		.authorizePayload(authorize ->
			authorize
					.anyRequest().authenticated()
					.anyExchange().permitAll()
		)
		.simpleAuthentication(Customizer.withDefaults());
	return rsocket.build();
}

@Bean
open fun rsocketInterceptor(rsocket: RSocketSecurity): PayloadSocketAcceptorInterceptor {
    rsocket
        .authorizePayload { authorize -> authorize
                .anyRequest().authenticated()
                .anyExchange().permitAll()
        }
        .simpleAuthentication(withDefaults())
    return rsocket.build()
}

The RSocket sender can send credentials by using SimpleAuthenticationEncoder, which you can add to Spring’s RSocketStrategies.

Java
Kotlin

RSocketStrategies.Builder strategies = ...;
strategies.encoder(new SimpleAuthenticationEncoder());

var strategies: RSocketStrategies.Builder = ...
strategies.encoder(SimpleAuthenticationEncoder())

You can then use it to send a username and password to the receiver in the setup:

Java
Kotlin

MimeType authenticationMimeType =
	MimeTypeUtils.parseMimeType(WellKnownMimeType.MESSAGE_RSOCKET_AUTHENTICATION.getString());
UsernamePasswordMetadata credentials = new UsernamePasswordMetadata("user", "password");
Mono<RSocketRequester> requester = RSocketRequester.builder()
	.setupMetadata(credentials, authenticationMimeType)
	.rsocketStrategies(strategies.build())
	.connectTcp(host, port);

val authenticationMimeType: MimeType =
    MimeTypeUtils.parseMimeType(WellKnownMimeType.MESSAGE_RSOCKET_AUTHENTICATION.string)
val credentials = UsernamePasswordMetadata("user", "password")
val requester: Mono<RSocketRequester> = RSocketRequester.builder()
    .setupMetadata(credentials, authenticationMimeType)
    .rsocketStrategies(strategies.build())
    .connectTcp(host, port)

Alternatively or additionally, a username and password can be sent in a request.

Java
Kotlin

Mono<RSocketRequester> requester;
UsernamePasswordMetadata credentials = new UsernamePasswordMetadata("user", "password");

public Mono<AirportLocation> findRadar(String code) {
	return this.requester.flatMap(req ->
		req.route("find.radar.{code}", code)
			.metadata(credentials, authenticationMimeType)
			.retrieveMono(AirportLocation.class)
	);
}

import org.springframework.messaging.rsocket.retrieveMono

// ...

var requester: Mono<RSocketRequester>? = null
var credentials = UsernamePasswordMetadata("user", "password")

open fun findRadar(code: String): Mono<AirportLocation> {
    return requester!!.flatMap { req ->
        req.route("find.radar.{code}", code)
            .metadata(credentials, authenticationMimeType)
            .retrieveMono<AirportLocation>()
    }
}

JWT

Spring Security has support for the Bearer Token Authentication Metadata Extension. The support comes in the form of authenticating a JWT (determining that the JWT is valid) and then using the JWT to make authorization decisions.

The RSocket receiver can decode the credentials by using BearerPayloadExchangeConverter, which is automatically setup by using the jwt portion of the DSL. The following listing shows an example configuration:

Java
Kotlin

@Bean
PayloadSocketAcceptorInterceptor rsocketInterceptor(RSocketSecurity rsocket) {
	rsocket
		.authorizePayload(authorize ->
			authorize
				.anyRequest().authenticated()
				.anyExchange().permitAll()
		)
		.jwt(Customizer.withDefaults());
	return rsocket.build();
}

@Bean
fun rsocketInterceptor(rsocket: RSocketSecurity): PayloadSocketAcceptorInterceptor {
    rsocket
        .authorizePayload { authorize -> authorize
            .anyRequest().authenticated()
            .anyExchange().permitAll()
        }
        .jwt(withDefaults())
    return rsocket.build()
}

The configuration above relies on the existence of a ReactiveJwtDecoder @Bean being present. An example of creating one from the issuer can be found below:

Java
Kotlin

@Bean
ReactiveJwtDecoder jwtDecoder() {
	return ReactiveJwtDecoders
		.fromIssuerLocation("https://example.com/auth/realms/demo");
}

@Bean
fun jwtDecoder(): ReactiveJwtDecoder {
    return ReactiveJwtDecoders
        .fromIssuerLocation("https://example.com/auth/realms/demo")
}

The RSocket sender does not need to do anything special to send the token, because the value is a simple String. The following example sends the token at setup time:

Java
Kotlin

MimeType authenticationMimeType =
	MimeTypeUtils.parseMimeType(WellKnownMimeType.MESSAGE_RSOCKET_AUTHENTICATION.getString());
BearerTokenMetadata token = ...;
Mono<RSocketRequester> requester = RSocketRequester.builder()
	.setupMetadata(token, authenticationMimeType)
	.connectTcp(host, port);

val authenticationMimeType: MimeType =
    MimeTypeUtils.parseMimeType(WellKnownMimeType.MESSAGE_RSOCKET_AUTHENTICATION.string)
val token: BearerTokenMetadata = ...

val requester = RSocketRequester.builder()
    .setupMetadata(token, authenticationMimeType)
    .connectTcp(host, port)

Alternatively or additionally, you can send the token in a request:

Java
Kotlin

MimeType authenticationMimeType =
	MimeTypeUtils.parseMimeType(WellKnownMimeType.MESSAGE_RSOCKET_AUTHENTICATION.getString());
Mono<RSocketRequester> requester;
BearerTokenMetadata token = ...;

public Mono<AirportLocation> findRadar(String code) {
	return this.requester.flatMap(req ->
		req.route("find.radar.{code}", code)
	        .metadata(token, authenticationMimeType)
			.retrieveMono(AirportLocation.class)
	);
}

val authenticationMimeType: MimeType =
    MimeTypeUtils.parseMimeType(WellKnownMimeType.MESSAGE_RSOCKET_AUTHENTICATION.string)
var requester: Mono<RSocketRequester>? = null
val token: BearerTokenMetadata = ...

open fun findRadar(code: String): Mono<AirportLocation> {
    return this.requester!!.flatMap { req ->
        req.route("find.radar.{code}", code)
            .metadata(token, authenticationMimeType)
            .retrieveMono<AirportLocation>()
    }
}

RSocket Authorization

RSocket authorization is performed with AuthorizationPayloadInterceptor, which acts as a controller to invoke a ReactiveAuthorizationManager instance. You can use the DSL to set up authorization rules based upon the PayloadExchange. The following listing shows an example configuration:

Java
Kotlin

rsocket
	.authorizePayload(authz ->
		authz
			.setup().hasRole("SETUP") (1)
			.route("fetch.profile.me").authenticated() (2)
			.matcher(payloadExchange -> isMatch(payloadExchange)) (3)
				.hasRole("CUSTOM")
			.route("fetch.profile.{username}") (4)
				.access((authentication, context) -> checkFriends(authentication, context))
			.anyRequest().authenticated() (5)
			.anyExchange().permitAll() (6)
	);

rsocket
    .authorizePayload { authz ->
        authz
            .setup().hasRole("SETUP") (1)
            .route("fetch.profile.me").authenticated() (2)
            .matcher { payloadExchange -> isMatch(payloadExchange) } (3)
            .hasRole("CUSTOM")
            .route("fetch.profile.{username}") (4)
            .access { authentication, context -> checkFriends(authentication, context) }
            .anyRequest().authenticated() (5)
            .anyExchange().permitAll()
    } (6)

1	Setting up a connection requires the `ROLE_SETUP` authority.
2	If the route is `fetch.profile.me`, authorization only requires the user to be authenticated.
3	In this rule, we set up a custom matcher, where authorization requires the user to have the `ROLE_CUSTOM` authority.
4	This rule uses custom authorization. The matcher expresses a variable with a name of `username` that is made available in the `context`. A custom authorization rule is exposed in the `checkFriends` method.
5	This rule ensures that a request that does not already have a rule requires the user to be authenticated. A request is where the metadata is included. It would not include additional payloads.
6	This rule ensures that any exchange that does not already have a rule is allowed for anyone. In this example, it means that payloads that have no metadata also have no authorization rules.

Note that authorization rules are performed in order. Only the first authorization rule that matches is invoked.