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 found in the PayloadSocketAcceptorInterceptor which adapts the RSocket APIs to allow intercepting a PayloadExchange with PayloadInterceptor implementations.

You can find a few sample applications that demonstrate the code below:

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. This is what connects our PayloadSocketAcceptorInterceptor we created with the RSocket infrastructure. In a Spring Boot application this is done automatically using RSocketSecurityAutoConfiguration with the following code.

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

RSocket Authentication

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

Authentication at Setup vs Request Time

Generally, authentication can occur at setup time and/or request time.

Authentication at setup time makes sense in a few scenarios. A common scenarios is when a single user (i.e. mobile connection) is leveraging an RSocket connection. In this case only a single user is leveraging 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 leverage. In this case, if the RSocket server needs to perform authorization based on the web application’s users credentials per request makes sense.

In some scenarios authentication at setup and per 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 would 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 Simple Authentication Metadata Extension.

Basic Authentication drafts 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 using AuthenticationPayloadExchangeConverter which is automatically setup using the simpleAuthentication portion of the DSL. An explicit configuration can be found below.

  • 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 using SimpleAuthenticationEncoder which can be added to Spring’s RSocketStrategies.

  • Java

  • Kotlin

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

It can then be used 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 Bearer Token Authentication Metadata Extension. The support comes in the form of authenticating a JWT (determining the JWT is valid) and then using the JWT to make authorization decisions.

The RSocket receiver can decode the credentials using BearerPayloadExchangeConverter which is automatically setup using the jwt portion of the DSL. An example configuration can be found below:

  • 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 just a simple String. For example, the token can be sent 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, the token can be sent 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. The DSL can be used to setup authorization rules based upon the PayloadExchange. An example configuration can be found below:

  • 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 authority ROLE_SETUP
2 If the route is fetch.profile.me authorization only requires the user be authenticated
3 In this rule we setup a custom matcher where authorization requires the user to have the authority ROLE_CUSTOM
4 This rule leverages custom authorization. The matcher expresses a variable with the name username that is made available in the context. A custom authorization rule is exposed in the checkFriends method.
5 This rule ensures that request that does not already have a rule will require 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 have no authorization rules.

It is important to understand that authorization rules are performed in order. Only the first authorization rule that matches will be invoked.