Advanced Configuration

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.

ServerHttpSecurity.oauth2Login() provides a number of configuration options for customizing OAuth 2.0 Login.

The following code shows the complete configuration options available for the oauth2Login() DSL:

OAuth2 Login Configuration Options
  • Java

  • Kotlin

@Configuration
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
		http
			.oauth2Login(oauth2 -> oauth2
				.authenticationConverter(this.authenticationConverter())
				.authenticationMatcher(this.authenticationMatcher())
				.authenticationManager(this.authenticationManager())
				.authenticationSuccessHandler(this.authenticationSuccessHandler())
				.authenticationFailureHandler(this.authenticationFailureHandler())
				.clientRegistrationRepository(this.clientRegistrationRepository())
				.authorizedClientRepository(this.authorizedClientRepository())
				.authorizedClientService(this.authorizedClientService())
				.authorizationRequestResolver(this.authorizationRequestResolver())
				.authorizationRequestRepository(this.authorizationRequestRepository())
				.securityContextRepository(this.securityContextRepository())
			);

		return http.build();
	}
}
@Configuration
@EnableWebFluxSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
        http {
            oauth2Login {
                authenticationConverter = authenticationConverter()
                authenticationMatcher = authenticationMatcher()
                authenticationManager = authenticationManager()
                authenticationSuccessHandler = authenticationSuccessHandler()
                authenticationFailureHandler = authenticationFailureHandler()
                clientRegistrationRepository = clientRegistrationRepository()
                authorizedClientRepository = authorizedClientRepository()
                authorizedClientService = authorizedClientService()
                authorizationRequestResolver = authorizationRequestResolver()
                authorizationRequestRepository = authorizationRequestRepository()
                securityContextRepository = securityContextRepository()
            }
        }

        return http.build()
    }
}

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 LoginPageGeneratingWebFilter. 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 LoginPageGeneratingWebFilter to show links for configured OAuth Clients, the registered ReactiveClientRegistrationRepository needs to also implement Iterable<ClientRegistration>. See InMemoryReactiveClientRegistrationRepository for reference.

The link’s destination for each OAuth Client defaults to the following:

"/oauth2/authorization/{registrationId}"

The following line shows an example:

<a href="/oauth2/authorization/google">Google</a>

To override the default login page, configure the exceptionHandling().authenticationEntryPoint() and (optionally) oauth2Login().authorizationRequestResolver().

The following listing shows an example:

OAuth2 Login Page Configuration
  • Java

  • Kotlin

@Configuration
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
		http
			.exceptionHandling(exceptionHandling -> exceptionHandling
				.authenticationEntryPoint(new RedirectServerAuthenticationEntryPoint("/login/oauth2"))
			)
			.oauth2Login(oauth2 -> oauth2
				.authorizationRequestResolver(this.authorizationRequestResolver())
			);

		return http.build();
	}

	private ServerOAuth2AuthorizationRequestResolver authorizationRequestResolver() {
		ServerWebExchangeMatcher authorizationRequestMatcher =
				new PathPatternParserServerWebExchangeMatcher(
						"/login/oauth2/authorization/{registrationId}");

		return new DefaultServerOAuth2AuthorizationRequestResolver(
				this.clientRegistrationRepository(), authorizationRequestMatcher);
	}

	...
}
@Configuration
@EnableWebFluxSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
        http {
            exceptionHandling {
                authenticationEntryPoint = RedirectServerAuthenticationEntryPoint("/login/oauth2")
            }
            oauth2Login {
                authorizationRequestResolver = authorizationRequestResolver()
            }
        }

        return http.build()
    }

    private fun authorizationRequestResolver(): ServerOAuth2AuthorizationRequestResolver {
        val authorizationRequestMatcher: ServerWebExchangeMatcher = PathPatternParserServerWebExchangeMatcher(
            "/login/oauth2/authorization/{registrationId}"
        )

        return DefaultServerOAuth2AuthorizationRequestResolver(
            clientRegistrationRepository(), authorizationRequestMatcher
        )
    }

    ...
}
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().authorizationRequestResolver() is optional. However, if you choose to customize it, ensure the link to each OAuth Client matches the pattern provided through the ServerWebExchangeMatcher.

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 redirection endpoint is /login/oauth2/code/{registrationId}.

If you would like to customize the Authorization Response redirection endpoint, configure it as shown in the following example:

Redirection Endpoint Configuration
  • Java

  • Kotlin

@Configuration
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
		http
			.oauth2Login(oauth2 -> oauth2
				.authenticationMatcher(new PathPatternParserServerWebExchangeMatcher("/login/oauth2/callback/{registrationId}"))
			);

		return http.build();
	}
}
@Configuration
@EnableWebFluxSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
        http {
            oauth2Login {
                authenticationMatcher = PathPatternParserServerWebExchangeMatcher("/login/oauth2/callback/{registrationId}")
            }
        }

        return http.build()
    }
}

You also need to ensure the ClientRegistration.redirectUri matches the custom Authorization Response redirection endpoint.

The following listing shows an example:

  • Java

  • Kotlin

return CommonOAuth2Provider.GOOGLE.getBuilder("google")
	.clientId("google-client-id")
	.clientSecret("google-client-secret")
	.redirectUri("{baseUrl}/login/oauth2/callback/{registrationId}")
	.build();
return CommonOAuth2Provider.GOOGLE.getBuilder("google")
    .clientId("google-client-id")
    .clientSecret("google-client-secret")
    .redirectUri("{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()) contains a list of granted authorities populated from OAuth2UserRequest.getAccessToken().getScopes() and prefixed with SCOPE_. These granted authorities 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

The GrantedAuthoritiesMapper is given a list of granted authorities which contains a special authority of type OAuth2UserAuthority and the authority string OAUTH2_USER (or OidcUserAuthority and the authority string OIDC_USER).

Register a GrantedAuthoritiesMapper @Bean to have it automatically applied to the configuration, as shown in the following example:

Granted Authorities Mapper Configuration
  • Java

  • Kotlin

@Configuration
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
		http
			...
			.oauth2Login(withDefaults());

		return http.build();
	}

	@Bean
	public 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;
		};
	}
}
@Configuration
@EnableWebFluxSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
        http {
            oauth2Login { }
        }

        return http.build()
    }

    @Bean
    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
    }
}

Delegation-based strategy with ReactiveOAuth2UserService

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:

ReactiveOAuth2UserService Configuration
  • Java

  • Kotlin

@Configuration
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
		http
			...
			.oauth2Login(withDefaults());

		return http.build();
	}

	@Bean
	public ReactiveOAuth2UserService<OidcUserRequest, OidcUser> oidcUserService() {
		final OidcReactiveOAuth2UserService delegate = new OidcReactiveOAuth2UserService();

		return (userRequest) -> {
			// Delegate to the default implementation for loading a user
			return delegate.loadUser(userRequest)
					.flatMap((oidcUser) -> {
						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 Mono.just(oidcUser);
					});
		};
	}
}
@Configuration
@EnableWebFluxSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
        http {
            oauth2Login { }
        }

        return http.build()
    }

    @Bean
    fun oidcUserService(): ReactiveOAuth2UserService<OidcUserRequest, OidcUser> {
        val delegate = OidcReactiveOAuth2UserService()

        return ReactiveOAuth2UserService { userRequest ->
            // Delegate to the default implementation for loading a user
            delegate.loadUser(userRequest)
                .flatMap { oidcUser ->
                    val accessToken = userRequest.accessToken
                    val mappedAuthorities = mutableSetOf<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
                    val mappedOidcUser = DefaultOidcUser(mappedAuthorities, oidcUser.idToken, oidcUser.userInfo)

                    Mono.just(mappedOidcUser)
                }
        }
    }
}

OAuth 2.0 UserService

DefaultReactiveOAuth2UserService is an implementation of a ReactiveOAuth2UserService that supports standard OAuth 2.0 Provider’s.

ReactiveOAuth2UserService 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.

DefaultReactiveOAuth2UserService uses a WebClient 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 DefaultReactiveOAuth2UserService.setWebClient() with a custom configured WebClient.

Whether you customize DefaultReactiveOAuth2UserService or provide your own implementation of ReactiveOAuth2UserService, you’ll need to configure it as shown in the following example:

  • Java

  • Kotlin

@Configuration
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
		http
			...
			.oauth2Login(withDefaults());

		return http.build();
	}

	@Bean
	public ReactiveOAuth2UserService<OAuth2UserRequest, OAuth2User> oauth2UserService() {
		...
	}
}
@Configuration
@EnableWebFluxSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
        http {
            oauth2Login { }
        }

        return http.build()
    }

    @Bean
    fun oauth2UserService(): ReactiveOAuth2UserService<OAuth2UserRequest, OAuth2User> {
        // ...
    }
}

OpenID Connect 1.0 UserService

OidcReactiveOAuth2UserService is an implementation of a ReactiveOAuth2UserService that supports OpenID Connect 1.0 Provider’s.

The OidcReactiveOAuth2UserService leverages the DefaultReactiveOAuth2UserService 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 OidcReactiveOAuth2UserService.setOauth2UserService() with a custom configured ReactiveOAuth2UserService.

Whether you customize OidcReactiveOAuth2UserService or provide your own implementation of ReactiveOAuth2UserService for OpenID Connect 1.0 Provider’s, you’ll need to configure it as shown in the following example:

  • Java

  • Kotlin

@Configuration
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
		http
			...
			.oauth2Login(withDefaults());

		return http.build();
	}

	@Bean
	public ReactiveOAuth2UserService<OidcUserRequest, OidcUser> oidcUserService() {
		...
	}
}
@Configuration
@EnableWebFluxSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
        http {
            oauth2Login { }
        }

        return http.build()
    }

    @Bean
    fun oidcUserService(): ReactiveOAuth2UserService<OidcUserRequest, OidcUser> {
        // ...
    }
}

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 ReactiveOidcIdTokenDecoderFactory provides a ReactiveJwtDecoder 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:

  • Java

  • Kotlin

@Bean
public ReactiveJwtDecoderFactory<ClientRegistration> idTokenDecoderFactory() {
	ReactiveOidcIdTokenDecoderFactory idTokenDecoderFactory = new ReactiveOidcIdTokenDecoderFactory();
	idTokenDecoderFactory.setJwsAlgorithmResolver(clientRegistration -> MacAlgorithm.HS256);
	return idTokenDecoderFactory;
}
@Bean
fun idTokenDecoderFactory(): ReactiveJwtDecoderFactory<ClientRegistration> {
    val idTokenDecoderFactory = ReactiveOidcIdTokenDecoderFactory()
    idTokenDecoderFactory.setJwsAlgorithmResolver { 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.

Then, you can proceed to configure logout.