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:

Advanced OAuth2 Login Configuration

Java
Kotlin

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
			.oauth2Login(oauth2 -> oauth2
			    .authorizationEndpoint(authorization -> authorization
			            ...
			    )
			    .redirectionEndpoint(redirection -> redirection
			            ...
			    )
			    .tokenEndpoint(token -> token
			            ...
			    )
			    .userInfoEndpoint(userInfo -> userInfo
			            ...
			    )
			);
		return http.build();
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Login {
                authorizationEndpoint {
                    ...
                }
                redirectionEndpoint {
                    ...
                }
                tokenEndpoint {
                    ...
                }
                userInfoEndpoint {
                    ...
                }
            }
        }
        return http.build()
    }
}

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 uses two authorization server endpoints (HTTP resources):

Authorization Endpoint: Used by the client to obtain authorization from the resource owner through user-agent redirection.
Token Endpoint: Used by the client to exchange an authorization grant for an access token, typically with client authentication.

The authorization process also uses one client endpoint:

Redirection Endpoint: Used by the authorization server to return responses that contain authorization credentials to the client through 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:

OAuth2 Login Configuration Options

Java
Kotlin

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityFilterChain filterChain(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())
			    )
			);
		return http.build();
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        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()
                }
            }
        }
        return http.build()
    }
}

In addition to the oauth2Login() DSL, XML configuration is also supported.

The following code shows the complete configuration options available in the security namespace:

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
Redirection Endpoint
UserInfo Endpoint
ID Token Signature Verification
[oauth2login-advanced-oidc-logout]

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).

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:

OAuth2 Login Page Configuration

Java
Kotlin
Xml

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
			.oauth2Login(oauth2 -> oauth2
			    .loginPage("/login/oauth2")
			    ...
			    .authorizationEndpoint(authorization -> authorization
			        .baseUri("/login/oauth2/authorization")
			        ...
			    )
			);
		return http.build();
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Login {
                loginPage = "/login/oauth2"
                authorizationEndpoint {
                    baseUri = "/login/oauth2/authorization"
                }
            }
        }
        return http.build()
    }
}

<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 through 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 follows:

Redirection Endpoint Configuration

Java
Kotlin
Xml

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

    @Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
			.oauth2Login(oauth2 -> oauth2
			    .redirectionEndpoint(redirection -> redirection
			        .baseUri("/login/oauth2/callback/*")
			        ...
			    )
			);
		return http.build();
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Login {
                redirectionEndpoint {
                    baseUri = "/login/oauth2/callback/*"
                }
            }
        }
        return http.build()
    }
}

<http>
	<oauth2-login login-processing-url="/login/oauth2/callback/*"
				  ...
    />
</http>

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

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
OAuth 2.0 UserService
OpenID Connect 1.0 UserService

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 can be mapped to a new set of GrantedAuthority instances, which are 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
Delegation-based Strategy with OAuth2UserService

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).

Provide an implementation of GrantedAuthoritiesMapper and configure it, as follows:

Granted Authorities Mapper Configuration

Java
Kotlin
Xml

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

    @Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
			.oauth2Login(oauth2 -> oauth2
			    .userInfoEndpoint(userInfo -> userInfo
			        .userAuthoritiesMapper(this.userAuthoritiesMapper())
			        ...
			    )
			);
		return http.build();
	}

	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;
		};
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Login {
                userInfoEndpoint {
                    userAuthoritiesMapper = userAuthoritiesMapper()
                }
            }
        }
        return http.build()
    }

    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
    }
}

<http>
	<oauth2-login user-authorities-mapper-ref="userAuthoritiesMapper"
				  ...
    />
</http>

Alternatively, you can register a GrantedAuthoritiesMapper @Bean to have it automatically applied to the configuration, as follows:

Granted Authorities Mapper Bean Configuration

Java
Kotlin

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
		    .oauth2Login(withDefaults());
		return http.build();
	}

	@Bean
	public GrantedAuthoritiesMapper userAuthoritiesMapper() {
		...
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Login { }
        }
        return http.build()
    }

    @Bean
    fun userAuthoritiesMapper(): GrantedAuthoritiesMapper {
        ...
    }
}

Delegation-based Strategy with OAuth2UserService

This strategy is advanced compared to using a GrantedAuthoritiesMapper. However, it is 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 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:

OAuth2UserService Configuration

Java
Kotlin
Xml

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
			.oauth2Login(oauth2 -> oauth2
			    .userInfoEndpoint(userInfo -> userInfo
			        .oidcUserService(this.oidcUserService())
			        ...
			    )
			);
		return http.build();
	}

	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
			ProviderDetails providerDetails = userRequest.getClientRegistration().getProviderDetails();
			String userNameAttributeName = providerDetails.getUserInfoEndpoint().getUserNameAttributeName();
			if (StringUtils.hasText(userNameAttributeName)) {
				oidcUser = new DefaultOidcUser(mappedAuthorities, oidcUser.getIdToken(), oidcUser.getUserInfo(), userNameAttributeName);
			} else {
				oidcUser = new DefaultOidcUser(mappedAuthorities, oidcUser.getIdToken(), oidcUser.getUserInfo());
			}

			return oidcUser;
		};
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig  {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Login {
                userInfoEndpoint {
                    oidcUserService = oidcUserService()
                }
            }
        }
        return http.build()
    }

    @Bean
    fun oidcUserService(): OAuth2UserService<OidcUserRequest, OidcUser> {
        val delegate = OidcUserService()

        return OAuth2UserService { userRequest ->
            // Delegate to the default implementation for loading a user
            val 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
            val providerDetails = userRequest.getClientRegistration().getProviderDetails()
            val userNameAttributeName = providerDetails.getUserInfoEndpoint().getUserNameAttributeName()
            if (StringUtils.hasText(userNameAttributeName)) {
                DefaultOidcUser(mappedAuthorities, oidcUser.idToken, oidcUser.userInfo, userNameAttributeName)
            } else {
                DefaultOidcUser(mappedAuthorities, oidcUser.idToken, oidcUser.userInfo)
            }
        }
    }
}

<http>
	<oauth2-login oidc-user-service-ref="oidcUserService"
				  ...
    />
</http>

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 instance 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 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 need to configure it as follows:

Java
Kotlin

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
			.oauth2Login(oauth2 -> oauth2
			    .userInfoEndpoint(userInfo -> userInfo
			        .userService(this.oauth2UserService())
			        ...
			    )
			);
		return http.build();
	}

	private OAuth2UserService<OAuth2UserRequest, OAuth2User> oauth2UserService() {
		...
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Login {
                userInfoEndpoint {
                    userService = oauth2UserService()
                    // ...
                }
            }
        }
        return http.build()
    }

    private fun oauth2UserService(): OAuth2UserService<OAuth2UserRequest, OAuth2User> {
        // ...
    }
}

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 or the post-handling of the UserInfo Response, you 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 need to configure it as follows:

Java
Kotlin

@Configuration
@EnableWebSecurity
public class OAuth2LoginSecurityConfig {

	@Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
			.oauth2Login(oauth2 -> oauth2
				.userInfoEndpoint(userInfo -> userInfo
				    .oidcUserService(this.oidcUserService())
				    ...
			    )
			);
		return http.build();
	}

	private OAuth2UserService<OidcUserRequest, OidcUser> oidcUserService() {
		...
	}
}

@Configuration
@EnableWebSecurity
class OAuth2LoginSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Login {
                userInfoEndpoint {
                    oidcUserService = oidcUserService()
                    // ...
                }
            }
        }
        return http.build()
    }

    private fun oidcUserService(): OAuth2UserService<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 by 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, you can configure a resolver 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, such as SignatureAlgorithm.RS256 or MacAlgorithm.HS256

The following code shows how to configure the OidcIdTokenDecoderFactory @Bean to default to MacAlgorithm.HS256 for all ClientRegistration instances:

Java
Kotlin

@Bean
public JwtDecoderFactory<ClientRegistration> idTokenDecoderFactory() {
	OidcIdTokenDecoderFactory idTokenDecoderFactory = new OidcIdTokenDecoderFactory();
	idTokenDecoderFactory.setJwsAlgorithmResolver(clientRegistration -> MacAlgorithm.HS256);
	return idTokenDecoderFactory;
}

@Bean
fun idTokenDecoderFactory(): JwtDecoderFactory<ClientRegistration?> {
    val idTokenDecoderFactory = OidcIdTokenDecoderFactory()
    idTokenDecoderFactory.setJwsAlgorithmResolver { MacAlgorithm.HS256 }
    return idTokenDecoderFactory
}

For MAC-based algorithms (such as HS256, HS384, or HS512), the client-secret that corresponds 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