Add OIDC Back-Channel Logout Support

Closes gh-12570

config/src/main/java/org/springframework/security/config/annotation/web/builders/HttpSecurity.java

@@ -70,6 +70,7 @@ import org.springframework.security.config.annotation.web.configurers.SessionMan
 import org.springframework.security.config.annotation.web.configurers.X509Configurer;
 import org.springframework.security.config.annotation.web.configurers.oauth2.client.OAuth2ClientConfigurer;
 import org.springframework.security.config.annotation.web.configurers.oauth2.client.OAuth2LoginConfigurer;
+import org.springframework.security.config.annotation.web.configurers.oauth2.client.OidcLogoutConfigurer;
 import org.springframework.security.config.annotation.web.configurers.oauth2.server.resource.OAuth2ResourceServerConfigurer;
 import org.springframework.security.config.annotation.web.configurers.saml2.Saml2LoginConfigurer;
 import org.springframework.security.config.annotation.web.configurers.saml2.Saml2LogoutConfigurer;
@@ -2835,6 +2836,16 @@ public final class HttpSecurity extends AbstractConfiguredSecurityBuilder<Defaul
 		return HttpSecurity.this;
 	}
 
+	public OidcLogoutConfigurer<HttpSecurity> oidcLogout() throws Exception {
+		return getOrApply(new OidcLogoutConfigurer<>());
+	}
+
+	public HttpSecurity oidcLogout(Customizer<OidcLogoutConfigurer<HttpSecurity>> oidcLogoutCustomizer)
+			throws Exception {
+		oidcLogoutCustomizer.customize(getOrApply(new OidcLogoutConfigurer<>()));
+		return HttpSecurity.this;
+	}
+
 	/**
 	 * Configures OAuth 2.0 Client support.
 	 * @return the {@link OAuth2ClientConfigurer} for further customizations

config/src/main/java/org/springframework/security/config/annotation/web/configurers/SessionManagementConfigurer.java

@@ -296,7 +296,7 @@ public final class SessionManagementConfigurer<H extends HttpSecurityBuilder<H>>
 	 * @param sessionAuthenticationStrategy
 	 * @return the {@link SessionManagementConfigurer} for further customizations
 	 */
-	SessionManagementConfigurer<H> addSessionAuthenticationStrategy(
+	public SessionManagementConfigurer<H> addSessionAuthenticationStrategy(
 			SessionAuthenticationStrategy sessionAuthenticationStrategy) {
 		this.sessionAuthenticationStrategies.add(sessionAuthenticationStrategy);
 		return this;

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/DefaultOidcLogoutTokenValidatorFactory.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import java.util.function.Function;
+
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.core.DelegatingOAuth2TokenValidator;
+import org.springframework.security.oauth2.core.OAuth2TokenValidator;
+import org.springframework.security.oauth2.jwt.Jwt;
+import org.springframework.security.oauth2.jwt.JwtTimestampValidator;
+
+final class DefaultOidcLogoutTokenValidatorFactory implements Function<ClientRegistration, OAuth2TokenValidator<Jwt>> {
+
+	@Override
+	public OAuth2TokenValidator<Jwt> apply(ClientRegistration clientRegistration) {
+		return new DelegatingOAuth2TokenValidator<>(new JwtTimestampValidator(),
+				new OidcBackChannelLogoutTokenValidator(clientRegistration));
+	}
+
+}

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OAuth2ClientConfigurerUtils.java

@@ -25,6 +25,8 @@ import org.springframework.security.config.annotation.web.HttpSecurityBuilder;
 import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
 import org.springframework.security.oauth2.client.InMemoryOAuth2AuthorizedClientService;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
+import org.springframework.security.oauth2.client.oidc.session.InMemoryOidcSessionRegistry;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionRegistry;
 import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
 import org.springframework.security.oauth2.client.web.AuthenticatedPrincipalOAuth2AuthorizedClientRepository;
 import org.springframework.security.oauth2.client.web.OAuth2AuthorizedClientRepository;
@@ -112,4 +114,13 @@ final class OAuth2ClientConfigurerUtils {
 		return (!authorizedClientServiceMap.isEmpty() ? authorizedClientServiceMap.values().iterator().next() : null);
 	}
 
+	static <B extends HttpSecurityBuilder<B>> OidcSessionRegistry getOidcSessionRegistry(B builder) {
+		OidcSessionRegistry sessionRegistry = builder.getSharedObject(OidcSessionRegistry.class);
+		if (sessionRegistry == null) {
+			sessionRegistry = new InMemoryOidcSessionRegistry();
+			builder.setSharedObject(OidcSessionRegistry.class, sessionRegistry);
+		}
+		return sessionRegistry;
+	}
+
 }

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OAuth2LoginConfigurer.java

@@ -22,9 +22,18 @@ import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import jakarta.servlet.http.HttpSession;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
 import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.event.GenericApplicationListenerAdapter;
+import org.springframework.context.event.SmartApplicationListener;
 import org.springframework.core.ResolvableType;
 import org.springframework.security.authentication.AuthenticationProvider;
 import org.springframework.security.config.Customizer;
@@ -32,9 +41,14 @@ import org.springframework.security.config.annotation.web.HttpSecurityBuilder;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configurers.AbstractAuthenticationFilterConfigurer;
 import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
+import org.springframework.security.config.annotation.web.configurers.SessionManagementConfigurer;
+import org.springframework.security.context.DelegatingApplicationListener;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.AuthenticationException;
 import org.springframework.security.core.authority.mapping.GrantedAuthoritiesMapper;
+import org.springframework.security.core.session.AbstractSessionEvent;
+import org.springframework.security.core.session.SessionDestroyedEvent;
+import org.springframework.security.core.session.SessionIdChangedEvent;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
 import org.springframework.security.oauth2.client.authentication.OAuth2LoginAuthenticationProvider;
 import org.springframework.security.oauth2.client.authentication.OAuth2LoginAuthenticationToken;
@@ -42,6 +56,9 @@ import org.springframework.security.oauth2.client.endpoint.DefaultAuthorizationC
 import org.springframework.security.oauth2.client.endpoint.OAuth2AccessTokenResponseClient;
 import org.springframework.security.oauth2.client.endpoint.OAuth2AuthorizationCodeGrantRequest;
 import org.springframework.security.oauth2.client.oidc.authentication.OidcAuthorizationCodeAuthenticationProvider;
+import org.springframework.security.oauth2.client.oidc.session.InMemoryOidcSessionRegistry;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionInformation;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionRegistry;
 import org.springframework.security.oauth2.client.oidc.userinfo.OidcUserRequest;
 import org.springframework.security.oauth2.client.oidc.userinfo.OidcUserService;
 import org.springframework.security.oauth2.client.registration.ClientRegistration;
@@ -67,7 +84,10 @@ import org.springframework.security.web.AuthenticationEntryPoint;
 import org.springframework.security.web.RedirectStrategy;
 import org.springframework.security.web.authentication.DelegatingAuthenticationEntryPoint;
 import org.springframework.security.web.authentication.LoginUrlAuthenticationEntryPoint;
+import org.springframework.security.web.authentication.session.SessionAuthenticationException;
+import org.springframework.security.web.authentication.session.SessionAuthenticationStrategy;
 import org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter;
+import org.springframework.security.web.csrf.CsrfToken;
 import org.springframework.security.web.savedrequest.RequestCache;
 import org.springframework.security.web.util.matcher.AndRequestMatcher;
 import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
@@ -124,6 +144,7 @@ import org.springframework.util.ReflectionUtils;
  * <li>{@link DefaultLoginPageGeneratingFilter} - if {@link #loginPage(String)} is not
  * configured and {@code DefaultLoginPageGeneratingFilter} is available, then a default
  * login page will be made available</li>
+ * <li>{@link OidcSessionRegistry}</li>
  * </ul>
  *
  * @author Joe Grandja
@@ -202,6 +223,18 @@ public final class OAuth2LoginConfigurer<B extends HttpSecurityBuilder<B>>
 		return this;
 	}
 
+	/**
+	 * Sets the registry for managing the OIDC client-provider session link
+	 * @param oidcSessionRegistry the {@link OidcSessionRegistry} to use
+	 * @return the {@link OAuth2LoginConfigurer} for further configuration
+	 * @since 6.2
+	 */
+	public OAuth2LoginConfigurer<B> oidcSessionRegistry(OidcSessionRegistry oidcSessionRegistry) {
+		Assert.notNull(oidcSessionRegistry, "oidcSessionRegistry cannot be null");
+		getBuilder().setSharedObject(OidcSessionRegistry.class, oidcSessionRegistry);
+		return this;
+	}
+
 	/**
 	 * Returns the {@link AuthorizationEndpointConfig} for configuring the Authorization
 	 * Server's Authorization Endpoint.
@@ -397,6 +430,7 @@ public final class OAuth2LoginConfigurer<B extends HttpSecurityBuilder<B>>
 			authenticationFilter
 					.setAuthorizationRequestRepository(this.authorizationEndpointConfig.authorizationRequestRepository);
 		}
+		configureOidcSessionRegistry(http);
 		super.configure(http);
 	}
 
@@ -546,6 +580,29 @@ public final class OAuth2LoginConfigurer<B extends HttpSecurityBuilder<B>>
 		return AnyRequestMatcher.INSTANCE;
 	}
 
+	private void configureOidcSessionRegistry(B http) {
+		OidcSessionRegistry sessionRegistry = OAuth2ClientConfigurerUtils.getOidcSessionRegistry(http);
+		SessionManagementConfigurer<B> sessionConfigurer = http.getConfigurer(SessionManagementConfigurer.class);
+		if (sessionConfigurer != null) {
+			OidcSessionRegistryAuthenticationStrategy sessionAuthenticationStrategy = new OidcSessionRegistryAuthenticationStrategy();
+			sessionAuthenticationStrategy.setSessionRegistry(sessionRegistry);
+			sessionConfigurer.addSessionAuthenticationStrategy(sessionAuthenticationStrategy);
+		}
+		OidcClientSessionEventListener listener = new OidcClientSessionEventListener();
+		listener.setSessionRegistry(sessionRegistry);
+		registerDelegateApplicationListener(listener);
+	}
+
+	private void registerDelegateApplicationListener(ApplicationListener<?> delegate) {
+		DelegatingApplicationListener delegating = getBeanOrNull(
+				ResolvableType.forType(DelegatingApplicationListener.class));
+		if (delegating == null) {
+			return;
+		}
+		SmartApplicationListener smartListener = new GenericApplicationListenerAdapter(delegate);
+		delegating.addListener(smartListener);
+	}
+
 	/**
 	 * Configuration options for the Authorization Server's Authorization Endpoint.
 	 */
@@ -793,4 +850,83 @@ public final class OAuth2LoginConfigurer<B extends HttpSecurityBuilder<B>>
 
 	}
 
+	private static final class OidcClientSessionEventListener implements ApplicationListener<AbstractSessionEvent> {
+
+		private final Log logger = LogFactory.getLog(OidcClientSessionEventListener.class);
+
+		private OidcSessionRegistry sessionRegistry = new InMemoryOidcSessionRegistry();
+
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public void onApplicationEvent(AbstractSessionEvent event) {
+			if (event instanceof SessionDestroyedEvent destroyed) {
+				this.logger.debug("Received SessionDestroyedEvent");
+				this.sessionRegistry.removeSessionInformation(destroyed.getId());
+				return;
+			}
+			if (event instanceof SessionIdChangedEvent changed) {
+				this.logger.debug("Received SessionIdChangedEvent");
+				OidcSessionInformation information = this.sessionRegistry.removeSessionInformation(changed.getOldSessionId());
+				if (information == null) {
+					this.logger.debug("Failed to register new session id since old session id was not found in registry");
+					return;
+				}
+				this.sessionRegistry.saveSessionInformation(information.withSessionId(changed.getNewSessionId()));
+			}
+		}
+
+		/**
+		 * The registry where OIDC Provider sessions are linked to the Client session.
+		 * Defaults to in-memory storage.
+		 * @param sessionRegistry the {@link OidcSessionRegistry} to use
+		 */
+		void setSessionRegistry(OidcSessionRegistry sessionRegistry) {
+			Assert.notNull(sessionRegistry, "sessionRegistry cannot be null");
+			this.sessionRegistry = sessionRegistry;
+		}
+
+	}
+
+	private static final class OidcSessionRegistryAuthenticationStrategy implements SessionAuthenticationStrategy {
+
+		private final Log logger = LogFactory.getLog(getClass());
+
+		private OidcSessionRegistry sessionRegistry = new InMemoryOidcSessionRegistry();
+
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public void onAuthentication(Authentication authentication, HttpServletRequest request, HttpServletResponse response) throws SessionAuthenticationException {
+			HttpSession session = request.getSession(false);
+			if (session == null) {
+				return;
+			}
+			if (!(authentication.getPrincipal() instanceof OidcUser user)) {
+				return;
+			}
+			String sessionId = session.getId();
+			CsrfToken csrfToken = (CsrfToken) request.getAttribute(CsrfToken.class.getName());
+			Map<String, String> headers = (csrfToken != null) ? Map.of(csrfToken.getHeaderName(), csrfToken.getToken()) : Collections.emptyMap();
+			OidcSessionInformation registration = new OidcSessionInformation(sessionId, headers, user);
+			if (this.logger.isTraceEnabled()) {
+				this.logger.trace(String.format("Linking a provider [%s] session to this client's session", user.getIssuer()));
+			}
+			this.sessionRegistry.saveSessionInformation(registration);
+		}
+
+		/**
+		 * The registration for linking OIDC Provider Session information to the Client's
+		 * session. Defaults to in-memory storage.
+		 * @param sessionRegistry the {@link OidcSessionRegistry} to use
+		 */
+		void setSessionRegistry(OidcSessionRegistry sessionRegistry) {
+			Assert.notNull(sessionRegistry, "sessionRegistry cannot be null");
+			this.sessionRegistry = sessionRegistry;
+		}
+
+	}
+
 }

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OidcBackChannelLogoutAuthentication.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import java.util.Collections;
+
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
+
+/**
+ * An {@link org.springframework.security.core.Authentication} implementation that
+ * represents the result of authenticating an OIDC Logout token for the purposes of
+ * performing Back-Channel Logout.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see OidcLogoutAuthenticationToken
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html">OIDC Back-Channel
+ * Logout</a>
+ */
+class OidcBackChannelLogoutAuthentication extends AbstractAuthenticationToken {
+
+	private final OidcLogoutToken logoutToken;
+
+	/**
+	 * Construct an {@link OidcBackChannelLogoutAuthentication}
+	 * @param logoutToken a deserialized, verified OIDC Logout Token
+	 */
+	OidcBackChannelLogoutAuthentication(OidcLogoutToken logoutToken) {
+		super(Collections.emptyList());
+		this.logoutToken = logoutToken;
+		setAuthenticated(true);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public OidcLogoutToken getPrincipal() {
+		return this.logoutToken;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public OidcLogoutToken getCredentials() {
+		return this.logoutToken;
+	}
+
+}

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OidcBackChannelLogoutAuthenticationProvider.java

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import org.springframework.security.authentication.AuthenticationProvider;
+import org.springframework.security.authentication.AuthenticationServiceException;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.AuthenticationException;
+import org.springframework.security.oauth2.client.oidc.authentication.OidcIdTokenDecoderFactory;
+import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.oauth2.jwt.BadJwtException;
+import org.springframework.security.oauth2.jwt.Jwt;
+import org.springframework.security.oauth2.jwt.JwtDecoder;
+import org.springframework.security.oauth2.jwt.JwtDecoderFactory;
+import org.springframework.util.Assert;
+
+/**
+ * An {@link AuthenticationProvider} that authenticates an OIDC Logout Token; namely
+ * deserializing it, verifying its signature, and validating its claims.
+ *
+ * <p>
+ * Intended to be included in a
+ * {@link org.springframework.security.authentication.ProviderManager}
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see OidcLogoutAuthenticationToken
+ * @see org.springframework.security.authentication.ProviderManager
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html">OIDC Back-Channel
+ * Logout</a>
+ */
+final class OidcBackChannelLogoutAuthenticationProvider implements AuthenticationProvider {
+
+	private JwtDecoderFactory<ClientRegistration> logoutTokenDecoderFactory;
+
+	/**
+	 * Construct an {@link OidcBackChannelLogoutAuthenticationProvider}
+	 */
+	OidcBackChannelLogoutAuthenticationProvider() {
+		OidcIdTokenDecoderFactory logoutTokenDecoderFactory = new OidcIdTokenDecoderFactory();
+		logoutTokenDecoderFactory.setJwtValidatorFactory(new DefaultOidcLogoutTokenValidatorFactory());
+		this.logoutTokenDecoderFactory = logoutTokenDecoderFactory;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Authentication authenticate(Authentication authentication) throws AuthenticationException {
+		if (!(authentication instanceof OidcLogoutAuthenticationToken token)) {
+			return null;
+		}
+		String logoutToken = token.getLogoutToken();
+		ClientRegistration registration = token.getClientRegistration();
+		Jwt jwt = decode(registration, logoutToken);
+		OidcLogoutToken oidcLogoutToken = OidcLogoutToken.withTokenValue(logoutToken)
+				.claims((claims) -> claims.putAll(jwt.getClaims())).build();
+		return new OidcBackChannelLogoutAuthentication(oidcLogoutToken);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public boolean supports(Class<?> authentication) {
+		return OidcLogoutAuthenticationToken.class.isAssignableFrom(authentication);
+	}
+
+	private Jwt decode(ClientRegistration registration, String token) {
+		JwtDecoder logoutTokenDecoder = this.logoutTokenDecoderFactory.createDecoder(registration);
+		try {
+			return logoutTokenDecoder.decode(token);
+		}
+		catch (BadJwtException failed) {
+			OAuth2Error error = new OAuth2Error(OAuth2ErrorCodes.INVALID_REQUEST, failed.getMessage(),
+					"https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation");
+			throw new OAuth2AuthenticationException(error, failed);
+		}
+		catch (Exception failed) {
+			throw new AuthenticationServiceException(failed.getMessage(), failed);
+		}
+	}
+
+	/**
+	 * Use this {@link JwtDecoderFactory} to generate {@link JwtDecoder}s that correspond
+	 * to the {@link ClientRegistration} associated with the OIDC logout token.
+	 * @param logoutTokenDecoderFactory the {@link JwtDecoderFactory} to use
+	 */
+	void setLogoutTokenDecoderFactory(JwtDecoderFactory<ClientRegistration> logoutTokenDecoderFactory) {
+		Assert.notNull(logoutTokenDecoderFactory, "logoutTokenDecoderFactory cannot be null");
+		this.logoutTokenDecoderFactory = logoutTokenDecoderFactory;
+	}
+
+}

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OidcBackChannelLogoutFilter.java

@@ -0,0 +1,139 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import java.io.IOException;
+
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.http.server.ServletServerHttpResponse;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.AuthenticationServiceException;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.oauth2.core.http.converter.OAuth2ErrorHttpMessageConverter;
+import org.springframework.security.web.authentication.AuthenticationConverter;
+import org.springframework.security.web.authentication.logout.LogoutHandler;
+import org.springframework.util.Assert;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+/**
+ * A filter for the Client-side OIDC Back-Channel Logout endpoint
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html">OIDC Back-Channel Logout
+ * Spec</a>
+ */
+class OidcBackChannelLogoutFilter extends OncePerRequestFilter {
+
+	private final Log logger = LogFactory.getLog(getClass());
+
+	private final AuthenticationConverter authenticationConverter;
+
+	private final AuthenticationManager authenticationManager;
+
+	private final OAuth2ErrorHttpMessageConverter errorHttpMessageConverter = new OAuth2ErrorHttpMessageConverter();
+
+	private LogoutHandler logoutHandler = new OidcBackChannelLogoutHandler();
+
+	/**
+	 * Construct an {@link OidcBackChannelLogoutFilter}
+	 * @param authenticationConverter the {@link AuthenticationConverter} for deriving
+	 * Logout Token authentication
+	 * @param authenticationManager the {@link AuthenticationManager} for authenticating
+	 * Logout Tokens
+	 */
+	OidcBackChannelLogoutFilter(AuthenticationConverter authenticationConverter,
+			AuthenticationManager authenticationManager) {
+		Assert.notNull(authenticationConverter, "authenticationConverter cannot be null");
+		Assert.notNull(authenticationManager, "authenticationManager cannot be null");
+		this.authenticationConverter = authenticationConverter;
+		this.authenticationManager = authenticationManager;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
+			throws ServletException, IOException {
+		Authentication token;
+		try {
+			token = this.authenticationConverter.convert(request);
+		}
+		catch (AuthenticationServiceException ex) {
+			this.logger.debug("Failed to process OIDC Back-Channel Logout", ex);
+			throw ex;
+		}
+		catch (AuthenticationException ex) {
+			handleAuthenticationFailure(response, ex);
+			return;
+		}
+		if (token == null) {
+			chain.doFilter(request, response);
+			return;
+		}
+		Authentication authentication;
+		try {
+			authentication = this.authenticationManager.authenticate(token);
+		}
+		catch (AuthenticationServiceException ex) {
+			this.logger.debug("Failed to process OIDC Back-Channel Logout", ex);
+			throw ex;
+		}
+		catch (AuthenticationException ex) {
+			handleAuthenticationFailure(response, ex);
+			return;
+		}
+		this.logoutHandler.logout(request, response, authentication);
+	}
+
+	private void handleAuthenticationFailure(HttpServletResponse response, Exception ex) throws IOException {
+		this.logger.debug("Failed to process OIDC Back-Channel Logout", ex);
+		response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
+		this.errorHttpMessageConverter.write(oauth2Error(ex), null, new ServletServerHttpResponse(response));
+	}
+
+	private OAuth2Error oauth2Error(Exception ex) {
+		if (ex instanceof OAuth2AuthenticationException oauth2) {
+			return oauth2.getError();
+		}
+		return new OAuth2Error(OAuth2ErrorCodes.INVALID_REQUEST, ex.getMessage(),
+				"https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation");
+	}
+
+	/**
+	 * The strategy for expiring all Client sessions indicated by the logout request.
+	 * Defaults to {@link OidcBackChannelLogoutHandler}.
+	 * @param logoutHandler the {@link LogoutHandler} to use
+	 */
+	void setLogoutHandler(LogoutHandler logoutHandler) {
+		Assert.notNull(logoutHandler, "logoutHandler cannot be null");
+		this.logoutHandler = logoutHandler;
+	}
+
+}

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OidcBackChannelLogoutHandler.java

@@ -0,0 +1,175 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Map;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.server.ServletServerHttpResponse;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
+import org.springframework.security.oauth2.client.oidc.session.InMemoryOidcSessionRegistry;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionInformation;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionRegistry;
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.oauth2.core.http.converter.OAuth2ErrorHttpMessageConverter;
+import org.springframework.security.web.authentication.logout.LogoutHandler;
+import org.springframework.util.Assert;
+import org.springframework.web.client.RestClientException;
+import org.springframework.web.client.RestOperations;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.util.UriComponentsBuilder;
+
+/**
+ * A {@link LogoutHandler} that locates the sessions associated with a given OIDC
+ * Back-Channel Logout Token and invalidates each one.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html">OIDC Back-Channel Logout
+ * Spec</a>
+ */
+final class OidcBackChannelLogoutHandler implements LogoutHandler {
+
+	private final Log logger = LogFactory.getLog(getClass());
+
+	private OidcSessionRegistry sessionRegistry = new InMemoryOidcSessionRegistry();
+
+	private RestOperations restOperations = new RestTemplate();
+
+	private String logoutEndpointName = "/logout";
+
+	private String sessionCookieName = "JSESSIONID";
+
+	private final OAuth2ErrorHttpMessageConverter errorHttpMessageConverter = new OAuth2ErrorHttpMessageConverter();
+
+	@Override
+	public void logout(HttpServletRequest request, HttpServletResponse response, Authentication authentication) {
+		if (!(authentication instanceof OidcBackChannelLogoutAuthentication token)) {
+			if (this.logger.isDebugEnabled()) {
+				String message = "Did not perform OIDC Back-Channel Logout since authentication [%s] was of the wrong type";
+				this.logger.debug(String.format(message, authentication.getClass().getSimpleName()));
+			}
+			return;
+		}
+		Iterable<OidcSessionInformation> sessions = this.sessionRegistry.removeSessionInformation(token.getPrincipal());
+		Collection<String> errors = new ArrayList<>();
+		int totalCount = 0;
+		int invalidatedCount = 0;
+		for (OidcSessionInformation session : sessions) {
+			totalCount++;
+			try {
+				eachLogout(request, session);
+				invalidatedCount++;
+			}
+			catch (RestClientException ex) {
+				this.logger.debug("Failed to invalidate session", ex);
+				errors.add(ex.getMessage());
+				this.sessionRegistry.saveSessionInformation(session);
+			}
+		}
+		if (this.logger.isTraceEnabled()) {
+			this.logger.trace(String.format("Invalidated %d out of %d sessions", invalidatedCount, totalCount));
+		}
+		if (!errors.isEmpty()) {
+			handleLogoutFailure(response, oauth2Error(errors));
+		}
+	}
+
+	private void eachLogout(HttpServletRequest request, OidcSessionInformation session) {
+		HttpHeaders headers = new HttpHeaders();
+		headers.add(HttpHeaders.COOKIE, this.sessionCookieName + "=" + session.getSessionId());
+		for (Map.Entry<String, String> credential : session.getAuthorities().entrySet()) {
+			headers.add(credential.getKey(), credential.getValue());
+		}
+		String url = request.getRequestURL().toString();
+		String logout = UriComponentsBuilder.fromHttpUrl(url).replacePath(this.logoutEndpointName).build()
+				.toUriString();
+		HttpEntity<?> entity = new HttpEntity<>(null, headers);
+		this.restOperations.postForEntity(logout, entity, Object.class);
+	}
+
+	private OAuth2Error oauth2Error(Collection<String> errors) {
+		return new OAuth2Error("partial_logout", "not all sessions were terminated: " + errors,
+				"https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation");
+	}
+
+	private void handleLogoutFailure(HttpServletResponse response, OAuth2Error error) {
+		response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
+		try {
+			this.errorHttpMessageConverter.write(error, null, new ServletServerHttpResponse(response));
+		}
+		catch (IOException ex) {
+			throw new IllegalStateException(ex);
+		}
+	}
+
+	/**
+	 * Use this {@link OidcSessionRegistry} to identify sessions to invalidate. Note that
+	 * this class uses
+	 * {@link OidcSessionRegistry#removeSessionInformation(OidcLogoutToken)} to identify
+	 * sessions.
+	 * @param sessionRegistry the {@link OidcSessionRegistry} to use
+	 */
+	void setSessionRegistry(OidcSessionRegistry sessionRegistry) {
+		Assert.notNull(sessionRegistry, "sessionRegistry cannot be null");
+		this.sessionRegistry = sessionRegistry;
+	}
+
+	/**
+	 * Use this {@link RestOperations} to perform the per-session back-channel logout
+	 * @param restOperations the {@link RestOperations} to use
+	 */
+	void setRestOperations(RestOperations restOperations) {
+		Assert.notNull(restOperations, "restOperations cannot be null");
+		this.restOperations = restOperations;
+	}
+
+	/**
+	 * Use this logout URI for performing per-session logout. Defaults to {@code /logout}
+	 * since that is the default URI for
+	 * {@link org.springframework.security.web.authentication.logout.LogoutFilter}.
+	 * @param logoutUri the URI to use
+	 */
+	void setLogoutUri(String logoutUri) {
+		Assert.hasText(logoutUri, "logoutUri cannot be empty");
+		this.logoutEndpointName = logoutUri;
+	}
+
+	/**
+	 * Use this cookie name for the session identifier. Defaults to {@code JSESSIONID}.
+	 *
+	 * <p>
+	 * Note that if you are using Spring Session, this likely needs to change to SESSION.
+	 * @param sessionCookieName the cookie name to use
+	 */
+	void setSessionCookieName(String sessionCookieName) {
+		Assert.hasText(sessionCookieName, "clientSessionCookieName cannot be empty");
+		this.sessionCookieName = sessionCookieName;
+	}
+
+}

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OidcBackChannelLogoutTokenValidator.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.security.oauth2.client.oidc.authentication.logout.LogoutTokenClaimAccessor;
+import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.oauth2.core.OAuth2TokenValidator;
+import org.springframework.security.oauth2.core.OAuth2TokenValidatorResult;
+import org.springframework.security.oauth2.jwt.Jwt;
+
+/**
+ * A {@link OAuth2TokenValidator} that validates OIDC Logout Token claims in conformance
+ * with the OIDC Back-Channel Logout Spec.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see OidcLogoutToken
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html#LogoutToken">Logout
+ * Token</a>
+ * @see <a target="blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation">the OIDC
+ * Back-Channel Logout spec</a>
+ */
+final class OidcBackChannelLogoutTokenValidator implements OAuth2TokenValidator<Jwt> {
+
+	private static final String LOGOUT_VALIDATION_URL = "https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation";
+
+	private static final String BACK_CHANNEL_LOGOUT_EVENT = "http://schemas.openid.net/event/backchannel-logout";
+
+	private final String audience;
+
+	private final String issuer;
+
+	OidcBackChannelLogoutTokenValidator(ClientRegistration clientRegistration) {
+		this.audience = clientRegistration.getClientId();
+		this.issuer = clientRegistration.getProviderDetails().getIssuerUri();
+	}
+
+	@Override
+	public OAuth2TokenValidatorResult validate(Jwt jwt) {
+		Collection<OAuth2Error> errors = new ArrayList<>();
+
+		LogoutTokenClaimAccessor logoutClaims = jwt::getClaims;
+		Map<String, Object> events = logoutClaims.getEvents();
+		if (events == null) {
+			errors.add(invalidLogoutToken("events claim must not be null"));
+		}
+		else if (events.get(BACK_CHANNEL_LOGOUT_EVENT) == null) {
+			errors.add(invalidLogoutToken("events claim map must contain \"" + BACK_CHANNEL_LOGOUT_EVENT + "\" key"));
+		}
+
+		String issuer = logoutClaims.getIssuer().toExternalForm();
+		if (issuer == null) {
+			errors.add(invalidLogoutToken("iss claim must not be null"));
+		}
+		else if (!this.issuer.equals(issuer)) {
+			errors.add(invalidLogoutToken(
+					"iss claim value must match `ClientRegistration#getProviderDetails#getIssuerUri`"));
+		}
+
+		List<String> audience = logoutClaims.getAudience();
+		if (audience == null) {
+			errors.add(invalidLogoutToken("aud claim must not be null"));
+		}
+		else if (!audience.contains(this.audience)) {
+			errors.add(invalidLogoutToken("aud claim value must include `ClientRegistration#getClientId`"));
+		}
+
+		Instant issuedAt = logoutClaims.getIssuedAt();
+		if (issuedAt == null) {
+			errors.add(invalidLogoutToken("iat claim must not be null"));
+		}
+
+		String jwtId = logoutClaims.getId();
+		if (jwtId == null) {
+			errors.add(invalidLogoutToken("jti claim must not be null"));
+		}
+
+		if (logoutClaims.getSubject() == null && logoutClaims.getSessionId() == null) {
+			errors.add(invalidLogoutToken("sub and sid claims must not both be null"));
+		}
+
+		if (logoutClaims.getClaim("nonce") != null) {
+			errors.add(invalidLogoutToken("nonce claim must not be present"));
+		}
+
+		return OAuth2TokenValidatorResult.failure(errors);
+	}
+
+	private static OAuth2Error invalidLogoutToken(String description) {
+		return new OAuth2Error(OAuth2ErrorCodes.INVALID_TOKEN, description, LOGOUT_VALIDATION_URL);
+	}
+
+}

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OidcLogoutAuthenticationConverter.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import jakarta.servlet.http.HttpServletRequest;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.security.core.Authentication;
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.web.authentication.AuthenticationConverter;
+import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
+import org.springframework.security.web.util.matcher.RequestMatcher;
+import org.springframework.util.Assert;
+
+/**
+ * An {@link AuthenticationConverter} that extracts the OIDC Logout Token authentication
+ * request
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ */
+final class OidcLogoutAuthenticationConverter implements AuthenticationConverter {
+
+	private static final String DEFAULT_LOGOUT_URI = "/logout/connect/back-channel/{registrationId}";
+
+	private final Log logger = LogFactory.getLog(getClass());
+
+	private final ClientRegistrationRepository clientRegistrationRepository;
+
+	private RequestMatcher requestMatcher = new AntPathRequestMatcher(DEFAULT_LOGOUT_URI, "POST");
+
+	OidcLogoutAuthenticationConverter(ClientRegistrationRepository clientRegistrationRepository) {
+		Assert.notNull(clientRegistrationRepository, "clientRegistrationRepository cannot be null");
+		this.clientRegistrationRepository = clientRegistrationRepository;
+	}
+
+	@Override
+	public Authentication convert(HttpServletRequest request) {
+		RequestMatcher.MatchResult result = this.requestMatcher.matcher(request);
+		if (!result.isMatch()) {
+			return null;
+		}
+		String registrationId = result.getVariables().get("registrationId");
+		ClientRegistration clientRegistration = this.clientRegistrationRepository.findByRegistrationId(registrationId);
+		if (clientRegistration == null) {
+			this.logger.debug("Did not process OIDC Back-Channel Logout since no ClientRegistration was found");
+			throw new OAuth2AuthenticationException(OAuth2ErrorCodes.INVALID_REQUEST);
+		}
+		String logoutToken = request.getParameter("logout_token");
+		if (logoutToken == null) {
+			this.logger.debug("Failed to process OIDC Back-Channel Logout since no logout token was found");
+			throw new OAuth2AuthenticationException(OAuth2ErrorCodes.INVALID_REQUEST);
+		}
+		return new OidcLogoutAuthenticationToken(logoutToken, clientRegistration);
+	}
+
+	/**
+	 * The logout endpoint. Defaults to
+	 * {@code /logout/connect/back-channel/{registrationId}}.
+	 * @param requestMatcher the {@link RequestMatcher} to use
+	 */
+	void setRequestMatcher(RequestMatcher requestMatcher) {
+		Assert.notNull(requestMatcher, "requestMatcher cannot be null");
+		this.requestMatcher = requestMatcher;
+	}
+
+}

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OidcLogoutAuthenticationToken.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.core.authority.AuthorityUtils;
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+
+/**
+ * An {@link org.springframework.security.core.Authentication} instance that represents a
+ * request to authenticate an OIDC Logout Token.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ */
+class OidcLogoutAuthenticationToken extends AbstractAuthenticationToken {
+
+	private final String logoutToken;
+
+	private final ClientRegistration clientRegistration;
+
+	/**
+	 * Construct an {@link OidcLogoutAuthenticationToken}
+	 * @param logoutToken a signed, serialized OIDC Logout token
+	 * @param clientRegistration the {@link ClientRegistration client} associated with
+	 * this token; this is usually derived from material in the logout HTTP request
+	 */
+	OidcLogoutAuthenticationToken(String logoutToken, ClientRegistration clientRegistration) {
+		super(AuthorityUtils.NO_AUTHORITIES);
+		this.logoutToken = logoutToken;
+		this.clientRegistration = clientRegistration;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public String getCredentials() {
+		return this.logoutToken;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public String getPrincipal() {
+		return this.logoutToken;
+	}
+
+	/**
+	 * Get the signed, serialized OIDC Logout token
+	 * @return the logout token
+	 */
+	String getLogoutToken() {
+		return this.logoutToken;
+	}
+
+	/**
+	 * Get the {@link ClientRegistration} associated with this logout token
+	 * @return the {@link ClientRegistration}
+	 */
+	ClientRegistration getClientRegistration() {
+		return this.clientRegistration;
+	}
+
+}

config/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/client/OidcLogoutConfigurer.java

@@ -0,0 +1,159 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.configurers.oauth2.client;
+
+import java.util.function.Consumer;
+
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.ProviderManager;
+import org.springframework.security.config.Customizer;
+import org.springframework.security.config.annotation.web.HttpSecurityBuilder;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionRegistry;
+import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
+import org.springframework.security.web.authentication.AuthenticationConverter;
+import org.springframework.security.web.authentication.logout.LogoutHandler;
+import org.springframework.security.web.csrf.CsrfFilter;
+import org.springframework.util.Assert;
+
+/**
+ * An {@link AbstractHttpConfigurer} for OIDC Logout flows
+ *
+ * <p>
+ * OIDC Logout provides an application with the capability to have users log out by using
+ * their existing account at an OAuth 2.0 or OpenID Connect 1.0 Provider.
+ *
+ *
+ * <h2>Security Filters</h2>
+ *
+ * The following {@code Filter} is populated:
+ *
+ * <ul>
+ * <li>{@link OidcBackChannelLogoutFilter}</li>
+ * </ul>
+ *
+ * <h2>Shared Objects Used</h2>
+ *
+ * The following shared objects are used:
+ *
+ * <ul>
+ * <li>{@link ClientRegistrationRepository}</li>
+ * </ul>
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see HttpSecurity#oidcLogout()
+ * @see OidcBackChannelLogoutFilter
+ * @see ClientRegistrationRepository
+ */
+public final class OidcLogoutConfigurer<B extends HttpSecurityBuilder<B>>
+		extends AbstractHttpConfigurer<OidcLogoutConfigurer<B>, B> {
+
+	private BackChannelLogoutConfigurer backChannel;
+
+	/**
+	 * Sets the repository of client registrations.
+	 * @param clientRegistrationRepository the repository of client registrations
+	 * @return the {@link OAuth2LoginConfigurer} for further configuration
+	 */
+	public OidcLogoutConfigurer<B> clientRegistrationRepository(
+			ClientRegistrationRepository clientRegistrationRepository) {
+		Assert.notNull(clientRegistrationRepository, "clientRegistrationRepository cannot be null");
+		this.getBuilder().setSharedObject(ClientRegistrationRepository.class, clientRegistrationRepository);
+		return this;
+	}
+
+	/**
+	 * Sets the registry for managing the OIDC client-provider session link
+	 * @param oidcSessionRegistry the {@link OidcSessionRegistry} to use
+	 * @return the {@link OAuth2LoginConfigurer} for further configuration
+	 */
+	public OidcLogoutConfigurer<B> oidcSessionRegistry(OidcSessionRegistry oidcSessionRegistry) {
+		Assert.notNull(oidcSessionRegistry, "oidcSessionRegistry cannot be null");
+		getBuilder().setSharedObject(OidcSessionRegistry.class, oidcSessionRegistry);
+		return this;
+	}
+
+	/**
+	 * Configure OIDC Back-Channel Logout using the provided {@link Consumer}
+	 * @return the {@link OidcLogoutConfigurer} for further configuration
+	 */
+	public OidcLogoutConfigurer<B> backChannel(Customizer<BackChannelLogoutConfigurer> backChannelLogoutConfigurer) {
+		if (this.backChannel == null) {
+			this.backChannel = new BackChannelLogoutConfigurer();
+		}
+		backChannelLogoutConfigurer.customize(this.backChannel);
+		return this;
+	}
+
+	@Deprecated(forRemoval = true, since = "6.2")
+	public B and() {
+		return getBuilder();
+	}
+
+	@Override
+	public void configure(B builder) throws Exception {
+		if (this.backChannel != null) {
+			this.backChannel.configure(builder);
+		}
+	}
+
+	/**
+	 * A configurer for configuring OIDC Back-Channel Logout
+	 */
+	public final class BackChannelLogoutConfigurer {
+
+		private AuthenticationConverter authenticationConverter;
+
+		private final AuthenticationManager authenticationManager = new ProviderManager(
+				new OidcBackChannelLogoutAuthenticationProvider());
+
+		private LogoutHandler logoutHandler;
+
+		private AuthenticationConverter authenticationConverter(B http) {
+			if (this.authenticationConverter == null) {
+				ClientRegistrationRepository clientRegistrationRepository = OAuth2ClientConfigurerUtils
+						.getClientRegistrationRepository(http);
+				this.authenticationConverter = new OidcLogoutAuthenticationConverter(clientRegistrationRepository);
+			}
+			return this.authenticationConverter;
+		}
+
+		private AuthenticationManager authenticationManager() {
+			return this.authenticationManager;
+		}
+
+		private LogoutHandler logoutHandler(B http) {
+			if (this.logoutHandler == null) {
+				OidcBackChannelLogoutHandler logoutHandler = new OidcBackChannelLogoutHandler();
+				logoutHandler.setSessionRegistry(OAuth2ClientConfigurerUtils.getOidcSessionRegistry(http));
+				this.logoutHandler = logoutHandler;
+			}
+			return this.logoutHandler;
+		}
+
+		void configure(B http) {
+			OidcBackChannelLogoutFilter filter = new OidcBackChannelLogoutFilter(authenticationConverter(http),
+					authenticationManager());
+			filter.setLogoutHandler(logoutHandler(http));
+			http.addFilterBefore(filter, CsrfFilter.class);
+		}
+
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/DefaultOidcLogoutTokenValidatorFactory.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server;
+
+import java.util.function.Function;
+
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.core.DelegatingOAuth2TokenValidator;
+import org.springframework.security.oauth2.core.OAuth2TokenValidator;
+import org.springframework.security.oauth2.jwt.Jwt;
+import org.springframework.security.oauth2.jwt.JwtTimestampValidator;
+
+final class DefaultOidcLogoutTokenValidatorFactory implements Function<ClientRegistration, OAuth2TokenValidator<Jwt>> {
+
+	@Override
+	public OAuth2TokenValidator<Jwt> apply(ClientRegistration clientRegistration) {
+		return new DelegatingOAuth2TokenValidator<>(new JwtTimestampValidator(),
+				new OidcBackChannelLogoutTokenValidator(clientRegistration));
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/OidcBackChannelLogoutAuthentication.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server;
+
+import java.util.Collections;
+
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
+
+/**
+ * An {@link org.springframework.security.core.Authentication} implementation that
+ * represents the result of authenticating an OIDC Logout token for the purposes of
+ * performing Back-Channel Logout.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see OidcLogoutAuthenticationToken
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html">OIDC Back-Channel
+ * Logout</a>
+ */
+class OidcBackChannelLogoutAuthentication extends AbstractAuthenticationToken {
+
+	private final OidcLogoutToken logoutToken;
+
+	/**
+	 * Construct an {@link OidcBackChannelLogoutAuthentication}
+	 * @param logoutToken a deserialized, verified OIDC Logout Token
+	 */
+	OidcBackChannelLogoutAuthentication(OidcLogoutToken logoutToken) {
+		super(Collections.emptyList());
+		this.logoutToken = logoutToken;
+		setAuthenticated(true);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public OidcLogoutToken getPrincipal() {
+		return this.logoutToken;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public OidcLogoutToken getCredentials() {
+		return this.logoutToken;
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/OidcBackChannelLogoutReactiveAuthenticationManager.java

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server;
+
+import reactor.core.publisher.Mono;
+
+import org.springframework.security.authentication.AuthenticationProvider;
+import org.springframework.security.authentication.AuthenticationServiceException;
+import org.springframework.security.authentication.ReactiveAuthenticationManager;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.AuthenticationException;
+import org.springframework.security.oauth2.client.oidc.authentication.ReactiveOidcIdTokenDecoderFactory;
+import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.oauth2.jwt.BadJwtException;
+import org.springframework.security.oauth2.jwt.Jwt;
+import org.springframework.security.oauth2.jwt.JwtDecoder;
+import org.springframework.security.oauth2.jwt.JwtDecoderFactory;
+import org.springframework.security.oauth2.jwt.ReactiveJwtDecoder;
+import org.springframework.security.oauth2.jwt.ReactiveJwtDecoderFactory;
+import org.springframework.util.Assert;
+
+/**
+ * An {@link AuthenticationProvider} that authenticates an OIDC Logout Token; namely
+ * deserializing it, verifying its signature, and validating its claims.
+ *
+ * <p>
+ * Intended to be included in a
+ * {@link org.springframework.security.authentication.ProviderManager}
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see OidcLogoutAuthenticationToken
+ * @see org.springframework.security.authentication.ProviderManager
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html">OIDC Back-Channel
+ * Logout</a>
+ */
+final class OidcBackChannelLogoutReactiveAuthenticationManager implements ReactiveAuthenticationManager {
+
+	private ReactiveJwtDecoderFactory<ClientRegistration> logoutTokenDecoderFactory;
+
+	/**
+	 * Construct an {@link OidcBackChannelLogoutReactiveAuthenticationManager}
+	 */
+	OidcBackChannelLogoutReactiveAuthenticationManager() {
+		ReactiveOidcIdTokenDecoderFactory logoutTokenDecoderFactory = new ReactiveOidcIdTokenDecoderFactory();
+		logoutTokenDecoderFactory.setJwtValidatorFactory(new DefaultOidcLogoutTokenValidatorFactory());
+		this.logoutTokenDecoderFactory = logoutTokenDecoderFactory;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Mono<Authentication> authenticate(Authentication authentication) throws AuthenticationException {
+		if (!(authentication instanceof OidcLogoutAuthenticationToken token)) {
+			return Mono.empty();
+		}
+		String logoutToken = token.getLogoutToken();
+		ClientRegistration registration = token.getClientRegistration();
+		return decode(registration, logoutToken)
+				.map((jwt) -> OidcLogoutToken
+						.withTokenValue(logoutToken)
+						.claims((claims) -> claims.putAll(jwt.getClaims())).build()
+				)
+				.map(OidcBackChannelLogoutAuthentication::new);
+	}
+
+	private Mono<Jwt> decode(ClientRegistration registration, String token) {
+		ReactiveJwtDecoder logoutTokenDecoder = this.logoutTokenDecoderFactory.createDecoder(registration);
+		try {
+			return logoutTokenDecoder.decode(token);
+		}
+		catch (BadJwtException failed) {
+			OAuth2Error error = new OAuth2Error(OAuth2ErrorCodes.INVALID_REQUEST, failed.getMessage(),
+					"https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation");
+			return Mono.error(new OAuth2AuthenticationException(error, failed));
+		}
+		catch (Exception failed) {
+			return Mono.error(new AuthenticationServiceException(failed.getMessage(), failed));
+		}
+	}
+
+	/**
+	 * Use this {@link ReactiveJwtDecoderFactory} to generate {@link JwtDecoder}s that
+	 * correspond to the {@link ClientRegistration} associated with the OIDC logout token.
+	 * @param logoutTokenDecoderFactory the {@link JwtDecoderFactory} to use
+	 */
+	void setLogoutTokenDecoderFactory(ReactiveJwtDecoderFactory<ClientRegistration> logoutTokenDecoderFactory) {
+		Assert.notNull(logoutTokenDecoderFactory, "logoutTokenDecoderFactory cannot be null");
+		this.logoutTokenDecoderFactory = logoutTokenDecoderFactory;
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/OidcBackChannelLogoutTokenValidator.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.security.oauth2.client.oidc.authentication.logout.LogoutTokenClaimAccessor;
+import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.oauth2.core.OAuth2TokenValidator;
+import org.springframework.security.oauth2.core.OAuth2TokenValidatorResult;
+import org.springframework.security.oauth2.jwt.Jwt;
+
+/**
+ * A {@link OAuth2TokenValidator} that validates OIDC Logout Token claims in conformance
+ * with the OIDC Back-Channel Logout Spec.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see OidcLogoutToken
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html#LogoutToken">Logout
+ * Token</a>
+ * @see <a target="blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation">the OIDC
+ * Back-Channel Logout spec</a>
+ */
+final class OidcBackChannelLogoutTokenValidator implements OAuth2TokenValidator<Jwt> {
+
+	private static final String LOGOUT_VALIDATION_URL = "https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation";
+
+	private static final String BACK_CHANNEL_LOGOUT_EVENT = "http://schemas.openid.net/event/backchannel-logout";
+
+	private final String audience;
+
+	private final String issuer;
+
+	OidcBackChannelLogoutTokenValidator(ClientRegistration clientRegistration) {
+		this.audience = clientRegistration.getClientId();
+		this.issuer = clientRegistration.getProviderDetails().getIssuerUri();
+	}
+
+	@Override
+	public OAuth2TokenValidatorResult validate(Jwt jwt) {
+		Collection<OAuth2Error> errors = new ArrayList<>();
+
+		LogoutTokenClaimAccessor logoutClaims = jwt::getClaims;
+		Map<String, Object> events = logoutClaims.getEvents();
+		if (events == null) {
+			errors.add(invalidLogoutToken("events claim must not be null"));
+		}
+		else if (events.get(BACK_CHANNEL_LOGOUT_EVENT) == null) {
+			errors.add(invalidLogoutToken("events claim map must contain \"" + BACK_CHANNEL_LOGOUT_EVENT + "\" key"));
+		}
+
+		String issuer = logoutClaims.getIssuer().toExternalForm();
+		if (issuer == null) {
+			errors.add(invalidLogoutToken("iss claim must not be null"));
+		}
+		else if (!this.issuer.equals(issuer)) {
+			errors.add(invalidLogoutToken(
+					"iss claim value must match `ClientRegistration#getProviderDetails#getIssuerUri`"));
+		}
+
+		List<String> audience = logoutClaims.getAudience();
+		if (audience == null) {
+			errors.add(invalidLogoutToken("aud claim must not be null"));
+		}
+		else if (!audience.contains(this.audience)) {
+			errors.add(invalidLogoutToken("aud claim value must include `ClientRegistration#getClientId`"));
+		}
+
+		Instant issuedAt = logoutClaims.getIssuedAt();
+		if (issuedAt == null) {
+			errors.add(invalidLogoutToken("iat claim must not be null"));
+		}
+
+		String jwtId = logoutClaims.getId();
+		if (jwtId == null) {
+			errors.add(invalidLogoutToken("jti claim must not be null"));
+		}
+
+		if (logoutClaims.getSubject() == null && logoutClaims.getSessionId() == null) {
+			errors.add(invalidLogoutToken("sub and sid claims must not both be null"));
+		}
+
+		if (logoutClaims.getClaim("nonce") != null) {
+			errors.add(invalidLogoutToken("nonce claim must not be present"));
+		}
+
+		return OAuth2TokenValidatorResult.failure(errors);
+	}
+
+	private static OAuth2Error invalidLogoutToken(String description) {
+		return new OAuth2Error(OAuth2ErrorCodes.INVALID_TOKEN, description, LOGOUT_VALIDATION_URL);
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/OidcBackChannelLogoutWebFilter.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server;
+
+import java.nio.charset.StandardCharsets;
+
+import jakarta.servlet.http.HttpServletResponse;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.AuthenticationServiceException;
+import org.springframework.security.authentication.ReactiveAuthenticationManager;
+import org.springframework.security.core.AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.web.authentication.AuthenticationConverter;
+import org.springframework.security.web.authentication.logout.LogoutHandler;
+import org.springframework.security.web.server.WebFilterExchange;
+import org.springframework.security.web.server.authentication.ServerAuthenticationConverter;
+import org.springframework.security.web.server.authentication.logout.ServerLogoutHandler;
+import org.springframework.util.Assert;
+import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+
+/**
+ * A filter for the Client-side OIDC Back-Channel Logout endpoint
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html">OIDC Back-Channel Logout
+ * Spec</a>
+ */
+class OidcBackChannelLogoutWebFilter implements WebFilter {
+
+	private final Log logger = LogFactory.getLog(getClass());
+
+	private final ServerAuthenticationConverter authenticationConverter;
+
+	private final ReactiveAuthenticationManager authenticationManager;
+
+	private ServerLogoutHandler logoutHandler = new OidcBackChannelServerLogoutHandler();
+
+	/**
+	 * Construct an {@link OidcBackChannelLogoutWebFilter}
+	 * @param authenticationConverter the {@link AuthenticationConverter} for deriving
+	 * Logout Token authentication
+	 * @param authenticationManager the {@link AuthenticationManager} for authenticating
+	 * Logout Tokens
+	 */
+	OidcBackChannelLogoutWebFilter(ServerAuthenticationConverter authenticationConverter,
+			ReactiveAuthenticationManager authenticationManager) {
+		Assert.notNull(authenticationConverter, "authenticationConverter cannot be null");
+		Assert.notNull(authenticationManager, "authenticationManager cannot be null");
+		this.authenticationConverter = authenticationConverter;
+		this.authenticationManager = authenticationManager;
+	}
+
+	@Override
+	public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
+		return this.authenticationConverter.convert(exchange).onErrorResume(AuthenticationException.class, (ex) -> {
+			this.logger.debug("Failed to process OIDC Back-Channel Logout", ex);
+			if (ex instanceof AuthenticationServiceException) {
+				return Mono.error(ex);
+			}
+			return handleAuthenticationFailure(exchange.getResponse(), ex).then(Mono.empty());
+		}).switchIfEmpty(chain.filter(exchange).then(Mono.empty())).flatMap(this.authenticationManager::authenticate)
+				.onErrorResume(AuthenticationException.class, (ex) -> {
+					this.logger.debug("Failed to process OIDC Back-Channel Logout", ex);
+					if (ex instanceof AuthenticationServiceException) {
+						return Mono.error(ex);
+					}
+					return handleAuthenticationFailure(exchange.getResponse(), ex).then(Mono.empty());
+				}).flatMap((authentication) -> {
+					WebFilterExchange webFilterExchange = new WebFilterExchange(exchange, chain);
+					return this.logoutHandler.logout(webFilterExchange, authentication);
+				});
+	}
+
+	private Mono<Void> handleAuthenticationFailure(ServerHttpResponse response, Exception ex) {
+		this.logger.debug("Failed to process OIDC Back-Channel Logout", ex);
+		response.setRawStatusCode(HttpServletResponse.SC_BAD_REQUEST);
+		OAuth2Error error = oauth2Error(ex);
+		byte[] bytes = String.format("""
+				{
+					"error_code": "%s",
+					"error_description": "%s",
+					"error_uri: "%s"
+				}
+				""", error.getErrorCode(), error.getDescription(), error.getUri())
+				.getBytes(StandardCharsets.UTF_8);
+		DataBuffer buffer = response.bufferFactory().wrap(bytes);
+		return response.writeWith(Flux.just(buffer));
+	}
+
+	private OAuth2Error oauth2Error(Exception ex) {
+		if (ex instanceof OAuth2AuthenticationException oauth2) {
+			return oauth2.getError();
+		}
+		return new OAuth2Error(OAuth2ErrorCodes.INVALID_REQUEST, ex.getMessage(),
+				"https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation");
+	}
+
+	/**
+	 * The strategy for expiring all Client sessions indicated by the logout request.
+	 * Defaults to {@link OidcBackChannelServerLogoutHandler}.
+	 * @param logoutHandler the {@link LogoutHandler} to use
+	 */
+	void setLogoutHandler(ServerLogoutHandler logoutHandler) {
+		Assert.notNull(logoutHandler, "logoutHandler cannot be null");
+		this.logoutHandler = logoutHandler;
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/OidcBackChannelServerLogoutHandler.java

@@ -0,0 +1,183 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server;
+
+import java.nio.charset.StandardCharsets;
+import java.util.Collection;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import jakarta.servlet.http.HttpServletResponse;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
+import org.springframework.security.oauth2.client.oidc.server.session.InMemoryReactiveOidcSessionRegistry;
+import org.springframework.security.oauth2.client.oidc.server.session.ReactiveOidcSessionRegistry;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionInformation;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionRegistry;
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.web.server.WebFilterExchange;
+import org.springframework.security.web.server.authentication.logout.ServerLogoutHandler;
+import org.springframework.util.Assert;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.util.UriComponentsBuilder;
+
+/**
+ * A {@link ServerLogoutHandler} that locates the sessions associated with a given OIDC
+ * Back-Channel Logout Token and invalidates each one.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ * @see <a target="_blank" href=
+ * "https://openid.net/specs/openid-connect-backchannel-1_0.html">OIDC Back-Channel Logout
+ * Spec</a>
+ */
+final class OidcBackChannelServerLogoutHandler implements ServerLogoutHandler {
+
+	private final Log logger = LogFactory.getLog(getClass());
+
+	private ReactiveOidcSessionRegistry sessionRegistry = new InMemoryReactiveOidcSessionRegistry();
+
+	private WebClient web = WebClient.create();
+
+	private String logoutEndpointName = "/logout";
+
+	private String sessionCookieName = "SESSION";
+
+	@Override
+	public Mono<Void> logout(WebFilterExchange exchange, Authentication authentication) {
+		if (!(authentication instanceof OidcBackChannelLogoutAuthentication token)) {
+			return Mono.defer(() -> {
+				if (this.logger.isDebugEnabled()) {
+					String message = "Did not perform OIDC Back-Channel Logout since authentication [%s] was of the wrong type";
+					this.logger.debug(String.format(message, authentication.getClass().getSimpleName()));
+				}
+				return Mono.empty();
+			});
+		}
+		AtomicInteger totalCount = new AtomicInteger(0);
+		AtomicInteger invalidatedCount = new AtomicInteger(0);
+		return this.sessionRegistry.removeSessionInformation(token.getPrincipal())
+			.concatMap((session) -> {
+				totalCount.incrementAndGet();
+				return eachLogout(exchange, session)
+						.flatMap((response) -> {
+							invalidatedCount.incrementAndGet();
+							return Mono.empty();
+						})
+						.onErrorResume((ex) -> {
+							this.logger.debug("Failed to invalidate session", ex);
+							return this.sessionRegistry.saveSessionInformation(session)
+									.then(Mono.just(ex.getMessage()));
+						});
+			}).collectList().flatMap((list) -> {
+				if (this.logger.isTraceEnabled()) {
+					this.logger.trace(String.format("Invalidated %d out of %d sessions", invalidatedCount.intValue(), totalCount.intValue()));
+				}
+				if (!list.isEmpty()) {
+					return handleLogoutFailure(exchange.getExchange().getResponse(), oauth2Error(list));
+				}
+				else {
+					return Mono.empty();
+				}
+			});
+	}
+
+	private Mono<ResponseEntity<Void>> eachLogout(WebFilterExchange exchange, OidcSessionInformation session) {
+		HttpHeaders headers = new HttpHeaders();
+		headers.add(HttpHeaders.COOKIE, this.sessionCookieName + "=" + session.getSessionId());
+		for (Map.Entry<String, String> credential : session.getAuthorities().entrySet()) {
+			headers.add(credential.getKey(), credential.getValue());
+		}
+		String url = exchange.getExchange().getRequest().getURI().toString();
+		String logout = UriComponentsBuilder.fromHttpUrl(url).replacePath(this.logoutEndpointName).build()
+				.toUriString();
+		return this.web.post().uri(logout).headers((h) -> h.putAll(headers)).retrieve().toBodilessEntity();
+	}
+
+	private OAuth2Error oauth2Error(Collection<?> errors) {
+		return new OAuth2Error("partial_logout", "not all sessions were terminated: " + errors,
+				"https://openid.net/specs/openid-connect-backchannel-1_0.html#Validation");
+	}
+
+	private Mono<Void> handleLogoutFailure(ServerHttpResponse response, OAuth2Error error) {
+		response.setRawStatusCode(HttpServletResponse.SC_BAD_REQUEST);
+		byte[] bytes = String.format("""
+				{
+					"error_code": "%s",
+					"error_description": "%s",
+					"error_uri: "%s"
+				}
+				""", error.getErrorCode(), error.getDescription(), error.getUri())
+				.getBytes(StandardCharsets.UTF_8);
+		DataBuffer buffer = response.bufferFactory().wrap(bytes);
+		return response.writeWith(Flux.just(buffer));
+	}
+
+	/**
+	 * Use this {@link OidcSessionRegistry} to identify sessions to invalidate. Note that
+	 * this class uses
+	 * {@link OidcSessionRegistry#removeSessionInformation(OidcLogoutToken)} to identify
+	 * sessions.
+	 * @param sessionRegistry the {@link OidcSessionRegistry} to use
+	 */
+	void setSessionRegistry(ReactiveOidcSessionRegistry sessionRegistry) {
+		Assert.notNull(sessionRegistry, "sessionRegistry cannot be null");
+		this.sessionRegistry = sessionRegistry;
+	}
+
+	/**
+	 * Use this {@link WebClient} to perform the per-session back-channel logout
+	 * @param web the {@link WebClient} to use
+	 */
+	void setWebClient(WebClient web) {
+		Assert.notNull(web, "web cannot be null");
+		this.web = web;
+	}
+
+	/**
+	 * Use this logout URI for performing per-session logout. Defaults to {@code /logout}
+	 * since that is the default URI for
+	 * {@link org.springframework.security.web.authentication.logout.LogoutFilter}.
+	 * @param logoutUri the URI to use
+	 */
+	void setLogoutUri(String logoutUri) {
+		Assert.hasText(logoutUri, "logoutUri cannot be empty");
+		this.logoutEndpointName = logoutUri;
+	}
+
+	/**
+	 * Use this cookie name for the session identifier. Defaults to {@code JSESSIONID}.
+	 *
+	 * <p>
+	 * Note that if you are using Spring Session, this likely needs to change to SESSION.
+	 * @param sessionCookieName the cookie name to use
+	 */
+	void setSessionCookieName(String sessionCookieName) {
+		Assert.hasText(sessionCookieName, "clientSessionCookieName cannot be empty");
+		this.sessionCookieName = sessionCookieName;
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/OidcLogoutAuthenticationToken.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server;
+
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.core.authority.AuthorityUtils;
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+
+/**
+ * An {@link org.springframework.security.core.Authentication} instance that represents a
+ * request to authenticate an OIDC Logout Token.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ */
+class OidcLogoutAuthenticationToken extends AbstractAuthenticationToken {
+
+	private final String logoutToken;
+
+	private final ClientRegistration clientRegistration;
+
+	/**
+	 * Construct an {@link OidcLogoutAuthenticationToken}
+	 * @param logoutToken a signed, serialized OIDC Logout token
+	 * @param clientRegistration the {@link ClientRegistration client} associated with
+	 * this token; this is usually derived from material in the logout HTTP request
+	 */
+	OidcLogoutAuthenticationToken(String logoutToken, ClientRegistration clientRegistration) {
+		super(AuthorityUtils.NO_AUTHORITIES);
+		this.logoutToken = logoutToken;
+		this.clientRegistration = clientRegistration;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public String getCredentials() {
+		return this.logoutToken;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public String getPrincipal() {
+		return this.logoutToken;
+	}
+
+	/**
+	 * Get the signed, serialized OIDC Logout token
+	 * @return the logout token
+	 */
+	String getLogoutToken() {
+		return this.logoutToken;
+	}
+
+	/**
+	 * Get the {@link ClientRegistration} associated with this logout token
+	 * @return the {@link ClientRegistration}
+	 */
+	ClientRegistration getClientRegistration() {
+		return this.clientRegistration;
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/OidcLogoutServerAuthenticationConverter.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import reactor.core.publisher.Mono;
+
+import org.springframework.http.HttpMethod;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.oauth2.client.registration.ReactiveClientRegistrationRepository;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
+import org.springframework.security.web.authentication.AuthenticationConverter;
+import org.springframework.security.web.server.authentication.ServerAuthenticationConverter;
+import org.springframework.security.web.server.util.matcher.PathPatternParserServerWebExchangeMatcher;
+import org.springframework.security.web.server.util.matcher.ServerWebExchangeMatcher;
+import org.springframework.util.Assert;
+import org.springframework.web.server.ServerWebExchange;
+
+/**
+ * An {@link AuthenticationConverter} that extracts the OIDC Logout Token authentication
+ * request
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ */
+final class OidcLogoutServerAuthenticationConverter implements ServerAuthenticationConverter {
+
+	private static final String DEFAULT_LOGOUT_URI = "/logout/connect/back-channel/{registrationId}";
+
+	private final Log logger = LogFactory.getLog(getClass());
+
+	private final ReactiveClientRegistrationRepository clientRegistrationRepository;
+
+	private ServerWebExchangeMatcher exchangeMatcher = new PathPatternParserServerWebExchangeMatcher(DEFAULT_LOGOUT_URI,
+			HttpMethod.POST);
+
+	OidcLogoutServerAuthenticationConverter(ReactiveClientRegistrationRepository clientRegistrationRepository) {
+		Assert.notNull(clientRegistrationRepository, "clientRegistrationRepository cannot be null");
+		this.clientRegistrationRepository = clientRegistrationRepository;
+	}
+
+	@Override
+	public Mono<Authentication> convert(ServerWebExchange exchange) {
+		return this.exchangeMatcher.matches(exchange).filter(ServerWebExchangeMatcher.MatchResult::isMatch)
+				.flatMap((match) -> {
+					String registrationId = (String) match.getVariables().get("registrationId");
+					return this.clientRegistrationRepository.findByRegistrationId(registrationId)
+							.switchIfEmpty(Mono.error(() -> {
+								this.logger.debug(
+										"Did not process OIDC Back-Channel Logout since no ClientRegistration was found");
+								return new OAuth2AuthenticationException(OAuth2ErrorCodes.INVALID_REQUEST);
+							}));
+				}).flatMap((clientRegistration) -> exchange.getFormData().map((data) -> {
+					String logoutToken = data.getFirst("logout_token");
+					return new OidcLogoutAuthenticationToken(logoutToken, clientRegistration);
+				}).switchIfEmpty(Mono.error(() -> {
+					this.logger.debug("Failed to process OIDC Back-Channel Logout since no logout token was found");
+					return new OAuth2AuthenticationException(OAuth2ErrorCodes.INVALID_REQUEST);
+				})));
+	}
+
+	/**
+	 * The logout endpoint. Defaults to
+	 * {@code /logout/connect/back-channel/{registrationId}}.
+	 * @param exchangeMatcher the {@link ServerWebExchangeMatcher} to use
+	 */
+	void setExchangeMatcher(ServerWebExchangeMatcher exchangeMatcher) {
+		Assert.notNull(exchangeMatcher, "exchangeMatcher cannot be null");
+		this.exchangeMatcher = exchangeMatcher;
+	}
+
+}

config/src/main/java/org/springframework/security/config/web/server/ServerHttpSecurity.java

@@ -21,6 +21,7 @@ import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.security.interfaces.RSAPublicKey;
 import java.time.Duration;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -28,10 +29,13 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
 import io.micrometer.observation.ObservationRegistry;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import reactor.core.publisher.Mono;
 import reactor.util.context.Context;
 
@@ -67,6 +71,9 @@ import org.springframework.security.oauth2.client.endpoint.OAuth2AuthorizationCo
 import org.springframework.security.oauth2.client.endpoint.ReactiveOAuth2AccessTokenResponseClient;
 import org.springframework.security.oauth2.client.endpoint.WebClientReactiveAuthorizationCodeTokenResponseClient;
 import org.springframework.security.oauth2.client.oidc.authentication.OidcAuthorizationCodeReactiveAuthenticationManager;
+import org.springframework.security.oauth2.client.oidc.server.session.InMemoryReactiveOidcSessionRegistry;
+import org.springframework.security.oauth2.client.oidc.server.session.ReactiveOidcSessionRegistry;
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionInformation;
 import org.springframework.security.oauth2.client.oidc.userinfo.OidcReactiveOAuth2UserService;
 import org.springframework.security.oauth2.client.oidc.userinfo.OidcUserRequest;
 import org.springframework.security.oauth2.client.registration.ClientRegistration;
@@ -113,6 +120,7 @@ import org.springframework.security.web.server.MatcherSecurityWebFilterChain;
 import org.springframework.security.web.server.SecurityWebFilterChain;
 import org.springframework.security.web.server.ServerAuthenticationEntryPoint;
 import org.springframework.security.web.server.ServerRedirectStrategy;
+import org.springframework.security.web.server.WebFilterExchange;
 import org.springframework.security.web.server.authentication.AnonymousAuthenticationWebFilter;
 import org.springframework.security.web.server.authentication.AuthenticationConverterServerWebExchangeMatcher;
 import org.springframework.security.web.server.authentication.AuthenticationWebFilter;
@@ -147,6 +155,7 @@ import org.springframework.security.web.server.context.SecurityContextServerWebE
 import org.springframework.security.web.server.context.ServerSecurityContextRepository;
 import org.springframework.security.web.server.context.WebSessionServerSecurityContextRepository;
 import org.springframework.security.web.server.csrf.CsrfServerLogoutHandler;
+import org.springframework.security.web.server.csrf.CsrfToken;
 import org.springframework.security.web.server.csrf.CsrfWebFilter;
 import org.springframework.security.web.server.csrf.ServerCsrfTokenRepository;
 import org.springframework.security.web.server.csrf.ServerCsrfTokenRequestHandler;
@@ -193,8 +202,10 @@ import org.springframework.web.cors.reactive.CorsWebFilter;
 import org.springframework.web.cors.reactive.DefaultCorsProcessor;
 import org.springframework.web.reactive.result.method.annotation.RequestMappingHandlerMapping;
 import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.ServerWebExchangeDecorator;
 import org.springframework.web.server.WebFilter;
 import org.springframework.web.server.WebFilterChain;
+import org.springframework.web.server.WebSession;
 import org.springframework.web.util.pattern.PathPatternParser;
 
 /**
@@ -295,6 +306,8 @@ public class ServerHttpSecurity {
 
 	private OAuth2ClientSpec client;
 
+	private OidcLogoutSpec oidcLogout;
+
 	private LogoutSpec logout = new LogoutSpec();
 
 	private LoginPageSpec loginPage = new LoginPageSpec();
@@ -1093,6 +1106,33 @@ public class ServerHttpSecurity {
 		return this;
 	}
 
+	/**
+	 * Configures OIDC Connect 1.0 Logout support.
+	 *
+	 * <pre class="code">
+	 *  &#064;Bean
+	 *  public SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
+	 *      http
+	 *          // ...
+	 *          .oidcLogout((logout) -&gt; logout
+	 *              .backChannel(Customizer.withDefaults())
+	 *          );
+	 *      return http.build();
+	 *  }
+	 * </pre>
+	 * @param oidcLogoutCustomizer the {@link Customizer} to provide more options for the
+	 * {@link OidcLogoutSpec}
+	 * @return the {@link ServerHttpSecurity} to customize
+	 * @since 6.2
+	 */
+	public ServerHttpSecurity oidcLogout(Customizer<OidcLogoutSpec> oidcLogoutCustomizer) {
+		if (this.oidcLogout == null) {
+			this.oidcLogout = new OidcLogoutSpec();
+		}
+		oidcLogoutCustomizer.customize(this.oidcLogout);
+		return this;
+	}
+
 	/**
 	 * Configures HTTP Response Headers. The default headers are:
 	 *
@@ -1537,6 +1577,9 @@ public class ServerHttpSecurity {
 		if (this.resourceServer != null) {
 			this.resourceServer.configure(this);
 		}
+		if (this.oidcLogout != null) {
+			this.oidcLogout.configure(this);
+		}
 		if (this.client != null) {
 			this.client.configure(this);
 		}
@@ -3689,6 +3732,8 @@ public class ServerHttpSecurity {
 
 		private ServerWebExchangeMatcher authenticationMatcher;
 
+		private ReactiveOidcSessionRegistry oidcSessionRegistry;
+
 		private ServerAuthenticationSuccessHandler authenticationSuccessHandler;
 
 		private ServerAuthenticationFailureHandler authenticationFailureHandler;
@@ -3720,6 +3765,20 @@ public class ServerHttpSecurity {
 			return this;
 		}
 
+		/**
+		 * Configures the {@link ReactiveOidcSessionRegistry} to use when logins use OIDC.
+		 * Default is to look the value up as a Bean, or else use an
+		 * {@link InMemoryReactiveOidcSessionRegistry}.
+		 * @param oidcSessionRegistry the registry to use
+		 * @return the {@link OidcLogoutSpec} to customize
+		 * @since 6.2
+		 */
+		public OAuth2LoginSpec oidcSessionRegistry(ReactiveOidcSessionRegistry oidcSessionRegistry) {
+			Assert.notNull(oidcSessionRegistry, "oidcSessionRegistry cannot be null");
+			this.oidcSessionRegistry = oidcSessionRegistry;
+			return this;
+		}
+
 		/**
 		 * The {@link ServerAuthenticationSuccessHandler} used after authentication
 		 * success. Defaults to {@link RedirectServerAuthenticationSuccessHandler}
@@ -3913,8 +3972,9 @@ public class ServerHttpSecurity {
 			oauthRedirectFilter.setRequestCache(http.requestCache.requestCache);
 
 			ReactiveAuthenticationManager manager = getAuthenticationManager();
-			AuthenticationWebFilter authenticationFilter = new OAuth2LoginAuthenticationWebFilter(manager,
-					authorizedClientRepository);
+			ReactiveOidcSessionRegistry sessionRegistry = getOidcSessionRegistry();
+			AuthenticationWebFilter authenticationFilter = new OidcSessionRegistryAuthenticationWebFilter(manager,
+					authorizedClientRepository, sessionRegistry);
 			authenticationFilter.setRequiresAuthenticationMatcher(getAuthenticationMatcher());
 			authenticationFilter
 					.setServerAuthenticationConverter(getAuthenticationConverter(clientRegistrationRepository));
@@ -3923,6 +3983,8 @@ public class ServerHttpSecurity {
 			authenticationFilter.setSecurityContextRepository(this.securityContextRepository);
 
 			setDefaultEntryPoints(http);
+			http.addFilterAfter(new OidcSessionRegistryWebFilter(sessionRegistry),
+					SecurityWebFiltersOrder.HTTP_HEADERS_WRITER);
 			http.addFilterAt(oauthRedirectFilter, SecurityWebFiltersOrder.HTTP_BASIC);
 			http.addFilterAt(authenticationFilter, SecurityWebFiltersOrder.AUTHENTICATION);
 		}
@@ -3967,6 +4029,16 @@ public class ServerHttpSecurity {
 			http.defaultEntryPoints.add(new DelegateEntry(defaultEntryPointMatcher, defaultEntryPoint));
 		}
 
+		private ReactiveOidcSessionRegistry getOidcSessionRegistry() {
+			if (this.oidcSessionRegistry == null) {
+				this.oidcSessionRegistry = getBeanOrNull(ReactiveOidcSessionRegistry.class);
+			}
+			if (this.oidcSessionRegistry == null) {
+				this.oidcSessionRegistry = new InMemoryReactiveOidcSessionRegistry();
+			}
+			return this.oidcSessionRegistry;
+		}
+
 		private ServerAuthenticationSuccessHandler getAuthenticationSuccessHandler(ServerHttpSecurity http) {
 			if (this.authenticationSuccessHandler == null) {
 				RedirectServerAuthenticationSuccessHandler handler = new RedirectServerAuthenticationSuccessHandler();
@@ -4083,6 +4155,154 @@ public class ServerHttpSecurity {
 			return new InMemoryReactiveOAuth2AuthorizedClientService(getClientRegistrationRepository());
 		}
 
+		private static final class OidcSessionRegistryWebFilter implements WebFilter {
+
+			private final ReactiveOidcSessionRegistry oidcSessionRegistry;
+
+			OidcSessionRegistryWebFilter(ReactiveOidcSessionRegistry oidcSessionRegistry) {
+				this.oidcSessionRegistry = oidcSessionRegistry;
+			}
+
+			@Override
+			public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
+				return chain.filter(new OidcSessionRegistryServerWebExchange(exchange));
+			}
+
+			private final class OidcSessionRegistryServerWebExchange extends ServerWebExchangeDecorator {
+
+				private final Mono<WebSession> sessionMono;
+
+				protected OidcSessionRegistryServerWebExchange(ServerWebExchange delegate) {
+					super(delegate);
+					this.sessionMono = delegate.getSession().map(OidcSessionRegistryWebSession::new);
+				}
+
+				@Override
+				public Mono<WebSession> getSession() {
+					return this.sessionMono;
+				}
+
+				private final class OidcSessionRegistryWebSession implements WebSession {
+
+					private final WebSession session;
+
+					OidcSessionRegistryWebSession(WebSession session) {
+						this.session = session;
+					}
+
+					@Override
+					public String getId() {
+						return this.session.getId();
+					}
+
+					@Override
+					public Map<String, Object> getAttributes() {
+						return this.session.getAttributes();
+					}
+
+					@Override
+					public void start() {
+						this.session.start();
+					}
+
+					@Override
+					public boolean isStarted() {
+						return this.session.isStarted();
+					}
+
+					@Override
+					public Mono<Void> changeSessionId() {
+						String currentId = this.session.getId();
+						return this.session.changeSessionId()
+								.then(Mono.defer(() -> OidcSessionRegistryWebFilter.this.oidcSessionRegistry
+										.removeSessionInformation(currentId).flatMap((information) -> {
+											information = information.withSessionId(this.session.getId());
+											return OidcSessionRegistryWebFilter.this.oidcSessionRegistry
+													.saveSessionInformation(information);
+										})));
+					}
+
+					@Override
+					public Mono<Void> invalidate() {
+						String currentId = this.session.getId();
+						return this.session.invalidate()
+								.then(Mono.defer(() -> OidcSessionRegistryWebFilter.this.oidcSessionRegistry
+										.removeSessionInformation(currentId).then(Mono.empty())));
+					}
+
+					@Override
+					public Mono<Void> save() {
+						return this.session.save();
+					}
+
+					@Override
+					public boolean isExpired() {
+						return this.session.isExpired();
+					}
+
+					@Override
+					public Instant getCreationTime() {
+						return this.session.getCreationTime();
+					}
+
+					@Override
+					public Instant getLastAccessTime() {
+						return this.session.getLastAccessTime();
+					}
+
+					@Override
+					public void setMaxIdleTime(Duration maxIdleTime) {
+						this.session.setMaxIdleTime(maxIdleTime);
+					}
+
+					@Override
+					public Duration getMaxIdleTime() {
+						return this.session.getMaxIdleTime();
+					}
+
+				}
+
+			}
+
+		}
+
+		private static final class OidcSessionRegistryAuthenticationWebFilter
+				extends OAuth2LoginAuthenticationWebFilter {
+
+			private final Log logger = LogFactory.getLog(getClass());
+
+			private final ReactiveOidcSessionRegistry oidcSessionRegistry;
+
+			OidcSessionRegistryAuthenticationWebFilter(ReactiveAuthenticationManager authenticationManager,
+					ServerOAuth2AuthorizedClientRepository authorizedClientRepository,
+					ReactiveOidcSessionRegistry oidcSessionRegistry) {
+				super(authenticationManager, authorizedClientRepository);
+				this.oidcSessionRegistry = oidcSessionRegistry;
+			}
+
+			@Override
+			protected Mono<Void> onAuthenticationSuccess(Authentication authentication, WebFilterExchange webFilterExchange) {
+				if (!(authentication.getPrincipal() instanceof OidcUser user)) {
+					return super.onAuthenticationSuccess(authentication, webFilterExchange);
+				}
+				return webFilterExchange.getExchange().getSession()
+						.doOnNext((session) -> {
+							if (this.logger.isTraceEnabled()) {
+								this.logger.trace(String.format("Linking a provider [%s] session to this client's session", user.getIssuer()));
+							}
+						})
+						.flatMap((session) -> {
+							Mono<CsrfToken> csrfToken = webFilterExchange.getExchange().getAttribute(CsrfToken.class.getName());
+							return (csrfToken != null) ?
+									csrfToken.map((token) -> new OidcSessionInformation(session.getId(), Map.of(token.getHeaderName(), token.getToken()), user)) :
+									Mono.just(new OidcSessionInformation(session.getId(), Map.of(), user));
+						})
+						.flatMap(this.oidcSessionRegistry::saveSessionInformation)
+						.then(super.onAuthenticationSuccess(authentication, webFilterExchange));
+			}
+
+		}
+
 	}
 
 	public final class OAuth2ClientSpec {
@@ -4755,6 +4975,129 @@ public class ServerHttpSecurity {
 
 	}
 
+	/**
+	 * Configures OIDC 1.0 Logout support
+	 *
+	 * @author Josh Cummings
+	 * @since 6.2
+	 */
+	public final class OidcLogoutSpec {
+
+		private ReactiveClientRegistrationRepository clientRegistrationRepository;
+
+		private ReactiveOidcSessionRegistry sessionRegistry;
+
+		private BackChannelLogoutConfigurer backChannel;
+
+		/**
+		 * Configures the {@link ReactiveClientRegistrationRepository}. Default is to look
+		 * the value up as a Bean.
+		 * @param clientRegistrationRepository the repository to use
+		 * @return the {@link OidcLogoutSpec} to customize
+		 */
+		public OidcLogoutSpec clientRegistrationRepository(
+				ReactiveClientRegistrationRepository clientRegistrationRepository) {
+			Assert.notNull(clientRegistrationRepository, "clientRegistrationRepository cannot be null");
+			this.clientRegistrationRepository = clientRegistrationRepository;
+			return this;
+		}
+
+		/**
+		 * Configures the {@link ReactiveOidcSessionRegistry}. Default is to use the value
+		 * from {@link OAuth2LoginSpec#oidcSessionRegistry}, then look the value up as a
+		 * Bean, or else use an {@link InMemoryReactiveOidcSessionRegistry}.
+		 * @param sessionRegistry the registry to use
+		 * @return the {@link OidcLogoutSpec} to customize
+		 */
+		public OidcLogoutSpec oidcSessionRegistry(ReactiveOidcSessionRegistry sessionRegistry) {
+			Assert.notNull(sessionRegistry, "sessionRegistry cannot be null");
+			this.sessionRegistry = sessionRegistry;
+			return this;
+		}
+
+		/**
+		 * Configure OIDC Back-Channel Logout using the provided {@link Consumer}
+		 * @return the {@link OidcLogoutSpec} for further configuration
+		 */
+		public OidcLogoutSpec backChannel(Customizer<BackChannelLogoutConfigurer> backChannelLogoutConfigurer) {
+			if (this.backChannel == null) {
+				this.backChannel = new OidcLogoutSpec.BackChannelLogoutConfigurer();
+			}
+			backChannelLogoutConfigurer.customize(this.backChannel);
+			return this;
+		}
+
+		@Deprecated(forRemoval = true, since = "6.2")
+		public ServerHttpSecurity and() {
+			return ServerHttpSecurity.this;
+		}
+
+		void configure(ServerHttpSecurity http) {
+			if (this.backChannel != null) {
+				this.backChannel.configure(http);
+			}
+		}
+
+		private ReactiveClientRegistrationRepository getClientRegistrationRepository() {
+			if (this.clientRegistrationRepository == null) {
+				this.clientRegistrationRepository = getBeanOrNull(ReactiveClientRegistrationRepository.class);
+			}
+			return this.clientRegistrationRepository;
+		}
+
+		private ReactiveOidcSessionRegistry getSessionRegistry() {
+			if (this.sessionRegistry == null && ServerHttpSecurity.this.oauth2Login == null) {
+				return new InMemoryReactiveOidcSessionRegistry();
+			}
+			if (this.sessionRegistry == null) {
+				return ServerHttpSecurity.this.oauth2Login.oidcSessionRegistry;
+			}
+			return this.sessionRegistry;
+		}
+
+		/**
+		 * A configurer for configuring OIDC Back-Channel Logout
+		 */
+		public final class BackChannelLogoutConfigurer {
+
+			private ServerAuthenticationConverter authenticationConverter;
+
+			private final ReactiveAuthenticationManager authenticationManager = new OidcBackChannelLogoutReactiveAuthenticationManager();
+
+			private ServerLogoutHandler logoutHandler;
+
+			private ServerAuthenticationConverter authenticationConverter() {
+				if (this.authenticationConverter == null) {
+					this.authenticationConverter = new OidcLogoutServerAuthenticationConverter(
+							OidcLogoutSpec.this.getClientRegistrationRepository());
+				}
+				return this.authenticationConverter;
+			}
+
+			private ReactiveAuthenticationManager authenticationManager() {
+				return this.authenticationManager;
+			}
+
+			private ServerLogoutHandler logoutHandler() {
+				if (this.logoutHandler == null) {
+					OidcBackChannelServerLogoutHandler logoutHandler = new OidcBackChannelServerLogoutHandler();
+					logoutHandler.setSessionRegistry(OidcLogoutSpec.this.getSessionRegistry());
+					this.logoutHandler = logoutHandler;
+				}
+				return this.logoutHandler;
+			}
+
+			void configure(ServerHttpSecurity http) {
+				OidcBackChannelLogoutWebFilter filter = new OidcBackChannelLogoutWebFilter(authenticationConverter(),
+						authenticationManager());
+				filter.setLogoutHandler(logoutHandler());
+				http.addFilterBefore(filter, SecurityWebFiltersOrder.CSRF);
+			}
+
+		}
+
+	}
+
 	/**
 	 * Configures anonymous authentication
 	 *

config/src/main/kotlin/org/springframework/security/config/annotation/web/HttpSecurityDsl.kt

@@ -868,6 +868,38 @@ class HttpSecurityDsl(private val http: HttpSecurity, private val init: HttpSecu
         this.http.oauth2ResourceServer(oauth2ResourceServerCustomizer)
     }
 
+    /**
+     * Configures OIDC 1.0 logout support.
+     *
+     * Example:
+     *
+     * ```
+     * @Configuration
+     * @EnableWebSecurity
+     * class SecurityConfig {
+     *
+     *     @Bean
+     *     fun securityFilterChain(http: HttpSecurity): SecurityFilterChain {
+     *         http {
+     *             oauth2Login { }
+     *             oidcLogout {
+     *                 backChannel { }
+     *             }
+     *         }
+     *         return http.build()
+     *     }
+     * }
+     * ```
+     *
+     * @param oidcLogoutConfiguration custom configuration to configure the
+     * OIDC 1.0 logout support
+     * @see [OidcLogoutDsl]
+     */
+    fun oidcLogout(oidcLogoutConfiguration: OidcLogoutDsl.() -> Unit) {
+        val oidcLogoutCustomizer = OidcLogoutDsl().apply(oidcLogoutConfiguration).get()
+        this.http.oidcLogout(oidcLogoutCustomizer)
+    }
+
     /**
      * Configures Remember Me authentication.
      *

config/src/main/kotlin/org/springframework/security/config/annotation/web/OidcLogoutDsl.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web
+
+import org.springframework.security.config.annotation.web.builders.HttpSecurity
+import org.springframework.security.config.annotation.web.configurers.oauth2.client.OidcLogoutConfigurer
+import org.springframework.security.config.annotation.web.oauth2.login.OidcBackChannelLogoutDsl
+import org.springframework.security.oauth2.client.oidc.session.OidcSessionRegistry
+import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository
+
+/**
+ * A Kotlin DSL to configure [HttpSecurity] OAuth 1.0 Logout using idiomatic Kotlin code.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ */
+@SecurityMarker
+class OidcLogoutDsl {
+    var clientRegistrationRepository: ClientRegistrationRepository? = null
+    var oidcSessionRegistry: OidcSessionRegistry? = null
+
+    private var backChannel: ((OidcLogoutConfigurer<HttpSecurity>.BackChannelLogoutConfigurer) -> Unit)? = null
+
+    /**
+     * Configures the OIDC 1.0 Back-Channel endpoint.
+     *
+     * Example:
+     *
+     * ```
+     * @Configuration
+     * @EnableWebSecurity
+     * class SecurityConfig {
+     *
+     *     @Bean
+     *     fun securityFilterChain(http: HttpSecurity): SecurityFilterChain {
+     *         http {
+     *             oauth2Login { }
+     *             oidcLogout {
+     *                 backChannel { }
+     *             }
+     *         }
+     *         return http.build()
+     *     }
+     * }
+     * ```
+     *
+     * @param backChannelConfig custom configurations to configure the back-channel endpoint
+     * @see [OidcBackChannelLogoutDsl]
+     */
+    fun backChannel(backChannelConfig: OidcBackChannelLogoutDsl.() -> Unit) {
+        this.backChannel = OidcBackChannelLogoutDsl().apply(backChannelConfig).get()
+    }
+
+    internal fun get(): (OidcLogoutConfigurer<HttpSecurity>) -> Unit {
+        return { oidcLogout ->
+            clientRegistrationRepository?.also { oidcLogout.clientRegistrationRepository(clientRegistrationRepository) }
+            oidcSessionRegistry?.also { oidcLogout.oidcSessionRegistry(oidcSessionRegistry) }
+            backChannel?.also { oidcLogout.backChannel(backChannel) }
+        }
+    }
+}

config/src/main/kotlin/org/springframework/security/config/annotation/web/oauth2/login/OidcBackChannelLogoutDsl.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.annotation.web.oauth2.login
+
+import org.springframework.security.config.annotation.web.builders.HttpSecurity
+import org.springframework.security.config.annotation.web.configurers.oauth2.client.OidcLogoutConfigurer
+
+/**
+ * A Kotlin DSL to configure the OIDC 1.0 Back-Channel configuration using
+ * idiomatic Kotlin code.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ */
+@OAuth2LoginSecurityMarker
+class OidcBackChannelLogoutDsl {
+    internal fun get(): (OidcLogoutConfigurer<HttpSecurity>.BackChannelLogoutConfigurer) -> Unit {
+        return { backChannel -> }
+    }
+}

config/src/main/kotlin/org/springframework/security/config/web/server/ServerHttpSecurityDsl.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -650,6 +650,38 @@ class ServerHttpSecurityDsl(private val http: ServerHttpSecurity, private val in
         this.http.oauth2ResourceServer(oauth2ResourceServerCustomizer)
     }
 
+    /**
+     * Configures logout support using an OpenID Connect 1.0 Provider.
+     * A [ReactiveClientRegistrationRepository] is required and must be registered as a Bean or
+     * configured via [ServerOidcLogoutDsl.clientRegistrationRepository].
+     *
+     * Example:
+     *
+     * ```
+     * @Configuration
+     * @EnableWebFluxSecurity
+     * class SecurityConfig {
+     *
+     *  @Bean
+     *  fun springWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
+     *      return http {
+     *          oauth2Login { }
+     *          oidcLogout {
+     *              backChannel { }
+     *          }
+     *       }
+     *   }
+     * }
+     * ```
+     *
+     * @param oidcLogoutConfiguration custom configuration to configure the OIDC 1.0 Logout
+     * @see [ServerOidcLogoutDsl]
+     */
+    fun oidcLogout(oidcLogoutConfiguration: ServerOidcLogoutDsl.() -> Unit) {
+        val oidcLogoutCustomizer = ServerOidcLogoutDsl().apply(oidcLogoutConfiguration).get()
+        this.http.oidcLogout(oidcLogoutCustomizer)
+    }
+
     /**
      * Apply all configurations to the provided [ServerHttpSecurity]
      */

config/src/main/kotlin/org/springframework/security/config/web/server/ServerOidcBackChannelLogoutDsl.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server
+
+/**
+ * A Kotlin DSL to configure [ServerHttpSecurity] OIDC 1.0 Back-Channel Logout support using idiomatic Kotlin code.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ */
+@ServerSecurityMarker
+class ServerOidcBackChannelLogoutDsl {
+    internal fun get(): (ServerHttpSecurity.OidcLogoutSpec.BackChannelLogoutConfigurer) -> Unit {
+        return { backChannel -> }
+    }
+}

config/src/main/kotlin/org/springframework/security/config/web/server/ServerOidcLogoutDsl.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.config.web.server
+
+import org.springframework.security.oauth2.client.oidc.server.session.ReactiveOidcSessionRegistry
+import org.springframework.security.oauth2.client.registration.ReactiveClientRegistrationRepository
+
+/**
+ * A Kotlin DSL to configure [ServerHttpSecurity] OIDC 1.0 login using idiomatic Kotlin code.
+ *
+ * @author Josh Cummings
+ * @since 6.2
+ */
+@ServerSecurityMarker
+class ServerOidcLogoutDsl {
+    var clientRegistrationRepository: ReactiveClientRegistrationRepository? = null
+    var oidcSessionRegistry: ReactiveOidcSessionRegistry? = null
+
+    private var backChannel: ((ServerHttpSecurity.OidcLogoutSpec.BackChannelLogoutConfigurer) -> Unit)? = null
+
+    /**
+     * Enables OIDC 1.0 Back-Channel Logout support.
+     *
+     * Example:
+     *
+     * ```
+     * @Configuration
+     * @EnableWebFluxSecurity
+     * class SecurityConfig {
+     *
+     *  @Bean
+     *  fun springWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
+     *      return http {
+     *          oauth2Login { }
+     *          oidcLogout {
+     *              backChannel { }
+     *          }
+     *       }
+     *   }
+     * }
+     * ```
+     *
+     * @param backChannelConfig custom configurations to configure OIDC 1.0 Back-Channel Logout support
+     * @see [ServerOidcBackChannelLogoutDsl]
+     */
+    fun backChannel(backChannelConfig: ServerOidcBackChannelLogoutDsl.() -> Unit) {
+        this.backChannel = ServerOidcBackChannelLogoutDsl().apply(backChannelConfig).get()
+    }
+
+    internal fun get(): (ServerHttpSecurity.OidcLogoutSpec) -> Unit {
+        return { oidcLogout ->
+            clientRegistrationRepository?.also { oidcLogout.clientRegistrationRepository(clientRegistrationRepository) }
+            oidcSessionRegistry?.also { oidcLogout.oidcSessionRegistry(oidcSessionRegistry) }
+            backChannel?.also { oidcLogout.backChannel(backChannel) }
+        }
+    }
+}