Logout Request Reads EntityId

Closes gh-12843
Closes gh-12845

docs/modules/ROOT/pages/servlet/saml2/logout.adoc

@@ -130,9 +130,9 @@ To add other values, you can use delegation, like so:
 [source,java]
 ----
 @Bean
-Saml2LogoutRequestResolver logoutRequestResolver(RelyingPartyRegistrationResolver registrationResolver) {
-	OpenSaml4LogoutRequestResolver logoutRequestResolver
-			new OpenSaml4LogoutRequestResolver(registrationResolver);
+Saml2LogoutRequestResolver logoutRequestResolver(RelyingPartyRegistrationRepository registrations) {
+	OpenSaml4LogoutRequestResolver logoutRequestResolver =
+			new OpenSaml4LogoutRequestResolver(registrations);
 	logoutRequestResolver.setParametersConsumer((parameters) -> {
 		String name = ((Saml2AuthenticatedPrincipal) parameters.getAuthentication().getPrincipal()).getFirstAttribute("CustomAttribute");
 		String format = "urn:oasis:names:tc:SAML:2.0:nameid-format:transient";
@@ -173,9 +173,9 @@ To add other values, you can use delegation, like so:
 [source,java]
 ----
 @Bean
-public Saml2LogoutResponseResolver logoutResponseResolver(RelyingPartyRegistrationResolver registrationResolver) {
+public Saml2LogoutResponseResolver logoutResponseResolver(RelyingPartyRegistrationRepository registrations) {
 	OpenSaml4LogoutResponseResolver logoutRequestResolver =
-			new OpenSaml3LogoutResponseResolver(relyingPartyRegistrationResolver);
+			new OpenSaml4LogoutResponseResolver(registrations);
 	logoutRequestResolver.setParametersConsumer((parameters) -> {
 		if (checkOtherPrevailingConditions(parameters.getRequest())) {
 			parameters.getLogoutRequest().getStatus().getStatusCode().setCode(StatusCode.PARTIAL_LOGOUT);

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/authentication/logout/OpenSaml4LogoutRequestResolver.java

@@ -27,6 +27,7 @@ import org.springframework.core.convert.converter.Converter;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequest;
 import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration;
+import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistrationRepository;
 import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationResolver;
 import org.springframework.util.Assert;
 
@@ -47,6 +48,15 @@ public final class OpenSaml4LogoutRequestResolver implements Saml2LogoutRequestR
 
 	private Clock clock = Clock.systemUTC();
 
+	public OpenSaml4LogoutRequestResolver(RelyingPartyRegistrationRepository registrations) {
+		this((request, id) -> {
+			if (id == null) {
+				return null;
+			}
+			return registrations.findByRegistrationId(id);
+		});
+	}
+
 	/**
 	 * Construct a {@link OpenSaml4LogoutRequestResolver}
 	 */

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/authentication/logout/OpenSaml4LogoutResponseResolver.java

@@ -26,6 +26,7 @@ import org.opensaml.saml.saml2.core.LogoutResponse;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutResponse;
 import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration;
+import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistrationRepository;
 import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationResolver;
 import org.springframework.util.Assert;
 
@@ -45,11 +46,20 @@ public final class OpenSaml4LogoutResponseResolver implements Saml2LogoutRespons
 
 	private Clock clock = Clock.systemUTC();
 
+	public OpenSaml4LogoutResponseResolver(RelyingPartyRegistrationRepository registrations) {
+		this.logoutResponseResolver = new OpenSamlLogoutResponseResolver(registrations, (request, id) -> {
+			if (id == null) {
+				return null;
+			}
+			return registrations.findByRegistrationId(id);
+		});
+	}
+
 	/**
 	 * Construct a {@link OpenSaml4LogoutResponseResolver}
 	 */
 	public OpenSaml4LogoutResponseResolver(RelyingPartyRegistrationResolver relyingPartyRegistrationResolver) {
-		this.logoutResponseResolver = new OpenSamlLogoutResponseResolver(relyingPartyRegistrationResolver);
+		this.logoutResponseResolver = new OpenSamlLogoutResponseResolver(null, relyingPartyRegistrationResolver);
 	}
 
 	/**

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/authentication/logout/OpenSamlLogoutRequestResolver.java

@@ -47,6 +47,8 @@ import org.springframework.security.saml2.provider.service.authentication.Saml2A
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequest;
 import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration;
 import org.springframework.security.saml2.provider.service.registration.Saml2MessageBinding;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers.UriResolver;
 import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationResolver;
 import org.springframework.security.saml2.provider.service.web.authentication.logout.OpenSamlSigningUtils.QueryParametersPartial;
 import org.springframework.util.Assert;
@@ -127,10 +129,12 @@ final class OpenSamlLogoutRequestResolver {
 		if (registration.getAssertingPartyDetails().getSingleLogoutServiceLocation() == null) {
 			return null;
 		}
+		UriResolver uriResolver = RelyingPartyRegistrationPlaceholderResolvers.uriResolver(request, registration);
+		String entityId = uriResolver.resolve(registration.getEntityId());
 		LogoutRequest logoutRequest = this.logoutRequestBuilder.buildObject();
 		logoutRequest.setDestination(registration.getAssertingPartyDetails().getSingleLogoutServiceLocation());
 		Issuer issuer = this.issuerBuilder.buildObject();
-		issuer.setValue(registration.getEntityId());
+		issuer.setValue(entityId);
 		logoutRequest.setIssuer(issuer);
 		NameID nameId = this.nameIdBuilder.buildObject();
 		nameId.setValue(authentication.getName());

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/authentication/logout/OpenSamlLogoutRequestValidatorParametersResolver.java

@@ -0,0 +1,228 @@
+/*
+ * 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.saml2.provider.service.web.authentication.logout;
+
+import java.io.ByteArrayInputStream;
+import java.nio.charset.StandardCharsets;
+
+import jakarta.servlet.http.HttpServletRequest;
+import net.shibboleth.utilities.java.support.xml.ParserPool;
+import org.opensaml.core.config.ConfigurationService;
+import org.opensaml.core.xml.config.XMLObjectProviderRegistry;
+import org.opensaml.core.xml.config.XMLObjectProviderRegistrySupport;
+import org.opensaml.saml.saml2.core.LogoutRequest;
+import org.opensaml.saml.saml2.core.impl.LogoutRequestUnmarshaller;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+import org.springframework.http.HttpMethod;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.saml2.Saml2Exception;
+import org.springframework.security.saml2.core.OpenSamlInitializationService;
+import org.springframework.security.saml2.core.Saml2Error;
+import org.springframework.security.saml2.core.Saml2ErrorCodes;
+import org.springframework.security.saml2.core.Saml2ParameterNames;
+import org.springframework.security.saml2.provider.service.authentication.Saml2AuthenticatedPrincipal;
+import org.springframework.security.saml2.provider.service.authentication.Saml2AuthenticationException;
+import org.springframework.security.saml2.provider.service.authentication.logout.OpenSamlLogoutRequestValidator;
+import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequest;
+import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequestValidatorParameters;
+import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration;
+import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistrationRepository;
+import org.springframework.security.saml2.provider.service.registration.Saml2MessageBinding;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers;
+import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
+import org.springframework.security.web.util.matcher.OrRequestMatcher;
+import org.springframework.security.web.util.matcher.RequestMatcher;
+import org.springframework.util.Assert;
+
+/**
+ * An OpenSAML-based implementation of
+ * {@link Saml2LogoutRequestValidatorParametersResolver}
+ */
+public final class OpenSamlLogoutRequestValidatorParametersResolver
+		implements Saml2LogoutRequestValidatorParametersResolver {
+
+	static {
+		OpenSamlInitializationService.initialize();
+	}
+
+	private RequestMatcher requestMatcher = new OrRequestMatcher(
+			new AntPathRequestMatcher("/logout/saml2/slo/{registrationId}"),
+			new AntPathRequestMatcher("/logout/saml2/slo"));
+
+	private final RelyingPartyRegistrationRepository registrations;
+
+	private final ParserPool parserPool;
+
+	private final LogoutRequestUnmarshaller unmarshaller;
+
+	/**
+	 * Constructs a {@link OpenSamlLogoutRequestValidator}
+	 */
+	public OpenSamlLogoutRequestValidatorParametersResolver(RelyingPartyRegistrationRepository registrations) {
+		Assert.notNull(registrations, "relyingPartyRegistrationRepository cannot be null");
+		XMLObjectProviderRegistry registry = ConfigurationService.get(XMLObjectProviderRegistry.class);
+		this.parserPool = registry.getParserPool();
+		this.unmarshaller = (LogoutRequestUnmarshaller) XMLObjectProviderRegistrySupport.getUnmarshallerFactory()
+				.getUnmarshaller(LogoutRequest.DEFAULT_ELEMENT_NAME);
+		this.registrations = registrations;
+	}
+
+	/**
+	 * Construct the parameters necessary for validating an asserting party's
+	 * {@code <saml2:LogoutRequest>} based on the given {@link HttpServletRequest}
+	 *
+	 * <p>
+	 * Uses the configured {@link RequestMatcher} to identify the processing request,
+	 * including looking for any indicated {@code registrationId}.
+	 *
+	 * <p>
+	 * If a {@code registrationId} is found in the request, it will attempt to use that,
+	 * erroring if no {@link RelyingPartyRegistration} is found.
+	 *
+	 * <p>
+	 * If no {@code registrationId} is found in the request, it will look for a currently
+	 * logged-in user and use the associated {@code registrationId}.
+	 *
+	 * <p>
+	 * In the event that neither the URL nor any logged in user could determine a
+	 * {@code registrationId}, this code then will try and derive a
+	 * {@link RelyingPartyRegistration} given the {@code <saml2:LogoutRequest>}'s
+	 * {@code Issuer} value.
+	 * @param request the HTTP request
+	 * @return a {@link Saml2LogoutRequestValidatorParameters} instance, or {@code null}
+	 * if one could not be resolved
+	 * @throws Saml2AuthenticationException if the {@link RequestMatcher} specifies a
+	 * non-existent {@code registrationId}
+	 */
+	@Override
+	public Saml2LogoutRequestValidatorParameters resolve(HttpServletRequest request, Authentication authentication) {
+		if (request.getParameter(Saml2ParameterNames.SAML_REQUEST) == null) {
+			return null;
+		}
+		RequestMatcher.MatchResult result = this.requestMatcher.matcher(request);
+		if (!result.isMatch()) {
+			return null;
+		}
+		String registrationId = getRegistrationId(result, authentication);
+		if (registrationId == null) {
+			return logoutRequestByEntityId(request, authentication);
+		}
+		return logoutRequestById(request, authentication, registrationId);
+	}
+
+	/**
+	 * The request matcher to use to identify a request to process a
+	 * {@code <saml2:LogoutRequest>}. By default, checks for {@code /logout/saml2/slo} and
+	 * {@code /logout/saml2/slo/{registrationId}}.
+	 *
+	 * <p>
+	 * Generally speaking, the URL does not need to have a {@code registrationId} in it
+	 * since either it can be looked up from the active logged in user or it can be
+	 * derived through the {@code Issuer} in the {@code <saml2:LogoutRequest>}.
+	 * @param requestMatcher the {@link RequestMatcher} to use
+	 */
+	public void setRequestMatcher(RequestMatcher requestMatcher) {
+		Assert.notNull(requestMatcher, "requestMatcher cannot be null");
+		this.requestMatcher = requestMatcher;
+	}
+
+	private String getRegistrationId(RequestMatcher.MatchResult result, Authentication authentication) {
+		String registrationId = result.getVariables().get("registrationId");
+		if (registrationId != null) {
+			return registrationId;
+		}
+		if (authentication == null) {
+			return null;
+		}
+		if (authentication.getPrincipal() instanceof Saml2AuthenticatedPrincipal principal) {
+			return principal.getRelyingPartyRegistrationId();
+		}
+		return null;
+	}
+
+	private Saml2LogoutRequestValidatorParameters logoutRequestById(HttpServletRequest request,
+			Authentication authentication, String registrationId) {
+		RelyingPartyRegistration registration = this.registrations.findByRegistrationId(registrationId);
+		if (registration == null) {
+			throw new Saml2AuthenticationException(
+					new Saml2Error(Saml2ErrorCodes.RELYING_PARTY_REGISTRATION_NOT_FOUND, "registration not found"),
+					"registration not found");
+		}
+		return logoutRequestByRegistration(request, registration, authentication);
+	}
+
+	private Saml2LogoutRequestValidatorParameters logoutRequestByEntityId(HttpServletRequest request,
+			Authentication authentication) {
+		String serialized = request.getParameter(Saml2ParameterNames.SAML_REQUEST);
+		byte[] b = Saml2Utils.samlDecode(serialized);
+		LogoutRequest logoutRequest = parse(inflateIfRequired(request, b));
+		String issuer = logoutRequest.getIssuer().getValue();
+		RelyingPartyRegistration registration = this.registrations.findUniqueByAssertingPartyEntityId(issuer);
+		return logoutRequestByRegistration(request, registration, authentication);
+	}
+
+	private Saml2LogoutRequestValidatorParameters logoutRequestByRegistration(HttpServletRequest request,
+			RelyingPartyRegistration registration, Authentication authentication) {
+		if (registration == null) {
+			return null;
+		}
+		Saml2MessageBinding saml2MessageBinding = Saml2MessageBindingUtils.resolveBinding(request);
+		registration = fromRequest(request, registration);
+		String serialized = request.getParameter(Saml2ParameterNames.SAML_REQUEST);
+		Saml2LogoutRequest logoutRequest = Saml2LogoutRequest.withRelyingPartyRegistration(registration)
+				.samlRequest(serialized).relayState(request.getParameter(Saml2ParameterNames.RELAY_STATE))
+				.binding(saml2MessageBinding).location(registration.getSingleLogoutServiceLocation())
+				.parameters((params) -> params.put(Saml2ParameterNames.SIG_ALG,
+						request.getParameter(Saml2ParameterNames.SIG_ALG)))
+				.parameters((params) -> params.put(Saml2ParameterNames.SIGNATURE,
+						request.getParameter(Saml2ParameterNames.SIGNATURE)))
+				.parametersQuery((params) -> request.getQueryString()).build();
+		return new Saml2LogoutRequestValidatorParameters(logoutRequest, registration, authentication);
+	}
+
+	private String inflateIfRequired(HttpServletRequest request, byte[] b) {
+		if (HttpMethod.GET.equals(request.getMethod())) {
+			return Saml2Utils.samlInflate(b);
+		}
+		return new String(b, StandardCharsets.UTF_8);
+	}
+
+	private LogoutRequest parse(String request) throws Saml2Exception {
+		try {
+			Document document = this.parserPool
+					.parse(new ByteArrayInputStream(request.getBytes(StandardCharsets.UTF_8)));
+			Element element = document.getDocumentElement();
+			return (LogoutRequest) this.unmarshaller.unmarshall(element);
+		}
+		catch (Exception ex) {
+			throw new Saml2Exception("Failed to deserialize LogoutRequest", ex);
+		}
+	}
+
+	private RelyingPartyRegistration fromRequest(HttpServletRequest request, RelyingPartyRegistration registration) {
+		RelyingPartyRegistrationPlaceholderResolvers.UriResolver uriResolver = RelyingPartyRegistrationPlaceholderResolvers
+				.uriResolver(request, registration);
+		String entityId = uriResolver.resolve(registration.getEntityId());
+		String logoutLocation = uriResolver.resolve(registration.getSingleLogoutServiceLocation());
+		String logoutResponseLocation = uriResolver.resolve(registration.getSingleLogoutServiceResponseLocation());
+		return registration.mutate().entityId(entityId).singleLogoutServiceLocation(logoutLocation)
+				.singleLogoutServiceResponseLocation(logoutResponseLocation).build();
+	}
+
+}

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/authentication/logout/OpenSamlLogoutResponseResolver.java

@@ -51,7 +51,10 @@ import org.springframework.security.saml2.core.Saml2ParameterNames;
 import org.springframework.security.saml2.provider.service.authentication.Saml2AuthenticatedPrincipal;
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutResponse;
 import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration;
+import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistrationRepository;
 import org.springframework.security.saml2.provider.service.registration.Saml2MessageBinding;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers.UriResolver;
 import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationResolver;
 import org.springframework.security.saml2.provider.service.web.authentication.logout.OpenSamlSigningUtils.QueryParametersPartial;
 import org.springframework.util.Assert;
@@ -82,12 +85,16 @@ final class OpenSamlLogoutResponseResolver {
 
 	private final StatusCodeBuilder statusCodeBuilder;
 
+	private final RelyingPartyRegistrationRepository registrations;
+
 	private final RelyingPartyRegistrationResolver relyingPartyRegistrationResolver;
 
 	/**
 	 * Construct a {@link OpenSamlLogoutResponseResolver}
 	 */
-	OpenSamlLogoutResponseResolver(RelyingPartyRegistrationResolver relyingPartyRegistrationResolver) {
+	OpenSamlLogoutResponseResolver(RelyingPartyRegistrationRepository registrations,
+			RelyingPartyRegistrationResolver relyingPartyRegistrationResolver) {
+		this.registrations = registrations;
 		this.relyingPartyRegistrationResolver = relyingPartyRegistrationResolver;
 		XMLObjectProviderRegistry registry = ConfigurationService.get(XMLObjectProviderRegistry.class);
 		this.parserPool = registry.getParserPool();
@@ -126,19 +133,25 @@ final class OpenSamlLogoutResponseResolver {
 
 	Saml2LogoutResponse resolve(HttpServletRequest request, Authentication authentication,
 			BiConsumer<RelyingPartyRegistration, LogoutResponse> logoutResponseConsumer) {
+		LogoutRequest logoutRequest = parse(extractSamlRequest(request));
 		String registrationId = getRegistrationId(authentication);
 		RelyingPartyRegistration registration = this.relyingPartyRegistrationResolver.resolve(request, registrationId);
+		if (registration == null && this.registrations != null) {
+			String issuer = logoutRequest.getIssuer().getValue();
+			registration = this.registrations.findUniqueByAssertingPartyEntityId(issuer);
+		}
 		if (registration == null) {
 			return null;
 		}
 		if (registration.getAssertingPartyDetails().getSingleLogoutServiceResponseLocation() == null) {
 			return null;
 		}
-		LogoutRequest logoutRequest = parse(extractSamlRequest(request));
+		UriResolver uriResolver = RelyingPartyRegistrationPlaceholderResolvers.uriResolver(request, registration);
+		String entityId = uriResolver.resolve(registration.getEntityId());
 		LogoutResponse logoutResponse = this.logoutResponseBuilder.buildObject();
 		logoutResponse.setDestination(registration.getAssertingPartyDetails().getSingleLogoutServiceResponseLocation());
 		Issuer issuer = this.issuerBuilder.buildObject();
-		issuer.setValue(registration.getEntityId());
+		issuer.setValue(entityId);
 		logoutResponse.setIssuer(issuer);
 		StatusCode code = this.statusCodeBuilder.buildObject();
 		code.setValue(StatusCode.SUCCESS);

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/authentication/logout/Saml2LogoutRequestFilter.java

@@ -30,8 +30,11 @@ import org.springframework.http.MediaType;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.security.core.context.SecurityContextHolderStrategy;
+import org.springframework.security.saml2.core.Saml2Error;
+import org.springframework.security.saml2.core.Saml2ErrorCodes;
 import org.springframework.security.saml2.core.Saml2ParameterNames;
 import org.springframework.security.saml2.provider.service.authentication.Saml2AuthenticatedPrincipal;
+import org.springframework.security.saml2.provider.service.authentication.Saml2AuthenticationException;
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequest;
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequestValidator;
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequestValidatorParameters;
@@ -39,6 +42,8 @@ import org.springframework.security.saml2.provider.service.authentication.logout
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutValidatorResult;
 import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration;
 import org.springframework.security.saml2.provider.service.registration.Saml2MessageBinding;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers.UriResolver;
 import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationResolver;
 import org.springframework.security.web.DefaultRedirectStrategy;
 import org.springframework.security.web.RedirectStrategy;
@@ -67,9 +72,9 @@ public final class Saml2LogoutRequestFilter extends OncePerRequestFilter {
 	private SecurityContextHolderStrategy securityContextHolderStrategy = SecurityContextHolder
 			.getContextHolderStrategy();
 
-	private final Saml2LogoutRequestValidator logoutRequestValidator;
+	private final Saml2LogoutRequestValidatorParametersResolver logoutRequestResolver;
 
-	private final RelyingPartyRegistrationResolver relyingPartyRegistrationResolver;
+	private final Saml2LogoutRequestValidator logoutRequestValidator;
 
 	private final Saml2LogoutResponseResolver logoutResponseResolver;
 
@@ -77,7 +82,14 @@ public final class Saml2LogoutRequestFilter extends OncePerRequestFilter {
 
 	private final RedirectStrategy redirectStrategy = new DefaultRedirectStrategy();
 
-	private RequestMatcher logoutRequestMatcher = new AntPathRequestMatcher("/logout/saml2/slo");
+	public Saml2LogoutRequestFilter(Saml2LogoutRequestValidatorParametersResolver logoutRequestResolver,
+			Saml2LogoutRequestValidator logoutRequestValidator, Saml2LogoutResponseResolver logoutResponseResolver,
+			LogoutHandler... handlers) {
+		this.logoutRequestResolver = logoutRequestResolver;
+		this.logoutRequestValidator = logoutRequestValidator;
+		this.logoutResponseResolver = logoutResponseResolver;
+		this.handler = new CompositeLogoutHandler(handlers);
+	}
 
 	/**
 	 * Constructs a {@link Saml2LogoutResponseFilter} for accepting SAML 2.0 Logout
@@ -91,7 +103,7 @@ public final class Saml2LogoutRequestFilter extends OncePerRequestFilter {
 	public Saml2LogoutRequestFilter(RelyingPartyRegistrationResolver relyingPartyRegistrationResolver,
 			Saml2LogoutRequestValidator logoutRequestValidator, Saml2LogoutResponseResolver logoutResponseResolver,
 			LogoutHandler... handlers) {
-		this.relyingPartyRegistrationResolver = relyingPartyRegistrationResolver;
+		this.logoutRequestResolver = new Saml2AssertingPartyLogoutRequestResolver(relyingPartyRegistrationResolver);
 		this.logoutRequestValidator = logoutRequestValidator;
 		this.logoutResponseResolver = logoutResponseResolver;
 		this.handler = new CompositeLogoutHandler(handlers);
@@ -100,26 +112,21 @@ public final class Saml2LogoutRequestFilter extends OncePerRequestFilter {
 	@Override
 	protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
 			throws ServletException, IOException {
-
-		if (!this.logoutRequestMatcher.matches(request)) {
-			chain.doFilter(request, response);
-			return;
+		Authentication authentication = this.securityContextHolderStrategy.getContext().getAuthentication();
+		Saml2LogoutRequestValidatorParameters parameters;
+		try {
+			parameters = this.logoutRequestResolver.resolve(request, authentication);
 		}
-
-		if (request.getParameter(Saml2ParameterNames.SAML_REQUEST) == null) {
-			chain.doFilter(request, response);
+		catch (Saml2AuthenticationException ex) {
+			this.logger.trace("Did not process logout request since failed to find requested RelyingPartyRegistration");
+			response.sendError(HttpServletResponse.SC_BAD_REQUEST);
 			return;
 		}
-
-		Authentication authentication = this.securityContextHolderStrategy.getContext().getAuthentication();
-		RelyingPartyRegistration registration = this.relyingPartyRegistrationResolver.resolve(request,
-				getRegistrationId(authentication));
-		if (registration == null) {
-			this.logger
-					.trace("Did not process logout request since failed to find associated RelyingPartyRegistration");
-			response.sendError(HttpServletResponse.SC_BAD_REQUEST);
+		if (parameters == null) {
+			chain.doFilter(request, response);
 			return;
 		}
+		RelyingPartyRegistration registration = parameters.getRelyingPartyRegistration();
 		if (registration.getSingleLogoutServiceLocation() == null) {
 			this.logger.trace(
 					"Did not process logout request since RelyingPartyRegistration has not been configured with a logout request endpoint");
@@ -134,17 +141,6 @@ public final class Saml2LogoutRequestFilter extends OncePerRequestFilter {
 			return;
 		}
 
-		String serialized = request.getParameter(Saml2ParameterNames.SAML_REQUEST);
-		Saml2LogoutRequest logoutRequest = Saml2LogoutRequest.withRelyingPartyRegistration(registration)
-				.samlRequest(serialized).relayState(request.getParameter(Saml2ParameterNames.RELAY_STATE))
-				.binding(saml2MessageBinding).location(registration.getSingleLogoutServiceLocation())
-				.parameters((params) -> params.put(Saml2ParameterNames.SIG_ALG,
-						request.getParameter(Saml2ParameterNames.SIG_ALG)))
-				.parameters((params) -> params.put(Saml2ParameterNames.SIGNATURE,
-						request.getParameter(Saml2ParameterNames.SIGNATURE)))
-				.parametersQuery((params) -> request.getQueryString()).build();
-		Saml2LogoutRequestValidatorParameters parameters = new Saml2LogoutRequestValidatorParameters(logoutRequest,
-				registration, authentication);
 		Saml2LogoutValidatorResult result = this.logoutRequestValidator.validate(parameters);
 		if (result.hasErrors()) {
 			response.sendError(HttpServletResponse.SC_UNAUTHORIZED, result.getErrors().iterator().next().toString());
@@ -168,7 +164,10 @@ public final class Saml2LogoutRequestFilter extends OncePerRequestFilter {
 
 	public void setLogoutRequestMatcher(RequestMatcher logoutRequestMatcher) {
 		Assert.notNull(logoutRequestMatcher, "logoutRequestMatcher cannot be null");
-		this.logoutRequestMatcher = logoutRequestMatcher;
+		Assert.isInstanceOf(Saml2AssertingPartyLogoutRequestResolver.class, this.logoutRequestResolver,
+				"saml2LogoutRequestResolver and logoutRequestMatcher cannot both be set. Please set the request matcher in the saml2LogoutRequestResolver itself.");
+		((Saml2AssertingPartyLogoutRequestResolver) this.logoutRequestResolver)
+				.setLogoutRequestMatcher(logoutRequestMatcher);
 	}
 
 	/**
@@ -182,17 +181,6 @@ public final class Saml2LogoutRequestFilter extends OncePerRequestFilter {
 		this.securityContextHolderStrategy = securityContextHolderStrategy;
 	}
 
-	private String getRegistrationId(Authentication authentication) {
-		if (authentication == null) {
-			return null;
-		}
-		Object principal = authentication.getPrincipal();
-		if (principal instanceof Saml2AuthenticatedPrincipal) {
-			return ((Saml2AuthenticatedPrincipal) principal).getRelyingPartyRegistrationId();
-		}
-		return null;
-	}
-
 	private void doRedirect(HttpServletRequest request, HttpServletResponse response,
 			Saml2LogoutResponse logoutResponse) throws IOException {
 		String location = logoutResponse.getResponseLocation();
@@ -252,4 +240,73 @@ public final class Saml2LogoutRequestFilter extends OncePerRequestFilter {
 		return html.toString();
 	}
 
+	private static class Saml2AssertingPartyLogoutRequestResolver
+			implements Saml2LogoutRequestValidatorParametersResolver {
+
+		private final RelyingPartyRegistrationResolver relyingPartyRegistrationResolver;
+
+		private RequestMatcher logoutRequestMatcher = new AntPathRequestMatcher("/logout/saml2/slo");
+
+		Saml2AssertingPartyLogoutRequestResolver(RelyingPartyRegistrationResolver relyingPartyRegistrationResolver) {
+			this.relyingPartyRegistrationResolver = relyingPartyRegistrationResolver;
+		}
+
+		@Override
+		public Saml2LogoutRequestValidatorParameters resolve(HttpServletRequest request,
+				Authentication authentication) {
+			String serialized = request.getParameter(Saml2ParameterNames.SAML_REQUEST);
+			if (serialized == null) {
+				return null;
+			}
+			RequestMatcher.MatchResult result = this.logoutRequestMatcher.matcher(request);
+			if (!result.isMatch()) {
+				return null;
+			}
+			String registrationId = getRegistrationId(result, authentication);
+			RelyingPartyRegistration registration = this.relyingPartyRegistrationResolver.resolve(request,
+					registrationId);
+			if (registration == null) {
+				throw new Saml2AuthenticationException(
+						new Saml2Error(Saml2ErrorCodes.RELYING_PARTY_REGISTRATION_NOT_FOUND, "registration not found"),
+						"registration not found");
+			}
+			UriResolver uriResolver = RelyingPartyRegistrationPlaceholderResolvers.uriResolver(request, registration);
+			String entityId = uriResolver.resolve(registration.getEntityId());
+			String logoutLocation = uriResolver.resolve(registration.getSingleLogoutServiceLocation());
+			String logoutResponseLocation = uriResolver.resolve(registration.getSingleLogoutServiceResponseLocation());
+			registration = registration.mutate().entityId(entityId).singleLogoutServiceLocation(logoutLocation)
+					.singleLogoutServiceResponseLocation(logoutResponseLocation).build();
+			Saml2MessageBinding saml2MessageBinding = Saml2MessageBindingUtils.resolveBinding(request);
+			Saml2LogoutRequest logoutRequest = Saml2LogoutRequest.withRelyingPartyRegistration(registration)
+					.samlRequest(serialized).relayState(request.getParameter(Saml2ParameterNames.RELAY_STATE))
+					.binding(saml2MessageBinding).location(registration.getSingleLogoutServiceLocation())
+					.parameters((params) -> params.put(Saml2ParameterNames.SIG_ALG,
+							request.getParameter(Saml2ParameterNames.SIG_ALG)))
+					.parameters((params) -> params.put(Saml2ParameterNames.SIGNATURE,
+							request.getParameter(Saml2ParameterNames.SIGNATURE)))
+					.parametersQuery((params) -> request.getQueryString()).build();
+			return new Saml2LogoutRequestValidatorParameters(logoutRequest, registration, authentication);
+		}
+
+		void setLogoutRequestMatcher(RequestMatcher logoutRequestMatcher) {
+			Assert.notNull(logoutRequestMatcher, "logoutRequestMatcher cannot be null");
+			this.logoutRequestMatcher = logoutRequestMatcher;
+		}
+
+		private String getRegistrationId(RequestMatcher.MatchResult result, Authentication authentication) {
+			String registrationId = result.getVariables().get("registrationId");
+			if (registrationId != null) {
+				return registrationId;
+			}
+			if (authentication == null) {
+				return null;
+			}
+			if (authentication.getPrincipal() instanceof Saml2AuthenticatedPrincipal principal) {
+				return principal.getRelyingPartyRegistrationId();
+			}
+			return null;
+		}
+
+	}
+
 }

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/authentication/logout/Saml2LogoutRequestValidatorParametersResolver.java

@@ -0,0 +1,45 @@
+/*
+ * 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.saml2.provider.service.web.authentication.logout;
+
+import jakarta.servlet.http.HttpServletRequest;
+
+import org.springframework.security.core.Authentication;
+import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequestValidatorParameters;
+
+/**
+ * Resolved a SAML 2.0 Logout Request and associated validation parameters from the given
+ * {@link HttpServletRequest} and current {@link Authentication}.
+ *
+ * The returned logout request is suitable for validating, logging out the logged-in user,
+ * and initiating the construction of a {@code LogoutResponse}.
+ *
+ * @author Josh Cummings
+ * @since 6.1
+ */
+public interface Saml2LogoutRequestValidatorParametersResolver {
+
+	/**
+	 * Resolve any SAML 2.0 Logout Request and associated
+	 * {@link org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration}
+	 * @param request the HTTP request
+	 * @param authentication the current user, if any; may be null
+	 * @return a SAML 2.0 Logout Request, if any; may be null
+	 */
+	Saml2LogoutRequestValidatorParameters resolve(HttpServletRequest request, Authentication authentication);
+
+}

saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/authentication/logout/Saml2LogoutResponseFilter.java

@@ -35,7 +35,10 @@ import org.springframework.security.saml2.provider.service.authentication.logout
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutResponseValidatorParameters;
 import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutValidatorResult;
 import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration;
+import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistrationRepository;
 import org.springframework.security.saml2.provider.service.registration.Saml2MessageBinding;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers;
+import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationPlaceholderResolvers.UriResolver;
 import org.springframework.security.saml2.provider.service.web.RelyingPartyRegistrationResolver;
 import org.springframework.security.web.authentication.logout.LogoutSuccessHandler;
 import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
@@ -71,6 +74,18 @@ public final class Saml2LogoutResponseFilter extends OncePerRequestFilter {
 
 	private RequestMatcher logoutRequestMatcher = new AntPathRequestMatcher("/logout/saml2/slo");
 
+	public Saml2LogoutResponseFilter(RelyingPartyRegistrationRepository registrations,
+			Saml2LogoutResponseValidator logoutResponseValidator, LogoutSuccessHandler logoutSuccessHandler) {
+		this.relyingPartyRegistrationResolver = (request, id) -> {
+			if (id == null) {
+				return null;
+			}
+			return registrations.findByRegistrationId(id);
+		};
+		this.logoutResponseValidator = logoutResponseValidator;
+		this.logoutSuccessHandler = logoutSuccessHandler;
+	}
+
 	/**
 	 * Constructs a {@link Saml2LogoutResponseFilter} for accepting SAML 2.0 Logout
 	 * Responses from the asserting party
@@ -125,7 +140,12 @@ public final class Saml2LogoutResponseFilter extends OncePerRequestFilter {
 			response.sendError(HttpServletResponse.SC_UNAUTHORIZED);
 			return;
 		}
-
+		UriResolver uriResolver = RelyingPartyRegistrationPlaceholderResolvers.uriResolver(request, registration);
+		String entityId = uriResolver.resolve(registration.getEntityId());
+		String logoutLocation = uriResolver.resolve(registration.getSingleLogoutServiceLocation());
+		String logoutResponseLocation = uriResolver.resolve(registration.getSingleLogoutServiceResponseLocation());
+		registration = registration.mutate().entityId(entityId).singleLogoutServiceLocation(logoutLocation)
+				.singleLogoutServiceResponseLocation(logoutResponseLocation).build();
 		Saml2MessageBinding saml2MessageBinding = Saml2MessageBindingUtils.resolveBinding(request);
 		if (!registration.getSingleLogoutServiceBindings().contains(saml2MessageBinding)) {
 			this.logger.trace("Did not process logout response since used incorrect binding");

saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/authentication/TestOpenSamlObjects.java

@@ -101,6 +101,8 @@ public final class TestOpenSamlObjects {
 
 	private static String DESTINATION = "https://localhost/login/saml2/sso/idp-alias";
 
+	private static String LOGOUT_DESTINATION = "http://localhost/logout/saml2/slo";
+
 	public static String RELYING_PARTY_ENTITY_ID = "https://localhost/saml2/service-provider-metadata/idp-alias";
 
 	private static String ASSERTING_PARTY_ENTITY_ID = "https://some.idp.test/saml2/idp";
@@ -204,6 +206,18 @@ public final class TestOpenSamlObjects {
 		return authnRequest;
 	}
 
+	public static LogoutRequest logoutRequest() {
+		Issuer issuer = build(Issuer.DEFAULT_ELEMENT_NAME);
+		issuer.setValue(ASSERTING_PARTY_ENTITY_ID);
+		NameID nameId = build(NameID.DEFAULT_ELEMENT_NAME);
+		nameId.setValue("user");
+		LogoutRequest logoutRequest = build(LogoutRequest.DEFAULT_ELEMENT_NAME);
+		logoutRequest.setIssuer(issuer);
+		logoutRequest.setDestination(LOGOUT_DESTINATION);
+		logoutRequest.setNameID(nameId);
+		return logoutRequest;
+	}
+
 	static Credential getSigningCredential(Saml2X509Credential credential, String entityId) {
 		BasicCredential cred = getBasicCredential(credential);
 		cred.setEntityId(entityId);

saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/authentication/TestSaml2Authentications.java

@@ -0,0 +1,40 @@
+/*
+ * 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.saml2.provider.service.authentication;
+
+import java.util.Collections;
+
+import org.springframework.security.core.authority.AuthorityUtils;
+
+/**
+ * Tests instances for {@link Saml2Authentication}
+ *
+ * @author Josh Cummings
+ */
+public final class TestSaml2Authentications {
+
+	private TestSaml2Authentications() {
+	}
+
+	public static Saml2Authentication authentication() {
+		DefaultSaml2AuthenticatedPrincipal principal = new DefaultSaml2AuthenticatedPrincipal("user",
+				Collections.emptyMap());
+		principal.setRelyingPartyRegistrationId("simplesamlphp");
+		return new Saml2Authentication(principal, "response", AuthorityUtils.createAuthorityList("ROLE_USER"));
+	}
+
+}

saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/web/authentication/logout/OpenSamlLogoutRequestValidatorParametersResolverTests.java

@@ -0,0 +1,143 @@
+/*
+ * 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.saml2.provider.service.web.authentication.logout;
+
+import java.nio.charset.StandardCharsets;
+
+import net.shibboleth.utilities.java.support.xml.SerializeSupport;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.opensaml.core.xml.XMLObject;
+import org.opensaml.core.xml.config.XMLObjectProviderRegistrySupport;
+import org.opensaml.core.xml.io.Marshaller;
+import org.opensaml.core.xml.io.MarshallingException;
+import org.w3c.dom.Element;
+
+import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.security.authentication.TestingAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.saml2.Saml2Exception;
+import org.springframework.security.saml2.core.Saml2ParameterNames;
+import org.springframework.security.saml2.provider.service.authentication.Saml2AuthenticationException;
+import org.springframework.security.saml2.provider.service.authentication.TestOpenSamlObjects;
+import org.springframework.security.saml2.provider.service.authentication.TestSaml2Authentications;
+import org.springframework.security.saml2.provider.service.authentication.logout.Saml2LogoutRequestValidatorParameters;
+import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration;
+import org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistrationRepository;
+import org.springframework.security.saml2.provider.service.registration.TestRelyingPartyRegistrations;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.mockito.BDDMockito.given;
+
+@ExtendWith(MockitoExtension.class)
+public final class OpenSamlLogoutRequestValidatorParametersResolverTests {
+
+	@Mock
+	RelyingPartyRegistrationRepository registrations;
+
+	private RelyingPartyRegistration registration = TestRelyingPartyRegistrations.relyingPartyRegistration().build();
+
+	private OpenSamlLogoutRequestValidatorParametersResolver resolver;
+
+	@BeforeEach
+	void setup() {
+		this.resolver = new OpenSamlLogoutRequestValidatorParametersResolver(this.registrations);
+	}
+
+	@Test
+	void saml2LogoutRegistrationIdResolveWhenMatchesThenParameters() {
+		String registrationId = this.registration.getRegistrationId();
+		MockHttpServletRequest request = post("/logout/saml2/slo/" + registrationId);
+		Authentication authentication = new TestingAuthenticationToken("user", "pass");
+		request.setParameter(Saml2ParameterNames.SAML_REQUEST, "request");
+		given(this.registrations.findByRegistrationId(registrationId)).willReturn(this.registration);
+		Saml2LogoutRequestValidatorParameters parameters = this.resolver.resolve(request, authentication);
+		assertThat(parameters.getAuthentication()).isEqualTo(authentication);
+		assertThat(parameters.getRelyingPartyRegistration().getRegistrationId()).isEqualTo(registrationId);
+		assertThat(parameters.getLogoutRequest().getSamlRequest()).isEqualTo("request");
+	}
+
+	@Test
+	void saml2LogoutRegistrationIdWhenUnauthenticatedThenParameters() {
+		String registrationId = this.registration.getRegistrationId();
+		MockHttpServletRequest request = post("/logout/saml2/slo/" + registrationId);
+		request.setParameter(Saml2ParameterNames.SAML_REQUEST, "request");
+		given(this.registrations.findByRegistrationId(registrationId)).willReturn(this.registration);
+		Saml2LogoutRequestValidatorParameters parameters = this.resolver.resolve(request, null);
+		assertThat(parameters.getAuthentication()).isNull();
+		assertThat(parameters.getRelyingPartyRegistration().getRegistrationId()).isEqualTo(registrationId);
+		assertThat(parameters.getLogoutRequest().getSamlRequest()).isEqualTo("request");
+	}
+
+	@Test
+	void saml2LogoutResolveWhenAuthenticatedThenParameters() {
+		String registrationId = this.registration.getRegistrationId();
+		MockHttpServletRequest request = post("/logout/saml2/slo");
+		Authentication authentication = TestSaml2Authentications.authentication();
+		request.setParameter(Saml2ParameterNames.SAML_REQUEST, "request");
+		given(this.registrations.findByRegistrationId(registrationId)).willReturn(this.registration);
+		Saml2LogoutRequestValidatorParameters parameters = this.resolver.resolve(request, authentication);
+		assertThat(parameters.getAuthentication()).isEqualTo(authentication);
+		assertThat(parameters.getRelyingPartyRegistration().getRegistrationId()).isEqualTo(registrationId);
+		assertThat(parameters.getLogoutRequest().getSamlRequest()).isEqualTo("request");
+	}
+
+	@Test
+	void saml2LogoutResolveWhenUnauthenticatedThenParameters() {
+		String registrationId = this.registration.getRegistrationId();
+		MockHttpServletRequest request = post("/logout/saml2/slo");
+		String logoutRequest = serialize(TestOpenSamlObjects.logoutRequest());
+		String encoded = Saml2Utils.samlEncode(logoutRequest.getBytes(StandardCharsets.UTF_8));
+		request.setParameter(Saml2ParameterNames.SAML_REQUEST, encoded);
+		given(this.registrations.findUniqueByAssertingPartyEntityId(TestOpenSamlObjects.ASSERTING_PARTY_ENTITY_ID))
+				.willReturn(this.registration);
+		Saml2LogoutRequestValidatorParameters parameters = this.resolver.resolve(request, null);
+		assertThat(parameters.getAuthentication()).isNull();
+		assertThat(parameters.getRelyingPartyRegistration().getRegistrationId()).isEqualTo(registrationId);
+		assertThat(parameters.getLogoutRequest().getSamlRequest()).isEqualTo(encoded);
+	}
+
+	@Test
+	void saml2LogoutRegistrationIdResolveWhenNoMatchingRegistrationIdThenSaml2Exception() {
+		MockHttpServletRequest request = post("/logout/saml2/slo/id");
+		request.setParameter(Saml2ParameterNames.SAML_REQUEST, "request");
+		assertThatExceptionOfType(Saml2AuthenticationException.class)
+				.isThrownBy(() -> this.resolver.resolve(request, null));
+	}
+
+	private MockHttpServletRequest post(String uri) {
+		MockHttpServletRequest request = new MockHttpServletRequest("POST", uri);
+		request.setServletPath(uri);
+		return request;
+	}
+
+	private String serialize(XMLObject object) {
+		try {
+			Marshaller marshaller = XMLObjectProviderRegistrySupport.getMarshallerFactory().getMarshaller(object);
+			Element element = marshaller.marshall(object);
+			return SerializeSupport.nodeToString(element);
+		}
+		catch (MarshallingException ex) {
+			throw new Saml2Exception(ex);
+		}
+	}
+
+}

saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/web/authentication/logout/OpenSamlLogoutResponseResolverTests.java

@@ -56,7 +56,7 @@ public class OpenSamlLogoutResponseResolverTests {
 
 	RelyingPartyRegistrationResolver relyingPartyRegistrationResolver = mock(RelyingPartyRegistrationResolver.class);
 
-	OpenSamlLogoutResponseResolver logoutResponseResolver = new OpenSamlLogoutResponseResolver(
+	OpenSamlLogoutResponseResolver logoutResponseResolver = new OpenSamlLogoutResponseResolver(null,
 			this.relyingPartyRegistrationResolver);
 
 	@Test