Add logoutRequestMatcher to Saml2LogoutConfigurer for custom matching

Closes: gh-10821

Signed-off-by: Andrey Litvitski <andrey1010102008@gmail.com>

Author: therepanic

config/src/main/java/org/springframework/security/config/annotation/web/configurers/saml2/Saml2LogoutConfigurer.java

@@ -105,6 +105,7 @@
  *
  * @author Josh Cummings
  * @author Ngoc Nhan
+ * @author Andrey Litvitski
  * @since 5.6
  * @see Saml2LogoutConfigurer
  */
@@ -127,6 +128,8 @@ public final class Saml2LogoutConfigurer<H extends HttpSecurityBuilder<H>>
 
 	private LogoutResponseConfigurer logoutResponseConfigurer;
 
+	private RequestMatcher logoutRequestMatcher;
+
 	/**
 	 * Creates a new instance
 	 * @see HttpSecurity#logout(Customizer)
@@ -195,6 +198,16 @@ public Saml2LogoutConfigurer<H> logoutResponse(
 		return this;
 	}
 
+	/**
+	 * Sets a custom {@link RequestMatcher} to use for SAML logout requests.
+	 * @param logoutRequestMatcher the matcher to use
+	 * @return the {@link Saml2LogoutConfigurer} for further customization
+	 */
+	public Saml2LogoutConfigurer<H> logoutRequestMatcher(RequestMatcher logoutRequestMatcher) {
+		this.logoutRequestMatcher = logoutRequestMatcher;
+		return this;
+	}
+
 	/**
 	 * {@inheritDoc}
 	 */
@@ -271,6 +284,9 @@ private Saml2RelyingPartyInitiatedLogoutFilter createRelyingPartyLogoutFilter(
 	}
 
 	private RequestMatcher createLogoutMatcher() {
+		if (this.logoutRequestMatcher != null) {
+			return this.logoutRequestMatcher;
+		}
 		RequestMatcher logout = getRequestMatcherBuilder().matcher(HttpMethod.POST, this.logoutUrl);
 		RequestMatcher saml2 = new Saml2RequestMatcher(getSecurityContextHolderStrategy());
 		return new AndRequestMatcher(logout, saml2);

config/src/test/java/org/springframework/security/config/annotation/web/configurers/saml2/Saml2LogoutConfigurerTests.java

@@ -543,6 +543,18 @@ public void saml2LogoutWhenLogoutFilterPostProcessedThenUses() {
 
 	}
 
+	// gh-10821
+	@Test
+	public void saml2LogoutWhenCustomLogoutRequestMatcherThenUsed() throws Exception {
+		this.spring.register(Saml2LogoutCustomMatcherConfig.class).autowire();
+		MvcResult result = this.mvc.perform(post("/saml/custom-logout").with(authentication(this.user)).with(csrf()))
+			.andExpect(status().isFound())
+			.andReturn();
+		assertThat(result.getResponse().getHeader("Location"))
+			.startsWith("https://ap.example.org/logout/saml2/request");
+		verify(getBean(LogoutHandler.class)).logout(any(), any(), any());
+	}
+
 	private <T> T getBean(Class<T> clazz) {
 		return this.spring.getContext().getBean(clazz);
 	}
@@ -577,6 +589,34 @@ LogoutHandler logoutHandler() {
 
 	}
 
+	@Configuration
+	@EnableWebSecurity
+	@Import(Saml2LoginConfigBeans.class)
+	static class Saml2LogoutCustomMatcherConfig {
+
+		LogoutHandler mockLogoutHandler = mock(LogoutHandler.class);
+
+		@Bean
+		SecurityFilterChain web(HttpSecurity http) throws Exception {
+			// @formatter:off
+			http
+					.authorizeHttpRequests((authorize) -> authorize.anyRequest().authenticated())
+					.logout((logout) -> logout.addLogoutHandler(this.mockLogoutHandler))
+					.saml2Login(withDefaults())
+					.saml2Logout((saml2) -> saml2
+							.logoutRequestMatcher(pathPattern(HttpMethod.POST, "/saml/custom-logout"))
+					);
+			return http.build();
+			// @formatter:on
+		}
+
+		@Bean
+		LogoutHandler logoutHandler() {
+			return this.mockLogoutHandler;
+		}
+
+	}
+
 	@Configuration
 	@EnableWebSecurity
 	@Import(Saml2LoginConfigBeans.class)