Use Spec Order for Verifying Signatures

Closes gh-12346

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

@@ -318,6 +318,34 @@ public class Saml2LogoutConfigurerTests {
 		verify(getBean(LogoutHandler.class)).logout(any(), any(), any());
 	}
 
+	// gh-12346
+	@Test
+	public void saml2LogoutRequestWhenLowercaseEncodingAndDifferentQueryParamOrderThenLogsOutAndSendsLogoutResponse()
+			throws Exception {
+		this.spring.register(Saml2LogoutDefaultsConfig.class).autowire();
+		String apLogoutRequest = "nZFNa4QwEIb/iuQeP6K7dYO6FKQg2B622x56G3WwgiY2E8v239fqCksPPfSWIXmfNw+THC9D73yi\r\n"
+				+ "oU6rlAWuzxxUtW461abs5fzAY3bMEoKhF6Msdasne8KPCck6c1KRXK9SNhklNVBHUsGAJG0tn+8f\r\n"
+				+ "SylcX45GW13rnjn5HOwU2KXt3dqRpOeZ0cULDGOPrjat1y8t3gL2zFrGnCJPWXkKcR8KCHY8xmrP\r\n"
+				+ "Iz868OpOVLwO4wohggagmd8STVgosqBsyoQvBPd3XITnIJaRL8PYjcThjTmvm/f8SXa1lEvY3Nr9\r\n"
+				+ "LQdEaH6EWAYjR2U7+8W7JvFucRv8aY4X+b/g03zaoCsmu46/FpN9Aw==";
+		String apLogoutRequestRelayState = "d118dbd5-3853-4268-b3e5-c40fc033fa2f";
+		String apLogoutRequestSignature = "VZ7rWa5u3hIX60fAQs/gBQZWDP2BAIlCMMrNrTHafoKKj0uXWnuITYLuL8NdsWmyQN0+fqWW4X05+BqiLpL80jHLmQR5RVqqL1EtVv1SpPUna938lgz2sOliuYmfQNj4Bmd+Z5G1K6QhbVrtfb7TQHURjUafzfRm8+jGz3dPjVBrn/rD/umfGoSn6RuWngugcMNL4U0A+JcEh1NSfSYNVz7y+MqlW1UhX2kF86rm97ERCrxay7Gh/bI2f3fJPJ1r+EyLjzrDUkqw5cva3rVlFgEQouMVu35lUJn7SFompW8oTxkI23oc/t+AGZqaBupNITNdjyGCBpfukZ69EZrj8g==";
+		DefaultSaml2AuthenticatedPrincipal principal = new DefaultSaml2AuthenticatedPrincipal("user",
+				Collections.emptyMap());
+		principal.setRelyingPartyRegistrationId("get");
+		Saml2Authentication user = new Saml2Authentication(principal, "response",
+				AuthorityUtils.createAuthorityList("ROLE_USER"));
+		MvcResult result = this.mvc
+				.perform(get("/logout/saml2/slo").param("SAMLRequest", apLogoutRequest)
+						.param("SigAlg", this.apLogoutRequestSigAlg).param("RelayState", apLogoutRequestRelayState)
+						.param("Signature", apLogoutRequestSignature)
+						.with(new SamlQueryStringRequestPostProcessor(true)).with(authentication(user)))
+				.andExpect(status().isFound()).andReturn();
+		String location = result.getResponse().getHeader("Location");
+		assertThat(location).startsWith("https://ap.example.org/logout/saml2/response");
+		verify(getBean(LogoutHandler.class)).logout(any(), any(), any());
+	}
+
 	@Test
 	public void saml2LogoutRequestWhenNoRegistrationThen400() throws Exception {
 		this.spring.register(Saml2LogoutDefaultsConfig.class).autowire();

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

@@ -21,6 +21,8 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 import net.shibboleth.utilities.java.support.resolver.CriteriaSet;
@@ -191,9 +193,9 @@ final class OpenSamlVerificationUtils {
 				else {
 					this.signature = null;
 				}
-				this.content = UriComponentsBuilder.newInstance().query(request.getParametersQuery())
-						.replaceQueryParam(Saml2ParameterNames.SIGNATURE).build(true).toUriString().substring(1)
-						.getBytes(StandardCharsets.UTF_8);
+				Map<String, String> queryParams = UriComponentsBuilder.newInstance().query(request.getParametersQuery())
+						.build(true).getQueryParams().toSingleValueMap();
+				this.content = getContent(Saml2ParameterNames.SAML_REQUEST, request.getRelayState(), queryParams);
 			}
 
 			RedirectSignature(Saml2LogoutResponse response) {
@@ -204,9 +206,24 @@ final class OpenSamlVerificationUtils {
 				else {
 					this.signature = null;
 				}
-				this.content = UriComponentsBuilder.newInstance().query(response.getParametersQuery())
-						.replaceQueryParam(Saml2ParameterNames.SIGNATURE).build(true).toUriString().substring(1)
-						.getBytes(StandardCharsets.UTF_8);
+				Map<String, String> queryParams = UriComponentsBuilder.newInstance()
+						.query(response.getParametersQuery()).build(true).getQueryParams().toSingleValueMap();
+				this.content = getContent(Saml2ParameterNames.SAML_RESPONSE, response.getRelayState(), queryParams);
+			}
+
+			static byte[] getContent(String samlObject, String relayState, final Map<String, String> queryParams) {
+				if (Objects.nonNull(relayState)) {
+					return String
+							.format("%s=%s&%s=%s&%s=%s", samlObject, queryParams.get(samlObject),
+									Saml2ParameterNames.RELAY_STATE, queryParams.get(Saml2ParameterNames.RELAY_STATE),
+									Saml2ParameterNames.SIG_ALG, queryParams.get(Saml2ParameterNames.SIG_ALG))
+							.getBytes(StandardCharsets.UTF_8);
+				}
+				else {
+					return String.format("%s=%s&%s=%s", samlObject, queryParams.get(samlObject),
+							Saml2ParameterNames.SIG_ALG, queryParams.get(Saml2ParameterNames.SIG_ALG))
+							.getBytes(StandardCharsets.UTF_8);
+				}
 			}
 
 			byte[] getContent() {