Start building against Spring Security 5.4.0-M2 snapshots

See gh-21932

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/oauth2/resource/reactive/ReactiveOAuth2ResourceServerAutoConfigurationTests.java

@@ -47,6 +47,7 @@ import org.springframework.security.config.web.server.ServerHttpSecurity;
 import org.springframework.security.core.userdetails.MapReactiveUserDetailsService;
 import org.springframework.security.oauth2.core.DelegatingOAuth2TokenValidator;
 import org.springframework.security.oauth2.core.OAuth2TokenValidator;
+import org.springframework.security.oauth2.jose.jws.SignatureAlgorithm;
 import org.springframework.security.oauth2.jwt.Jwt;
 import org.springframework.security.oauth2.jwt.JwtIssuerValidator;
 import org.springframework.security.oauth2.jwt.NimbusReactiveJwtDecoder;
@@ -105,8 +106,8 @@ class ReactiveOAuth2ResourceServerAutoConfigurationTests {
 						"spring.security.oauth2.resourceserver.jwt.jws-algorithm=RS512")
 				.run((context) -> {
 					NimbusReactiveJwtDecoder nimbusReactiveJwtDecoder = context.getBean(NimbusReactiveJwtDecoder.class);
-					assertThat(nimbusReactiveJwtDecoder).extracting("jwtProcessor.arg$2")
+					assertThat(nimbusReactiveJwtDecoder).extracting("jwtProcessor.arg$1.signatureAlgorithms").matches(
-							.matches((algorithms) -> ((Set<JWSAlgorithm>) algorithms).contains(JWSAlgorithm.RS512));
+							(algorithms) -> ((Set<SignatureAlgorithm>) algorithms).contains(SignatureAlgorithm.RS512));
 				});
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/oauth2/resource/servlet/OAuth2ResourceServerAutoConfigurationTests.java

@@ -99,7 +99,8 @@ class OAuth2ResourceServerAutoConfigurationTests {
 					JwtDecoder jwtDecoder = context.getBean(JwtDecoder.class);
 					Object processor = ReflectionTestUtils.getField(jwtDecoder, "jwtProcessor");
 					Object keySelector = ReflectionTestUtils.getField(processor, "jwsKeySelector");
-					assertThat(keySelector).hasFieldOrPropertyWithValue("jwsAlg", JWSAlgorithm.RS256);
+					assertThat(keySelector).hasFieldOrPropertyWithValue("jwsAlgs",
+							Collections.singleton(JWSAlgorithm.RS256));
 				});
 	}
 
@@ -112,7 +113,8 @@ class OAuth2ResourceServerAutoConfigurationTests {
 					JwtDecoder jwtDecoder = context.getBean(JwtDecoder.class);
 					Object processor = ReflectionTestUtils.getField(jwtDecoder, "jwtProcessor");
 					Object keySelector = ReflectionTestUtils.getField(processor, "jwsKeySelector");
-					assertThat(keySelector).hasFieldOrPropertyWithValue("jwsAlg", JWSAlgorithm.RS384);
+					assertThat(keySelector).hasFieldOrPropertyWithValue("jwsAlgs",
+							Collections.singleton(JWSAlgorithm.RS384));
 					assertThat(getBearerTokenFilter(context)).isNotNull();
 				});
 	}

spring-boot-project/spring-boot-dependencies/build.gradle

@@ -1712,7 +1712,7 @@ bom {
 			]
 		}
 	}
-	library("Spring Security", "5.3.2.RELEASE") {
+	library("Spring Security", "5.4.0-SNAPSHOT") {
 		group("org.springframework.security") {
 			imports = [
 				"spring-security-bom"