Merge branch '1.0.x' into 1.1.x

Closes gh-1383

Author: jgrandja

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/oidc/authentication/OidcClientRegistrationAuthenticationProvider.java

@@ -211,6 +211,10 @@ private OidcClientRegistrationAuthenticationToken registerClient(OidcClientRegis
 					.clientSecret(this.passwordEncoder.encode(registeredClient.getClientSecret()))
 					.build();
 			this.registeredClientRepository.save(updatedRegisteredClient);
+			if (ClientAuthenticationMethod.CLIENT_SECRET_JWT.getValue().equals(clientRegistrationAuthentication.getClientRegistration().getTokenEndpointAuthenticationMethod())) {
+				// gh-1344 Return the hashed client_secret
+				registeredClient = updatedRegisteredClient;
+			}
 		} else {
 			this.registeredClientRepository.save(registeredClient);
 		}

oauth2-authorization-server/src/test/java/org/springframework/security/oauth2/server/authorization/config/annotation/web/configurers/OidcClientRegistrationTests.java

@@ -23,6 +23,8 @@
 import java.util.UUID;
 import java.util.function.Consumer;
 
+import javax.crypto.spec.SecretKeySpec;
+
 import com.nimbusds.jose.jwk.JWKSet;
 import com.nimbusds.jose.jwk.source.JWKSource;
 import com.nimbusds.jose.proc.SecurityContext;
@@ -406,6 +408,55 @@ public void requestWhenClientRegistersWithSecretThenClientAuthenticationSuccess(
 				.andReturn();
 	}
 
+	// gh-1344
+	@Test
+	public void requestWhenClientRegistersWithClientSecretJwtThenClientAuthenticationSuccess() throws Exception {
+		this.spring.register(AuthorizationServerConfiguration.class).autowire();
+
+		// @formatter:off
+		OidcClientRegistration clientRegistration = OidcClientRegistration.builder()
+				.clientName("client-name")
+				.redirectUri("https://client.example.com")
+				.grantType(AuthorizationGrantType.AUTHORIZATION_CODE.getValue())
+				.grantType(AuthorizationGrantType.CLIENT_CREDENTIALS.getValue())
+				.tokenEndpointAuthenticationMethod(ClientAuthenticationMethod.CLIENT_SECRET_JWT.getValue())
+				.scope("scope1")
+				.scope("scope2")
+				.build();
+		// @formatter:on
+
+		OidcClientRegistration clientRegistrationResponse = registerClient(clientRegistration);
+
+		JwsHeader jwsHeader = JwsHeader.with(MacAlgorithm.HS256)
+				.build();
+
+		Instant issuedAt = Instant.now();
+		Instant expiresAt = issuedAt.plus(1, ChronoUnit.HOURS);
+		JwtClaimsSet jwtClaimsSet = JwtClaimsSet.builder()
+				.issuer(clientRegistrationResponse.getClientId())
+				.subject(clientRegistrationResponse.getClientId())
+				.audience(Collections.singletonList(asUrl(this.authorizationServerSettings.getIssuer(), this.authorizationServerSettings.getTokenEndpoint())))
+				.issuedAt(issuedAt)
+				.expiresAt(expiresAt)
+				.build();
+
+		JWKSet jwkSet = new JWKSet(TestJwks.jwk(
+				new SecretKeySpec(clientRegistrationResponse.getClientSecret().getBytes(), "HS256")).build());
+		JwtEncoder jwtClientAssertionEncoder = new NimbusJwtEncoder((jwkSelector, securityContext) -> jwkSelector.select(jwkSet));
+
+		Jwt jwtAssertion = jwtClientAssertionEncoder.encode(JwtEncoderParameters.from(jwsHeader, jwtClaimsSet));
+
+		this.mvc.perform(post(DEFAULT_TOKEN_ENDPOINT_URI)
+						.param(OAuth2ParameterNames.GRANT_TYPE, AuthorizationGrantType.CLIENT_CREDENTIALS.getValue())
+						.param(OAuth2ParameterNames.SCOPE, "scope1")
+						.param(OAuth2ParameterNames.CLIENT_ASSERTION_TYPE, "urn:ietf:params:oauth:client-assertion-type:jwt-bearer")
+						.param(OAuth2ParameterNames.CLIENT_ASSERTION, jwtAssertion.getTokenValue())
+						.param(OAuth2ParameterNames.CLIENT_ID, clientRegistrationResponse.getClientId()))
+				.andExpect(status().isOk())
+				.andExpect(jsonPath("$.access_token").isNotEmpty())
+				.andExpect(jsonPath("$.scope").value("scope1"));
+	}
+
 	@Test
 	public void requestWhenClientRegistersWithCustomMetadataThenSavedToRegisteredClient() throws Exception {
 		this.spring.register(CustomClientMetadataConfiguration.class).autowire();