Implement OAuth 2.0 Server Metadata (RFC 8414)

See See https://tools.ietf.org/html/rfc8414

Closes gh-54

Author: Kehrlann

oauth2-authorization-server/src/main/java/org/springframework/security/config/annotation/web/configurers/oauth2/server/authorization/OAuth2AuthorizationServerConfigurer.java

@@ -48,6 +48,7 @@
 import org.springframework.security.oauth2.server.authorization.oidc.web.OidcProviderConfigurationEndpointFilter;
 import org.springframework.security.oauth2.server.authorization.web.NimbusJwkSetEndpointFilter;
 import org.springframework.security.oauth2.server.authorization.web.OAuth2AuthorizationEndpointFilter;
+import org.springframework.security.oauth2.server.authorization.web.OAuth2AuthorizationServerConfigurationEndpointFilter;
 import org.springframework.security.oauth2.server.authorization.web.OAuth2ClientAuthenticationFilter;
 import org.springframework.security.oauth2.server.authorization.web.OAuth2TokenEndpointFilter;
 import org.springframework.security.oauth2.server.authorization.web.OAuth2TokenRevocationEndpointFilter;
@@ -84,12 +85,14 @@ public final class OAuth2AuthorizationServerConfigurer<B extends HttpSecurityBui
 	private RequestMatcher tokenRevocationEndpointMatcher;
 	private RequestMatcher jwkSetEndpointMatcher;
 	private RequestMatcher oidcProviderConfigurationEndpointMatcher;
+	private RequestMatcher oauth2ServerConfigurationEndpointMatcher;
 	private final RequestMatcher endpointsMatcher = (request) ->
 			this.authorizationEndpointMatcher.matches(request) ||
 			this.tokenEndpointMatcher.matches(request) ||
 			this.tokenRevocationEndpointMatcher.matches(request) ||
 			this.jwkSetEndpointMatcher.matches(request) ||
-			this.oidcProviderConfigurationEndpointMatcher.matches(request);
+			this.oidcProviderConfigurationEndpointMatcher.matches(request) ||
+			this.oauth2ServerConfigurationEndpointMatcher.matches(request);
 
 	/**
 	 * Sets the repository of registered clients.
@@ -201,6 +204,10 @@ public void configure(B builder) {
 			OidcProviderConfigurationEndpointFilter oidcProviderConfigurationEndpointFilter =
 					new OidcProviderConfigurationEndpointFilter(providerSettings);
 			builder.addFilterBefore(postProcess(oidcProviderConfigurationEndpointFilter), AbstractPreAuthenticatedProcessingFilter.class);
+
+			OAuth2AuthorizationServerConfigurationEndpointFilter authorizationServerConfigurationFilter
+					= new OAuth2AuthorizationServerConfigurationEndpointFilter(providerSettings);
+			builder.addFilterBefore(postProcess(authorizationServerConfigurationFilter), AbstractPreAuthenticatedProcessingFilter.class);
 		}
 
 		JWKSource<SecurityContext> jwkSource = getJwkSource(builder);
@@ -255,6 +262,8 @@ private void initEndpointMatchers(ProviderSettings providerSettings) {
 				providerSettings.jwkSetEndpoint(), HttpMethod.GET.name());
 		this.oidcProviderConfigurationEndpointMatcher = new AntPathRequestMatcher(
 				OidcProviderConfigurationEndpointFilter.DEFAULT_OIDC_PROVIDER_CONFIGURATION_ENDPOINT_URI, HttpMethod.GET.name());
+		this.oauth2ServerConfigurationEndpointMatcher = new AntPathRequestMatcher(
+				OAuth2AuthorizationServerConfigurationEndpointFilter.DEFAULT_OAUTH2_AUTHORIZATION_SERVER_CONFIGURATION_ENDPOINT_URI, HttpMethod.GET.name());
 	}
 
 	private static void validateProviderSettings(ProviderSettings providerSettings) {

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/core/AbstractOAuth2AuthorizationServerConfiguration.java

@@ -0,0 +1,134 @@
+/*
+ * Copyright 2020 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.oauth2.core;
+
+
+import java.net.URL;
+import java.util.List;
+
+/**
+ * A base {@link ClaimAccessor} for the "claims" the Authorization Server can make about
+ * its configuration, used either in OpenID Connect Discovery 1.0 or OAuth 2.0 Authorization
+ * Server Metadata.
+ *
+ * @author Daniel Garnier-Moiroux
+ * @since 0.1.1
+ * @see ClaimAccessor
+ * @see <a target="_blank" href="https://tools.ietf.org/html/rfc8414#section-2">2. Authorization Server Metadata</a>
+ * @see <a target="_blank" href="https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata">3. OpenID Provider Metadata</a>
+ */
+public interface OAuth2AuthorizationServerMetadataClaimAccessor extends ClaimAccessor {
+
+	/**
+	 * Returns the {@code URL} the Authorization Server asserts as its Issuer Identifier {@code (issuer)}.
+	 *
+	 * @return the {@code URL} the Authorization Server asserts as its Issuer Identifier
+	 */
+	default URL getIssuer() {
+		return getClaimAsURL(OAuth2AuthorizationServerMetadataClaimNames.ISSUER);
+	}
+
+	/**
+	 * Returns the {@code URL} of the OAuth 2.0 Authorization Endpoint {@code (authorization_endpoint)}.
+	 *
+	 * @return the {@code URL} of the OAuth 2.0 Authorization Endpoint
+	 */
+	default URL getAuthorizationEndpoint() {
+		return getClaimAsURL(OAuth2AuthorizationServerMetadataClaimNames.AUTHORIZATION_ENDPOINT);
+	}
+
+	/**
+	 * Returns the {@code URL} of the OAuth 2.0 Token Endpoint {@code (token_endpoint)}.
+	 *
+	 * @return the {@code URL} of the OAuth 2.0 Token Endpoint
+	 */
+	default URL getTokenEndpoint() {
+		return getClaimAsURL(OAuth2AuthorizationServerMetadataClaimNames.TOKEN_ENDPOINT);
+	}
+
+	/**
+	 * Returns the client authentication methods supported by the OAuth 2.0 Token Endpoint {@code (token_endpoint_auth_methods_supported)}.
+	 *
+	 * @return the client authentication methods supported by the OAuth 2.0 Token Endpoint
+	 */
+	default List<String> getTokenEndpointAuthenticationMethods() {
+		return getClaimAsStringList(OAuth2AuthorizationServerMetadataClaimNames.TOKEN_ENDPOINT_AUTH_METHODS_SUPPORTED);
+	}
+
+	/**
+	 * Returns the {@code URL} of the JSON Web Key Set {@code (jwks_uri)}.
+	 *
+	 * @return the {@code URL} of the JSON Web Key Set
+	 */
+	default URL getJwkSetUri() {
+		return getClaimAsURL(OAuth2AuthorizationServerMetadataClaimNames.JWKS_URI);
+	}
+
+	/**
+	 * Returns the OAuth 2.0 {@code response_type} values supported {@code (response_types_supported)}.
+	 *
+	 * @return the OAuth 2.0 {@code response_type} values supported
+	 */
+	default List<String> getResponseTypes() {
+		return getClaimAsStringList(OAuth2AuthorizationServerMetadataClaimNames.RESPONSE_TYPES_SUPPORTED);
+	}
+
+	/**
+	 * Returns the OAuth 2.0 {@code grant_type} values supported {@code (grant_types_supported)}.
+	 *
+	 * @return the OAuth 2.0 {@code grant_type} values supported
+	 */
+	default List<String> getGrantTypes() {
+		return getClaimAsStringList(OAuth2AuthorizationServerMetadataClaimNames.GRANT_TYPES_SUPPORTED);
+	}
+
+	/**
+	 * Returns the OAuth 2.0 {@code scope} values supported {@code (scopes_supported)}.
+	 *
+	 * @return the OAuth 2.0 {@code scope} values supported
+	 */
+	default List<String> getScopes() {
+		return this.getClaimAsStringList(OAuth2AuthorizationServerMetadataClaimNames.SCOPES_SUPPORTED);
+	}
+
+	/**
+	 * Returns the {@code URL} of the OAuth 2.0 Token Revocation Endpoint {@code (revocation_endpoint)}.
+	 *
+	 * @return the {@code URL} of the OAuth 2.0 Token Revocation Endpoint
+	 */
+	default URL getTokenRevocationEndpoint() {
+		return this.getClaimAsURL(OAuth2AuthorizationServerMetadataClaimNames.REVOCATION_ENDPOINT);
+	}
+
+	/**
+	 * Returns the client authentication methods supported by the OAuth 2.0 Token Revocation Endpoint {@code (revocation_endpoint_auth_methods_supported)}.
+	 *
+	 * @return the client authentication methods supported by the OAuth 2.0 Token Revocation Endpoint
+	 */
+	default List<String> getTokenRevocationEndpointAuthenticationMethods() {
+		return this.getClaimAsStringList(OAuth2AuthorizationServerMetadataClaimNames.REVOCATION_ENDPOINT_AUTH_METHODS_SUPPORTED);
+	}
+
+	/**
+	 * Returns the Proof Key for Code Exchange (PKCE) code challenge methods supported by the
+	 * OAuth 2.0 Authorization Server {@code (code_challenge_methods_supported)}.
+	 *
+	 * @return the code challenge methods supported by the OAuth 2.0 Authorization Server
+	 */
+	default List<String> getCodeChallengeMethods() {
+		return this.getClaimAsStringList(OAuth2AuthorizationServerMetadataClaimNames.CODE_CHALLENGE_METHODS_SUPPORTED);
+	}
+}

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/core/OAuth2AuthorizationServerMetadataClaimAccessor.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2020 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.oauth2.core;
+
+import org.springframework.security.oauth2.core.oidc.OidcProviderMetadataClaimNames;
+
+/**
+ * The names of the "claims" an Authorization Server can make about its configuration,
+ * used either in OpenID Connect Discovery 1.0 or OAuth 2.0 Authorization Server Metadata.
+ *
+ * @author Daniel Garnier-Moiroux
+ * @since 0.1.1
+ * @see OidcProviderMetadataClaimNames
+ * @see <a target="_blank" href="https://tools.ietf.org/html/rfc8414#section-2">2. Authorization Server Metadata</a>
+ * @see <a target="_blank" href="https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata">3. OpenID Provider Metadata</a>
+ */
+public interface OAuth2AuthorizationServerMetadataClaimNames {
+
+	/**
+	 * {@code issuer} - the {@code URL} the Authorization Server asserts as its Issuer Identifier
+	 */
+	String ISSUER = "issuer";
+
+	/**
+	 * {@code authorization_endpoint} - the {@code URL} of the OAuth 2.0 Authorization Endpoint
+	 */
+	String AUTHORIZATION_ENDPOINT = "authorization_endpoint";
+
+	/**
+	 * {@code token_endpoint} - the {@code URL} of the OAuth 2.0 Token Endpoint
+	 */
+	String TOKEN_ENDPOINT = "token_endpoint";
+
+	/**
+	 * {@code token_endpoint_auth_methods_supported} - the client authentication methods supported by the OAuth 2.0 Token Endpoint
+	 */
+	String TOKEN_ENDPOINT_AUTH_METHODS_SUPPORTED = "token_endpoint_auth_methods_supported";
+
+	/**
+	 * {@code jwks_uri} - the {@code URL} of the JSON Web Key Set
+	 */
+	String JWKS_URI = "jwks_uri";
+
+	/**
+	 * {@code response_types_supported} - the OAuth 2.0 {@code response_type} values supported
+	 */
+	String RESPONSE_TYPES_SUPPORTED = "response_types_supported";
+
+	/**
+	 * {@code grant_types_supported} - the OAuth 2.0 {@code grant_type} values supported
+	 */
+	String GRANT_TYPES_SUPPORTED = "grant_types_supported";
+
+	/**
+	 * {@code scopes_supported} - the OAuth 2.0 {@code scope} values supported
+	 */
+	String SCOPES_SUPPORTED = "scopes_supported";
+
+	/**
+	 * {@code revocation_endpoint} - the {@code URL} of the OAuth 2.0 Token Revocation Endpoint
+	 */
+	String REVOCATION_ENDPOINT = "revocation_endpoint";
+
+	/**
+	 * {@code token_endpoint_auth_methods_supported} - the client authentication methods supported by the OAuth 2.0 Token Revocation Endpoint
+	 */
+	String REVOCATION_ENDPOINT_AUTH_METHODS_SUPPORTED = "revocation_endpoint_auth_methods_supported";
+
+	/**
+	 * {@code code_challenge_methods_supported} - the Proof Key for Code Exchange (PKCE) code challenge methods
+	 * supported by the OAuth 2.0 Authorization Server
+	 */
+	String CODE_CHALLENGE_METHODS_SUPPORTED = "code_challenge_methods_supported";
+}

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/core/OAuth2AuthorizationServerMetadataClaimNames.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2020 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.oauth2.core.endpoint;
+
+import org.springframework.security.oauth2.core.AbstractOAuth2AuthorizationServerConfiguration;
+import org.springframework.security.oauth2.core.OAuth2AuthorizationServerMetadataClaimAccessor;
+import org.springframework.security.oauth2.core.Version;
+import org.springframework.util.Assert;
+
+import java.io.Serializable;
+import java.util.Map;
+
+/**
+ * A representation of an OAuth 2.0 Authorization Server Configuration response,
+ * which is returned form an OAuth 2.0 Authorization Server's Configuration Endpoint,
+ * and contains a set of claims about the Authorization Server's configuration.
+ * The claims are defined by the OAuth 2.0 Authorization Server Metadata
+ * specification (RFC 8414).
+ *
+ * @author Daniel Garnier-Moiroux
+ * @since 0.1.1
+ * @see AbstractOAuth2AuthorizationServerConfiguration
+ * @see OAuth2AuthorizationServerMetadataClaimAccessor
+ * @see <a target="_blank" href="https://tools.ietf.org/html/rfc8414#section-3.2">3.2. Authorization Server Metadata Response</a>
+ */
+public final class OAuth2AuthorizationServerConfiguration extends AbstractOAuth2AuthorizationServerConfiguration
+		implements OAuth2AuthorizationServerMetadataClaimAccessor, Serializable {
+	private static final long serialVersionUID = Version.SERIAL_VERSION_UID;
+
+	private OAuth2AuthorizationServerConfiguration(Map<String, Object> claims) {
+		super(claims);
+	}
+
+	/**
+	 * Constructs a new {@link Builder} with empty claims.
+	 *
+	 * @return the {@link Builder}
+	 */
+	public static Builder builder() {
+		return new Builder();
+	}
+
+	/**
+	 * Constructs a new {@link Builder} with the provided claims.
+	 *
+	 * @param claims the claims to initialize the builder
+	 * @return the {@link Builder}
+	 */
+	public static Builder withClaims(Map<String, Object> claims) {
+		Assert.notEmpty(claims, "claims cannot be empty");
+		return new Builder()
+				.claims(c -> c.putAll(claims));
+	}
+
+	/**
+	 * Helps configure an {@link OAuth2AuthorizationServerConfiguration}.
+	 */
+	public static class Builder
+			extends AbstractOAuth2AuthorizationServerConfiguration.AbstractBuilder<OAuth2AuthorizationServerConfiguration, Builder> {
+		private Builder() {
+		}
+
+		/**
+		 * Validate the claims and build the {@link OAuth2AuthorizationServerConfiguration}.
+		 * <p>
+		 * The following claims are REQUIRED:
+		 * {@code issuer}, {@code authorization_endpoint}, {@code token_endpoint},
+		 * {@code jwks_uri} and {@code response_types_supported}.
+		 *
+		 * @return the {@link OAuth2AuthorizationServerConfiguration}
+		 */
+		public OAuth2AuthorizationServerConfiguration build() {
+			validateCommonClaims();
+			removeEmptyClaims();
+			return new OAuth2AuthorizationServerConfiguration(this.claims);
+		}
+
+	}
+}