Add ClientRegistration from OpenID Connect Discovery

Fixes: gh-4413

config/spring-security-config.gradle

@@ -34,6 +34,7 @@ dependencies {
 	testCompile apachedsDependencies
 	testCompile powerMock2Dependencies
 	testCompile spockDependencies
+	testCompile 'com.squareup.okhttp3:mockwebserver'
 	testCompile 'ch.qos.logback:logback-classic'
 	testCompile 'io.projectreactor.ipc:reactor-netty'
 	testCompile 'javax.annotation:jsr250-api:1.0'

config/src/main/java/org/springframework/security/config/oauth2/client/OidcConfigurationProvider.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2002-2018 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
+ *
+ *      http://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.config.oauth2.client;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.List;
+
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.core.AuthorizationGrantType;
+import org.springframework.security.oauth2.core.ClientAuthenticationMethod;
+import org.springframework.security.oauth2.core.oidc.IdTokenClaimNames;
+import org.springframework.web.client.RestTemplate;
+
+import com.nimbusds.oauth2.sdk.GrantType;
+import com.nimbusds.oauth2.sdk.ParseException;
+import com.nimbusds.oauth2.sdk.Scope;
+import com.nimbusds.openid.connect.sdk.op.OIDCProviderMetadata;
+
+/**
+ * Allows creating a {@link ClientRegistration.Builder} from an
+ * <a href="https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfig">OpenID Provider Configuration</a>.
+ *
+ * @author Rob Winch
+ * @since 5.1
+ */
+public final class OidcConfigurationProvider {
+
+	/**
+	 * Given the <a href="http://openid.net/specs/openid-connect-core-1_0.html#IssuerIdentifier">Issuer</a> creates a
+	 * {@link ClientRegistration.Builder} by making an
+	 * <a href="https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfigurationRequest">OpenID Provider
+	 * Configuration Request</a> and using the values in the
+	 * <a href="https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfigurationResponse">OpenID
+	 * Provider Configuration Response</a> to initialize the {@link ClientRegistration.Builder}.
+	 *
+	 * <p>
+	 * For example if the issuer provided is "https://example.com", then an "OpenID Provider Configuration Request" will
+	 * be made to "https://example.com/.well-known/openid-configuration". The result is expected to be an "OpenID
+	 * Provider Configuration Response".
+	 * </p>
+	 *
+	 * <p>
+	 * Example usage:
+	 * </p>
+	 * <pre>
+	 * ClientRegistration registration = OidcConfigurationProvider.issuer("https://example.com")
+	 *     .clientId("client-id")
+	 *     .clientSecret("client-secret")
+	 *     .build();
+	 * </pre>
+	 * @param issuer the <a href="http://openid.net/specs/openid-connect-core-1_0.html#IssuerIdentifier">Issuer</a>
+	 * @return a {@link ClientRegistration.Builder} that was initialized by the OpenID Provider Configuration.
+	 */
+	public static ClientRegistration.Builder issuer(String issuer) {
+		RestTemplate rest = new RestTemplate();
+		String openidConfiguration = rest.getForObject(issuer + "/.well-known/openid-configuration", String.class);
+		OIDCProviderMetadata metadata = parse(openidConfiguration);
+		String name = URI.create(issuer).getHost();
+		List<com.nimbusds.oauth2.sdk.auth.ClientAuthenticationMethod> metadataAuthMethods = metadata.getTokenEndpointAuthMethods();
+			// if null, the default includes client_secret_basic
+		if (metadataAuthMethods != null && !metadataAuthMethods.contains(com.nimbusds.oauth2.sdk.auth.ClientAuthenticationMethod.CLIENT_SECRET_BASIC)) {
+			throw new IllegalArgumentException("Only ClientAuthenticationMethod.BASIC is supported. The issuer \"" + issuer + "\" returned a configuration of " + metadataAuthMethods);
+		}
+		List<GrantType> grantTypes = metadata.getGrantTypes();
+			// If null, the default includes authorization_code
+		if (grantTypes != null && !grantTypes.contains(GrantType.AUTHORIZATION_CODE)) {
+			throw new IllegalArgumentException("Only AuthorizationGrantType.AUTHORIZATION_CODE is supported. The issuer \"" + issuer + "\" returned a configuration of " + grantTypes);
+		}
+		List<String> scopes = getScopes(metadata);
+		return ClientRegistration.withRegistrationId(name)
+				.userNameAttributeName(IdTokenClaimNames.SUB)
+				.scope(scopes)
+				.authorizationGrantType(AuthorizationGrantType.AUTHORIZATION_CODE)
+				.clientAuthenticationMethod(ClientAuthenticationMethod.BASIC)
+				.redirectUriTemplate("{baseUrl}/{action}/oauth2/code/{registrationId}")
+				.authorizationUri(metadata.getAuthorizationEndpointURI().toASCIIString())
+				.jwkSetUri(metadata.getJWKSetURI().toASCIIString())
+				.userInfoUri(metadata.getUserInfoEndpointURI().toASCIIString())
+				.tokenUri(metadata.getTokenEndpointURI().toASCIIString())
+				.clientName(issuer);
+	}
+
+	private static List<String> getScopes(OIDCProviderMetadata metadata) {
+		Scope scope = metadata.getScopes();
+		if (scope == null) {
+			// If null, default to "openid" which must be supported
+			return Arrays.asList("openid");
+		} else {
+			return scope.toStringList();
+		}
+	}
+
+	private static OIDCProviderMetadata parse(String body) {
+		try {
+			return OIDCProviderMetadata.parse(body);
+		}
+		catch (ParseException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	private OidcConfigurationProvider() {}
+}

config/src/test/java/org/springframework/security/config/oauth2/client/OidcConfigurationProviderTests.java

@@ -0,0 +1,209 @@
+/*
+ * Copyright 2002-2018 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
+ *
+ *      http://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.config.oauth2.client;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.security.oauth2.client.registration.ClientRegistration;
+import org.springframework.security.oauth2.core.AuthorizationGrantType;
+import org.springframework.security.oauth2.core.ClientAuthenticationMethod;
+
+import java.util.Arrays;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.*;
+
+/**
+ * @author Rob Winch
+ * @since 5.1
+ */
+public class OidcConfigurationProviderTests {
+
+	/**
+	 * Contains all optional parameters that are found in ClientRegistration
+	 */
+	private static final String DEFAULT_RESPONSE =
+			"{\n"
+			+ "    \"authorization_endpoint\": \"https://example.com/o/oauth2/v2/auth\", \n"
+			+ "    \"claims_supported\": [\n"
+			+ "        \"aud\", \n"
+			+ "        \"email\", \n"
+			+ "        \"email_verified\", \n"
+			+ "        \"exp\", \n"
+			+ "        \"family_name\", \n"
+			+ "        \"given_name\", \n"
+			+ "        \"iat\", \n"
+			+ "        \"iss\", \n"
+			+ "        \"locale\", \n"
+			+ "        \"name\", \n"
+			+ "        \"picture\", \n"
+			+ "        \"sub\"\n"
+			+ "    ], \n"
+			+ "    \"code_challenge_methods_supported\": [\n"
+			+ "        \"plain\", \n"
+			+ "        \"S256\"\n"
+			+ "    ], \n"
+			+ "    \"id_token_signing_alg_values_supported\": [\n"
+			+ "        \"RS256\"\n"
+			+ "    ], \n"
+			+ "    \"issuer\": \"https://example.com\", \n"
+			+ "    \"jwks_uri\": \"https://example.com/oauth2/v3/certs\", \n"
+			+ "    \"response_types_supported\": [\n"
+			+ "        \"code\", \n"
+			+ "        \"token\", \n"
+			+ "        \"id_token\", \n"
+			+ "        \"code token\", \n"
+			+ "        \"code id_token\", \n"
+			+ "        \"token id_token\", \n"
+			+ "        \"code token id_token\", \n"
+			+ "        \"none\"\n"
+			+ "    ], \n"
+			+ "    \"revocation_endpoint\": \"https://example.com/o/oauth2/revoke\", \n"
+			+ "    \"scopes_supported\": [\n"
+			+ "        \"openid\", \n"
+			+ "        \"email\", \n"
+			+ "        \"profile\"\n"
+			+ "    ], \n"
+			+ "    \"subject_types_supported\": [\n"
+			+ "        \"public\"\n"
+			+ "    ], \n"
+			+ "    \"grant_types_supported\" : [\"authorization_code\"], \n"
+			+ "    \"token_endpoint\": \"https://example.com/oauth2/v4/token\", \n"
+			+ "    \"token_endpoint_auth_methods_supported\": [\n"
+			+ "        \"client_secret_post\", \n"
+			+ "        \"client_secret_basic\"\n"
+			+ "    ], \n"
+			+ "    \"userinfo_endpoint\": \"https://example.com/oauth2/v3/userinfo\"\n"
+			+ "}";
+
+	private MockWebServer server;
+
+	private ObjectMapper mapper = new ObjectMapper();
+
+	private Map<String, Object> response;
+
+	private String issuer;
+
+	@Before
+	public void setup() throws Exception {
+		this.server = new MockWebServer();
+		this.server.start();
+		this.response = this.mapper.readValue(DEFAULT_RESPONSE, new TypeReference<Map<String, Object>>(){});
+	}
+
+	@After
+	public void cleanup() throws Exception {
+		this.server.shutdown();
+	}
+
+	@Test
+	public void issuerWhenAllInformationThenSuccess() throws Exception {
+		ClientRegistration registration = registration("");
+		ClientRegistration.ProviderDetails provider = registration.getProviderDetails();
+
+		assertThat(registration.getClientAuthenticationMethod()).isEqualTo(ClientAuthenticationMethod.BASIC);
+		assertThat(registration.getAuthorizationGrantType()).isEqualTo(AuthorizationGrantType.AUTHORIZATION_CODE);
+		assertThat(registration.getRegistrationId()).isEqualTo(this.server.getHostName());
+		assertThat(registration.getClientName()).isEqualTo(this.issuer);
+		assertThat(registration.getScopes()).containsOnly("openid", "email", "profile");
+		assertThat(provider.getAuthorizationUri()).isEqualTo("https://example.com/o/oauth2/v2/auth");
+		assertThat(provider.getTokenUri()).isEqualTo("https://example.com/oauth2/v4/token");
+		assertThat(provider.getJwkSetUri()).isEqualTo("https://example.com/oauth2/v3/certs");
+		assertThat(provider.getUserInfoEndpoint().getUri()).isEqualTo("https://example.com/oauth2/v3/userinfo");
+	}
+
+	/**
+	 * https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
+	 *
+	 * RECOMMENDED. JSON array containing a list of the OAuth 2.0 [RFC6749] scope values that this server supports. The
+	 * server MUST support the openid scope value.
+	 * @throws Exception
+	 */
+	@Test
+	public void issuerWhenScopesNullThenScopesDefaulted() throws Exception {
+		this.response.remove("scopes_supported");
+
+		ClientRegistration registration = registration("");
+
+		assertThat(registration.getScopes()).containsOnly("openid");
+	}
+
+	@Test
+	public void issuerWhenGrantTypesSupportedNullThenDefaulted() throws Exception {
+		this.response.remove("grant_types_supported");
+
+		ClientRegistration registration = registration("");
+
+		assertThat(registration.getAuthorizationGrantType()).isEqualTo(AuthorizationGrantType.AUTHORIZATION_CODE);
+	}
+
+	/**
+	 * We currently only support authorization_code, so verify we have a meaningful error until we add support.
+	 * @throws Exception
+	 */
+	@Test
+	public void issuerWhenGrantTypesSupportedInvalidThenException() throws Exception {
+		this.response.put("grant_types_supported", Arrays.asList("implicit"));
+
+		assertThatThrownBy(() -> registration(""))
+				.isInstanceOf(IllegalArgumentException.class)
+				.hasMessageContaining("Only AuthorizationGrantType.AUTHORIZATION_CODE is supported. The issuer \"" + this.issuer + "\" returned a configuration of [implicit]");
+	}
+
+	@Test
+	public void issuerWhenTokenEndpointAuthMethodsNullThenDefaulted() throws Exception {
+		this.response.remove("token_endpoint_auth_methods_supported");
+
+		ClientRegistration registration = registration("");
+
+		assertThat(registration.getClientAuthenticationMethod()).isEqualTo(ClientAuthenticationMethod.BASIC);
+	}
+
+	/**
+	 * We currently only support client_secret_basic, so verify we have a meaningful error until we add support.
+	 * @throws Exception
+	 */
+	@Test
+	public void issuerWhenTokenEndpointAuthMethodsInvalidThenException() throws Exception {
+		this.response.put("token_endpoint_auth_methods_supported", Arrays.asList("client_secret_post"));
+
+		assertThatThrownBy(() -> registration(""))
+				.isInstanceOf(IllegalArgumentException.class)
+				.hasMessageContaining("Only ClientAuthenticationMethod.BASIC is supported. The issuer \"" + this.issuer + "\" returned a configuration of [client_secret_post]");
+	}
+
+	private ClientRegistration registration(String path) throws Exception {
+		String body = this.mapper.writeValueAsString(this.response);
+		MockResponse mockResponse = new MockResponse()
+				.setBody(body)
+				.setHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE);
+		this.server.enqueue(mockResponse);
+		this.issuer = this.server.url(path).toString();
+
+		return OidcConfigurationProvider.issuer(this.issuer)
+			.clientId("client-id")
+			.clientSecret("client-secret")
+			.build();
+	}
+}

oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/registration/ClientRegistration.java

@@ -21,6 +21,7 @@ import org.springframework.security.oauth2.core.oidc.OidcScopes;
 import org.springframework.util.Assert;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Set;
@@ -324,6 +325,20 @@ public final class ClientRegistration {
 			return this;
 		}
 
+		/**
+		 * Sets the scope(s) used for the client.
+		 *
+		 * @param scope the scope(s) used for the client
+		 * @return the {@link Builder}
+		 */
+		public Builder scope(Collection<String> scope) {
+			if (scope != null && !scope.isEmpty()) {
+				this.scopes = Collections.unmodifiableSet(
+						new LinkedHashSet<>(scope));
+			}
+			return this;
+		}
+
 		/**
 		 * Sets the uri for the authorization endpoint.
 		 *