Support configurable JwtDecoder for IdToken verification

Fixes gh-5717

oauth2/oauth2-core/src/test/java/org/springframework/security/oauth2/core/endpoint/TestOAuth2AuthorizationRequests.java

@@ -32,6 +32,7 @@ public class TestOAuth2AuthorizationRequests {
 		return OAuth2AuthorizationRequest.authorizationCode()
 				.authorizationUri("https://example.com/login/oauth/authorize")
 				.clientId(clientId)
+				.scope("openid")
 				.redirectUri("https://example.com/authorize/oauth2/code/registration-id")
 				.state("state")
 				.additionalParameters(additionalParameters);

oauth2/oauth2-core/src/test/java/org/springframework/security/oauth2/core/oidc/user/TestOidcUsers.java

@@ -0,0 +1,47 @@
+/*
+ * 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.oauth2.core.oidc.user;
+
+import org.springframework.security.core.GrantedAuthority;
+import org.springframework.security.core.authority.AuthorityUtils;
+import org.springframework.security.oauth2.core.oidc.IdTokenClaimNames;
+import org.springframework.security.oauth2.core.oidc.OidcIdToken;
+
+import java.time.Instant;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * @author Joe Grandja
+ */
+public class TestOidcUsers {
+
+	public static DefaultOidcUser create() {
+		List<GrantedAuthority> roles = AuthorityUtils.createAuthorityList("ROLE_USER");
+		return new DefaultOidcUser(roles, idToken());
+	}
+
+	private static OidcIdToken idToken() {
+		Map<String, Object> claims = new HashMap<>();
+		claims.put(IdTokenClaimNames.SUB, "subject");
+		claims.put(IdTokenClaimNames.ISS, "http://localhost/issuer");
+		claims.put(IdTokenClaimNames.AUD, Collections.singletonList("client"));
+		claims.put(IdTokenClaimNames.AZP, "client");
+		return new OidcIdToken("id-token", Instant.now(), Instant.now().plusSeconds(3600), claims);
+	}
+}