feat: Adding functional tests for Compute Engine (#1105)

* feat: Adding functional tests for Compute Engine Credentials

* add copyright

* fix format

* rename `tokenCredential` to `idTokenCredential`

Co-authored-by: Timur Sadykov <[email protected]>

Author: poanc

oauth2_http/javatests/com/google/auth/oauth2/functional/FTComputeEngineCredentialsTest.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ *    * Neither the name of Google LLC nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.google.auth.oauth2.functional;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+import com.google.api.client.json.gson.GsonFactory;
+import com.google.api.client.json.webtoken.JsonWebSignature;
+import com.google.auth.oauth2.AccessToken;
+import com.google.auth.oauth2.ComputeEngineCredentials;
+import com.google.auth.oauth2.GoogleCredentials;
+import com.google.auth.oauth2.IdToken;
+import com.google.auth.oauth2.IdTokenCredentials;
+import com.google.auth.oauth2.IdTokenProvider;
+import org.junit.Test;
+
+public final class FTComputeEngineCredentialsTest {
+  private final String computeUrl =
+      "https://compute.googleapis.com/compute/v1/projects/gcloud-devel/zones/us-central1-a/instances";
+  private final String cloudPlatformScope = "https://www.googleapis.com/auth/cloud-platform";
+
+  @Test
+  public void RefreshCredentials() throws Exception {
+    final ComputeEngineCredentials credentials = ComputeEngineCredentials.create();
+
+    AccessToken accessToken = credentials.refreshAccessToken();
+    assertNotNull(accessToken);
+    assertNotNull(credentials.getAccount());
+    assertTrue(accessToken.getExpirationTime().getTime() > System.currentTimeMillis());
+  }
+
+  @Test
+  public void DefaultCredentials() throws Exception {
+    final GoogleCredentials defaultCredential =
+        GoogleCredentials.getApplicationDefault().createScoped(cloudPlatformScope);
+
+    AccessToken accessToken = defaultCredential.refreshAccessToken();
+    assertNotNull(accessToken);
+    assertTrue(accessToken.getExpirationTime().getTime() > System.currentTimeMillis());
+  }
+
+  @Test
+  public void IdTokenFromMetadata() throws Exception {
+    final ComputeEngineCredentials credentials = ComputeEngineCredentials.create();
+    IdToken idToken = credentials.idTokenWithAudience(computeUrl, null);
+    assertNotNull(idToken);
+    assertTrue(idToken.getExpirationTime().getTime() > System.currentTimeMillis());
+    JsonWebSignature jws =
+        JsonWebSignature.parse(GsonFactory.getDefaultInstance(), idToken.getTokenValue());
+    assertEquals(computeUrl, jws.getPayload().get("aud"));
+    assertEquals("https://accounts.google.com", jws.getPayload().get("iss"));
+  }
+
+  @Test
+  public void FetchIdToken() throws Exception {
+    final ComputeEngineCredentials credentials = ComputeEngineCredentials.create();
+    IdTokenCredentials idTokenCredential =
+        IdTokenCredentials.newBuilder()
+            .setIdTokenProvider((IdTokenProvider) credentials)
+            .setTargetAudience(computeUrl)
+            .build();
+
+    assertNull(idTokenCredential.getIdToken());
+    idTokenCredential.refresh();
+    IdToken idToken = idTokenCredential.getIdToken();
+    assertNotNull(idToken);
+    assertTrue(idToken.getExpirationTime().getTime() > System.currentTimeMillis());
+    JsonWebSignature jws =
+        JsonWebSignature.parse(GsonFactory.getDefaultInstance(), idToken.getTokenValue());
+    assertEquals(computeUrl, jws.getPayload().get("aud"));
+    assertEquals("https://accounts.google.com", jws.getPayload().get("iss"));
+  }
+}