docs(samples): added authexplicit and copyright

samples/snippets/src/main/java/AuthenticateExplicit.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2022 Google Inc.
+ *
+ * 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.
+ */
+
+import com.google.api.gax.paging.Page;
+import com.google.auth.oauth2.GoogleCredentials;
+import com.google.cloud.storage.Bucket;
+import com.google.cloud.storage.Storage;
+import com.google.cloud.storage.StorageOptions;
+import com.google.common.collect.Lists;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+
+public class AuthenticateExplicit {
+
+  public static void main(String[] args) throws IOException, GeneralSecurityException {
+    // TODO(Developer):
+    //  1. Replace the below variable.
+    //  2. Make sure you have the necessary permission to list storage buckets "storage.buckets.list"
+    String projectId = "your-google-cloud-project-id";
+
+    // Path to the service account json credential file.
+    String jsonCredentialPath = "path-to-json-credential-file";
+
+    // Provide the scopes that you might need to request to access Google APIs,
+    // depending on the level of access you need.
+    // Example: The following scope lets you view and manage Pub/Sub topics and subscriptions.
+    // For more information, see: https://developers.google.com/identity/protocols/oauth2/scopes
+    String scope = "https://www.googleapis.com/auth/devstorage.full_control";
+
+    authenticateExplicit(projectId, jsonCredentialPath, scope);
+  }
+
+  // Authenticating using Client libraries can be done in one of the following ways:
+  // 1. Implicit authentication with ADC (Application Default Credentials)
+  // 2. Explicit authentication by specifying the service account
+  // 3. Bring your own (BYO) access token
+  // 4. Using API keys (for libraries that support)
+  //
+  // In this snippet, we demonstrate "Explicit authentication by specifying the service account".
+  public static void authenticateExplicit(String project, String jsonCredentialPath, String scope)
+      throws IOException {
+
+    // This snippet demonstrates how to initialize Cloud Storage and list buckets.
+    // Note that the credentials are explicitly specified when constructing the client.
+    Storage storage = initService(project, jsonCredentialPath, scope);
+
+    System.out.println("Buckets:");
+    Page<Bucket> buckets = storage.list();
+    for (Bucket bucket : buckets.iterateAll()) {
+      System.out.println(bucket.toString());
+    }
+  }
+
+  // Initialize the Storage client by explicitly setting the Service account to use.
+  public static Storage initService(String projectId, String jsonCredentialPath, String scope)
+      throws IOException {
+    // Construct the GoogleCredentials object which accepts the service account json file and
+    // scope as the input parameters.
+    GoogleCredentials credentials = GoogleCredentials
+        .fromStream(new FileInputStream(jsonCredentialPath))
+        .createScoped(Lists.newArrayList(scope));
+
+    // Construct the Storage client.
+    // Note that, here we explicitly specify the service account to use.
+    return StorageOptions.newBuilder()
+        .setCredentials(credentials)
+        .setProjectId(projectId)
+        .build()
+        .getService();
+  }
+}

samples/snippets/src/main/java/ApplicationDefaultCredentialsImplicit.java → samples/snippets/src/main/java/AuthenticateImplicitWithAdc.java

@@ -1,8 +1,24 @@
+/*
+ * Copyright 2022 Google Inc.
+ *
+ * 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.
+ */
+
 import com.google.cloud.compute.v1.Instance;
 import com.google.cloud.compute.v1.InstancesClient;
 import java.io.IOException;
 
-public class ApplicationDefaultCredentialsImplicit {
+public class AuthenticateImplicitWithAdc {
 
   public static void main(String[] args) throws IOException {
     // TODO(Developer):
@@ -14,6 +30,13 @@ public static void main(String[] args) throws IOException {
     authenticateImplicitWithAdc(projectId);
   }
 
+  // Authenticating using Client libraries can be done in one of the following ways:
+  // 1. Implicit authentication with ADC (Application Default Credentials)
+  // 2. Explicit authentication by specifying the service account
+  // 3. Bring your own (BYO) access token
+  // 4. Using API keys (for libraries that support)
+  //
+  // In this snippet, we demonstrate "Implicit authentication with ADC".
   // ADC - Application Default Credentials
   // When interacting with Google Cloud Client libraries, the library can auto-detect the
   // credentials to use, if the "APPLICATION_DEFAULT_CREDENTIALS" is set.

samples/snippets/src/main/java/IdTokenFromImpersonatedCredentials.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2022 Google Inc.
+ *
+ * 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.
+ */
+
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken.Payload;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier;

samples/snippets/src/main/java/IdTokenFromImpersonatedCredentialsREST.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2022 Google Inc.
+ *
+ * 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.
+ */
+
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken.Payload;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier;

samples/snippets/src/main/java/IdTokenFromMetadataServer.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2022 Google Inc.
+ *
+ * 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.
+ */
+
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken.Payload;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier;

samples/snippets/src/main/java/IdTokenFromServiceAccount.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2022 Google Inc.
+ *
+ * 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.
+ */
+
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken.Payload;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier;
@@ -90,39 +106,4 @@ public static boolean verifyGoogleIdToken(String idTokenString, String audience)
     return false;
   }
 
-}
-
-//
-// Iam service =
-//     new Iam.Builder(
-//         GoogleNetHttpTransport.newTrustedTransport(),
-//         GsonFactory.getDefaultInstance(),
-//         new HttpCredentialsAdapter(googleCredentials))
-//         .setApplicationName("service-accounts")
-//         .build();
-//
-// try {
-//   ServiceAccount serviceAccount = new ServiceAccount();
-//   serviceAccount.setDisplayName("serviceaccdummy");
-//   CreateServiceAccountRequest request = new CreateServiceAccountRequest();
-//   request.setAccountId("serviceAccountName");
-//   request.setServiceAccount(serviceAccount);
-//
-//   serviceAccount =
-//       service.projects().serviceAccounts().create("projects/" + projectId, request).execute();
-//
-//   System.out.println("Created service account: " + serviceAccount.getEmail());
-//
-//
-// GenerateIdToken iamCredentials = new IAMCredentials(
-//     GoogleNetHttpTransport.newTrustedTransport(),
-//     GsonFactory.getDefaultInstance(),
-//     new HttpCredentialsAdapter(googleCredentialsProvider)
-// ).projects().serviceAccounts().generateIdToken(String.format("projects/%s/serviceAccounts/%s", projectId, serviceAccount),
-//     new GenerateIdTokenRequest().setAudience("https://www.googleapis.com/auth/cloud-platform"));
-//
-// System.out.println(iamCredentials);
-//
-// } catch (IOException e) {
-//   System.out.println("Unable to create service account: \n" + e.toString());
-// }
+}

samples/snippets/src/main/java/IdTokenFromServiceAccountREST.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2022 Google Inc.
+ *
+ * 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.
+ */
+
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken.Payload;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier;

samples/snippets/src/main/java/VerifyNonGoogleIdToken.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2022 Google Inc.
+ *
+ * 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.
+ */
+
 import com.auth0.jwk.Jwk;
 import com.auth0.jwk.JwkException;
 import com.auth0.jwk.JwkProvider;