feat: implements the OAuth token exchange spec based on rfc8693 (#1026)

README.md

@@ -335,20 +335,24 @@ main().catch(console.error);
 
 ## Working with ID Tokens
 ### Fetching ID Tokens
-If your application is running behind Cloud Run, or using Cloud Identity-Aware
+If your application is running on Cloud Run or Cloud Functions, or using Cloud Identity-Aware
 Proxy (IAP), you will need to fetch an ID token to access your application. For
 this, use the method `getIdTokenClient` on the `GoogleAuth` client.
 
 For invoking Cloud Run services, your service account will need the
 [`Cloud Run Invoker`](https://cloud.google.com/run/docs/authenticating/service-to-service)
 IAM permission.
 
+For invoking Cloud Functions, your service account will need the
+[`Function Invoker`](https://cloud.google.com/functions/docs/securing/authenticating#function-to-function)
+IAM permission.
+
 ``` js
-// Make a request to a protected Cloud Run
+// Make a request to a protected Cloud Run service.
 const {GoogleAuth} = require('google-auth-library');
 
 async function main() {
-  const url = 'https://cloud-run-url.com';
+  const url = 'https://cloud-run-1234-uc.a.run.app';
   const auth = new GoogleAuth();
   const client = auth.getIdTokenClient(url);
   const res = await client.request({url});
@@ -358,7 +362,7 @@ async function main() {
 main().catch(console.error);
 ```
 
-A complete example can be found in [`samples/idtokens-cloudrun.js`](https://github.com/googleapis/google-auth-library-nodejs/blob/master/samples/idtokens-cloudrun.js).
+A complete example can be found in [`samples/idtokens-serverless.js`](https://github.com/googleapis/google-auth-library-nodejs/blob/master/samples/idtokens-serverless.js).
 
 For invoking Cloud Identity-Aware Proxy, you will need to pass the Client ID
 used when you set up your protected resource as the target audience.

samples/README.md

@@ -16,8 +16,8 @@
   * [Compute](#compute)
   * [Credentials](#credentials)
   * [Headers](#headers)
-  * [ID Tokens for Cloud Run](#id-tokens-for-cloud-run)
   * [ID Tokens for Identity-Aware Proxy (IAP)](#id-tokens-for-identity-aware-proxy-iap)
+  * [ID Tokens for Serverless](#id-tokens-for-serverless)
   * [Jwt](#jwt)
   * [Keepalive](#keepalive)
   * [Keyfile](#keyfile)
@@ -110,37 +110,37 @@ __Usage:__
 
 
 
-### ID Tokens for Cloud Run
+### ID Tokens for Identity-Aware Proxy (IAP)
 
-Requests a Cloud Run URL with an ID Token.
+Requests an IAP-protected resource with an ID Token.
 
-View the [source code](https://github.com/googleapis/google-auth-library-nodejs/blob/master/samples/idtokens-cloudrun.js).
+View the [source code](https://github.com/googleapis/google-auth-library-nodejs/blob/master/samples/idtokens-iap.js).
 
-[![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/google-auth-library-nodejs&page=editor&open_in_editor=samples/idtokens-cloudrun.js,samples/README.md)
+[![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/google-auth-library-nodejs&page=editor&open_in_editor=samples/idtokens-iap.js,samples/README.md)
 
 __Usage:__
 
 
-`node idtokens-cloudrun.js <url> [<target-audience>]`
+`node idtokens-iap.js <url> <target-audience>`
 
 
 -----
 
 
 
 
-### ID Tokens for Identity-Aware Proxy (IAP)
+### ID Tokens for Serverless
 
-Requests an IAP-protected resource with an ID Token.
+Requests a Cloud Run or Cloud Functions URL with an ID Token.
 
-View the [source code](https://github.com/googleapis/google-auth-library-nodejs/blob/master/samples/idtokens-iap.js).
+View the [source code](https://github.com/googleapis/google-auth-library-nodejs/blob/master/samples/idtokens-serverless.js).
 
-[![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/google-auth-library-nodejs&page=editor&open_in_editor=samples/idtokens-iap.js,samples/README.md)
+[![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/google-auth-library-nodejs&page=editor&open_in_editor=samples/idtokens-serverless.js,samples/README.md)
 
 __Usage:__
 
 
-`node idtokens-iap.js <url> <target-audience>`
+`node idtokens-serverless.js <url> [<target-audience>]`
 
 
 -----

samples/idtokens-cloudrun.js → samples/idtokens-serverless.js

@@ -12,33 +12,33 @@
 // limitations under the License.
 
 // sample-metadata:
-//   title: ID Tokens for Cloud Run
-//   description: Requests a Cloud Run URL with an ID Token.
-//   usage: node idtokens-cloudrun.js <url> [<target-audience>]
+//   title: ID Tokens for Serverless
+//   description: Requests a Cloud Run or Cloud Functions URL with an ID Token.
+//   usage: node idtokens-serverless.js <url> [<target-audience>]
 
 'use strict';
 
 function main(
   url = 'https://service-1234-uc.a.run.app',
   targetAudience = null
 ) {
-  // [START google_auth_idtoken_cloudrun]
+  // [START google_auth_idtoken_serverless]
+  // [START run_service_to_service_auth]
+  // [START functions_bearer_token]
   /**
    * TODO(developer): Uncomment these variables before running the sample.
    */
-  // const url = 'https://YOUR_CLOUD_RUN_URL.run.app';
+  // const url = 'https://TARGET_URL';
   const {GoogleAuth} = require('google-auth-library');
   const auth = new GoogleAuth();
 
   async function request() {
     if (!targetAudience) {
-      // Use the request URL hostname as the target audience for Cloud Run requests
+      // Use the request URL hostname as the target audience for requests.
       const {URL} = require('url');
       targetAudience = new URL(url).origin;
     }
-    console.info(
-      `request Cloud Run ${url} with target audience ${targetAudience}`
-    );
+    console.info(`request ${url} with target audience ${targetAudience}`);
     const client = await auth.getIdTokenClient(targetAudience);
     const res = await client.request({url});
     console.info(res.data);
@@ -48,7 +48,9 @@ function main(
     console.error(err.message);
     process.exitCode = 1;
   });
-  // [END google_auth_idtoken_cloudrun]
+  // [END functions_bearer_token]
+  // [END run_service_to_service_auth]
+  // [END google_auth_idtoken_serverless]
 }
 
 const args = process.argv.slice(2);

samples/test/jwt.test.js

@@ -65,17 +65,16 @@ describe('samples', () => {
   });
 
   it('should fetch ID token for Cloud Run', async () => {
-    // process.env.CLOUD_RUN_URL should be a cloud run container, protected with
-    // IAP, running gcr.io/cloudrun/hello:
+    // process.env.CLOUD_RUN_URL should be a cloud run service running
+    // gcr.io/cloudrun/hello:
     const url =
       process.env.CLOUD_RUN_URL || 'https://hello-rftcw63abq-uc.a.run.app';
-    const output = execSync(`node idtokens-cloudrun ${url}`);
+    const output = execSync(`node idtokens-serverless ${url}`);
     assert.match(output, /What's next?/);
   });
 
   it('should fetch ID token for IAP', async () => {
-    // process.env.CLOUD_RUN_URL should be a cloud run container, protected with
-    // IAP, running gcr.io/cloudrun/hello:
+    // process.env.IAP_URL should be an App Engine app, protected with IAP:
     const url =
       process.env.IAP_URL || 'https://nodejs-docs-samples-iap.appspot.com';
     const targetAudience =

src/auth/oauth2common.ts

@@ -186,10 +186,13 @@ export abstract class OAuthClientAuthHandler {
 /**
  * Converts an OAuth error response to a native JavaScript Error.
  * @param resp The OAuth error response to convert to a native Error object.
+ * @param err The optional original error. If provided, the error properties
+ *   will be copied to the new error.
  * @return The converted native Error object.
  */
 export function getErrorFromOAuthErrorResponse(
-  resp: OAuthErrorResponse
+  resp: OAuthErrorResponse,
+  err?: Error
 ): Error {
   // Error response.
   const errorCode = resp.error;
@@ -202,5 +205,25 @@ export function getErrorFromOAuthErrorResponse(
   if (typeof errorUri !== 'undefined') {
     message += ` - ${errorUri}`;
   }
-  return new Error(message);
+  const newError = new Error(message);
+  // Copy properties from original error to newly generated error.
+  if (err) {
+    const keys = Object.keys(err);
+    if (err.stack) {
+      // Copy error.stack if available.
+      keys.push('stack');
+    }
+    keys.forEach(key => {
+      // Do not overwrite the message field.
+      if (key !== 'message') {
+        Object.defineProperty(newError, key, {
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          value: (err! as {[index: string]: any})[key],
+          writable: false,
+          enumerable: true,
+        });
+      }
+    });
+  }
+  return newError;
 }