fix: support PEM and p12 when using factory

src/auth/googleauth.ts

@@ -518,9 +518,21 @@ export class GoogleAuth {
         .on('data', chunk => (s += chunk))
         .on('end', () => {
           try {
-            const data = JSON.parse(s);
-            const r = this._cacheClientFromJSON(data, options);
-            return resolve(r);
+            try {
+              const data = JSON.parse(s);
+              const r = this._cacheClientFromJSON(data, options);
+              return resolve(r);
+            } catch (err) {
+              // If we failed parsing this.keyFileName, assume that it
+              // is a PEM or p12 certificate:
+              if (!this.keyFilename) throw err;
+              const client = new JWT({
+                ...this.clientOptions,
+                keyFile: this.keyFilename,
+              });
+              this.cachedCredential = client;
+              return resolve(client);
+            }
           } catch (err) {
             return reject(err);
           }

test/test.googleauth.ts

@@ -16,6 +16,7 @@ import * as assert from 'assert';
 import {describe, it, beforeEach, afterEach} from 'mocha';
 import * as child_process from 'child_process';
 import * as crypto from 'crypto';
+import {CredentialRequest} from '../src/auth/credentials';
 import * as fs from 'fs';
 import {
   BASE_PATH,
@@ -44,6 +45,8 @@ describe('googleauth', () => {
   const instancePath = `${BASE_PATH}/instance`;
   const svcAccountPath = `${instancePath}/service-accounts/?recursive=true`;
   const API_KEY = 'test-123';
+  const PEM_PATH = './test/fixtures/private.pem';
+  const P12_PATH = './test/fixtures/key.p12';
   const STUB_PROJECT = 'my-awesome-project';
   const ENDPOINT = '/events:report';
   const RESPONSE_BODY = 'RESPONSE_BODY';
@@ -74,6 +77,11 @@ describe('googleauth', () => {
     'gcloud',
     'application_default_credentials.json'
   );
+  function createGTokenMock(body: CredentialRequest) {
+    return nock('https://www.googleapis.com')
+      .post('/oauth2/v4/token')
+      .reply(200, body);
+  }
 
   describe('googleauth', () => {
     let auth: GoogleAuth;
@@ -1524,4 +1532,45 @@ describe('googleauth', () => {
         .reply(200, {});
     }
   });
+
+  // Allows a client to be instantiated from a certificate,
+  // See: https://github.com/googleapis/google-auth-library-nodejs/issues/808
+  it('allows client to be instantiated from PEM key file', async () => {
+    const auth = new GoogleAuth({
+      keyFile: PEM_PATH,
+      clientOptions: {
+        scopes: 'http://foo',
+        email: 'foo@serviceaccount.com',
+        subject: 'bar@subjectaccount.com',
+      },
+    });
+    const jwt = await auth.getClient();
+    const scope = createGTokenMock({access_token: 'initial-access-token'});
+    const headers = await jwt.getRequestHeaders();
+    assert.deepStrictEqual(
+      headers.Authorization,
+      'Bearer initial-access-token'
+    );
+    scope.done();
+    assert.strictEqual('http://foo', (jwt as JWT).gtoken!.scope);
+  });
+  it('allows client to be instantiated from p12 key file', async () => {
+    const auth = new GoogleAuth({
+      keyFile: P12_PATH,
+      clientOptions: {
+        scopes: 'http://foo',
+        email: 'foo@serviceaccount.com',
+        subject: 'bar@subjectaccount.com',
+      },
+    });
+    const jwt = await auth.getClient();
+    const scope = createGTokenMock({access_token: 'initial-access-token'});
+    const headers = await jwt.getRequestHeaders();
+    assert.deepStrictEqual(
+      headers.Authorization,
+      'Bearer initial-access-token'
+    );
+    scope.done();
+    assert.strictEqual('http://foo', (jwt as JWT).gtoken!.scope);
+  });
 });

test/test.jwt.ts

@@ -118,8 +118,8 @@ describe('jwt', () => {
       scopes: 'http://foo',
       subject: 'bar@subjectaccount.com',
     });
-
     const scope = createGTokenMock({access_token: 'initial-access-token'});
+
     jwt.authorize(() => {
       scope.done();
       assert.strictEqual('http://foo', jwt.gtoken!.scope);