Dart

Get Firebase Access Token from JSON Service Account Private Key

See more Firebase Examples

Demonstrates how to get a Firebase access token using a JSON service account private key. Your Firebase service account can be used to authenticate multiple Firebase features, such as Database, Storage and Auth, programmatically.

A Firebase JSON service account private key can be created in the Firebase settings/admin portion of the console.firebase.google.com site as shown here:

Scroll down to see the example code...

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // First load the Firebase JSON private key into a string.
  final fac = CkFileAccess();
  final String jsonKey;
  try {
    jsonKey = fac.readEntireTextFile('qa_data/firebase/firebase-chilkat-firebase-adminsdk-n28n4-1b664ee163.json', 'utf-8');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // A Firebase JSON private key should look something like this:

  // { 
  //   "type": "service_account",
  //   "project_id": "firebase-chilkat",
  //   "private_key_id": "1c664ee164907413c91ddefcf5b765ecba8779e2",
  //   "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvQIBA ... Ya2UZii/lXn73/ZOK8=\n-----END PRIVATE KEY-----\n",
  //   "client_email": "firebase-adminsdk-n28n4@firebase-chilkat.iam.gserviceaccount.com",
  //   "client_id": "134846322329335418431",
  //   "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  //   "token_uri": "https://accounts.google.com/o/oauth2/token",
  //   "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  //   "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/firebase-adminsdk-n28n4%40firebase-chilkat.iam.gserviceaccount.com"
  // } 
  // 

  final gAuth = CkAuthGoogle();
  gAuth.jsonKey = jsonKey;

  // Choose a scope.
  // The scope could be "https://www.googleapis.com/auth/firebase.database"
  // or a space-delimited list of scopes:
  // "https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email"

  gAuth.scope = 'https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email';

  // Request an access token that is valid for this many seconds.
  gAuth.expireNumSeconds = 3600;

  // If the application is requesting delegated access:
  // The email address of the user for which the application is requesting delegated access,
  // then set the email address here. (Otherwise leave it empty.)
  gAuth.subEmailAddress = '';

  // Connect to www.googleapis.com using TLS (TLS 1.2 is the default.)
  // The Chilkat socket object is used so that the connection can be established
  // through proxies or an SSH tunnel if desired.
  final tlsSock = CkSocket();
  try {
    tlsSock.connect('www.googleapis.com', 443, true, 5000);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Send the request to obtain the access token.
  try {
    gAuth.obtainAccessToken(tlsSock);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Examine the access token:
  print('Firebase Access Token: ${gAuth.accessToken}');

  // Save the token to a file (or wherever desired).  This token is valid for 1 hour.
  fac.writeEntireTextFile('qa_data/tokens/firebaseToken.txt', gAuth.accessToken, 'utf-8', false);
}