Just Google JWT decoder

A simple Google JWT decoder library for Dart with all necessary verifiers.

Usage

import 'package:just_google_jwt_decoder/just_google_jwt_decoder.dart';

main() async {
  var clientId = '<CLIENT_ID>';
  var decoder = new GoogleJwtDecoder(clientId, expirationTolerance: const Duration(seconds: 30));
  
  var encodedJwt = new EncodedJwt('<HEADER.PAYLOAD.SIGNATURE>');
  var jwt = await decoder.convert(encodedJwt);
  
  print(jwt.payload);
}

Verification

Library verifies following data:

• Whether issuer is Google Accounts server
• Whether user's email is verified
• Whether JWT not expires
• Whether audience is equal to Client ID
• Whether signature is valid (automatically downloads certificates from Google servers and keep them in memory until they expires).

Get Google JWT

You can obtain a Google JWT (a.k.a. idToken) with just_google_signin library.