Did anyone manage to get the id token from google sign in (Flutter)

Question

I am trying to connect my users with my back end server , i used the example from the official google sign in plugin for flutter : https://pub.dartlang.org/packages/google_sign_in

the sign process goes fine and i get the username and email ect.. but i need the id Token to authenticate the user with my server.

Ps: Not using firebase , only google sign in.

Can anyone guide me how to get the id Token ?

Answer 1

You can try using this

 _googleSignIn.signIn().then((result){
          result.authentication.then((googleKey){
              print(googleKey.accessToken);
              print(googleKey.idToken);
              print(_googleSignIn.currentUser.displayName);
          }).catchError((err){
            print('inner error');
          });
      }).catchError((err){
          print('error occured');
      });

Answer 2

You can get access token and id token more simple like this:

final result = await _googleSignIn.signIn();
final ggAuth = await result.authentication;
print(ggAuth.idToken);
print(ggAuth.accessToken);

Or you also can add it to try-catch to handle an error.

try {
   final result = await _googleSignIn.signIn();
   final ggAuth = await result.authentication;
   print(ggAuth.idToken);
   print(ggAuth.accessToken);
} catch (error) {
  print(error);
}

Answer 3

or try like this if id token was null, it worked for me.

As the docs point out you need oauth2 client id of your backend to request idToken or serverAuthCode.

from firebase google sigin in authentication copy the Web SDK configuration add paste in the following to res/values/strings.xml, That should work

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="default_web_client_id">{Web app Client id goes here}</string>
</resources>

Answer 4

To retrieve the Is idToken worked for me:

1. The google-services.json file must be placed in /android/app/

2. you need to add to your /android/app/build.gradle

apply plugin: 'com.google.gms.google-services'

3. and to /android/build.gradle

classpath 'com.google.gms:google-services:4.3.4'

And that's it. GoogleSignIn will return a real idToken instead of null.

font: https://github.com/flutter/flutter/issues/12140#issuecomment-348720774