React Native OAuth2 and REST API authentication flow

Question

I'm having a bit trouble understanding this predicament a REST API supporting React Native (Mobile App) with OAuth2 authentication.

I've managed to setup the OAuth2 flow and can login via OAuth2 provider. This communication is still just between the Mobile App and the 3rd party OAuth2 provider. How can I use those tokens I've obtained (and actually trust the request) to create an account in my REST API so that the server can actually generate a JWT token that will be used for future requests?

Can't seem to find an answer to this question. Would love some help with this one

Answer 1

Ok, I've managed to figure this one out.

To achieve what I want the Client (in this case mobile app) does the authentication flow and will receive an access_token and a refresh_token along with an id_token . The last one ( id_token ) contains the info about the user which the app should send to my REST API. Once the server receives it it will make an HTTP request to Google (my OAuth2 Provider) to verify that this token is in fact a valid one and issued by them.

After that I just create an account and issue my own token in response to the Mobile's App request.

It's explained herein Google Docs

Most likely all the major identity providers would follow along this path. Or, at least I'm hoping they do.