OAUTH2 - Login to Google Account - No Services needed

Question

It would be great if somebody could help me with strategic input, how to achieve my goal:

• I wrote a C# Desktop Application (WPF)
• I have a Google App Engine Project, which delivers Data for an Android App

Now my Desktop Application needs to pass some Data to my App Engine Application. Therefore, the Application must authenticate as Owner of the App Engine Application. As, all other Google Methods are deprecated, I have to go heading OAUTH2 to let my Desktop App authenticate itself as owner.

Therefore I have to register a project at Google Apis Console.

BUT: I dont need any Service(s) of the listed Google APIS (Maps, ...), because to authenticate as Owner, its absolutely enough to sign in to a Google Account (GmailAccount, Google Account, whatever). This lets my App Engine App recognize me as Owner.

I would appreciate advice about:

• Should I register a project without Service just to Sign In via OAUTH2? (Is this possible?)

• Sign in to another Service (means, taking the easiest way, just to be able to authenticate as Owner) seems not to be very "clean" sollution. Is this right, or should I go this way?

.. I also read about Service Accounts, but dont want to use this, because I want to be able to manipulate my app also via my "Human"-Account via any Webbrowser.

Thanks for any advice!

Answer 1

You can provide Google OAuth sign in without using any of Google's other services. Your OAuth client would just have an empty scope. You should be able to get the basic user info and email (so you can figure out who is who by something other than full name) without enabling any services as well.

You will still need a way to flag that you are you in your app (probably just hardcode your email in your app, then check it against who authenticates with OAuth would be the easiest)