Android Account Manager with Google App Engine App

Question

I am very confused on how to do user authentication on a custom Google app engine. I am writing an app that uses GAE and Google Cloud Messaging. My app is a derivative of a sample GAE application that can send messages to GCM. I want use user authentication in order to be able to validate and keep a database of known users in the app.

I have read about OAUTH2 and User (ClientLogin) but not sure what and which method to use. Can someone clarify what would be the best way to authenticate users as well as store them in a datastore? Is clientLogin the best method?

Answer 1

ClientLogin is deprecated since 20/04/2012, so I highly advise you to use Google Sign-in (that is, OpenID Connect with google+ accounts). Before itching to write some code immediately, I'd spend a good while learning as much as I can about this in the developers.google.com docs on the "Google Identity Platform".

The hardest part of auth for most developers is that there's a bit of a learning curve in terms of understanding the domain of the problem, the various solutions in the past, the current progress of various standards (OpenID connect and OAuth being the leaders), and the implementation details at various specific providers.

If you invest a good chunk of time just studying, with your code editor closed and maybe some pencil and paper in hand to draw a mental map or take notes, you'll have a much better time moving forward. This is my advice for any developer who wants to go from "zero" to "google sign-in" in 60 seconds.