Can you use Google's oAuth to just authenticate?

Question

Can you use oAuth to only authenticate like you can with Twitter?

Answer 1

Sounds like there is some plans afoot on this...

http://googlecode.blogspot.com/2011/03/making-auth-easier-oauth-20-for-google.html?showComment=1300267218233#c6336940633709651714

some chap: "Can someone help by pointing to the documentation for the API of "just get basic information for a user"

other chap: "The problem is, that you get a lot of different login mechanisms because Twitter is using OAuth 1.0 (Or am I wrong?), Facebook is using OAuth 2.0 and Google is using OpenID for login. Please correct me if I´m wrong. So basically I have the same question. Will Google support login for basic user informations with OAuth 2.0 for Google APIs?"

google dude: "Today we're supporting OpenID for login, but we've heard your pain about mess of different identity protocols on the web. Stay tuned :)"

Seems to me, as OAuth2 covers authentication and authorization, it would make sense to allow basic info and make it easy on the integrator using one method for all

I'm plumping for this possibility anyway, hopefully by the time I'm ready to put my app live it will be available from Google - Facebook has this anyway and in my case that's a big enough draw

Answer 2

OAuth is an authorization protocol and can't be used for authentication only unless the provider defines a dummy scope which, in effect, authorizes you to access "nothing", or "basic user info" (name, e-mail, etc.).

AFAIK, Google provides no such "dummy" scope. However, they do implement OpenID for such authentication purposes, as the protocol is better suited for that task, anyways.

Answer 3

If you check Google's docs at http://code.google.com/apis/accounts/docs/OAuth2.html you'll find that the scope (meaning, the service you're supposed to ask permission to) is a required field. It may be a turn off for many users if you ask them to access their contact list when the most you really do is authenticate, so I rather stick with OpenID which is designed just to retrieve the UID.

So, the answer is really NO, unless you're planning on using an additional API with Google.

Answer 4

Yes you can there are many options it depens on your platform advice you to check

oauth.net

You can find there options for Java, .NET, Cold Fusion,PHP,etc.

There are many Frameworks that have OAuth capabilities, on Spring you can use this