Google Cloud Endpoints with another oAuth2 provider

Question

Is there a way to use another OAuth2 provider with Google Cloud Endpoints? I mean for example, get authentication from Facebook and use it the same way we use Google Account Auth (using gapi js and putting User class on @ApiMethod)

Henequen

Check this out: #18717174 – Lucialucian

Answer 1

No. I came across someone else asking this question and the answer from the google folks (if I remember correctly) was that the endpoints user authentication currently only supports Google accounts.

Fizgig

Is there a way to implement an alternative? Like storing User in the session? (I just discovered that session also does not work in Google Cloud Endpoint) – Henequen

Sure, you can implement any alternative you want, and you can pass your systems' tokens via endpoints, but you will have to implement the authentication yourself. – Fizgig

the problem here is how to control the user session, because Google Endpoint not provide session, right? – Henequen

Yes, that is my understanding. – Fizgig

You can use endpoints with Sessions enabled. You just need to enable them in your appengine-web.xml using <sessions-enabled>true</sessions-enabled> – Heraldry

@InsaurraldeAP it's not true. You can either implement your own auth schema or implement OAuth with some other provider. – Conic

Answer 2

You have to implement your own Authenticator and update @Api configuration. Based on this answer a simple authenticator will look like this:

public class MyAuthenticator implements Authenticator {

    @Override
    public User authenticate(HttpServletRequest request) {
        String token = request.getHeader("Authorization");
        if (token != null) {
            // apply your Facebook/Twitter/OAuth2 authentication
            String user = authenticate(token);
            if (user != null) {
                return new User(user);
            }
        }
        return null;
    }
}

And your API definition

@Api(name = "example", authenticators = {MyAuthenticator.class})

More about custom authenticators you can find in Google documentation.

Chatav

Is there a python equivalent? – Charil

@JanuszSkonieczny I've no idea whether or not it's available for python, you should probably ask a new question on SO – Chatav

anyone know how to put the data inside the header from android client? – Byars

Answer 3

I wrote an example exchanging a Facebook access token for one generated by my application, and validating it from within an endpoints method:

https://github.com/loudnate/appengine-endpoints-auth-example

Cantu

Answer 4

Google Cloud Endpoints allow you to recover User, HttpServletRequest and HttpServletContext into you API methods by injecting it as parameters.

It is not OAuth2 but here is a begining of a solution: https://www.yanchware.com/custom-authentication-for-google-cloud-endpoints/

The proposed solution is to inject HttpServletRequest in specific api methods to access the session.

Susa