I'm not sure this is the correct place to post and ask but here goes (I am using DNN 6.2)

I am building a couple of JSON web services that will post to the users journal through the Journal API. This works great.

Now, I am trying to figure out how to build a web service that will "login with facebook" but I cant seem how to figure out how to login or register the user with facebook authentication (or google+) on my site.

I am building an app where the use can take a picture, add a comment add post. When it comes to login and registering, I would like DNN to handle that so when the user downloads the app, the user has 2 choices:

1. Login with FB

2. Login normal

or register "manually" without using FB.

Now, when the user clicks on "Login with FB" I would like to "use" the same execution as is if the user would have clicked "login with FB" on the web page. I would like to call that API that DNN uses and execute it.

Anyone knows how to achieve this?