Server side authorization with OAuth

Question

is there a way to ask for an OAuth authorization without redirecting the user to the service and then back again to my app? In detail, I'm creating a web service that need access to the Facebook Graph API, that requires the OAuth 2.0 authentication. Is that possible?

Thanks

Answer 1

The authorization request has to happen for an authenticated (by the OAuth provider, not you) account, and for security reasons the authentication has to be a direct interaction between the end user and the OAuth provider.

Of course, the provider might decide the user is already authenticated properly (there is a fresh auth ticket in a provider-specific cookie for example) and skip the authentication sequence, but there is no way for you to force it to take your word that the user on whose behalf you are requesting the authorization indeed is an authenticated user of the OAuth provider.