I'm using DotNetOpenAuth to allow users to log into my website using their Google account. Since Google allows users to be logged in to several accounts at the same time it would be helpful to be able to pass in an identifier in the authentication request to select the correct session without having to display the irrelevant accounts.
Does anyone know if this is possible, if so what parameters do I need to use in the request?
OpenID absolutely supports an RP requesting that a specific Claimed Identifier be the one that the OP logs in. Most Providers would look at the auth request and then switch the account that the user is logged in with to match the claimed identifier in the auth request as necessary.
Google however does not support this. Sorry, out of luck. The best you could do is send a message in the auth request to force the user to re-login to Google regardless as to whether they fit the pattern of having multiple accounts at Google. So you'd end up annoying most of your users to help a few users avoid accidentally logging in with the wrong one of their several personal Google accounts.
