What information do you have to keep about a user to be an OpenID consumer?
I want to use OpenID to let users register and authenticate on my system. So while I'm at it I want to not duplicate effort, and eliminate unnecessary passwords, etc from being stored.
I assume that besides the user's Profile details, you would need to store a copy of the user's Authentication/ID token from the ID provider as well as the user's ID URI, and a recovery email address in case the ID provider becomes inaccessible or the user wants to link a new ID provider to their account on your system. It also appears that there is a temporary "request" Token used during sign-up and/or during re-authentication, but this is short lived and used once only, so may not need to be stored in the database ever.
Does different ID providers, eg Facebook, Twitter, LinkedIn, Google Connect all provide similar enough authentication tokens that I can simply call the database columns something like "IDProviderToken" and "IDProviderURI", or do I need data specific to Facebook/Google/etc ?