How would you integrate web services with an SSO provider? I know you can use the SSO-provider's security ticket to validate that the user is authenticated, but what about when you have a desktop application which uses web services? How do you authenticate the user of a desktop app by integrating with an SSO provider?
I don't think SSO providers allow you to pass the username and password of the user trying to authenticate, they just provide a login web page on which the user must login, then their security ticket is issued. So I can't just write an authentication provider web service.