Why not use OpenID in the first place?
I did not think it could be used for authenticating gane servers at first.
But I did a solid hour of searching yesterday and hadn't seen one instance of somebody using it on a game server. Also, steamID's seem to have been designed for logging into web sites, not using them with games.
I will ask about this on the Steam forums. The more I read, the more convinced I become that Badspot must do something in order for passwordless Steam authentication to work with dedi-servers.