I've got an easy question, but can't find the answer so far. I would like to assign to a same Joomla user more than one login credential set (username/password). More precisely, I would like to allow to do such a login using social networks (especially LinkedIn). More than one social account should be associable to a given Joomla! user. For example, if Jack and John work for Alpha Enterprise, they should both use the Alpha Enterprise account for Joomla!, but using their own LinkedIn profile for login.
Is there any extension that does what I need?