External Authentication plugin with Elgg site like Facebook Connect

By Adam

Is there a plugin that would allow users to log into another website using their [Elgg] username and password? Just like Facebook Connect where you click "Login with Facebook" and the popup comes requesting Authentication. 

I looked through the pages in the "Authentication" category in the plugin directory but could only find using other site's social auth. I did find External Auth Link, which seems in the right playing field but not exactly what I'm looking for.