Questios about Omniauth and cross SSO

Hello, I'm starting to gather all the information pieces to start with my project and on of the things I need is to get Omniauth and corss SSO working together. My project is based on a Mediawiki + Drupal and I need complete cross multi auth. That is, having a Mediawiki in domain A and Drupal in domain B, a user that registers / login in to any of those domains will be registered and authenticated across both domains or subdomains at the same time. Did somebody do this already ? I would like to gather all the info possible to figure out how to achieve it.

Thank you so much for your collaboration.