XF 1.2 OpenID for XenForo - MyBB?

hello everyone!

I own a gaming community and my main site is XenForo. I have a subdomain with MyBB and I was wondering if there is an add-on so that if a user signs up on my main page or on that subdomain their login will be the same for the MyBB subdomain and the XenForo home site.

Thank you.