I am working on an external game that can check usernames/passwords against a DB. I tried searching but the password schema seems sort of over my head any pointers/examples as to how I can auth against Xenforo's DB? PS the DB is imported from IPB. thank you.
The passwords are stored in the xf_user_authenticate table in the database.
Authentication can't be reduced to a single query because there are different auth classes to consider. You will need to use XenForo_Model_User::validateAuthentication. If you are a programmer then you can post in the Development Questions forum for help with this.