Is there a way to authenticate users against my own datasource, but not have JBP synchronize the users/roles to itself?

JBP seems to be tightly coupled with Hibernate so that it can synchronize/retrieve user info from a database managed by JBP.

But for security purposes though, I do not want JBP to synchronize this kind of data. Instead, I have my own code module and would like it to supply this data to JBP whenever it is needed. So I only want user/role data stored in one location that can only be accessed from my code module.

Is this possible? I'm using JBP 2.6.2. Thanks!