Separate authentication form data

I'm wondering if it's possible to add an additional mechanism for authentication, for my current implementation it would be very nice to have simple file like user:password (or user:hash) that will perform authentication, and than limit access to data only with maxscale filters - without the need to keep users in mariadb databases.

Maybe even more functional would be to integrate maxscale with pam, so I'll probably be able to allow acces on LDAP users in our office.