pppd-sql is a plugin for the Point-to-Point server
(pppd) on Linux and Solaris that adds an
authentication backend using a MySQL or PostgreSQL
database for the Challenge Handshake
Authentication Protocol (CHAP) and Password
Authentication Protocol (PAP). It supports
MS-CHAPv1 and MS-CHAPv2 too. The IPCP negotiation
after authentication handshake is also supported.
pppd-sql supports a flexible configuration scheme,
has concurrent connection handling for single
users across multiple tunnel servers, and comes with
easy and handy documentation.