I'm looking to deploy openvpn as a linux RAS server (rather than site-to-site) and i'd like to use two factor authentication, specifically the use of ssl certificates and passwords tied into an ntlm domain or ldap server.
Is this even possible ? I'm really struggling to dig up information on doing such a thing so I'm starting to doubt it a little. If anyone has done this it'd be good to know (or knows of an open source way to do such a thing), or even better has the openvpn server config needed to pull this off.
edit: i know an ssl cert isn't an ideal factor. :)