[Openswan Users] Openswan + L2TP + Domain Controller?

[Martin Spinassi]

Hi list,

I've been looking for the way of making a secure VPN with Ipsec/L2TP.
I've read some documentation at openswan web site, and a link I've found
googling around (http://www.jacco2.dds.nl/networking/openswan-l2tp.html)

What I don't have very clear is that is possible to use a certificate to
authenticate to openswan, but what I also want is to check the
credentials using user/password and checking them in a MS Domain
Controller. This way looks pretty secure (something I have and something
I know), but couldn't find some documentation that tells it is
possible....
¿Does exists what I'm looking for? ¿Have you tried it? 
Any link or documentation is welcome!


Cheers


Martin