[Samba] Samba Authentication against Radius server

[Nelson Vale]

Hello guys,

I have my linux system configured to authenticate/authorize (windows XP
and Vista) users for several services, like PPTP, SMTP and POP3, against
a radius server (using PAM), and now I want to add support for samba
authentication also. I was planning to do it by using one tdbsam backend
(I can not have LDAP for several reasons, unfortunately) but I have some
doubts:

Is it possible to authenticate samba users directly against the radius
server (is there a way to do it)?

For tdbsam is there any solution to keep passwords sync with radius
server?

Tanks