[Samba] Workstation Logon Restrictions (Log On To) with samba 4 AD

[Andrew Bartlett]

On Sun, 2016-10-30 at 20:20 +0100, Trenta sis via samba wrote:
> Hi,
> 
> After a migration from samba 3 nt domain to samba 4 AD we have
> detected
> that Workstation Logon Restrictions (Log On To) is not working
> correctly,
> with samba 3 was working perfect, but after migration we have
> detected that
> some resources are not available, for example roaming profiles, home
> folders... we have tried to add as log on to workstations  samba
> machine
> (dc), machine that has roaming profiles, home folders.... but without
> success only works if we disable all restrictions to log on to, but
> then
> for our environment is a security problem
> 
> How can I solve?

The implementation of the workstation logon restrictions has always
been a bit of a hack in Windows domains, and so to in Samba.  In NTLM,
it was enforced largely by the client-supplied and unverified
'workstation' in the NTLM packet.  The protections in the NETLOGON
server are a bit stronger, but your issue is that the KDC is now
issuing the ticket, and perhaps that isn't checking the optional
'workstation name' 'address' that is put in the krb5 request.

The correct way to enforce a login restriction would be to deny the
service ticket, but then we would have to tell which TGS-REQ packets
were for desktop logon, and which were for other services on other
hosts.

All in all, this is very hard to on the DC.  The workstation itself
would be better placed to enforce such a restriction as an ACL, but I
don't know of a way to do that.

Andrew Bartlett

-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba