On Thu, 2014-07-31 at 13:27 +0200, Daniel Gollub wrote:
What do you think about a generic parameter for the pam section:
trust_all_pam_clients = <[false]|true>
Which is "false" by default, and should be only set if the target
system can guarantee that no untrusted users can connect to sssd_pam?
(e.g. systems with no shell access to "untrusted" users)
Or by configuring which users are trusted as PAM client, where it is
safe to interpret the domains= parameter?
trusted_pam_clients = root, openvpn, strongswan, ...
It should be: trusted_pam_users = root, openvpn, ...
Defaults to root only
(Haven't checked how hard it is to actually determine on a safe
how the callee is ... or is there already something in place in the
pam responder or so?)
We could also introduce:
pam_services = it-dep, ...
But here we would loose flexibility, when new (e.g. VPN-) service
instances get spawned with their individual PAM service configuration -
which would require then each time a sssd restart - due to
No, this is useless as the pam service is sent by the client, so it
cannot be trusted on its own.
> > > Or is it merely a way to avoid mistakes but not a security
> > > measure ?
> > No.
> To be honest, in the openvpn -> sssd case this is what it is, as the
> openvpn process collaborates with sssd to define the security
> boundaries of what domain should be used.
It depends on the perspective ... for the PAM client - some service
like OpenVPN - it can be seen as security measure. By only allowing
certain users to authenticate for a particular service.
From the sssd perspective this is different ... since the entire
control would be on the client side - which should not be trusted in
> Don't think about my questions with your narrow use case in mind, they
> are directed at a system where random user processes can be run, like
> on a multiseat system.
So the trusted_pam_users should be allowed to auth against any domain
and be trusted to limit themselves via the domains parameter.
All other users should be confined to a list of configured domains, by
default that may be none or all, depending on which configuration we
think is more reasonable in a standard system, right now we do not limit
anything so we could say "all" is the default and admin need to
explicitly change it to none when they want to apply limitations.
So something like:
allowed_pam_auth_domains = all|none|[comma separate domain names]
Password changes should still be allowed in any case so when a user
connect it's domain need to be retrieved and access to auth to that
domain (at least for the "self") need to be allowed.