[Freeipa-users] .k5login and auth_to_local_names principal -> account mapping and localauth plugin not working on 6.7

[Simo Sorce]

On Mon, 2015-12-07 at 18:04 +0100, Stefano Cortese wrote:
> > > So the questions are:
> > > - is there another cleaner way to exclude the localauth sssd plugin
> > > (considering that the configuration snippet is recreated at every sssd
> > > restart)?
> >
> > Can you test if this hack would help:
> >     # service sssd stop
> >     # rm /var/lib/sss/pubconf/krb5.include.d/localauth_plugin
> >     # touch /var/lib/sss/pubconf/krb5.include.d/localauth_plugin
> >     # chattr +i /var/lib/sss/pubconf/krb5.include.d/localauth_plugin
> >     # service sssd start
> 
> It works, thanks
> 
> >
> > btw also check out this ticket:
> >     https://fedorahosted.org/sssd/ticket/2788
> not needing principal switching from/to root for the moment
> 
> >
> > > - is there the possibility on IPA 4.1 (the version of our server) to 
> > manage
> > > the mapping letting the plugin in place, namely to associate or 
> > authorize
> > > one or multiple service principals with an ipa posix account so that the
> > > getpwent() works?
> >
> > I wonder why the mapping fails, can you invalidate the cache with
> > sss_cache and try to look up the principal from the command line, using
> > getent passwd primary REALM ?
> >
> Maybe I wasn't clear in describing the setup.
> 
> I am attempting to log from a local machine as "userA"  using the 
> credentials of a "service principal" defined in IPA to a remote machine 
> as "userB"
> The userB principal is resolvable on the remote host via "getent passwd 
> userB" because it is a user principal.
> Also the userA principal is resolvable on the local machine, but this 
> should not play a role because the user's credentials are not used for 
> the connection, only the service credentials, as a client.
> The service principal is not resolvable via "getent passwd" neither on 
> the originating host nor on the destination host.
> The trick with .k5login is that the service principal used in the 
> connection is granted access as userB because it is listed as one of the 
> principals that correspond to the userB posix account on the remote host.
> 
> 
> > > - is there a more suitable way to obtain the above delegation and 
> > security
> > > context switching using other mechanisms supported by IPA?
> > >
> > > Thanks in advance
> > > Stefano

FWIW a better way to solve this would be to use constrained delegation,
allowing the service principal to obtain the target user credentials.
This way you do not allow users to mess with .k5login files (which
allows them to permit in an account whoever they please w/o central
control.

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York