Hi all,
I'm using openSUSE Leap 15.1 on a machine which was previously configured
with samba/winbind for enumeration of users from a Microsoft AD. It was
also possible for those users to login to the machine.
After upgrades and changes to the domain controllers (Windows Server
2019), I got lots of winbind errors in the logs.
I decided to do a fresh start and use sssd instead of winbind. I
configured it using realmd (realmd join mydomain.xxx --user myadminuser),
and it worked quite well. I also configured ssh login in the following
way (/etc/pam.d):
(please forgive the strange stuff in the auth section, but after some
fighting it worked :))
sshd:
auth requisite pam_nologin.so
auth required pam_env.so
auth [default=1 ignore=ignore success=ok] pam_succeed_if.so uid >= 1000 quiet
auth [default=1 success=ok] pam_localuser.so
auth sufficient pam_unix.so nullok try_first_pass
auth requisite pam_succeed_if.so uid >= 1000 quiet
auth sufficient pam_sss.so
account requisite pam_nologin.so
account include common-account <===== check this
[... password, session omitted ...]
common-account:
account required pam_unix.so try_first_pass
account sufficient pam_sss.so forward_pass
Now I installed recent upgrades, which obviously executed pam-config. The
common-account was updated and contained only the following lines:
account requisite pam_unix.so try_first_pass
account sufficient pam_localuser.so
account required pam_sss.so use_first_pass
My users could no longer login, because the pam_unix requisite kills the
login before pam_sss is even called. I checked the source of pam-config
and it is doing exactly that:
https://github.com/SUSE/pam-config/blob/master/src/mod_pam_unix.c#L64
case ACCOUNT:
if (with_krb5 || with_ldap || with_lum || with_winbind || with_sss)
fprintf (fp, "account\trequisite\tpam_unix.so\t");
else
fprintf (fp, "account\trequired\tpam_unix.so\t");
break;
QUESTION: Why does pam-config use account "requisite" for pam_unix.so in
case of pam_sss presence? I'd expect "required", and that also works
if I change it manually. But unfortunately, my changes are lost every time
pam-config is run again ...
Also, pam_sss should be "sufficient" afterwards, not "required" ...
(At least that works, and while I've learned a lot about PAM during the
last days, I'm not there yet I think :)
thanks!
Markus
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