[Samba] sendmail getting domain\user as email userId

[Rowland Penny]

On Thu, 30 Nov 2017 11:34:54 -0500
Mark Foley via samba <samba at lists.samba.org> wrote:

> I've figured out a work-around to the problem of "winbind use default
> domain = yes" not working on the AD/DC. As mention below, in my
> specific case procmail does not see HPRS\charmaine as the actual
> owner 'charmaine' and I get a "Suspicious rcfile
> "/home/HPRS/charmaine/.procmailrc" message in maillog and the mail
> does not get delivered to her $HOME/Maildir file, but rather
> to /var/spool/mail/HPRScharmaine.
> 
> Per the procmail man page, this error is because, "The owner of the
> rcfile was not the recipient or root, ... ". My work-around was to
> change the ownership of the .procmailrc file to root since that
> seemed acceptable to procmail. This worked and mail was then
> delivered.
> 
> Comments:
> 
> This "bug" has been hanging around in Samba since April, 2013,
> https://bugzilla.samba.org/show_bug.cgi?id=9780 It is currently
> marked as RESOLVED FIXED by Andrew Bartlett of as 2016-07-28, but it
> is clearly not solved. Anyone running `getent passwd` or `wbinfo` on
> the AD/DC will get "DOMAIN/user" instead of "user". Therefore, not
> solved.
> 
> This functionality is inconsistent with the values returned by the
> same commands on a domain member. 
> 
> It currently breaks authentication for various facilities on the
> AD/DC, not limited to mail MTAs and MDAs. 
> 
> I've found a number of postings on this list about this problem.
> Some people, (Mike E. (posting Thu Jul 21 12:30:40 2016) have found
> other work-arounds including using sssd in nsswitch.conf instead of
> winbind.  There are 10 postings on the bug report for people having
> the same problem including another (Luc Lalonde) who also switched to
> sssd. 
> 
> I believe this is a problem in the real-world and should be more
> urgently addressed by the Samba team. I think this is a fundamental
> piece of Samba4 and it should work correctly.
> 
> My two cents worth.
> 
> --Mark
> 
> -----Original Message-----
> Date: Wed, 29 Nov 2017 10:48:06 -0500
> To: samba at lists.samba.org
> User-Agent: Heirloom mailx 12.5 7/5/10
> Subject: Re: [Samba] sendmail getting domain\user as email userId
> 
> About a year-and-a-half ago I wrote in a thread having this same
> subject about a problem my sendmail server was having on my Samba4
> AD/DC. To solve that problem at the time, I maintained domain user
> entries in both the sam.ldb and in /etc/passwd, and did not have
> winbind specified in /etc/nsswitch.conf. I am now trying to remove
> all users from /etc/passwd and use winbind. Unfortunately, I'm
> running into the same problem. In short:
> 
> AD/DC:
> > getent passwd charmaine
> HPRS\charmaine:*:10003:10000:Charmaine
> Carter:/home/HPRS/charmaine:/bin/bash
> 
> other domain member:
> $ getent passwd charmaine
> charmaine:*:10003:10000:Charmaine
> Carter:/home/HPRS/charmaine:/bin/bash
> 
> The ID being return of "HPRS\charmaine" apparently confuses sendmail
> and procmail and causes the error, "Suspicious rcfile
> "/home/HPRS/charmaine/.procmailrc", probably due to "The owner of the
> rcfile was not the recipient or root" (from procmail manpage).  Note
> that mail delivery worked OK when the user was in /etc/passwd.
> Currently, mail is not getting delivered the the Maildir
> as .procmailrc specifies, but rather it is sent
> to /var/spool/mail/HPRScharmaine, so it is obviously construction a
> mbox name based on the winbind returned ID.
> 
> Regarding this issue, On Thu Jul 21 04:02  Rowland penny wrote:
> 
> > There is another line, which works on a domain member:
> >                                                                                              
> >      winbind use default domain = yes
> >
> > This (on a domain member) removes the NetBIOS domain name, but it 
> > doesn't seem to work on an AD DC.
> >
> 
> Various other participants on this thread confirmed that "winbind use
> default domain = yes" did not work on the AD/DC. Later (Mon Jul 25
> 12:05), Roland referenced a bug report on this issue:
> 
> https://bugzilla.samba.org/show_bug.cgi?id=9780
> 
> Interestingly, on 2016-07-27 15:42:36 Björn Jacke posted to bugzilla
> that the issue was solved, and set the status to RESOLVED FIXED:
> 
>   "Samba 4.1 is old and out of support by us. Update to a recent
> version if you need this to be solved. Current Samba versions use a
> unified winbind with a more unified feature set."
> 
> I am currently running version 4.4.16 and it is clearly not solved.
> 
> Does anyone have a workaround for this? Later in that same thread
> (Thu Jul 21 12:30:40 2016) Mike E. suggested trying sssd, which was
> solving the problem for him. My distro (Slackware) does not have an
> sssd package, though I'll continue researching that. Otherwise,
> barring some other solution, I'll have to put my users back
> in /etc/passwd! 
> 
> Thanks for your help -- Mark
> 

I have re-opened the bug report, the problem is that the devs don't see
it as a problem, whilst a lot of users do :-(

Rowland