[Samba] [PATCH] Re: Using samba4 with kerberos outside of an AD realm

[Andrew Bartlett]

On Mon, 2013-01-21 at 23:25 -0700, Kyle Brantley wrote:
> On 1/21/2013 9:14 PM, Kyle Brantley wrote:
> > On 1/21/2013 8:46 PM, Andrew Bartlett wrote:
> >> On Mon, 2013-01-21 at 15:44 -0700, Kyle Brantley wrote:
> >>> On 1/21/2013 3:15 PM, Andrew Bartlett wrote:
> >>>> On Mon, 2013-01-21 at 11:34 -0700, Kyle Brantley wrote:
> >>>>> Hello --
> >>>>>
> >>>>> I'm trying to run a samba4 server (note: Fedora packaged version,
> >>>>> samba-4.0.0-174.fc18.x86_64) under a kerberos realm that isn't AD.
> >>>>>
> >>>>> This is a summation of the config that I'm using (works under 
> >>>>> samba 3.6):
> >>>>>
> >>>>>            security = ADS
> >>>>>            passdb backend = tdbsam
> >>>>>            restrict anonymous = yes
> >>>>>            server signing = auto
> >>>>>            client signing = auto
> >>>>>            smb encrypt = auto
> >>>>>            realm = MYREALM.COM
> >>>>>            kerberos method = system keytab
> >>>>>
> >>>>> However, whenever I try to access the samba server, the client 
> >>>>> fails to
> >>>>> connect. I can see that a ticket has been issued for
> >>>>> cifs/hostname at MYREALM.COM, but in /var/log/messages I get this:
> >>>>>
> >>>>> Jan 21 11:27:00 elastic smbd[1573]: [2013/01/21 11:27:00.675545,  0]
> >>>>> ../auth/kerberos/gssapi_pac.c:116(gssapi_obtain_pac_blob)
> >>>>> Jan 21 11:27:00 elastic smbd[1573]:   obtaining PAC via GSSAPI
> >>>>> gss_get_name_attribute failed: The operation or option is not 
> >>>>> available
> >>>>> or unsupported: No such file or directory
> >>>>> Jan 21 11:27:07 elastic smbd[1574]: [2013/01/21 11:27:07.559656,  0]
> >>>>> ../auth/kerberos/gssapi_pac.c:116(gssapi_obtain_pac_blob)
> >>>>> Jan 21 11:27:07 elastic smbd[1574]:   obtaining PAC via GSSAPI
> >>>>> gss_get_name_attribute failed: The operation or option is not 
> >>>>> available
> >>>>> or unsupported: No such file or directory
> >>>>> Jan 21 11:27:07 elastic smbd[1576]: [2013/01/21 11:27:07.643158,  0]
> >>>>> ../auth/kerberos/gssapi_pac.c:116(gssapi_obtain_pac_blob)
> >>>>> Jan 21 11:27:07 elastic smbd[1576]:   obtaining PAC via GSSAPI
> >>>>> gss_get_name_attribute failed: The operation or option is not 
> >>>>> available
> >>>>> or unsupported: No such file or directory
> >>>>>
> >>>>> Well, no kidding there is no PAC available, it's an MIT kerberos 
> >>>>> realm! :)
> >>>>>
> >>>>> Does anyone know what I need to be doing to get this working again?
> >>>> It is probably a bug in the reworked krb5 code.  The code paths to
> >>>> support this are still there, but clearly something doesn't trigger
> >>>> correctly.
> >>>>
> >>>> The first thing to do would be to turn up the log level, to see 
> >>>> what the
> >>>> real failure is (the mentioned message shouldn't actually be fatal).
> >>>>
> >>>> Then, once we rule out it being something else, it probably just 
> >>>> needs a
> >>>> new test environment to be created in our 'make test' that tells 
> >>>> our AD
> >>>> server to not send the PAC.  This will allow this code path to be
> >>>> covered, and prevent regressions.
> >>>>
> >>>> Andrew Bartlett
> >>>>
> >>> As far as I can tell, prior to accepting a connection:
> >>> Full logs:
> >>> http://averageurl.com/samba/samba-log.gz
> >>> http://averageurl.com/samba/samba-strace-log.gz
> >>>
> >>> I've already changed the keys out, so I'm not too worried about what 
> >>> key
> >>> data is actually in those logs.
> >> The logs were very helpful.  The attached patch should fix it, or at
> >> least move the failure to somewhere else :-).  Please file the bug, so
> >> we can get this into 4.0.2
> >>
> >> Andrew Bartlett
> >
> > Thanks. I've filed the bug 
> > (https://bugzilla.samba.org/show_bug.cgi?id=9581) and am currently 
> > rebuilding samba with the patch applied. I'll let you know how it goes...
> >
> > --Kyle
> 
> That worked great. I've been able to enumerate the shares and connect to 
> them now. I validated with wireshark that the kerberos authentication 
> was occurring, and it looks like everything functions now thanks to your 
> previously attached patch.

Metze, Can you get this into master?  I'll try and follow-up with a
testcase (setting the UF_NO_AUTH_DATA_REQUIRED on an account and doing a
kerberos login) soon, but this much needs to get to 4.0.2

-- 
Andrew Bartlett                                http://samba.org/~abartlet/
Authentication Developer, Samba Team           http://samba.org

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