[squid-users] Kerberos Authentication Failing for Windows 7+ with BH gss_accept_sec_context() failed

Sat Oct 25 13:50:51 UTC 2014

Hi Markus,

I initially had it configured as such and changed it to `auth_param negotiate program /usr/lib/squid3/negotiate_kerberos_auth -d -r -s HTTP/proxy01tst.fake.net` as a troubleshooting step. I've since then changed it back. Dan pointed out earlier that it could be a permissions problem, and sure enough, permissions on /etc/squid3/PROXY.keytab were wrong (group had no read permissions). Fixing that seems to have sorted out the problem. I'll be doing more extensive testes on Monday when the test group start surfing the web.

Thanks for all the help!

On 25 Oct 2014, at 14:13, Markus Moeller wrote:

> Hi Pedro,
>
> I wonder if he upper case in the name is a problem. Can you try
>
> auth_param negotiate program /usr/lib/squid3/negotiate_kerberos_auth -d -r -s GSS_C_NO_NAME
>
> instead of
>
> auth_param negotiate program /usr/lib/squid3/negotiate_kerberos_auth -d -r -s HTTP/proxy01tst.fake.net
>
> Markus
>
> "Pedro Lobo" <palobo at gmail.com> wrote in message news:FD6832B9-3F1F-48C6-A76F-47A224F1697B at gmail.com...
> Hi Markus,
>
> I used msktutil to create the keytab.
>
> msktutil -c -s HTTP/proxy01tst.fake.net -h proxy01tst.fake.net -k /etc/squid3/PROXY.keytab --computer-name proxy01-tst --upn HTTP/proxy01tst.fake.net --server srv01.fake.net --verbose
> Output of klist -ekt:
>
> 2 10/24/2014 22:59:50 proxy01-tst$@FAKE.NET (arcfour-hmac)
> 2 10/24/2014 22:59:50 proxy01-tst$@FAKE.NET (aes128-cts-hmac-sha1-96)
> 2 10/24/2014 22:59:50 proxy01-tst$@FAKE.NET (aes256-cts-hmac-sha1-96)
> 2 10/24/2014 22:59:50 HTTP/proxy01tst.FAKE.net at FAKE.NET (arcfour-hmac)
> 2 10/24/2014 22:59:50 HTTP/proxy01tst.FAKE.net at FAKE.NET (aes128-cts-hmac-sha1-96)
> 2 10/24/2014 22:59:50 HTTP/proxy01tst.FAKE.net at FAKE.NET (aes256-cts-hmac-sha1-96)
> 2 10/24/2014 22:59:50 host/proxy01tst.FAKE.net at FAKE.NET (arcfour-hmac)
> 2 10/24/2014 22:59:50 host/proxy01tst.FAKE.net at FAKE.NET (aes128-cts-hmac-sha1-96)
> 2 10/24/2014 22:59:50 host/proxy01tst.FAKE.net at FAKE.NET (aes256-cts-hmac-sha1-96)
> Yep, using MIT Kerberos
>
> Thanks in advance for any help.
>
> Cheers,
> Pedro
>
> On 25 Oct 2014, at 1:26, Markus Moeller wrote:
>
> Hi Pedro,
>
> How did you create your keytab ? What does klist –ekt <squid.keytab> show ( I assume you use MIT Kerberos) ?
>
> Markus
>
> "Pedro Lobo" palobo at gmail.com wrote in message news:40E1E0E7-50C6-4117-94AA-50B06573430A at gmail.com...
> Hi Squid Gurus,
>
> I'm at my wit's end and in dire need of some squid expertise.
>
> We've got a production environment with a couple of squid 2.7 servers using NTLM and basic authentication. Recently though, we decided to upgrade and I'm now setting up squid 3.3 with Kerberos and NTLM Fallback. I've followed just about every guide I could find and in my testing environment, things were working great. Now that I've hooked it up to the main domain, things are awry.
>
> If I use a machine that's not part of the domain, NTLM kicks in and I can surf the web fine. If I use a Windows XP or Windows Server 2003, kerberos works just fine, however, if I use a machine Windows 7, 8 or 2008 server, I keep getting a popup asking me to authenticate and even then, it's and endless loop until it fails. My cache.log is littered with:
>
> negotiate_kerberos_auth.cc(200): pid=1607 :2014/10/24 23:03:01| negotiate_kerberos_auth: ERROR: gss_accept_sec_context() failed: Unspecified GSS failure. Minor code may provide more information.
> 2014/10/24 23:03:01| ERROR: Negotiate Authentication validating user. Error returned 'BH gss_accept_sec_context() failed: Unspecified GSS failure. Minor code may provide more information. '
> The odd thing, is that this has worked before. Help me Obi Wan... You're my only hope! :)
>
> Current Setup
> Squid 3.3 running on Ubuntu 14.04 server. It's connected to a 2003 server with function level 2000 (I know, we're trying to fase out the older servers).
>
> krb5.conf
>
> [libdefaults]
> default_realm = FAKE.NET
> dns_lookup_kdc = yes
> dns_lookup_realm = yes
> ticket_lifetime = 24h
> default_keytab_name = /etc/squid3/PROXY.keytab
>
> ; for Windows 2003
> default_tgs_enctypes = rc4-hmac des-cbc-crc des-cbc-md5
> default_tkt_enctypes = rc4-hmac des-cbc-crc des-cbc-md5
> permitted_enctypes = rc4-hmac des-cbc-crc des-cbc-md5
>
> [realms]
> FAKE.NET = {
> kdc = srv01.fake.net
> kdc = srv02.fake.net
> kdc = srv03.fake.net
> admin_server = srv01.fake.net
> default_domain = fake.net
> }
>
> [domain_realm]
> .fake.net = FAKE.NET
> fake.net = FAKE.NET
>
> [logging]
> kdc = FILE:/var/log/kdc.log
> admin_server = FILE:/var/log/kadmin.log
> default = FILE:/var/log/krb5lib.log
> squid.conf
>
> auth_param negotiate program /usr/lib/squid3/negotiate_kerberos_auth -d -r -s HTTP/proxy01tst.fake.net
> auth_param negotiate children 20 startup=0 idle=1
> auth_param negotiate keep_alive off
>
> auth_param ntlm program /usr/bin/ntlm_auth --diagnostics --helper-protocol=squid-2.5-ntlmssp --domain=FAKE.NET
> auth_param ntlm children 10
> auth_param ntlm keep_alive off
> Cheers,
> Pedro
>
> Cumprimentos
> Pedro Lobo
> Solutions Architect | System Engineer
>
> pedro.lobo at pt.clara.net
> Tlm.: +351 939 528 827 | Tel.: +351 214 127 314
>
> Claranet Portugal
> Ed. Parque Expo
> Av. D. João II, 1.07-2.1, 4º Piso
> 1998-014 Lisboa
> www.claranet.pt
>
> Empresa certificada ISO 9001, ISO 20000 e ISO 27001
>
>
> ------------------------------------------------------------------------------
>
> ------------------------------------------------------------------------------
>
> squid-users mailing list
> squid-users at lists.squid-cache.org
> http://lists.squid-cache.org/listinfo/squid-users
>
>
> ------------------------------------------------------------------------------
>
> squid-users mailing list
> squid-users at lists.squid-cache.org
> http://lists.squid-cache.org/listinfo/squid-users
>
> Cumprimentos
> Pedro Lobo
> Solutions Architect | System Engineer
>
> pedro.lobo at pt.clara.net
> Tlm.: +351 939 528 827 | Tel.: +351 214 127 314
>
> Claranet Portugal
> Ed. Parque Expo
> Av. D. João II, 1.07-2.1, 4º Piso
> 1998-014 Lisboa
> www.claranet.pt
>
>
>
>
>
> Empresa certificada ISO 9001, ISO 20000 e ISO 27001
>
>
>
>
> --------------------------------------------------------------------------------
> _______________________________________________
> squid-users mailing list
> squid-users at lists.squid-cache.org
> http://lists.squid-cache.org/listinfo/squid-users
> _______________________________________________
> squid-users mailing list
> squid-users at lists.squid-cache.org
> http://lists.squid-cache.org/listinfo/squid-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squid-cache.org/pipermail/squid-users/attachments/20141025/6d5f37db/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 536 bytes
Desc: OpenPGP digital signature
URL: <http://lists.squid-cache.org/pipermail/squid-users/attachments/20141025/6d5f37db/attachment-0001.sig>