Re: [squid-users] Re: squid_kerb_auth: Unspecified GSS failure (W2K8)

From: Mihail Lukin <mihail.lukin_at_gmail.com>
Date: Sun, 3 Nov 2013 09:36:38 +0400

I wonder why `net ads keytab add HTTP` doesn't change the keytab. The
output of this command is:

<pre>Warning: "kerberos method" must be set to a keytab method to use
keytab functions.
Processing principals to add...</pre>

and exit code is 0, so there is no sign of an error.
I sniffed network traffic while running this command and found that
there was an LDAP search query and the result contained this
computer's entry which has servicePrincipalName with 4 values and
HTTP/squidsrv.my.doma.in is there.

Unfortunately, this service principal didn't appear in keytab.

On Sun, Nov 3, 2013 at 4:20 AM, Markus Moeller <huaraz_at_moeller.plus.com> wrote:
> Exactly you need the HTTP service principal in the keytab.
>
> Regards
> Markus
>
>
> "Mihail Lukin" wrote in message
> news:CAAmm_rYG0GiLjvaT50eeFL4JTzU9Ux0k01CvDCXH7D5H2C=0uQ_at_mail.gmail.com...
>
>
> Thanks for the tip!
>
> Here is what it shows:
> Server Name (Service and Instance): HTTP/squidsrv.my.doma.in
>
> So, it is the right protocol and host name. But I do not see exact
> much in keytab. I'm not sure if it is the issue. I created keytab
> exactly as was shown here:
> http://wiki.squid-cache.org/ConfigExamples/Authenticate/Kerberos#Create_keytab
> (samba version, not msktutil).
>
>
> On Sun, Nov 3, 2013 at 1:29 AM, Markus Moeller <huaraz_at_moeller.plus.com>
> wrote:
>>
>> Hi Mihail,
>>
>> If you use wireshark you can expand the details of:
>>
>> Proxy-Authorization: Negotiate YIIHoAYGKwYBB...
>>
>> It will tell you which service principal the client is sending to the
>> server ? I wonder if the name matches the names in your keytab.
>>
>>
>> Markus
>>
>> -----Original Message----- From: Mihail Lukin
>> Sent: Saturday, November 02, 2013 9:15 PM
>> To: Markus Moeller
>> Cc: squid-users
>> Subject: Re: [squid-users] Re: squid_kerb_auth: Unspecified GSS failure
>> (W2K8)
>>
>>
>> Hi, Markus!
>>
>> 1) Here is the output:
>> Keytab name: FILE:/etc/squid/HTTP.keytab
>> KVNO Timestamp Principal
>> ---- -----------------
>> --------------------------------------------------------
>> 2 10/30/13 14:14:09 host/squidsrv.my.doma.in_at_MY.DOMA.IN (des-cbc-crc)
>> 2 10/30/13 14:14:09 host/squidsrv.my.doma.in_at_MY.DOMA.IN (des-cbc-md5)
>> 2 10/30/13 14:14:09 host/squidsrv.my.doma.in_at_MY.DOMA.IN (arcfour-hmac)
>> 2 10/30/13 14:14:09 host/squidsrv.my.doma.in_at_MY.DOMA.IN
>> (aes128-cts-hmac-sha1-96)
>> 2 10/30/13 14:14:09 host/squidsrv.my.doma.in_at_MY.DOMA.IN
>> (aes256-cts-hmac-sha1-96)
>> 2 10/30/13 14:14:09 host/squidsrv_at_MY.DOMA.IN (des-cbc-crc)
>> 2 10/30/13 14:14:09 host/squidsrv_at_MY.DOMA.IN (des-cbc-md5)
>> 2 10/30/13 14:14:09 host/squidsrv_at_MY.DOMA.IN (arcfour-hmac)
>> 2 10/30/13 14:14:09 host/squidsrv_at_MY.DOMA.IN (aes128-cts-hmac-sha1-96)
>> 2 10/30/13 14:14:09 host/squidsrv_at_MY.DOMA.IN (aes256-cts-hmac-sha1-96)
>> 2 10/30/13 14:14:09 SQUIDSRV$@MY.DOMA.IN (des-cbc-crc)
>> 2 10/30/13 14:14:10 SQUIDSRV$@MY.DOMA.IN (des-cbc-md5)
>> 2 10/30/13 14:14:10 SQUIDSRV$@MY.DOMA.IN (arcfour-hmac)
>> 2 10/30/13 14:14:10 SQUIDSRV$@MY.DOMA.IN (aes128-cts-hmac-sha1-96)
>> 2 10/30/13 14:14:10 SQUIDSRV$@MY.DOMA.IN (aes256-cts-hmac-sha1-96)
>>
>> 2) I see request header "Proxy-Authorization: Negotiate YIIHoAYGKwYBB..."
>> 3) It worth to mention that using ntlm_auth instead of squid_kerb_auth
>> works fine on this server.
>>
>>
>> On Fri, Nov 1, 2013 at 1:45 AM, Markus Moeller <huaraz_at_moeller.plus.com>
>> wrote:
>>>
>>>
>>> Hi Mihail,
>>>
>>> What does a klist -ekt <keytab> show ? ( I assume you use MIT Kerberos
>>> on
>>> the squid server)
>>>
>>> What do you see with wireshark in the authentication header send to
>>> squid
>>> ?
>>>
>>> Markus
>>>
>>> "Mihail Lukin" wrote in message
>>>
>>> news:CAAmm_rZHZ8m1VbYF5mVW-ZbQYvOQhW0Nmf4saOp8GsY5x9KVJQ_at_mail.gmail.com...
>>>
>>>
>>> I don't know why access-time is not being updated, but strace has
>>> shown that keytab is being read successfully by squid_kerb_auth
>>> process.
>>>
>>> On Thu, Oct 31, 2013 at 8:15 AM, Mihail Lukin <mihail.lukin_at_gmail.com>
>>> wrote:
>>>>
>>>>
>>>>
>>>> Hello, Markus!
>>>>
>>>> Sorry for not mentioning it at once, KRB5_KTNAME is being exported in
>>>> /etc/sysconfig/squid and is readable by squid group. But there is
>>>> still something wrong with it: keytab's access time is not changed
>>>> neither when I restart squid not when I request an URL through the
>>>> proxy.
>>>>
>>>> I think I should strace squid_kerb_auth to see what happens. Thanks
>>>> for the hint!
>>>>
>>>> On Thu, Oct 31, 2013 at 12:53 AM, Markus Moeller
>>>> <huaraz_at_moeller.plus.com> wrote:
>>>>>
>>>>>
>>>>>
>>>>> Hi Mihail,
>>>>>
>>>>> Did you use export KRB5_KTNAME to point to the right keytab ? Is the
>>>>> keytab readable by the user under which squid runs ?
>>>>>
>>>>> Markus
>>>>>
>>>>> "Mihail Lukin" wrote in message
>>>>>
>>>>>
>>>>>
>>>>> news:CAAmm_rZ8jNoeFMRGthiYeHQ+GgSfmySFnw8708dwdDVUW3=R_g_at_mail.gmail.com...
>>>>>
>>>>> Hello,
>>>>>
>>>>> I'm trying to configure Squid 3.1 to authenticate through AD with W2K8
>>>>> DC with Kerberos. I used this how-to:
>>>>> http://wiki.squid-cache.org/ConfigExamples/Authenticate/Kerberos on
>>>>> CentOS 6 box that I've joined to domain with `net ads join`.
>>>>>
>>>>> Now I'm getting the error in cache.log when I'm trying to visit any
>>>>> URL through this proxy:
>>>>>
>>>>> 2013/10/30 17:07:41| squid_kerb_auth: DEBUG: Got 'YR base64 encoded
>>>>> data' from squid (length: 2295).
>>>>> 2013/10/30 17:07:41| squid_kerb_auth: DEBUG: Decode 'base64 encoded
>>>>> data' (decoded length: 1717).
>>>>> 2013/10/30 17:07:41| squid_kerb_auth: ERROR: gss_acquire_cred()
>>>>> failed: Unspecified GSS failure. Minor code may provide more
>>>>> information.
>>>>> 2013/10/30 17:07:41| authenticateNegotiateHandleReply: Error
>>>>> validating user via Negotiate. Error returned 'BH gss_acquire_cred()
>>>>> failed: Unspecified GSS failure. Minor code may provide more
>>>>> information. '
>>>>>
>>>>> I could not figure out what the "minor code" is... I googled a lot with
>>>>> no
>>>>> luck.
>>>>> Any help is very appreciated. Thanks in advance!
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> С уважением,
>>>> Михаил Лукин
>>>
>>>
>>>
>>>
>>>
>>>
>>> --
>>> С уважением,
>>> Михаил Лукин
>>>
>>
>>
>
>
Received on Sun Nov 03 2013 - 05:37:05 MST

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