AW: [squid-users] Problem with kerberos against AD

Hi Tom,

I�ve read about the importance of synchronous times, but we�re using ntp and all machines have the same time.

Kind Regards,
Ralf

-----Urspr�ngliche Nachricht-----
Von: Tom Tux [mailto:tomtux80_at_gmail.com]
Gesendet: Mittwoch, 3. Februar 2010 13:34
An: Lutz, Ralf
Betreff: Re: [squid-users] Problem with kerberos against AD

Hi

Is it possible that you had a time difference between your centos-box
and the domain-controller? I know, that a domain-joined-client don't
feel happy (and could not be authenticated on the domain), if the
time-drift between the kerberos-client and the domain-controller is
bigger than 5 minutes.

Regards,
Tom

2010/2/3 <Ralf.Lutz_at_heidelberg.de>:
> Hi,
>
> we want to use squid with kerberos authentication and ldap authorization in the future. We use ntlm with windbind for a few years and it worked great, but now it�s time for kerberos.
>
> We have squid-3.0.STABLE9-1.el5 running CentOS 5.4. The rpm is from this website: http://www.osnets.de/wordpress/squid/squid-proxy-authentifizierung/
>
> We created a keytab using ktpass on the DC with the following command:
>
> ktpass -princ http/proxy-kerberos.heidelberg.bw-online.de_at_HEIDELBERG.BW-ONLINE.DE -mapuser DNT1\proxy-kerberos_kerb -crypto All -pass PASSWORD -ptype KRB5_NT_SRV_HST -out c:\http.keytab
>
> The keytab-file is generated without any errors and we copied it to the centos running squid.
>
> The krb5.file looks like described in many postings I�ve read:
>
> [logging]
> �Default = FILE:/var/log/krb5libs.log
> �kdc = FILE:/var/log/krb5kdc.log
> �admin_server = FILE:/var/log/kadmind.log
>
> [libdefaults]
> �deafult_realm = HEIDELBERG.BW-ONLINE.DE
> �dns_lookup_realm = true
> �dns_lookup_kdc = 24h
> �ticket_lifetime = 24h
> �forwardable = yes
>
> [realms]
> �HEIDELBERG.BW-ONLINE.DE = {
> �kdc = dc3.heidelberg.bw-online.de:88
> �admin_server = dc3.heidelberg.bw-online.de:749
> �default_domain = heidelberg.bw-online.de
> �}
>
> [domain_realm]
> �.heidelberg.bw-online.de = HEIDELBERG.BW-ONLINE.DE
> �heidelberg.bw-online.de = HEIDELBERG.BW-ONLINE.DE
>
>
> I can kinit USER, he asks fort he password and I get a ticket.
>
> I can also do a kinit -V -k -t /etc/http.keytab HTTP/proxy-kerberos.heidelberg.bw-online.de and I get the message "Authenticated to Kerberos v5".
>
> The problem ist, that sometimes I get authenticated in the proxy, the client (WinXP, IE 7) doens�t ask f�r credentials, but when I then reboot the machine with squid, the client asks for credentials and will not get authenticated. I can then see the following entry in /var/log/squid/cache.log:
>
> squid_kerb_auth: gss_acquire_cred() failed: Unspecified GSS faliure. Minor code may provide more information. No such file or directory
>
>
> I also get the following message in cache.log, even when the auth works:, so I think, this is not the great problem:
>
> squid_kerb_auth: parseNegTokenInit failed with rc=102
>
>
> After undefined time, the authentication works again. I thought, it works again when I delete the client from the AD and joined again, but it was not reproduceable.
>
> Has anyone an idea ?
>
>
> Best regards
>
> Ralf Lutz
>
>
>
Received on Wed Feb 03 2010 - 12:39:37 MST