I have done the following: 1. created a key on the KDC with the following command: ktpass -princ HTTP/squidtest.hdq.xyz.com@xxxxxxxxxxx -pass password -mapuser squidtest -out c:\temp\squidtest.HTTP.keytab 2. Setup the /etc/krb5.conf for our domain and realm. 3. I then copied the key to the linux box, set the permissions so it is read only by squid, and ran the kutil command: ktutil: rkt /opt/squid/etc/squidtest.HTTP.keytab ktutil: wkt /etc/krb5.keytab ktutil: q 4. I ran the kinit command and it seemed not to error: kinit -k -t /opt/squid/etc/squidtest.HTTP.keytab HTTP/squidtest.hdq.xyz.com 5. Output from the klist is as follows: klist Ticket cache: FILE:/tmp/krb5cc_0 Default principal: HTTP/squidtest.hdq.xyz.com@xxxxxxxxxxx Valid starting Expires Service principal 07/11/08 19:08:55 07/12/08 05:08:55 krbtgt/HDQ.XYZ.COM@xxxxxxxxxxx renew until 07/12/08 05:08:55 Kerberos 4 ticket cache: /tmp/tkt0 klist: You have no tickets cached 6. I created a token with the squid_kerb_auth_test.c program and authenticated with it: [root@squidtest tmp]# /opt/squid/libexec/squid_kerb_auth -d -i -s HTTP/squidtest.hdq.xyz.com </tmp/kir1864.token 2008/07/11 19:13:31| squid_kerb_auth: Got 'YR YIIP1QYJKoZIhvcSAQICAQBugg/EMIIPwKADAgEFoQMCAQ6iBwMFAAAAAACjgg74YYI.............................................................................................................................................pfdL/itMByBZYZshBJQgRViHFQgCsPdrJGRE4ePTRwS25ejLg==' from squid (length: 5415). AF AA== kir1864@xxxxxxxxxxx 2008/07/11 19:13:31| squid_kerb_auth: AF AA== kir1864@xxxxxxxxxxx 2008/07/11 19:13:31| squid_kerb_auth: User kir1864@xxxxxxxxxxx authenticated 7. I recompiled squid_kerb_auth with the -DHAVE_SPNEGO: gcc -o squid_kerb_auth -DHAVE_SPNEGO -D__LITTLE_ENDIAN__ -Ispnegohelp squid_kerb_auth.c base64.c spnegohelp/derparse.c spnegohelp/spnego.c spnegohelp/spnegohelp.c spnegohelp/spnegoparse.c -lgssapi_krb5 -lkrb5 -lcom_err 8. Added this to my squid startup script and restarted squid, note I have the auth_param in my squid.conf also below: /etc/init.d/squid:export KRB5_KTNAME=FILE:/opt/squid/etc/squidtest.HTTP.keytab /etc/squid.conf:auth_param negotiate program /opt/squid/libexec/squid_kerb_auth -d 9 /etc/squid.conf:auth_param negotiate children 1 /etc/squid.conf:auth_param negotiate keep_alive on 9. When I authenticate with IE 6, it goes to the basic authentication, even with the "Enable Integrated Windows Authentication" checked, I think I found that there is no way to do proxy kerberos authentication with IE 6, if someone know differently let me know how. With IE 7 I do get the following in the cache.log: 2008/07/11 17:55:12| squid_kerb_auth: Got 'YR YIIQHwYGKwYBBQUCoIIQEzCCEA+gJDAiBgkqhkiC9xIBAgIGCSqGSIb3EgECAgYKK..............................................................................................................................................bfhfphT7/Qu6CVQNdsKIK5Neq/ULSjfWmDdhxag4ZFDH6/V9/EJnNoNS/BQPwIqEgyzK5+nkg' from squid (length: 5511). 2008/07/11 17:55:12| squid_kerb_auth: gss_accept_sec_context() failed: A token was invalid. Mechanism is incorrect Can anyone help with this problem? Thank you, Brian Kirk