Ubuntu Manpage: negotiate_kerberos_auth - Squid kerberos based authentication helper

Provided by: squid3_3.3.8-1ubuntu6.11_amd64

NAME

       negotiate_kerberos_auth - Squid kerberos based authentication helper

       Version 3.0.4sq

SYNOPSIS

       negotiate_kerberos_auth [-h] [-d] [-i] [-r] [-s Service-Principal-Name]

DESCRIPTION

       negotiate_kerberos_auth  is an installed binary and allows Squid to authenticate users via
       the Negotiate protocol and Kerberos.

OPTIONS

       -h          Display the binary help and command line syntax info using stderr.

       -d          Write debug messages to stderr.

       -i          Write informational messages to stderr.

       -r          Remove realm from username before returning the username to squid.

       -s Service-Principal-name
                   Provide Service Principal Name.

CONFIGURATION

This helper is intended to be used as an authentication helper in squid.conf.

auth_param negotiate program /path/to/negotiate_kerberos_auth
auth_param negotiate children 10
auth_param negotiate keep_alive on

NOTE: The following squid startup file modification may be required:

Add the following lines to the squid startup script to point squid to a keytab file which
contains the HTTP/fqdn service principal for the default Kerberos domain. The fqdn must be
the proxy name set in IE or firefox. You can not use an IP address.

KRB5_KTNAME=/etc/squid/HTTP.keytab export KRB5_KTNAME

If you use a different Kerberos domain than the machine itself is in you can point squid
to the seperate Kerberos config file by setting the following environmnet variable in the
startup script.

KRB5_CONFIG=/etc/krb5-squid.conf export KRB5_CONFIG

Kerberos can keep a replay cache to detect the reuse of Kerberos tickets (usually only
possible in a 5 minute window) . If squid is under high load with Negotiate(Kerberos)
proxy authentication requests the replay cache checks can create high CPU load. If the
environment does not require high security the replay cache check can be disabled for MIT
based Kerberos implementations by adding the following to the startup script

KRB5RCACHETYPE=none export KRB5RCACHETYPE

If negotiate_kerberos_auth doesn't determine for some reason the right service principal
you can provide it with -s HTTP/fqdn.

If you serve multiple Kerberos realms add a HTTP/fqdn@REALM service principal per realm to
the HTTP.keytab file and use the -s GSS_C_NO_NAME option with negotiate_kerberos_auth.

AUTHOR

       This program was written by Markus Moeller <markus_moeller@compuserve.com>

       This manual was written by Markus Moeller <markus_moeller@compuserve.com>

COPYRIGHT

       This program and documentation is copyright to the authors named above.

       Distributed under the GNU General Public License (GNU GPL) version 2 or later (GPLv2+).

QUESTIONS

       Questions on the usage of this program can be sent to the Squid Users mailing list <squid-
       users@squid-cache.org>

REPORTING BUGS

       Bug    reports    need    to    be    made    in    English.     See    http://wiki.squid-
       cache.org/SquidFaq/BugReporting for details of what you need  to  include  with  your  bug
       report.

       Report bugs or bug fixes using http://bugs.squid-cache.org/

       Report serious security bugs to Squid Bugs <squid-bugs@squid-cache.org>

       Report  ideas  for new improvements to the Squid Developers mailing list <squid-dev@squid-
       cache.org>