SlackBuildsOrg/network/mod_auth_kerb

Mod_auth_kerb is an Apache module designed to provide Kerberos
authentication to the Apache web server. The module also supports
the Negotiate authentication method, which performs full Kerberos
authentication based on ticket exchanges, and does not require users
to insert their passwords to the browser.

You will need to add the following line to /etc/httpd/httpd.conf:
  Include /etc/httpd/extra/mod_auth_kerb.conf

Mod_auth_kerb can be further configured through the Apache
configuration file; see the README in the package's documentation
directory for details.