mod_auth_kerb is an Apache module for authenticating Web clients
in a Kerberos v5 realm.  Because the Kerberos password is transmitted
in plain text, this module MUST be used in conjunction with an
encryption-capable Web server (by default, apache13-modssl).  There is
no documentation provided; see the Web site for more details.  This
package is built with the KRB5_VERIFY_TICKET and KRB5_SAVE_CREDENTIALS
options, and *without* Kerberos v4 support.  In order to successfully
authenticate users, the Web server will need a keytab file containing
a key for the principal `www/my.host.name.example@MY.REALM.EXAMPLE'
which is readable only by the user Apache runs as; the location of this
keytab defaults to ${LOCALBASE}/etc/apache/keytab but can be modified
in the server configuration.

WWW: http://modauthkerb.sourceforge.net/