To use PAM authentication, you need to activate it in the /etc/savane/savane.conf.pl configuration file:

Pam_auth must be installed. It can be found at http://www.math.ohio-state.edu/~ccunning/pam_auth/

You need php-devel libraries to compile it.

You need to activate the install module, for instance, assuming that /etc/php.d is the directory used for extra modules (otherwise, add it in php.ini):
echo "; Enable pam extension module extension=pam_auth.so " > /etc/php.d/pam.ini

You need to add a PAM PHP configuration, like the following (that applies to AFS accounts):
echo "#%PAM-1.0 # # PHP PAM configuration file for use with the # pam_auth extension # (http://www.math.ohio-state.edu/~ccunning/pam_auth/) # # authenticate against AFS user db and passwords auth sufficient /lib/security/pam_afs.krb.so # the account entry always returns success. account sufficient /lib/security/pam_permit.so " > /etc/pam.d/php