This is what the user name hooks are for.

In my environment the entire username + domain is required to 
manipulate authentication tokens.  Therefore, I have added a conf.php 
option to passwd to allow the administrator to choose whether or not 
to strip the domain from the username.  The default is to replicate 
the functionality before the patch.  Trivial diff included.

---------- snip patch below -------------

diff -urN passwd-2.2.1/main.php passwd/main.php

--- passwd-2.2.1/main.php       2004-03-26 17:43:28.000000000 -0500

+++ passwd/main.php     2004-08-24 23:05:19.000000000 -0400

@@ -224,8 +224,12 @@

                                       Auth::getAuth());

          }

      } else {

-        $splitted  = split("@", Auth::getAuth());

-        $userid = @$splitted[0];

+        if($conf['prefs']['strip_domain']) {

+               $splitted  = split("@", Auth::getAuth());

+               $userid = @$splitted[0];

+       } else {

+               $userid = Auth::getAuth();

+       }

      }

  }



diff -urN passwd-2.2.1/config/conf.php.dist passwd/config/conf.php.dist

--- passwd-2.2.1/config/conf.php.dist   2003-01-20 20:28:29.000000000 -0500

+++ passwd/config/conf.php.dist 2004-08-24 23:06:42.000000000 -0400

@@ -25,6 +25,10 @@



  $conf['backend']['backend_list'] = 'hidden';



+// Determine whether or not to strip of the domain portion of the user's

+// authentication token.  By default we do.

+$conf['prefs']['strip_domain'] = 1;

+

  // Define usernames for which we will refuse to change passwords.

  // This may or may not work with realms or virtual hosting, 
depending on setup