php and apache...single sign on

I would like to piggyback on an Apache realm/dialog authentication and feed these credentials to a mysql connection (or connection to anything else) in my php scripts. Is there a way using the php Apache apis (seems like no) or via apache itself to make these credentials available/visible to a php script? I'm not sure if this presents a security risk as I trust the pages in my web server to not be malevolent. mike