title: Apache authentication via DOD PKI CAC
body: <p>How does one implement Apache (within Linux) authentication using Department of
  Defense CAC cards?  I've heard it can be done but have not come across any details.
  Currently we use Windows Active directory for Apache authentication but only using
  Logins/Passwords.  Soon the requirement will to be use CAC cards only.  Any hints
  would be appreciated.</p>