anchor.diff:  -----------------------------------------------------------------------
   
   Append the following line to the beginning of /etc/pam.d/radiusd file:
  -------
  -   auth required pam_yubico.so id=16 debug authfile=/path/to/mapping/file
  -------
  +
  + auth required pam_yubico.so id=16 debug authfile=/path/to/mapping/file
   
   After the above configuration changes, whenever a user connects to the
   server using any RADIUS client, the PAM authentication interface will
  
positive.code: contents to the file:
  
  ------
     account         required        pam_radius_auth.so
     account         required        pam_radius_auth.so
     auth            required        pam_radius_auth.so no_warn try_first_pass
  ------
  
  * Create a file “/etc/raddb/server” to configure FreeRADIUS server that is
  
negative.code: 
  Successful configuration of the Yubico PAM module to support two factor authentication for OpenVPN has the following prerequisites:
  
  Operating System:: 
  Any Unix operating system which supports 
  http://www.kernel.org/pub/linux/libs/pam[PAM] (Pluggable Authentication Module)
  Complier:: http://gcc.gnu.org[GNU GCC complier]
  https://developers.yubico.com/yubico-pam[Yubico PAM Module]:: Version 1.8
  http://openvpn.net/index.php/downloads.html[OpenVPN]:: Version 2.0.9.
  http://freeradius.org/download.html[FreeRADIUS]: Version 1.1.7 or later.
  Pam_Radius:: ftp://ftp.freeradius.org/pub/radius/pam_radius-1.3.17.tar.gz[Version 1.3.17].
  
  Configuration
  -------------
  