anchor.diff:   auth-user-pass
   
   
  -b) Installation of pam_yubico module:
  --------------------------------------
  +==== Installation of pam_yubico module:
   
   Build instructions for pam_yubico are available in its README.
   
  -c) Configuration of pam_yubico module:
  ---------------------------------------
  +==== Configuration of pam_yubico module:
   
   *) Configuration for user and YubiKey PublicID mapping
   
   There are two ways of user and YubiKey PublicID (token ID) mapping.
   It can be either done at administrative level or at individual user level.
   
  -Administrative Level
  ---------------------
  +===== Administrative Level
   
   In Administrative level, system administrators hold right to configure
   the user and YubiKey PublicID mapping. Administrators can achieve this
  
positive.code: We can configure failover support for RADIUS server by creating additional
  RADIUS server entries per line of “/etc/raddb/server” file.
  
  A) Test Setup:
  --------------
  
  Our test environment is as follows:
  
  
negative.code: of Yubico PAM module for OpenVPN authentication.
  
  
  ====== Configuration of modified pam_yubico.so module at administrative level:
  
  Append the following line to the beginning of /etc/pam.d/radiusd file:
  
  