anchor.diff: -=== Introduction ===
  +== Introduction ==
   
   The purpose of this document is to guide readers through the configuration
   steps to use two factor authentication for SSH using Yubikey. This document
  
positive.code: to the user.
  
  
  === Build yubico-c-client and pam_yubico ===
  
  Build instructions for yubico-c-client and pam_yubico are found in their
  respective README.
  
  
  === Configuration ===
  
  ==== Configuration for user and YubiKey token ID mapping ====
  
  There are two ways of user and YubiKey token ID mapping. It can be either
  done at administrative level or at individual user level.
  
  ===== Administrative Level =====
  
  In Administrative level, system administrators hold right to configure the
  user and yubikey token ID mapping. Administrators can achieve this by creating
  
negative.code: module for SSH authentication.
  
  
  ===== Configuration of modified pam_yubico.so module at user level =====
  
  Append the following line to the beginning of the `/etc/pam.d/sshd` file:
  
  