<?php
function base64url_encode($data) 
{ 
  return rtrim(strtr(base64_encode($data), '+/', '-_'), '='); 
} 

function base64url_decode($data) 
{ 
	return base64_decode(str_pad(strtr($data, '-_', '+/'), strlen($data) % 4, '=', STR_PAD_RIGHT)); 
} 
?>