portal/patient/fwk/libs/verysimple/Encryption/McryptUtil.php

   1 <?php
   2 /** @package    verysimple::Encryption */
   3
   4 /**
   5  * require supporting files
   6  */
   7
   8 /**
   9  * A static utility class for encryption/decrytion using the php mcrypt functionality
  10  *
  11  * @package verysimple::Encryption::McryptUtil
  12  */
  13 class McryptUtil
  14 {
  15     static $IV;
  16     static $CIPHER = MCRYPT_RIJNDAEL_256;
  17     static $MODE = MCRYPT_MODE_ECB;
  18
  19     /**
  20      * Creates the initialization vector.
  21      * This method is called automatically
  22      * when encrypt/decrypt are called and does not need to be explicitly called
  23      */
  24     static function Init()
  25     {
  26         if (! McryptUtil::$IV) {
  27             if (! function_exists("mcrypt_get_iv_size")) {
  28                 throw new Exception("The mcrypt extension does not appear to be enabled.");
  29             }
  30
  31             $iv_size = mcrypt_get_iv_size(McryptUtil::$CIPHER, McryptUtil::$MODE);
  32             McryptUtil::$IV = mcrypt_create_iv($iv_size, MCRYPT_RAND);
  33         }
  34     }
  35
  36     /**
  37      * Encrypts data
  38      *
  39      * @param
  40      *          string data to be encrypted
  41      * @param
  42      *          string encryption key/passphrase
  43      * @param
  44      *          bool [optional] true to base64 encode the result
  45      * @return string encrypted data
  46      */
  47     static function Encrypt($data, $key, $encode = true)
  48     {
  49         McryptUtil::Init();
  50
  51         $encrypted = mcrypt_encrypt(McryptUtil::$CIPHER, $key, $data, McryptUtil::$MODE, McryptUtil::$IV);
  52
  53         return ($encode) ? base64_encode($encrypted) : $encrypted;
  54     }
  55
  56     /**
  57      * Decrypts data that was previously encrypted
  58      *
  59      * @param
  60      *          string data to be decrypted
  61      * @param
  62      *          string encryption key/passphrase
  63      * @param
  64      *          bool [optional] true if the encrypted string is base64 encoded
  65      * @param
  66      *          bool [optional] true to strip the null character padding at the end
  67      * @return string decrypted data
  68      */
  69     static function Decrypt($data, $key, $decode = true, $strip_nulls = true)
  70     {
  71         McryptUtil::Init();
  72
  73         if ($decode) {
  74             $data = base64_decode($data);
  75         }
  76
  77         $decrypted = mcrypt_decrypt(McryptUtil::$CIPHER, $key, $data, McryptUtil::$MODE, McryptUtil::$IV);
  78
  79         // mcrypt pads the end of the block with null chars, so we need to strip them
  80         return $strip_nulls ? rtrim($decrypted, "\0") : $decrypted;
  81     }
  82 }