CryptLib/Random/Mixer/DES.php

   1 <?php
   2 /**
   3  * The DES medium strength mixer class
   4  *
   5  * This class implements a mixer based upon the recommendations in RFC 4086
   6  * section 5.2
   7  *
   8  * PHP version 5.3
   9  *
  10  * @see        http://tools.ietf.org/html/rfc4086#section-5.2
  11  * @category   PHPCryptLib
  12  * @package    Random
  13  * @subpackage Mixer
  14  * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
  15  * @copyright  2011 The Authors
  16  * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
  17  * @version    Build @@version@@
  18  */
  19
  20 namespace CryptLib\Random\Mixer;
  21
  22 use \CryptLib\Cipher\Factory       as CipherFactory;
  23 use \CryptLib\Core\Strength;
  24
  25 /**
  26  * The DES medium strength mixer class
  27  *
  28  * This class implements a mixer based upon the recommendations in RFC 4086
  29  * section 5.2
  30  *
  31  * @see        http://tools.ietf.org/html/rfc4086#section-5.2
  32  * @category   PHPCryptLib
  33  * @package    Random
  34  * @subpackage Mixer
  35  * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
  36  */
  37 class DES extends \CryptLib\Random\AbstractMixer {
  38
  39     /**
  40      * An instance of a DES symmetric encryption cipher
  41      *
  42      * @var Cipher The DES cipher instance
  43      */
  44     protected $cipher = 'des';
  45
  46     /**
  47      * Return an instance of Strength indicating the strength of the source
  48      *
  49      * @return Strength An instance of one of the strength classes
  50      */
  51     public static function getStrength() {
  52         return new Strength(Strength::MEDIUM);
  53     }
  54
  55     /**
  56      * Test to see if the mixer is available
  57      *
  58      * @return boolean If the mixer is available on the system
  59      */
  60     public static function test() {
  61         return true;
  62     }
  63
  64     /**
  65      * Build a new instance of the DES mixing function
  66      *
  67      * @param Factory $factory The optional encryption factory to use
  68      *
  69      * @return void
  70      */
  71     public function __construct(\CryptLib\Cipher\Factory $factory = null) {
  72         if (is_null($factory)) {
  73             $factory = new CipherFactory();
  74         }
  75         $this->cipher = $factory->getBlockCipher($this->cipher);
  76     }
  77
  78     /**
  79      * Get the block size (the size of the individual blocks used for the mixing)
  80      *
  81      * @return int The block size
  82      */
  83     protected function getPartSize() {
  84         return $this->cipher->getBlockSize();
  85     }
  86
  87     /**
  88      * Mix 2 parts together using one method
  89      *
  90      * @param string $part1 The first part to mix
  91      * @param string $part2 The second part to mix
  92      *
  93      * @return string The mixed data
  94      */
  95     protected function mixParts1($part1, $part2) {
  96         $this->cipher->setKey($part2);
  97         return $this->cipher->encryptBlock($part1);
  98     }
  99
 100     /**
 101      * Mix 2 parts together using another different method
 102      *
 103      * @param string $part1 The first part to mix
 104      * @param string $part2 The second part to mix
 105      *
 106      * @return string The mixed data
 107      */
 108     protected function mixParts2($part1, $part2) {
 109         $this->cipher->setKey($part1);
 110         return $this->cipher->decryptBlock($part2);
 111     }
 112
 113 }