CryptLib/Random/Mixer/Hash.php

   1 <?php
   2 /**
   3  * The Hash 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\Core\Strength;
  23
  24 /**
  25  * The Hash medium strength mixer class
  26  *
  27  * This class implements a mixer based upon the recommendations in RFC 4086
  28  * section 5.2
  29  *
  30  * @see        http://tools.ietf.org/html/rfc4086#section-5.2
  31  * @category   PHPCryptLib
  32  * @package    Random
  33  * @subpackage Mixer
  34  * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
  35  */
  36 class Hash extends \CryptLib\Random\AbstractMixer {
  37
  38     /**
  39      * @var string The hash instance to use
  40      */
  41     protected $hash = null;
  42
  43     /**
  44      * Build the hash mixer
  45      *
  46      * @param string $hash The hash instance to use (defaults to sha512)
  47      *
  48      * @return void
  49      */
  50     public function __construct($hash = 'sha512') {
  51         $this->hash = $hash;
  52     }
  53
  54     /**
  55      * Return an instance of Strength indicating the strength of the source
  56      *
  57      * @return Strength An instance of one of the strength classes
  58      */
  59     public static function getStrength() {
  60         return new Strength(Strength::LOW);
  61     }
  62
  63     /**
  64      * Test to see if the mixer is available
  65      *
  66      * @return boolean If the mixer is available on the system
  67      */
  68     public static function test() {
  69         return true;
  70     }
  71
  72     /**
  73      * Get the block size (the size of the individual blocks used for the mixing)
  74      *
  75      * @return int The block size
  76      */
  77     protected function getPartSize() {
  78         return strlen(hash($this->hash, '', true));
  79     }
  80
  81     /**
  82      * Mix 2 parts together using one method
  83      *
  84      * @param string $part1 The first part to mix
  85      * @param string $part2 The second part to mix
  86      *
  87      * @return string The mixed data
  88      */
  89     protected function mixParts1($part1, $part2) {
  90         return hash_hmac($this->hash, $part1, $part2, true);
  91     }
  92
  93     /**
  94      * Mix 2 parts together using another different method
  95      *
  96      * @param string $part1 The first part to mix
  97      * @param string $part2 The second part to mix
  98      *
  99      * @return string The mixed data
 100      */
 101     protected function mixParts2($part1, $part2) {
 102         return hash_hmac($this->hash, $part2, $part1, true);
 103     }
 104
 105 }