| 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 | } |