CryptLib/Key/Derivation/PBKDF/SHA512.php

   1 <?php
   2 /**
   3  * An implementation of the crypt library's SHA512 hash method
   4  *
   5  * PHP version 5.3
   6  *
   7  * @category   PHPCryptLib
   8  * @package    Key
   9  * @subpackage Derivation
  10  * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
  11  * @copyright  2011 The Authors
  12  * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
  13  * @version    Build @@version@@
  14  */
  15
  16 namespace CryptLib\Key\Derivation\PBKDF;
  17
  18 /**
  19  * An implementation of the crypt library's SHA512 hash method
  20  *
  21  * @category   PHPCryptLib
  22  * @package    Key
  23  * @subpackage Derivation
  24  * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
  25  */
  26 class SHA512
  27     extends \CryptLib\Key\Derivation\AbstractDerivation
  28     implements \CryptLib\Key\Derivation\PBKDF
  29 {
  30
  31     /**
  32      * Derive a key from the supplied arguments
  33      *
  34      * @param string $password   The password to derive from
  35      * @param string $salt       The salt string to use
  36      * @param int    $iterations The number of iterations to use
  37      * @param int    $length     The size of the string to generate
  38      *
  39      * @return string The derived key
  40      */
  41     public function derive($password, $salt, $iterations, $length) {
  42         $salt = substr(str_pad($salt, 16, chr(0)), 0, 16);
  43         $salt = '$6$rounds='.$iterations.'$'.$salt;
  44         return crypt($password, $salt);
  45     }
  46
  47     /**
  48      * Get the signature for this implementation
  49      *
  50      * This should include all information needed to build the same isntance
  51      * later.
  52      *
  53      * @return string The signature for this instance
  54      */
  55     public function getSignature() {
  56         return 'sha512';
  57     }
  58
  59 }
  60