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   1  <?php
   2  /**
   3   * Zend Framework
   4   *
   5   * LICENSE
   6   *
   7   * This source file is subject to the new BSD license that is bundled
   8   * with this package in the file LICENSE.txt.
   9   * It is also available through the world-wide-web at this URL:
  10   * http://framework.zend.com/license/new-bsd
  11   * If you did not receive a copy of the license and are unable to
  12   * obtain it through the world-wide-web, please send an email
  13   * to [email protected] so we can send you a copy immediately.
  14   *
  15   * @category   Zend
  16   * @package    Zend_Crypt
  17   * @subpackage Hmac
  18   * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
  19   * @license    http://framework.zend.com/license/new-bsd     New BSD License
  20   * @version    $Id: Hmac.php 24593 2012-01-05 20:35:02Z matthew $
  21   */
  22  
  23  /**
  24   * @see Zend_Crypt
  25   */
  26  require_once  'Zend/Crypt.php';
  27  
  28  /**
  29   * PHP implementation of the RFC 2104 Hash based Message Authentication Code
  30   * algorithm.
  31   *
  32   * @todo  Patch for refactoring failed tests (key block sizes >80 using internal algo)
  33   * @todo       Check if mhash() is a required alternative (will be PECL-only soon)
  34   * @category   Zend
  35   * @package    Zend_Crypt
  36   * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
  37   * @license    http://framework.zend.com/license/new-bsd     New BSD License
  38   */
  39  class Zend_Crypt_Hmac extends Zend_Crypt
  40  {
  41  
  42      /**
  43       * The key to use for the hash
  44       *
  45       * @var string
  46       */
  47      protected static $_key = null;
  48  
  49      /**
  50       * pack() format to be used for current hashing method
  51       *
  52       * @var string
  53       */
  54      protected static $_packFormat = null;
  55  
  56      /**
  57       * Hashing algorithm; can be the md5/sha1 functions or any algorithm name
  58       * listed in the output of PHP 5.1.2+ hash_algos().
  59       *
  60       * @var string
  61       */
  62      protected static $_hashAlgorithm = 'md5';
  63  
  64      /**
  65       * List of algorithms supported my mhash()
  66       *
  67       * @var array
  68       */
  69      protected static $_supportedMhashAlgorithms = array('adler32',' crc32', 'crc32b', 'gost',
  70              'haval128', 'haval160', 'haval192', 'haval256', 'md4', 'md5', 'ripemd160',
  71              'sha1', 'sha256', 'tiger', 'tiger128', 'tiger160');
  72  
  73      /**
  74       * Constants representing the output mode of the hash algorithm
  75       */
  76      const STRING = 'string';
  77      const BINARY = 'binary';
  78  
  79      /**
  80       * Performs a HMAC computation given relevant details such as Key, Hashing
  81       * algorithm, the data to compute MAC of, and an output format of String,
  82       * Binary notation or BTWOC.
  83       *
  84       * @param string $key
  85       * @param string $hash
  86       * @param string $data
  87       * @param string $output
  88       * @param boolean $internal
  89       * @return string
  90       */
  91      public static function compute($key, $hash, $data, $output = self::STRING)
  92      {
  93          // set the key
  94          if (!isset($key) || empty($key)) {
  95              require_once  'Zend/Crypt/Hmac/Exception.php';
  96              throw new Zend_Crypt_Hmac_Exception('provided key is null or empty');
  97          }
  98          self::$_key = $key;
  99  
 100          // set the hash
 101          self::_setHashAlgorithm($hash);
 102  
 103          // perform hashing and return
 104          return self::_hash($data, $output);
 105      }
 106  
 107      /**
 108       * Setter for the hash method.
 109       *
 110       * @param string $hash
 111       * @return Zend_Crypt_Hmac
 112       */
 113      protected static function _setHashAlgorithm($hash)
 114      {
 115          if (!isset($hash) || empty($hash)) {
 116              require_once  'Zend/Crypt/Hmac/Exception.php';
 117              throw new Zend_Crypt_Hmac_Exception('provided hash string is null or empty');
 118          }
 119  
 120          $hash = strtolower($hash);
 121          $hashSupported = false;
 122  
 123          if (function_exists('hash_algos') && in_array($hash, hash_algos())) {
 124              $hashSupported = true;
 125          }
 126  
 127          if ($hashSupported === false && function_exists('mhash') && in_array($hash, self::$_supportedAlgosMhash)) {
 128              $hashSupported = true;
 129          }
 130  
 131          if ($hashSupported === false) {
 132              require_once  'Zend/Crypt/Hmac/Exception.php';
 133              throw new Zend_Crypt_Hmac_Exception('hash algorithm provided is not supported on this PHP installation; please enable the hash or mhash extensions');
 134          }
 135          self::$_hashAlgorithm = $hash;
 136      }
 137  
 138      /**
 139       * Perform HMAC and return the keyed data
 140       *
 141       * @param string $data
 142       * @param string $output
 143       * @param bool $internal Option to not use hash() functions for testing
 144       * @return string
 145       */
 146      protected static function _hash($data, $output = self::STRING, $internal = false)
 147      {
 148          if (function_exists('hash_hmac')) {
 149              if ($output == self::BINARY) {
 150                  return hash_hmac(self::$_hashAlgorithm, $data, self::$_key, 1);
 151              }
 152              return hash_hmac(self::$_hashAlgorithm, $data, self::$_key);
 153          }
 154  
 155          if (function_exists('mhash')) {
 156              if ($output == self::BINARY) {
 157                  return mhash(self::_getMhashDefinition(self::$_hashAlgorithm), $data, self::$_key);
 158              }
 159              $bin = mhash(self::_getMhashDefinition(self::$_hashAlgorithm), $data, self::$_key);
 160              return bin2hex($bin);
 161          }
 162      }
 163  
 164      /**
 165       * Since MHASH accepts an integer constant representing the hash algorithm
 166       * we need to make a small detour to get the correct integer matching our
 167       * algorithm's name.
 168       *
 169       * @param string $hashAlgorithm
 170       * @return integer
 171       */
 172      protected static function _getMhashDefinition($hashAlgorithm)
 173      {
 174          for ($i = 0; $i <= mhash_count(); $i++)
 175          {
 176              $types[mhash_get_hash_name($i)] = $i;
 177          }
 178          return $types[strtoupper($hashAlgorithm)];
 179      }
 180  
 181  }