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<?php
/**
* Zend Framework
*
* LICENSE
*
* This source file is subject to the new BSD license that is bundled
* with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://framework.zend.com/license/new-bsd
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@zend.com so we can send you a copy immediately.
*
* @category Zend
* @package Zend_Crypt
* @subpackage Hmac
* @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @version $Id: Hmac.php 16971 2009-07-22 18:05:45Z mikaelkael $
*/
/**
* @see Zend_Crypt
*/
require_once 'Zend/Crypt.php';
/**
* PHP implementation of the RFC 2104 Hash based Message Authentication Code
* algorithm.
*
* @todo Patch for refactoring failed tests (key block sizes >80 using internal algo)
* @todo Check if mhash() is a required alternative (will be PECL-only soon)
* @category Zend
* @package Zend_Crypt
* @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
class Zend_Crypt_Hmac extends Zend_Crypt
{
/**
* The key to use for the hash
*
* @var string
*/
protected static $_key = null;
/**
* pack() format to be used for current hashing method
*
* @var string
*/
protected static $_packFormat = null;
/**
* Hashing algorithm; can be the md5/sha1 functions or any algorithm name
* listed in the output of PHP 5.1.2+ hash_algos().
*
* @var string
*/
protected static $_hashAlgorithm = 'md5';
/**
* List of algorithms supported my mhash()
*
* @var array
*/
protected static $_supportedMhashAlgorithms = array('adler32',' crc32', 'crc32b', 'gost',
'haval128', 'haval160', 'haval192', 'haval256', 'md4', 'md5', 'ripemd160',
'sha1', 'sha256', 'tiger', 'tiger128', 'tiger160');
/**
* Constants representing the output mode of the hash algorithm
*/
const STRING = 'string';
const BINARY = 'binary';
/**
* Performs a HMAC computation given relevant details such as Key, Hashing
* algorithm, the data to compute MAC of, and an output format of String,
* Binary notation or BTWOC.
*
* @param string $key
* @param string $hash
* @param string $data
* @param string $output
* @param boolean $internal
* @return string
*/
public static function compute($key, $hash, $data, $output = self::STRING)
{
// set the key
if (!isset($key) || empty($key)) {
require_once 'Zend/Crypt/Hmac/Exception.php';
throw new Zend_Crypt_Hmac_Exception('provided key is null or empty');
}
self::$_key = $key;
// set the hash
self::_setHashAlgorithm($hash);
// perform hashing and return
return self::_hash($data, $output);
}
/**
* Setter for the hash method.
*
* @param string $hash
* @return Zend_Crypt_Hmac
*/
protected static function _setHashAlgorithm($hash)
{
if (!isset($hash) || empty($hash)) {
require_once 'Zend/Crypt/Hmac/Exception.php';
throw new Zend_Crypt_Hmac_Exception('provided hash string is null or empty');
}
$hash = strtolower($hash);
$hashSupported = false;
if (function_exists('hash_algos') && in_array($hash, hash_algos())) {
$hashSupported = true;
}
if ($hashSupported === false && function_exists('mhash') && in_array($hash, self::$_supportedAlgosMhash)) {
$hashSupported = true;
}
if ($hashSupported === false) {
require_once 'Zend/Crypt/Hmac/Exception.php';
throw new Zend_Crypt_Hmac_Exception('hash algorithm provided is not supported on this PHP installation; please enable the hash or mhash extensions');
}
self::$_hashAlgorithm = $hash;
}
/**
* Perform HMAC and return the keyed data
*
* @param string $data
* @param string $output
* @param bool $internal Option to not use hash() functions for testing
* @return string
*/
protected static function _hash($data, $output = self::STRING, $internal = false)
{
if (function_exists('hash_hmac')) {
if ($output == self::BINARY) {
return hash_hmac(self::$_hashAlgorithm, $data, self::$_key, 1);
}
return hash_hmac(self::$_hashAlgorithm, $data, self::$_key);
}
if (function_exists('mhash')) {
if ($output == self::BINARY) {
return mhash(self::_getMhashDefinition(self::$_hashAlgorithm), $data, self::$_key);
}
$bin = mhash(self::_getMhashDefinition(self::$_hashAlgorithm), $data, self::$_key);
return bin2hex($bin);
}
}
/**
* Since MHASH accepts an integer constant representing the hash algorithm
* we need to make a small detour to get the correct integer matching our
* algorithm's name.
*
* @param string $hashAlgorithm
* @return integer
*/
protected static function _getMhashDefinition($hashAlgorithm)
{
for ($i = 0; $i <= mhash_count(); $i++)
{
$types[mhash_get_hash_name($i)] = $i;
}
return $types[strtoupper($hashAlgorithm)];
}
}
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