/**
* 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;
}
