<?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
 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Crypt.php 20096 2010-01-06 02:05:09Z bkarwin $
 */

/**
 * @category   Zend
 * @package    Zend_Crypt
 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Crypt
{

    const TYPE_OPENSSL = 'openssl';
    const TYPE_HASH = 'hash';
    const TYPE_MHASH = 'mhash';

    protected static $_type = null;

    /**
     * @var array
     */
    protected static $_supportedAlgosOpenssl = array(
        'md2',
        'md4',
        'mdc2',
        'rmd160',
        'sha',
        'sha1',
        'sha224',
        'sha256',
        'sha384',
        'sha512'
    );

    /**
     * @var array
     */
    protected static $_supportedAlgosMhash = array(
        'adler32',
        'crc32',
        'crc32b',
        'gost',
        'haval128',
        'haval160',
        'haval192',
        'haval256',
        'md4',
        'md5',
        'ripemd160',
        'sha1',
        'sha256',
        'tiger',
        'tiger128',
        'tiger160'
    );

    /**
     * @param string $algorithm
     * @param string $data
     * @param bool $binaryOutput
     * @return unknown
     */
    public static function hash($algorithm, $data, $binaryOutput = false)
    {
        $algorithm = strtolower($algorithm);
        if (function_exists($algorithm)) {
            return $algorithm($data, $binaryOutput);
        }
        self::_detectHashSupport($algorithm);
        $supportedMethod = '_digest' . ucfirst(self::$_type);
        $result = self::$supportedMethod($algorithm, $data, $binaryOutput);
    }

    /**
     * @param string $algorithm
     * @throws Zend_Crypt_Exception
     */
    protected static function _detectHashSupport($algorithm)
    {
        if (function_exists('hash')) {
            self::$_type = self::TYPE_HASH;
            if (in_array($algorithm, hash_algos())) {
               return;
            }
        }
        if (function_exists('mhash')) {
            self::$_type = self::TYPE_MHASH;
            if (in_array($algorithm, self::$_supportedAlgosMhash)) {
               return;
            }
        }
        if (function_exists('openssl_digest')) {
            if ($algorithm == 'ripemd160') {
                $algorithm = 'rmd160';
            }
            self::$_type = self::TYPE_OPENSSL;
            if (in_array($algorithm, self::$_supportedAlgosOpenssl)) {
               return;
            }
        }
        /**
         * @see Zend_Crypt_Exception
         */
        require_once 'Zend/Crypt/Exception.php';
        throw new Zend_Crypt_Exception('\'' . $algorithm . '\' is not supported by any available extension or native function');
    }

    /**
     * @param string $algorithm
     * @param string $data
     * @param bool $binaryOutput
     * @return string
     */
    protected static function _digestHash($algorithm, $data, $binaryOutput)
    {
        return hash($algorithm, $data, $binaryOutput);
    }

    /**
     * @param string $algorithm
     * @param string $data
     * @param bool $binaryOutput
     * @return string
     */
    protected static function _digestMhash($algorithm, $data, $binaryOutput)
    {
        $constant = constant('MHASH_' . strtoupper($algorithm));
        $binary = mhash($constant, $data);
        if ($binaryOutput) {
            return $binary;
        }
        return bin2hex($binary);
    }

    /**
     * @param string $algorithm
     * @param string $data
     * @param bool $binaryOutput
     * @return string
     */
    protected static function _digestOpenssl($algorithm, $data, $binaryOutput)
    {
        if ($algorithm == 'ripemd160') {
            $algorithm = 'rmd160';
        }
        return openssl_digest($data, $algorithm, $binaryOutput);
    }

}