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1428 lines
43 KiB
PHP
1428 lines
43 KiB
PHP
<?php
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/**
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*
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* @package sftp
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* @version $Id$
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* @copyright (c) 2006 phpBB Group
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* @license http://opensource.org/licenses/gpl-license.php GNU Public License
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*
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*/
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/**
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* @ignore
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*/
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if (!defined('IN_PHPBB'))
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{
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exit;
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}
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/**
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* Code from http://phpseclib.sourceforge.net/
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*
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* Modified by phpBB Group to meet our coding standards
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* and being able to integrate into phpBB
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*
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* Pure-PHP implementation of DES.
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*
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* Copyright 2007-2009 TerraFrost <terrafrost@php.net>
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* Copyright 2009+ phpBB
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*
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* @package sftp
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* @author TerraFrost <terrafrost@php.net>
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*/
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/**#@+
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* @access private
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* @see des::_prepare_key()
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* @see des::_process_block()
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*/
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/**
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* Contains array_reverse($keys[CRYPT_DES_DECRYPT])
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*/
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define('CRYPT_DES_ENCRYPT', 0);
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/**
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* Contains array_reverse($keys[CRYPT_DES_ENCRYPT])
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*/
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define('CRYPT_DES_DECRYPT', 1);
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/**#@-*/
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/**#@+
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* @access public
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* @see des::encrypt()
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* @see des::decrypt()
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*/
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/**
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* Encrypt / decrypt using the Electronic Code Book mode.
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*
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* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29
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*/
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define('CRYPT_DES_MODE_ECB', 1);
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/**
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* Encrypt / decrypt using the Code Book Chaining mode.
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*
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* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29
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*/
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define('CRYPT_DES_MODE_CBC', 2);
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/**#@-*/
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/**
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* Encrypt / decrypt using inner chaining
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*
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* Inner chaining is used by SSH-1 and is generally considered to be less secure then outer chaining (CRYPT_DES_MODE_CBC3).
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*/
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define('CRYPT_DES_MODE_3CBC', 3);
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/**
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* Encrypt / decrypt using outer chaining
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*
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* Outer chaining is used by SSH-2 and when the mode is set to CRYPT_DES_MODE_CBC.
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*/
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define('CRYPT_DES_MODE_CBC3', CRYPT_DES_MODE_CBC);
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/**#@+
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* @access private
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* @see des::__construct()
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*/
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/**
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* Toggles the internal implementation
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*/
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define('CRYPT_DES_MODE_INTERNAL', 1);
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/**
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* Toggles the mcrypt implementation
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*/
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define('CRYPT_DES_MODE_MCRYPT', 2);
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/**#@-*/
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/**
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* Pure-PHP implementation of DES.
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*
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* @author Jim Wigginton <terrafrost@php.net>
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* @version 0.1.0
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* @access public
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* @package des
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*/
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class des
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{
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/**
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* The Key Schedule
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*
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* @see des::setKey()
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* @var Array
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* @access private
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*/
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var $keys = "\0\0\0\0\0\0\0\0";
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/**
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* The Encryption Mode
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*
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* @see des::des()
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* @var Integer
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* @access private
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*/
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var $mode;
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/**
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* Continuous Buffer status
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*
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* @see des::enableContinuousBuffer()
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* @var Boolean
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* @access private
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*/
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var $continuousBuffer = false;
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/**
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* Padding status
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*
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* @see des::enablePadding()
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* @var Boolean
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* @access private
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*/
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var $padding = true;
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/**
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* The Initialization Vector
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*
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* @see des::setIV()
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* @var String
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* @access private
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*/
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var $iv = "\0\0\0\0\0\0\0\0";
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/**
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* A "sliding" Initialization Vector
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*
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* @see des::enableContinuousBuffer()
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* @var String
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* @access private
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*/
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var $encryptIV = "\0\0\0\0\0\0\0\0";
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/**
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* A "sliding" Initialization Vector
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*
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* @see des::enableContinuousBuffer()
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* @var String
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* @access private
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*/
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var $decryptIV = "\0\0\0\0\0\0\0\0";
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/**
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* MCrypt parameters
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*
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* @see des::setMCrypt()
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* @var Array
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* @access private
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*/
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var $mcrypt = array('', '');
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/**
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* Default Constructor.
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*
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* Determines whether or not the mcrypt extension should be used. $mode should only, at present, be
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* CRYPT_DES_MODE_ECB or CRYPT_DES_MODE_CBC. If not explictly set, CRYPT_DES_MODE_CBC will be used.
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*
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* @param optional Integer $mode
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* @return des
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* @access public
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*/
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function __construct($mode = CRYPT_MODE_DES_CBC)
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{
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if ( !defined('CRYPT_DES_MODE') )
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{
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switch (true)
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{
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case extension_loaded('mcrypt'):
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// i'd check to see if des was supported, by doing in_array('des', mcrypt_list_algorithms('')),
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// but since that can be changed after the object has been created, there doesn't seem to be
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// a lot of point...
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define('CRYPT_DES_MODE', CRYPT_DES_MODE_MCRYPT);
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break;
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default:
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define('CRYPT_DES_MODE', CRYPT_DES_MODE_INTERNAL);
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}
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}
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switch ( CRYPT_DES_MODE )
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{
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case CRYPT_DES_MODE_MCRYPT:
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switch ($mode)
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{
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case CRYPT_DES_MODE_ECB:
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$this->mode = MCRYPT_MODE_ECB;
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break;
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case CRYPT_DES_MODE_CBC:
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default:
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$this->mode = MCRYPT_MODE_CBC;
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}
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break;
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default:
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switch ($mode)
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{
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case CRYPT_DES_MODE_ECB:
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case CRYPT_DES_MODE_CBC:
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$this->mode = $mode;
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break;
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default:
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$this->mode = CRYPT_DES_MODE_CBC;
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}
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}
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}
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/**
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* Sets the key.
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*
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* Keys can be of any length. DES, itself, uses 64-bit keys (eg. strlen($key) == 8), however, we
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* only use the first eight, if $key has more then eight characters in it, and pad $key with the
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* null byte if it is less then eight characters long.
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*
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* DES also requires that every eighth bit be a parity bit, however, we'll ignore that.
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*
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* If the key is not explicitly set, it'll be assumed to be all zero's.
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*
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* @access public
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* @param String $key
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*/
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function set_key($key)
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{
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$this->keys = ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) ? substr($key, 0, 8) : $this->_prepare_key($key);
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}
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/**
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* Sets the initialization vector. (optional)
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*
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* SetIV is not required when CRYPT_DES_MODE_ECB is being used. If not explictly set, it'll be assumed
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* to be all zero's.
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*
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* @access public
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* @param String $iv
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*/
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function set_iv($iv)
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{
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$this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($iv, 0, 8), 8, chr(0));;
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}
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/**
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* Sets MCrypt parameters. (optional)
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*
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* If MCrypt is being used, empty strings will be used, unless otherwise specified.
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*
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* @link http://php.net/function.mcrypt-module-open#function.mcrypt-module-open
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* @access public
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* @param optional Integer $algorithm_directory
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* @param optional Integer $mode_directory
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*/
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function set_mcrypt($algorithm_directory = '', $mode_directory = '')
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{
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$this->mcrypt = array($algorithm_directory, $mode_directory);
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}
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/**
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* Encrypts a message.
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*
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* $plaintext will be padded with up to 8 additional bytes. Other DES implementations may or may not pad in the
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* same manner. Other common approaches to padding and the reasons why it's necessary are discussed in the following
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* URL:
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*
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* {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html}
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*
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* An alternative to padding is to, separately, send the length of the file. This is what SSH, in fact, does.
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* strlen($plaintext) will still need to be a multiple of 8, however, arbitrary values can be added to make it that
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* length.
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*
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* @see des::decrypt()
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* @access public
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* @param String $plaintext
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*/
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function encrypt($plaintext)
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{
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$plaintext = $this->_pad($plaintext);
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if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT )
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{
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$td = mcrypt_module_open(MCRYPT_DES, $this->mcrypt[0], $this->mode, $this->mcrypt[1]);
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mcrypt_generic_init($td, $this->keys, $this->encryptIV);
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$ciphertext = mcrypt_generic($td, $plaintext);
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mcrypt_generic_deinit($td);
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mcrypt_module_close($td);
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if ($this->continuousBuffer)
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{
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$this->encryptIV = substr($ciphertext, -8);
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}
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return $ciphertext;
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}
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if (!is_array($this->keys))
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{
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$this->keys = $this->_prepare_key("\0\0\0\0\0\0\0\0");
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}
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$ciphertext = '';
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switch ($this->mode)
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{
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case CRYPT_DES_MODE_ECB:
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for ($i = 0; $i < strlen($plaintext); $i+=8)
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{
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$ciphertext.= $this->_process_block(substr($plaintext, $i, 8), CRYPT_DES_ENCRYPT);
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}
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break;
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case CRYPT_DES_MODE_CBC:
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$xor = $this->encryptIV;
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for ($i = 0; $i < strlen($plaintext); $i+=8)
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{
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$block = substr($plaintext, $i, 8);
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$block = $this->_process_block($block ^ $xor, CRYPT_DES_ENCRYPT);
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$xor = $block;
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$ciphertext.= $block;
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}
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if ($this->continuousBuffer)
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{
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$this->encryptIV = $xor;
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}
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}
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return $ciphertext;
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}
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/**
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* Decrypts a message.
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*
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* If strlen($ciphertext) is not a multiple of 8, null bytes will be added to the end of the string until it is.
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*
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* @see des::encrypt()
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* @access public
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* @param String $ciphertext
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*/
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function decrypt($ciphertext)
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{
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// we pad with chr(0) since that's what mcrypt_generic does. to quote from http://php.net/function.mcrypt-generic :
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// "The data is padded with "\0" to make sure the length of the data is n * blocksize."
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$ciphertext = str_pad($ciphertext, (strlen($ciphertext) + 7) & 0xFFFFFFF8, chr(0));
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if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT )
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{
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$td = mcrypt_module_open(MCRYPT_DES, $this->mcrypt[0], $this->mode, $this->mcrypt[1]);
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mcrypt_generic_init($td, $this->keys, $this->decryptIV);
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$plaintext = mdecrypt_generic($td, $ciphertext);
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mcrypt_generic_deinit($td);
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mcrypt_module_close($td);
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if ($this->continuousBuffer)
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{
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$this->decryptIV = substr($ciphertext, -8);
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}
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return $this->_unpad($plaintext);
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}
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if (!is_array($this->keys))
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{
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$this->keys = $this->_prepare_key("\0\0\0\0\0\0\0\0");
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}
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$plaintext = '';
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switch ($this->mode)
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{
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case CRYPT_DES_MODE_ECB:
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for ($i = 0; $i < strlen($ciphertext); $i+=8)
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{
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$plaintext.= $this->_process_block(substr($ciphertext, $i, 8), CRYPT_DES_DECRYPT);
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}
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break;
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case CRYPT_DES_MODE_CBC:
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$xor = $this->decryptIV;
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for ($i = 0; $i < strlen($ciphertext); $i+=8)
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{
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$block = substr($ciphertext, $i, 8);
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$plaintext.= $this->_process_block($block, CRYPT_DES_DECRYPT) ^ $xor;
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$xor = $block;
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}
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if ($this->continuousBuffer)
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{
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$this->decryptIV = $xor;
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}
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}
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return $this->_unpad($plaintext);
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}
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/**
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* Treat consecutive "packets" as if they are a continuous buffer.
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*
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* Say you have a 16-byte plaintext $plaintext. Using the default behavior, the two following code snippets
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* will yield different outputs:
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*
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* <code>
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* echo $des->encrypt(substr($plaintext, 0, 8));
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* echo $des->encrypt(substr($plaintext, 8, 8));
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* </code>
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* <code>
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* echo $des->encrypt($plaintext);
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* </code>
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*
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* The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates
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* another, as demonstrated with the following:
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*
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* <code>
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* $des->encrypt(substr($plaintext, 0, 8));
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* echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8)));
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* </code>
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* <code>
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* echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8)));
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* </code>
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*
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* With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different
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* outputs. The reason is due to the fact that the initialization vector's change after every encryption /
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* decryption round when the continuous buffer is enabled. When it's disabled, they remain constant.
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*
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* Put another way, when the continuous buffer is enabled, the state of the des() object changes after each
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* encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that
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* continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them),
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* however, they are also less intuitive and more likely to cause you problems.
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*
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* @see des::disableContinuousBuffer()
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* @access public
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*/
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function enable_continuous_buffer()
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{
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$this->continuousBuffer = true;
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}
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/**
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* Treat consecutive packets as if they are a discontinuous buffer.
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*
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* The default behavior.
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*
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* @see des::enableContinuousBuffer()
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* @access public
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*/
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function disable_continuous_buffer()
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{
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$this->continuousBuffer = false;
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$this->encryptIV = $this->iv;
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$this->decryptIV = $this->iv;
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}
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/**
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* Pad "packets".
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*
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* DES works by encrypting eight bytes at a time. If you ever need to encrypt or decrypt something that's not
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* a multiple of eight, it becomes necessary to pad the input so that it's length is a multiple of eight.
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*
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* Padding is enabled by default. Sometimes, however, it is undesirable to pad strings. Such is the case in SSH1,
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* where "packets" are padded with random bytes before being encrypted. Unpad these packets and you risk stripping
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* away characters that shouldn't be stripped away. (SSH knows how many bytes are added because the length is
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* transmitted separately)
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*
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* @see des::disablePadding()
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* @access public
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*/
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function enable_padding()
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{
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$this->padding = true;
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}
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|
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/**
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* Do not pad packets.
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*
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* @see des::enablePadding()
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* @access public
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*/
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function disable_padding()
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{
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$this->padding = false;
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}
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|
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/**
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* Pads a string
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*
|
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* Pads a string using the RSA PKCS padding standards so that its length is a multiple of the blocksize (8).
|
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* 8 - (strlen($text) & 7) bytes are added, each of which is equal to chr(8 - (strlen($text) & 7)
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*
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* If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless
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* and padding will, hence forth, be enabled.
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*
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* @see des::_unpad()
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* @access private
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*/
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function _pad($text)
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{
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$length = strlen($text);
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if (!$this->padding)
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{
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if (($length & 7) == 0)
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{
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return $text;
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}
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else
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{
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$this->padding = true;
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}
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}
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$pad = 8 - ($length & 7);
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return str_pad($text, $length + $pad, chr($pad));
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}
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/**
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* Unpads a string
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*
|
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* If padding is enabled and the reported padding length exceeds the block size, padding will be, hence forth, disabled.
|
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*
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* @see des::_pad()
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* @access private
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*/
|
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function _unpad($text)
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{
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if (!$this->padding)
|
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{
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return $text;
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}
|
|
|
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$length = ord($text[strlen($text) - 1]);
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|
|
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if ($length > 8)
|
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{
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$this->padding = false;
|
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return $text;
|
|
}
|
|
|
|
return substr($text, 0, -$length);
|
|
}
|
|
|
|
/**
|
|
* Encrypts or decrypts a 64-bit block
|
|
*
|
|
* $mode should be either CRYPT_DES_ENCRYPT or CRYPT_DES_DECRYPT. See
|
|
* {@link http://en.wikipedia.org/wiki/Image:Feistel.png Feistel.png} to get a general
|
|
* idea of what this function does.
|
|
*
|
|
* @access private
|
|
* @param String $block
|
|
* @param Integer $mode
|
|
* @return String
|
|
*/
|
|
function _process_block($block, $mode)
|
|
{
|
|
// s-boxes. in the official DES docs, they're described as being matrices that
|
|
// one accesses by using the first and last bits to determine the row and the
|
|
// middle four bits to determine the column. in this implementation, they've
|
|
// been converted to vectors
|
|
static $sbox = array(
|
|
array(
|
|
14, 0, 4, 15, 13, 7, 1, 4, 2, 14, 15, 2, 11, 13, 8, 1,
|
|
3, 10 ,10, 6, 6, 12, 12, 11, 5, 9, 9, 5, 0, 3, 7, 8,
|
|
4, 15, 1, 12, 14, 8, 8, 2, 13, 4, 6, 9, 2, 1, 11, 7,
|
|
15, 5, 12, 11, 9, 3, 7, 14, 3, 10, 10, 0, 5, 6, 0, 13
|
|
),
|
|
array(
|
|
15, 3, 1, 13, 8, 4, 14, 7, 6, 15, 11, 2, 3, 8, 4, 14,
|
|
9, 12, 7, 0, 2, 1, 13, 10, 12, 6, 0, 9, 5, 11, 10, 5,
|
|
0, 13, 14, 8, 7, 10, 11, 1, 10, 3, 4, 15, 13, 4, 1, 2,
|
|
5, 11, 8, 6, 12, 7, 6, 12, 9, 0, 3, 5, 2, 14, 15, 9
|
|
),
|
|
array(
|
|
10, 13, 0, 7, 9, 0, 14, 9, 6, 3, 3, 4, 15, 6, 5, 10,
|
|
1, 2, 13, 8, 12, 5, 7, 14, 11, 12, 4, 11, 2, 15, 8, 1,
|
|
13, 1, 6, 10, 4, 13, 9, 0, 8, 6, 15, 9, 3, 8, 0, 7,
|
|
11, 4, 1, 15, 2, 14, 12, 3, 5, 11, 10, 5, 14, 2, 7, 12
|
|
),
|
|
array(
|
|
7, 13, 13, 8, 14, 11, 3, 5, 0, 6, 6, 15, 9, 0, 10, 3,
|
|
1, 4, 2, 7, 8, 2, 5, 12, 11, 1, 12, 10, 4, 14, 15, 9,
|
|
10, 3, 6, 15, 9, 0, 0, 6, 12, 10, 11, 1, 7, 13, 13, 8,
|
|
15, 9, 1, 4, 3, 5, 14, 11, 5, 12, 2, 7, 8, 2, 4, 14
|
|
),
|
|
array(
|
|
2, 14, 12, 11, 4, 2, 1, 12, 7, 4, 10, 7, 11, 13, 6, 1,
|
|
8, 5, 5, 0, 3, 15, 15, 10, 13, 3, 0, 9, 14, 8, 9, 6,
|
|
4, 11, 2, 8, 1, 12, 11, 7, 10, 1, 13, 14, 7, 2, 8, 13,
|
|
15, 6, 9, 15, 12, 0, 5, 9, 6, 10, 3, 4, 0, 5, 14, 3
|
|
),
|
|
array(
|
|
12, 10, 1, 15, 10, 4, 15, 2, 9, 7, 2, 12, 6, 9, 8, 5,
|
|
0, 6, 13, 1, 3, 13, 4, 14, 14, 0, 7, 11, 5, 3, 11, 8,
|
|
9, 4, 14, 3, 15, 2, 5, 12, 2, 9, 8, 5, 12, 15, 3, 10,
|
|
7, 11, 0, 14, 4, 1, 10, 7, 1, 6, 13, 0, 11, 8, 6, 13
|
|
),
|
|
array(
|
|
4, 13, 11, 0, 2, 11, 14, 7, 15, 4, 0, 9, 8, 1, 13, 10,
|
|
3, 14, 12, 3, 9, 5, 7, 12, 5, 2, 10, 15, 6, 8, 1, 6,
|
|
1, 6, 4, 11, 11, 13, 13, 8, 12, 1, 3, 4, 7, 10, 14, 7,
|
|
10, 9, 15, 5, 6, 0, 8, 15, 0, 14, 5, 2, 9, 3, 2, 12
|
|
),
|
|
array(
|
|
13, 1, 2, 15, 8, 13, 4, 8, 6, 10, 15, 3, 11, 7, 1, 4,
|
|
10, 12, 9, 5, 3, 6, 14, 11, 5, 0, 0, 14, 12, 9, 7, 2,
|
|
7, 2, 11, 1, 4, 14, 1, 7, 9, 4, 12, 10, 14, 8, 2, 13,
|
|
0, 15, 6, 12, 10, 9, 13, 0, 15, 3, 3, 5, 5, 6, 8, 11
|
|
)
|
|
);
|
|
|
|
$temp = unpack('Na/Nb', $block);
|
|
$block = array($temp['a'], $temp['b']);
|
|
|
|
// because php does arithmetic right shifts, if the most significant bits are set, right
|
|
// shifting those into the correct position will add 1's - not 0's. this will intefere
|
|
// with the | operation unless a second & is done. so we isolate these bits and left shift
|
|
// them into place. we then & each block with 0x7FFFFFFF to prevennt 1's from being added
|
|
// for any other shifts.
|
|
$msb = array(
|
|
($block[0] >> 31) & 1,
|
|
($block[1] >> 31) & 1
|
|
);
|
|
$block[0] &= 0x7FFFFFFF;
|
|
$block[1] &= 0x7FFFFFFF;
|
|
|
|
// we isolate the appropriate bit in the appropriate integer and shift as appropriate. in
|
|
// some cases, there are going to be multiple bits in the same integer that need to be shifted
|
|
// in the same way. we combine those into one shift operation.
|
|
$block = array(
|
|
(($block[1] & 0x00000040) << 25) | (($block[1] & 0x00004000) << 16) |
|
|
(($block[1] & 0x00400001) << 7) | (($block[1] & 0x40000100) >> 2) |
|
|
(($block[0] & 0x00000040) << 21) | (($block[0] & 0x00004000) << 12) |
|
|
(($block[0] & 0x00400001) << 3) | (($block[0] & 0x40000100) >> 6) |
|
|
(($block[1] & 0x00000010) << 19) | (($block[1] & 0x00001000) << 10) |
|
|
(($block[1] & 0x00100000) << 1) | (($block[1] & 0x10000000) >> 8) |
|
|
(($block[0] & 0x00000010) << 15) | (($block[0] & 0x00001000) << 6) |
|
|
(($block[0] & 0x00100000) >> 3) | (($block[0] & 0x10000000) >> 12) |
|
|
(($block[1] & 0x00000004) << 13) | (($block[1] & 0x00000400) << 4) |
|
|
(($block[1] & 0x00040000) >> 5) | (($block[1] & 0x04000000) >> 14) |
|
|
(($block[0] & 0x00000004) << 9) | ( $block[0] & 0x00000400 ) |
|
|
(($block[0] & 0x00040000) >> 9) | (($block[0] & 0x04000000) >> 18) |
|
|
(($block[1] & 0x00010000) >> 11) | (($block[1] & 0x01000000) >> 20) |
|
|
(($block[0] & 0x00010000) >> 15) | (($block[0] & 0x01000000) >> 24)
|
|
,
|
|
(($block[1] & 0x00000080) << 24) | (($block[1] & 0x00008000) << 15) |
|
|
(($block[1] & 0x00800002) << 6) | (($block[0] & 0x00000080) << 20) |
|
|
(($block[0] & 0x00008000) << 11) | (($block[0] & 0x00800002) << 2) |
|
|
(($block[1] & 0x00000020) << 18) | (($block[1] & 0x00002000) << 9) |
|
|
( $block[1] & 0x00200000 ) | (($block[1] & 0x20000000) >> 9) |
|
|
(($block[0] & 0x00000020) << 14) | (($block[0] & 0x00002000) << 5) |
|
|
(($block[0] & 0x00200000) >> 4) | (($block[0] & 0x20000000) >> 13) |
|
|
(($block[1] & 0x00000008) << 12) | (($block[1] & 0x00000800) << 3) |
|
|
(($block[1] & 0x00080000) >> 6) | (($block[1] & 0x08000000) >> 15) |
|
|
(($block[0] & 0x00000008) << 8) | (($block[0] & 0x00000800) >> 1) |
|
|
(($block[0] & 0x00080000) >> 10) | (($block[0] & 0x08000000) >> 19) |
|
|
(($block[1] & 0x00000200) >> 3) | (($block[0] & 0x00000200) >> 7) |
|
|
(($block[1] & 0x00020000) >> 12) | (($block[1] & 0x02000000) >> 21) |
|
|
(($block[0] & 0x00020000) >> 16) | (($block[0] & 0x02000000) >> 25) |
|
|
($msb[1] << 28) | ($msb[0] << 24)
|
|
);
|
|
|
|
for ($i = 0; $i < 16; $i++)
|
|
{
|
|
// start of "the Feistel (F) function" - see the following URL:
|
|
// http://en.wikipedia.org/wiki/Image:Data_Encryption_Standard_InfoBox_Diagram.png
|
|
$temp = (($sbox[0][((($block[1] >> 27) & 0x1F) | (($block[1] & 1) << 5)) ^ $this->keys[$mode][$i][0]]) << 28)
|
|
| (($sbox[1][(($block[1] & 0x1F800000) >> 23) ^ $this->keys[$mode][$i][1]]) << 24)
|
|
| (($sbox[2][(($block[1] & 0x01F80000) >> 19) ^ $this->keys[$mode][$i][2]]) << 20)
|
|
| (($sbox[3][(($block[1] & 0x001F8000) >> 15) ^ $this->keys[$mode][$i][3]]) << 16)
|
|
| (($sbox[4][(($block[1] & 0x0001F800) >> 11) ^ $this->keys[$mode][$i][4]]) << 12)
|
|
| (($sbox[5][(($block[1] & 0x00001F80) >> 7) ^ $this->keys[$mode][$i][5]]) << 8)
|
|
| (($sbox[6][(($block[1] & 0x000001F8) >> 3) ^ $this->keys[$mode][$i][6]]) << 4)
|
|
| ( $sbox[7][((($block[1] & 0x1F) << 1) | (($block[1] >> 31) & 1)) ^ $this->keys[$mode][$i][7]]);
|
|
|
|
$msb = ($temp >> 31) & 1;
|
|
$temp &= 0x7FFFFFFF;
|
|
$newBlock = (($temp & 0x00010000) << 15) | (($temp & 0x02020120) << 5)
|
|
| (($temp & 0x00001800) << 17) | (($temp & 0x01000000) >> 10)
|
|
| (($temp & 0x00000008) << 24) | (($temp & 0x00100000) << 6)
|
|
| (($temp & 0x00000010) << 21) | (($temp & 0x00008000) << 9)
|
|
| (($temp & 0x00000200) << 12) | (($temp & 0x10000000) >> 27)
|
|
| (($temp & 0x00000040) << 14) | (($temp & 0x08000000) >> 8)
|
|
| (($temp & 0x00004000) << 4) | (($temp & 0x00000002) << 16)
|
|
| (($temp & 0x00442000) >> 6) | (($temp & 0x40800000) >> 15)
|
|
| (($temp & 0x00000001) << 11) | (($temp & 0x20000000) >> 20)
|
|
| (($temp & 0x00080000) >> 13) | (($temp & 0x00000004) << 3)
|
|
| (($temp & 0x04000000) >> 22) | (($temp & 0x00000480) >> 7)
|
|
| (($temp & 0x00200000) >> 19) | ($msb << 23);
|
|
// end of "the Feistel (F) function" - $newBlock is F's output
|
|
|
|
$temp = $block[1];
|
|
$block[1] = $block[0] ^ $newBlock;
|
|
$block[0] = $temp;
|
|
}
|
|
|
|
$msb = array(
|
|
($block[0] >> 31) & 1,
|
|
($block[1] >> 31) & 1
|
|
);
|
|
$block[0] &= 0x7FFFFFFF;
|
|
$block[1] &= 0x7FFFFFFF;
|
|
|
|
$block = array(
|
|
(($block[0] & 0x01000004) << 7) | (($block[1] & 0x01000004) << 6) |
|
|
(($block[0] & 0x00010000) << 13) | (($block[1] & 0x00010000) << 12) |
|
|
(($block[0] & 0x00000100) << 19) | (($block[1] & 0x00000100) << 18) |
|
|
(($block[0] & 0x00000001) << 25) | (($block[1] & 0x00000001) << 24) |
|
|
(($block[0] & 0x02000008) >> 2) | (($block[1] & 0x02000008) >> 3) |
|
|
(($block[0] & 0x00020000) << 4) | (($block[1] & 0x00020000) << 3) |
|
|
(($block[0] & 0x00000200) << 10) | (($block[1] & 0x00000200) << 9) |
|
|
(($block[0] & 0x00000002) << 16) | (($block[1] & 0x00000002) << 15) |
|
|
(($block[0] & 0x04000000) >> 11) | (($block[1] & 0x04000000) >> 12) |
|
|
(($block[0] & 0x00040000) >> 5) | (($block[1] & 0x00040000) >> 6) |
|
|
(($block[0] & 0x00000400) << 1) | ( $block[1] & 0x00000400 ) |
|
|
(($block[0] & 0x08000000) >> 20) | (($block[1] & 0x08000000) >> 21) |
|
|
(($block[0] & 0x00080000) >> 14) | (($block[1] & 0x00080000) >> 15) |
|
|
(($block[0] & 0x00000800) >> 8) | (($block[1] & 0x00000800) >> 9)
|
|
,
|
|
(($block[0] & 0x10000040) << 3) | (($block[1] & 0x10000040) << 2) |
|
|
(($block[0] & 0x00100000) << 9) | (($block[1] & 0x00100000) << 8) |
|
|
(($block[0] & 0x00001000) << 15) | (($block[1] & 0x00001000) << 14) |
|
|
(($block[0] & 0x00000010) << 21) | (($block[1] & 0x00000010) << 20) |
|
|
(($block[0] & 0x20000080) >> 6) | (($block[1] & 0x20000080) >> 7) |
|
|
( $block[0] & 0x00200000 ) | (($block[1] & 0x00200000) >> 1) |
|
|
(($block[0] & 0x00002000) << 6) | (($block[1] & 0x00002000) << 5) |
|
|
(($block[0] & 0x00000020) << 12) | (($block[1] & 0x00000020) << 11) |
|
|
(($block[0] & 0x40000000) >> 15) | (($block[1] & 0x40000000) >> 16) |
|
|
(($block[0] & 0x00400000) >> 9) | (($block[1] & 0x00400000) >> 10) |
|
|
(($block[0] & 0x00004000) >> 3) | (($block[1] & 0x00004000) >> 4) |
|
|
(($block[0] & 0x00800000) >> 18) | (($block[1] & 0x00800000) >> 19) |
|
|
(($block[0] & 0x00008000) >> 12) | (($block[1] & 0x00008000) >> 13) |
|
|
($msb[0] << 7) | ($msb[1] << 6)
|
|
);
|
|
|
|
return pack('NN', $block[0], $block[1]);
|
|
}
|
|
|
|
/**
|
|
* Creates the key schedule.
|
|
*
|
|
* @access private
|
|
* @param String $key
|
|
* @return Array
|
|
*/
|
|
function _prepare_key($key)
|
|
{
|
|
static $shifts = array( // number of key bits shifted per round
|
|
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
|
|
);
|
|
|
|
// pad the key and remove extra characters as appropriate.
|
|
$key = str_pad(substr($key, 0, 8), 8, chr(0));
|
|
|
|
$temp = unpack('Na/Nb', $key);
|
|
$key = array($temp['a'], $temp['b']);
|
|
$msb = array(
|
|
($key[0] >> 31) & 1,
|
|
($key[1] >> 31) & 1
|
|
);
|
|
$key[0] &= 0x7FFFFFFF;
|
|
$key[1] &= 0x7FFFFFFF;
|
|
|
|
$key = array(
|
|
(($key[1] & 0x00000002) << 26) | (($key[1] & 0x00000204) << 17) |
|
|
(($key[1] & 0x00020408) << 8) | (($key[1] & 0x02040800) >> 1) |
|
|
(($key[0] & 0x00000002) << 22) | (($key[0] & 0x00000204) << 13) |
|
|
(($key[0] & 0x00020408) << 4) | (($key[0] & 0x02040800) >> 5) |
|
|
(($key[1] & 0x04080000) >> 10) | (($key[0] & 0x04080000) >> 14) |
|
|
(($key[1] & 0x08000000) >> 19) | (($key[0] & 0x08000000) >> 23) |
|
|
(($key[0] & 0x00000010) >> 1) | (($key[0] & 0x00001000) >> 10) |
|
|
(($key[0] & 0x00100000) >> 19) | (($key[0] & 0x10000000) >> 28)
|
|
,
|
|
(($key[1] & 0x00000080) << 20) | (($key[1] & 0x00008000) << 11) |
|
|
(($key[1] & 0x00800000) << 2) | (($key[0] & 0x00000080) << 16) |
|
|
(($key[0] & 0x00008000) << 7) | (($key[0] & 0x00800000) >> 2) |
|
|
(($key[1] & 0x00000040) << 13) | (($key[1] & 0x00004000) << 4) |
|
|
(($key[1] & 0x00400000) >> 5) | (($key[1] & 0x40000000) >> 14) |
|
|
(($key[0] & 0x00000040) << 9) | ( $key[0] & 0x00004000 ) |
|
|
(($key[0] & 0x00400000) >> 9) | (($key[0] & 0x40000000) >> 18) |
|
|
(($key[1] & 0x00000020) << 6) | (($key[1] & 0x00002000) >> 3) |
|
|
(($key[1] & 0x00200000) >> 12) | (($key[1] & 0x20000000) >> 21) |
|
|
(($key[0] & 0x00000020) << 2) | (($key[0] & 0x00002000) >> 7) |
|
|
(($key[0] & 0x00200000) >> 16) | (($key[0] & 0x20000000) >> 25) |
|
|
(($key[1] & 0x00000010) >> 1) | (($key[1] & 0x00001000) >> 10) |
|
|
(($key[1] & 0x00100000) >> 19) | (($key[1] & 0x10000000) >> 28) |
|
|
($msb[1] << 24) | ($msb[0] << 20)
|
|
);
|
|
|
|
$keys = array();
|
|
for ($i = 0; $i < 16; $i++)
|
|
{
|
|
$key[0] <<= $shifts[$i];
|
|
$temp = ($key[0] & 0xF0000000) >> 28;
|
|
$key[0] = ($key[0] | $temp) & 0x0FFFFFFF;
|
|
|
|
$key[1] <<= $shifts[$i];
|
|
$temp = ($key[1] & 0xF0000000) >> 28;
|
|
$key[1] = ($key[1] | $temp) & 0x0FFFFFFF;
|
|
|
|
$temp = array(
|
|
(($key[1] & 0x00004000) >> 9) | (($key[1] & 0x00000800) >> 7) |
|
|
(($key[1] & 0x00020000) >> 14) | (($key[1] & 0x00000010) >> 2) |
|
|
(($key[1] & 0x08000000) >> 26) | (($key[1] & 0x00800000) >> 23)
|
|
,
|
|
(($key[1] & 0x02400000) >> 20) | (($key[1] & 0x00000001) << 4) |
|
|
(($key[1] & 0x00002000) >> 10) | (($key[1] & 0x00040000) >> 18) |
|
|
(($key[1] & 0x00000080) >> 6)
|
|
,
|
|
( $key[1] & 0x00000020 ) | (($key[1] & 0x00000200) >> 5) |
|
|
(($key[1] & 0x00010000) >> 13) | (($key[1] & 0x01000000) >> 22) |
|
|
(($key[1] & 0x00000004) >> 1) | (($key[1] & 0x00100000) >> 20)
|
|
,
|
|
(($key[1] & 0x00001000) >> 7) | (($key[1] & 0x00200000) >> 17) |
|
|
(($key[1] & 0x00000002) << 2) | (($key[1] & 0x00000100) >> 6) |
|
|
(($key[1] & 0x00008000) >> 14) | (($key[1] & 0x04000000) >> 26)
|
|
,
|
|
(($key[0] & 0x00008000) >> 10) | ( $key[0] & 0x00000010 ) |
|
|
(($key[0] & 0x02000000) >> 22) | (($key[0] & 0x00080000) >> 17) |
|
|
(($key[0] & 0x00000200) >> 8) | (($key[0] & 0x00000002) >> 1)
|
|
,
|
|
(($key[0] & 0x04000000) >> 21) | (($key[0] & 0x00010000) >> 12) |
|
|
(($key[0] & 0x00000020) >> 2) | (($key[0] & 0x00000800) >> 9) |
|
|
(($key[0] & 0x00800000) >> 22) | (($key[0] & 0x00000100) >> 8)
|
|
,
|
|
(($key[0] & 0x00001000) >> 7) | (($key[0] & 0x00000088) >> 3) |
|
|
(($key[0] & 0x00020000) >> 14) | (($key[0] & 0x00000001) << 2) |
|
|
(($key[0] & 0x00400000) >> 21)
|
|
,
|
|
(($key[0] & 0x00000400) >> 5) | (($key[0] & 0x00004000) >> 10) |
|
|
(($key[0] & 0x00000040) >> 3) | (($key[0] & 0x00100000) >> 18) |
|
|
(($key[0] & 0x08000000) >> 26) | (($key[0] & 0x01000000) >> 24)
|
|
);
|
|
|
|
$keys[] = $temp;
|
|
}
|
|
|
|
$temp = array(
|
|
CRYPT_DES_ENCRYPT => $keys,
|
|
CRYPT_DES_DECRYPT => array_reverse($keys)
|
|
);
|
|
|
|
return $temp;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* Pure-PHP implementation of Triple DES.
|
|
*
|
|
* @author Jim Wigginton <terrafrost@php.net>
|
|
* @version 0.1.0
|
|
* @access public
|
|
* @package Crypt_TerraDES
|
|
*/
|
|
class tripledes
|
|
{
|
|
/**
|
|
* The Three Keys
|
|
*
|
|
* @see tripledes::setKey()
|
|
* @var String
|
|
* @access private
|
|
*/
|
|
var $key = "\0\0\0\0\0\0\0\0";
|
|
|
|
/**
|
|
* The Encryption Mode
|
|
*
|
|
* @see tripledes::tripledes()
|
|
* @var Integer
|
|
* @access private
|
|
*/
|
|
var $mode = CRYPT_DES_MODE_CBC;
|
|
|
|
/**
|
|
* Continuous Buffer status
|
|
*
|
|
* @see tripledes::enableContinuousBuffer()
|
|
* @var Boolean
|
|
* @access private
|
|
*/
|
|
var $continuousBuffer = false;
|
|
|
|
/**
|
|
* Padding status
|
|
*
|
|
* @see tripledes::enablePadding()
|
|
* @var Boolean
|
|
* @access private
|
|
*/
|
|
var $padding = true;
|
|
|
|
/**
|
|
* The Initialization Vector
|
|
*
|
|
* @see tripledes::setIV()
|
|
* @var String
|
|
* @access private
|
|
*/
|
|
var $iv = "\0\0\0\0\0\0\0\0";
|
|
|
|
/**
|
|
* A "sliding" Initialization Vector
|
|
*
|
|
* @see tripledes::enableContinuousBuffer()
|
|
* @var String
|
|
* @access private
|
|
*/
|
|
var $encryptIV = "\0\0\0\0\0\0\0\0";
|
|
|
|
/**
|
|
* A "sliding" Initialization Vector
|
|
*
|
|
* @see tripledes::enableContinuousBuffer()
|
|
* @var String
|
|
* @access private
|
|
*/
|
|
var $decryptIV = "\0\0\0\0\0\0\0\0";
|
|
|
|
/**
|
|
* MCrypt parameters
|
|
*
|
|
* @see tripledes::setMCrypt()
|
|
* @var Array
|
|
* @access private
|
|
*/
|
|
var $mcrypt = array('', '');
|
|
|
|
/**
|
|
* The des objects
|
|
*
|
|
* @var Array
|
|
* @access private
|
|
*/
|
|
var $des;
|
|
|
|
/**
|
|
* Default Constructor.
|
|
*
|
|
* Determines whether or not the mcrypt extension should be used. $mode should only, at present, be
|
|
* CRYPT_DES_MODE_ECB or CRYPT_DES_MODE_CBC. If not explictly set, CRYPT_DES_MODE_CBC will be used.
|
|
*
|
|
* @param optional Integer $mode
|
|
* @return tripledes
|
|
* @access public
|
|
*/
|
|
function __construct($mode = CRYPT_DES_MODE_CBC)
|
|
{
|
|
if ( !defined('CRYPT_DES_MODE') )
|
|
{
|
|
switch (true)
|
|
{
|
|
case extension_loaded('mcrypt'):
|
|
// i'd check to see if des was supported, by doing in_array('des', mcrypt_list_algorithms('')),
|
|
// but since that can be changed after the object has been created, there doesn't seem to be
|
|
// a lot of point...
|
|
define('CRYPT_DES_MODE', CRYPT_DES_MODE_MCRYPT);
|
|
break;
|
|
default:
|
|
define('CRYPT_DES_MODE', CRYPT_DES_MODE_INTERNAL);
|
|
}
|
|
}
|
|
|
|
if ( $mode == CRYPT_DES_MODE_3CBC )
|
|
{
|
|
$this->mode = CRYPT_DES_MODE_3CBC;
|
|
$this->des = array(
|
|
new des(CRYPT_DES_MODE_CBC),
|
|
new des(CRYPT_DES_MODE_CBC),
|
|
new des(CRYPT_DES_MODE_CBC)
|
|
);
|
|
|
|
// we're going to be doing the padding, ourselves, so disable it in the des objects
|
|
$this->des[0]->disable_padding();
|
|
$this->des[1]->disable_padding();
|
|
$this->des[2]->disable_padding();
|
|
|
|
return;
|
|
}
|
|
|
|
switch ( CRYPT_DES_MODE )
|
|
{
|
|
case CRYPT_DES_MODE_MCRYPT:
|
|
switch ($mode)
|
|
{
|
|
case CRYPT_DES_MODE_ECB:
|
|
$this->mode = MCRYPT_MODE_ECB; break;
|
|
case CRYPT_DES_MODE_CBC:
|
|
default:
|
|
$this->mode = MCRYPT_MODE_CBC;
|
|
}
|
|
|
|
break;
|
|
default:
|
|
$this->des = array(
|
|
new des(CRYPT_DES_MODE_ECB),
|
|
new des(CRYPT_DES_MODE_ECB),
|
|
new des(CRYPT_DES_MODE_ECB)
|
|
);
|
|
|
|
// we're going to be doing the padding, ourselves, so disable it in the des objects
|
|
$this->des[0]->disable_padding();
|
|
$this->des[1]->disable_padding();
|
|
$this->des[2]->disable_padding();
|
|
|
|
switch ($mode)
|
|
{
|
|
case CRYPT_DES_MODE_ECB:
|
|
case CRYPT_DES_MODE_CBC:
|
|
$this->mode = $mode;
|
|
break;
|
|
default:
|
|
$this->mode = CRYPT_DES_MODE_CBC;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Sets the key.
|
|
*
|
|
* Keys can be of any length. Triple DES, itself, can use 128-bit (eg. strlen($key) == 16) or
|
|
* 192-bit (eg. strlen($key) == 24) keys. This function pads and truncates $key as appropriate.
|
|
*
|
|
* DES also requires that every eighth bit be a parity bit, however, we'll ignore that.
|
|
*
|
|
* If the key is not explicitly set, it'll be assumed to be all zero's.
|
|
*
|
|
* @access public
|
|
* @param String $key
|
|
*/
|
|
function set_key($key)
|
|
{
|
|
$length = strlen($key);
|
|
if ($length > 8)
|
|
{
|
|
$key = str_pad($key, 24, chr(0));
|
|
// if $key is between 64 and 128-bits, use the first 64-bits as the last, per this:
|
|
// http://php.net/function.mcrypt-encrypt#47973
|
|
$key = $length <= 16 ? substr_replace($key, substr($key, 0, 8), 16) : substr($key, 0, 24);
|
|
}
|
|
$this->key = $key;
|
|
switch (true)
|
|
{
|
|
case CRYPT_DES_MODE == CRYPT_DES_MODE_INTERNAL:
|
|
case $this->mode == CRYPT_DES_MODE_3CBC:
|
|
$this->des[0]->set_key(substr($key, 0, 8));
|
|
$this->des[1]->set_key(substr($key, 8, 8));
|
|
$this->des[2]->set_key(substr($key, 16, 8));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Sets the initialization vector. (optional)
|
|
*
|
|
* SetIV is not required when CRYPT_DES_MODE_ECB is being used. If not explictly set, it'll be assumed
|
|
* to be all zero's.
|
|
*
|
|
* @access public
|
|
* @param String $iv
|
|
*/
|
|
function set_iv($iv)
|
|
{
|
|
$this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($iv, 0, 8), 8, chr(0));
|
|
if ($this->mode == CRYPT_DES_MODE_3CBC)
|
|
{
|
|
$this->des[0]->set_iv($iv);
|
|
$this->des[1]->set_iv($iv);
|
|
$this->des[2]->set_iv($iv);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Sets MCrypt parameters. (optional)
|
|
*
|
|
* If MCrypt is being used, empty strings will be used, unless otherwise specified.
|
|
*
|
|
* @link http://php.net/function.mcrypt-module-open#function.mcrypt-module-open
|
|
* @access public
|
|
* @param optional Integer $algorithm_directory
|
|
* @param optional Integer $mode_directory
|
|
*/
|
|
function set_mcrypt($algorithm_directory = '', $mode_directory = '')
|
|
{
|
|
$this->mcrypt = array($algorithm_directory, $mode_directory);
|
|
if ( $this->mode == CRYPT_DES_MODE_3CBC )
|
|
{
|
|
$this->des[0]->set_mcrypt($algorithm_directory, $mode_directory);
|
|
$this->des[1]->set_mcrypt($algorithm_directory, $mode_directory);
|
|
$this->des[2]->set_mcrypt($algorithm_directory, $mode_directory);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Encrypts a message.
|
|
*
|
|
* @access public
|
|
* @param String $plaintext
|
|
*/
|
|
function encrypt($plaintext)
|
|
{
|
|
$plaintext = $this->_pad($plaintext);
|
|
|
|
// if the key is smaller then 8, do what we'd normally do
|
|
if ($this->mode == CRYPT_DES_MODE_3CBC && strlen($this->key) > 8)
|
|
{
|
|
$ciphertext = $this->des[2]->encrypt($this->des[1]->decrypt($this->des[0]->encrypt($plaintext)));
|
|
|
|
return $ciphertext;
|
|
}
|
|
|
|
if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT )
|
|
{
|
|
$td = mcrypt_module_open(MCRYPT_3DES, $this->mcrypt[0], $this->mode, $this->mcrypt[1]);
|
|
mcrypt_generic_init($td, $this->key, $this->encryptIV);
|
|
|
|
$ciphertext = mcrypt_generic($td, $plaintext);
|
|
|
|
mcrypt_generic_deinit($td);
|
|
mcrypt_module_close($td);
|
|
|
|
if ($this->continuousBuffer)
|
|
{
|
|
$this->encryptIV = substr($ciphertext, -8);
|
|
}
|
|
|
|
return $ciphertext;
|
|
}
|
|
|
|
if (strlen($this->key) <= 8)
|
|
{
|
|
$this->des[0]->mode = $this->mode;
|
|
|
|
return $this->des[0]->encrypt($plaintext);
|
|
}
|
|
|
|
// we pad with chr(0) since that's what mcrypt_generic does. to quote from http://php.net/function.mcrypt-generic :
|
|
// "The data is padded with "\0" to make sure the length of the data is n * blocksize."
|
|
$plaintext = str_pad($plaintext, ceil(strlen($plaintext) / 8) * 8, chr(0));
|
|
|
|
$ciphertext = '';
|
|
switch ($this->mode)
|
|
{
|
|
case CRYPT_DES_MODE_ECB:
|
|
for ($i = 0; $i < strlen($plaintext); $i+=8)
|
|
{
|
|
$block = substr($plaintext, $i, 8);
|
|
$block = $this->des[0]->_process_block($block, CRYPT_DES_ENCRYPT);
|
|
$block = $this->des[1]->_process_block($block, CRYPT_DES_DECRYPT);
|
|
$block = $this->des[2]->_process_block($block, CRYPT_DES_ENCRYPT);
|
|
$ciphertext.= $block;
|
|
}
|
|
break;
|
|
case CRYPT_DES_MODE_CBC:
|
|
$xor = $this->encryptIV;
|
|
for ($i = 0; $i < strlen($plaintext); $i+=8)
|
|
{
|
|
$block = substr($plaintext, $i, 8) ^ $xor;
|
|
$block = $this->des[0]->_process_block($block, CRYPT_DES_ENCRYPT);
|
|
$block = $this->des[1]->_process_block($block, CRYPT_DES_DECRYPT);
|
|
$block = $this->des[2]->_process_block($block, CRYPT_DES_ENCRYPT);
|
|
$xor = $block;
|
|
$ciphertext.= $block;
|
|
}
|
|
if ($this->continuousBuffer)
|
|
{
|
|
$this->encryptIV = $xor;
|
|
}
|
|
}
|
|
|
|
return $ciphertext;
|
|
}
|
|
|
|
/**
|
|
* Decrypts a message.
|
|
*
|
|
* @access public
|
|
* @param String $ciphertext
|
|
*/
|
|
function decrypt($ciphertext)
|
|
{
|
|
if ($this->mode == CRYPT_DES_MODE_3CBC && strlen($this->key) > 8)
|
|
{
|
|
$plaintext = $this->des[0]->decrypt($this->des[1]->encrypt($this->des[2]->decrypt($ciphertext)));
|
|
|
|
return $this->_unpad($plaintext);
|
|
}
|
|
|
|
// we pad with chr(0) since that's what mcrypt_generic does. to quote from http://php.net/function.mcrypt-generic :
|
|
// "The data is padded with "\0" to make sure the length of the data is n * blocksize."
|
|
$ciphertext = str_pad($ciphertext, (strlen($ciphertext) + 7) & 0xFFFFFFF8, chr(0));
|
|
|
|
if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT )
|
|
{
|
|
$td = mcrypt_module_open(MCRYPT_3DES, $this->mcrypt[0], $this->mode, $this->mcrypt[1]);
|
|
mcrypt_generic_init($td, $this->key, $this->decryptIV);
|
|
|
|
$plaintext = mdecrypt_generic($td, $ciphertext);
|
|
|
|
mcrypt_generic_deinit($td);
|
|
mcrypt_module_close($td);
|
|
|
|
if ($this->continuousBuffer)
|
|
{
|
|
$this->decryptIV = substr($ciphertext, -8);
|
|
}
|
|
|
|
return $this->_unpad($plaintext);
|
|
}
|
|
|
|
if (strlen($this->key) <= 8)
|
|
{
|
|
$this->des[0]->mode = $this->mode;
|
|
|
|
return $this->_unpad($this->des[0]->decrypt($plaintext));
|
|
}
|
|
|
|
$plaintext = '';
|
|
switch ($this->mode)
|
|
{
|
|
case CRYPT_DES_MODE_ECB:
|
|
for ($i = 0; $i < strlen($ciphertext); $i+=8)
|
|
{
|
|
$block = substr($ciphertext, $i, 8);
|
|
$block = $this->des[2]->_process_block($block, CRYPT_DES_DECRYPT);
|
|
$block = $this->des[1]->_process_block($block, CRYPT_DES_ENCRYPT);
|
|
$block = $this->des[0]->_process_block($block, CRYPT_DES_DECRYPT);
|
|
$plaintext.= $block;
|
|
}
|
|
break;
|
|
case CRYPT_DES_MODE_CBC:
|
|
$xor = $this->decryptIV;
|
|
for ($i = 0; $i < strlen($ciphertext); $i+=8)
|
|
{
|
|
$orig = $block = substr($ciphertext, $i, 8);
|
|
$block = $this->des[2]->_process_block($block, CRYPT_DES_DECRYPT);
|
|
$block = $this->des[1]->_process_block($block, CRYPT_DES_ENCRYPT);
|
|
$block = $this->des[0]->_process_block($block, CRYPT_DES_DECRYPT);
|
|
$plaintext.= $block ^ $xor;
|
|
$xor = $orig;
|
|
}
|
|
if ($this->continuousBuffer)
|
|
{
|
|
$this->decryptIV = $xor;
|
|
}
|
|
}
|
|
|
|
return $this->_unpad($plaintext);
|
|
}
|
|
|
|
/**
|
|
* Treat consecutive "packets" as if they are a continuous buffer.
|
|
*
|
|
* Say you have a 16-byte plaintext $plaintext. Using the default behavior, the two following code snippets
|
|
* will yield different outputs:
|
|
*
|
|
* <code>
|
|
* echo $des->encrypt(substr($plaintext, 0, 8));
|
|
* echo $des->encrypt(substr($plaintext, 8, 8));
|
|
* </code>
|
|
* <code>
|
|
* echo $des->encrypt($plaintext);
|
|
* </code>
|
|
*
|
|
* The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates
|
|
* another, as demonstrated with the following:
|
|
*
|
|
* <code>
|
|
* $des->encrypt(substr($plaintext, 0, 8));
|
|
* echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8)));
|
|
* </code>
|
|
* <code>
|
|
* echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8)));
|
|
* </code>
|
|
*
|
|
* With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different
|
|
* outputs. The reason is due to the fact that the initialization vector's change after every encryption /
|
|
* decryption round when the continuous buffer is enabled. When it's disabled, they remain constant.
|
|
*
|
|
* Put another way, when the continuous buffer is enabled, the state of the des() object changes after each
|
|
* encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that
|
|
* continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them),
|
|
* however, they are also less intuitive and more likely to cause you problems.
|
|
*
|
|
* @see tripledes::disableContinuousBuffer()
|
|
* @access public
|
|
*/
|
|
function enable_continuous_buffer()
|
|
{
|
|
$this->continuousBuffer = true;
|
|
if ($this->mode == CRYPT_DES_MODE_3CBC)
|
|
{
|
|
$this->des[0]->enable_continuous_buffer();
|
|
$this->des[1]->enable_continuous_buffer();
|
|
$this->des[2]->enable_continuous_buffer();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Treat consecutive packets as if they are a discontinuous buffer.
|
|
*
|
|
* The default behavior.
|
|
*
|
|
* @see tripledes::enableContinuousBuffer()
|
|
* @access public
|
|
*/
|
|
function disable_continuous_buffer()
|
|
{
|
|
$this->continuousBuffer = false;
|
|
$this->encryptIV = $this->iv;
|
|
$this->decryptIV = $this->iv;
|
|
|
|
if ($this->mode == CRYPT_DES_MODE_3CBC)
|
|
{
|
|
$this->des[0]->disable_continuous_buffer();
|
|
$this->des[1]->disable_continuous_buffer();
|
|
$this->des[2]->disable_continuous_buffer();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Pad "packets".
|
|
*
|
|
* DES works by encrypting eight bytes at a time. If you ever need to encrypt or decrypt something that's not
|
|
* a multiple of eight, it becomes necessary to pad the input so that it's length is a multiple of eight.
|
|
*
|
|
* Padding is enabled by default. Sometimes, however, it is undesirable to pad strings. Such is the case in SSH1,
|
|
* where "packets" are padded with random bytes before being encrypted. Unpad these packets and you risk stripping
|
|
* away characters that shouldn't be stripped away. (SSH knows how many bytes are added because the length is
|
|
* transmitted separately)
|
|
*
|
|
* @see tripledes::disable_padding()
|
|
* @access public
|
|
*/
|
|
function enable_padding()
|
|
{
|
|
$this->padding = true;
|
|
}
|
|
|
|
/**
|
|
* Do not pad packets.
|
|
*
|
|
* @see tripledes::enablePadding()
|
|
* @access public
|
|
*/
|
|
function disable_padding()
|
|
{
|
|
$this->padding = false;
|
|
}
|
|
|
|
/**
|
|
* Pads a string
|
|
*
|
|
* Pads a string using the RSA PKCS padding standards so that its length is a multiple of the blocksize (8).
|
|
* 8 - (strlen($text) & 7) bytes are added, each of which is equal to chr(8 - (strlen($text) & 7)
|
|
*
|
|
* If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless
|
|
* and padding will, hence forth, be enabled.
|
|
*
|
|
* @see tripledes::_unpad()
|
|
* @access private
|
|
*/
|
|
function _pad($text)
|
|
{
|
|
$length = strlen($text);
|
|
|
|
if (!$this->padding)
|
|
{
|
|
if (($length & 7) == 0)
|
|
{
|
|
return $text;
|
|
}
|
|
else
|
|
{
|
|
$this->padding = true;
|
|
}
|
|
}
|
|
|
|
$pad = 8 - ($length & 7);
|
|
return str_pad($text, $length + $pad, chr($pad));
|
|
}
|
|
|
|
/**
|
|
* Unpads a string
|
|
*
|
|
* If padding is enabled and the reported padding length exceeds the block size, padding will be, hence forth, disabled.
|
|
*
|
|
* @see tripledes::_pad()
|
|
* @access private
|
|
*/
|
|
function _unpad($text)
|
|
{
|
|
if (!$this->padding)
|
|
{
|
|
return $text;
|
|
}
|
|
|
|
$length = ord($text[strlen($text) - 1]);
|
|
|
|
if ($length > 8)
|
|
{
|
|
$this->padding = false;
|
|
return $text;
|
|
}
|
|
|
|
return substr($text, 0, -$length);
|
|
}
|
|
}
|
|
|
|
?>
|