1009 lines
37 KiB
PHP
1009 lines
37 KiB
PHP
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<?php
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/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
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/**
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* Pure-PHP implementation of Triple DES.
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*
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* Uses mcrypt, if available, and an internal implementation, otherwise. Operates in the EDE3 mode (encrypt-decrypt-encrypt).
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*
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* PHP versions 4 and 5
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*
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* Here's a short example of how to use this library:
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* <code>
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* <?php
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* include('Crypt/TripleDES.php');
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*
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* $des = new Crypt_TripleDES();
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*
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* $des->setKey('abcdefghijklmnopqrstuvwx');
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*
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* $size = 10 * 1024;
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* $plaintext = '';
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* for ($i = 0; $i < $size; $i++) {
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* $plaintext.= 'a';
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* }
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*
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* echo $des->decrypt($des->encrypt($plaintext));
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* ?>
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* </code>
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*
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* LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*
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* @category Crypt
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* @package Crypt_TripleDES
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* @author Jim Wigginton <terrafrost@php.net>
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* @copyright MMVII Jim Wigginton
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* @license http://www.opensource.org/licenses/mit-license.html MIT License
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* @version $Id$
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* @link http://phpseclib.sourceforge.net
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*/
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/**
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* Include Crypt_DES
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*/
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require_once('DES.php');
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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', -2);
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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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* Pure-PHP implementation of Triple 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 Crypt_TerraDES
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*/
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class Crypt_TripleDES {
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/**
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* The Three Keys
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*
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* @see Crypt_TripleDES::setKey()
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* @var String
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* @access private
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*/
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var $key = "\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 Crypt_TripleDES::Crypt_TripleDES()
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* @var Integer
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* @access private
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*/
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var $mode = CRYPT_DES_MODE_CBC;
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/**
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* Continuous Buffer status
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*
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* @see Crypt_TripleDES::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 Crypt_TripleDES::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 Crypt_TripleDES::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 Crypt_TripleDES::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 Crypt_TripleDES::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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* The Crypt_DES objects
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*
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* @var Array
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* @access private
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*/
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var $des;
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/**
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* mcrypt resource for encryption
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*
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* The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
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* Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
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*
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* @see Crypt_TripleDES::encrypt()
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* @var String
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* @access private
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*/
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var $enmcrypt;
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/**
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* mcrypt resource for decryption
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*
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* The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
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* Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
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*
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* @see Crypt_TripleDES::decrypt()
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* @var String
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* @access private
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*/
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var $demcrypt;
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/**
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* Does the enmcrypt resource need to be (re)initialized?
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*
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* @see Crypt_TripleDES::setKey()
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* @see Crypt_TripleDES::setIV()
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* @var Boolean
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* @access private
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*/
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var $enchanged = true;
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/**
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* Does the demcrypt resource need to be (re)initialized?
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*
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* @see Crypt_TripleDES::setKey()
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* @see Crypt_TripleDES::setIV()
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* @var Boolean
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* @access private
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*/
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var $dechanged = true;
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/**
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* Is the mode one that is paddable?
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*
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* @see Crypt_TripleDES::Crypt_TripleDES()
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* @var Boolean
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* @access private
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*/
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var $paddable = false;
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/**
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* Encryption buffer for CTR, OFB and CFB modes
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*
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* @see Crypt_TripleDES::encrypt()
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* @var String
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* @access private
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*/
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var $enbuffer = '';
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/**
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* Decryption buffer for CTR, OFB and CFB modes
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*
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* @see Crypt_TripleDES::decrypt()
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* @var String
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* @access private
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*/
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var $debuffer = '';
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/**
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* mcrypt resource for CFB mode
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*
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* @see Crypt_TripleDES::encrypt()
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* @see Crypt_TripleDES::decrypt()
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* @var String
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* @access private
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*/
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var $ecb;
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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 $mode
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* @return Crypt_TripleDES
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* @access public
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*/
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function Crypt_TripleDES($mode = CRYPT_DES_MODE_CBC)
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{
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if ( !defined('CRYPT_DES_MODE') ) {
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switch (true) {
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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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if ( $mode == CRYPT_DES_MODE_3CBC ) {
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$this->mode = CRYPT_DES_MODE_3CBC;
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$this->des = array(
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new Crypt_DES(CRYPT_DES_MODE_CBC),
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new Crypt_DES(CRYPT_DES_MODE_CBC),
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new Crypt_DES(CRYPT_DES_MODE_CBC)
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);
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// we're going to be doing the padding, ourselves, so disable it in the Crypt_DES objects
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$this->des[0]->disablePadding();
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$this->des[1]->disablePadding();
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$this->des[2]->disablePadding();
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return;
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}
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switch ( CRYPT_DES_MODE ) {
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case CRYPT_DES_MODE_MCRYPT:
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switch ($mode) {
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case CRYPT_DES_MODE_ECB:
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$this->paddable = true;
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$this->mode = MCRYPT_MODE_ECB;
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break;
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case CRYPT_DES_MODE_CTR:
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$this->mode = 'ctr';
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break;
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case CRYPT_DES_MODE_CFB:
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$this->mode = 'ncfb';
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break;
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case CRYPT_DES_MODE_OFB:
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$this->mode = MCRYPT_MODE_NOFB;
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break;
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case CRYPT_DES_MODE_CBC:
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default:
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$this->paddable = true;
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$this->mode = MCRYPT_MODE_CBC;
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}
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break;
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default:
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$this->des = array(
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new Crypt_DES(CRYPT_DES_MODE_ECB),
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new Crypt_DES(CRYPT_DES_MODE_ECB),
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new Crypt_DES(CRYPT_DES_MODE_ECB)
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);
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// we're going to be doing the padding, ourselves, so disable it in the Crypt_DES objects
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$this->des[0]->disablePadding();
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$this->des[1]->disablePadding();
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$this->des[2]->disablePadding();
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switch ($mode) {
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case CRYPT_DES_MODE_ECB:
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case CRYPT_DES_MODE_CBC:
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$this->paddable = true;
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$this->mode = $mode;
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break;
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case CRYPT_DES_MODE_CTR:
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case CRYPT_DES_MODE_CFB:
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case CRYPT_DES_MODE_OFB:
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$this->mode = $mode;
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break;
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default:
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$this->paddable = true;
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$this->mode = CRYPT_DES_MODE_CBC;
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}
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}
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}
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/**
|
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* Sets the key.
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*
|
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* Keys can be of any length. Triple DES, itself, can use 128-bit (eg. strlen($key) == 16) or
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* 192-bit (eg. strlen($key) == 24) keys. This function pads and truncates $key as appropriate.
|
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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 $key
|
||
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*/
|
||
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function setKey($key)
|
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{
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$length = strlen($key);
|
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if ($length > 8) {
|
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|
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$key = str_pad($key, 24, chr(0));
|
||
|
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// if $key is between 64 and 128-bits, use the first 64-bits as the last, per this:
|
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|
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// http://php.net/function.mcrypt-encrypt#47973
|
||
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//$key = $length <= 16 ? substr_replace($key, substr($key, 0, 8), 16) : substr($key, 0, 24);
|
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} else {
|
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$key = str_pad($key, 8, chr(0));
|
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}
|
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$this->key = $key;
|
||
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switch (true) {
|
||
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case CRYPT_DES_MODE == CRYPT_DES_MODE_INTERNAL:
|
||
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case $this->mode == CRYPT_DES_MODE_3CBC:
|
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$this->des[0]->setKey(substr($key, 0, 8));
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$this->des[1]->setKey(substr($key, 8, 8));
|
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$this->des[2]->setKey(substr($key, 16, 8));
|
||
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}
|
||
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$this->enchanged = $this->dechanged = true;
|
||
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}
|
||
|
|
|
||
|
|
/**
|
||
|
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* 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 $iv
|
||
|
|
*/
|
||
|
|
function setIV($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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if ($this->mode == CRYPT_DES_MODE_3CBC) {
|
||
|
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$this->des[0]->setIV($iv);
|
||
|
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$this->des[1]->setIV($iv);
|
||
|
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$this->des[2]->setIV($iv);
|
||
|
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}
|
||
|
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$this->enchanged = $this->dechanged = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Generate CTR XOR encryption key
|
||
|
|
*
|
||
|
|
* Encrypt the output of this and XOR it against the ciphertext / plaintext to get the
|
||
|
|
* plaintext / ciphertext in CTR mode.
|
||
|
|
*
|
||
|
|
* @see Crypt_TripleDES::decrypt()
|
||
|
|
* @see Crypt_TripleDES::encrypt()
|
||
|
|
* @access private
|
||
|
|
* @param Integer $length
|
||
|
|
* @param String $iv
|
||
|
|
*/
|
||
|
|
function _generate_xor($length, &$iv)
|
||
|
|
{
|
||
|
|
$xor = '';
|
||
|
|
$num_blocks = ($length + 7) >> 3;
|
||
|
|
for ($i = 0; $i < $num_blocks; $i++) {
|
||
|
|
$xor.= $iv;
|
||
|
|
for ($j = 4; $j <= 8; $j+=4) {
|
||
|
|
$temp = substr($iv, -$j, 4);
|
||
|
|
switch ($temp) {
|
||
|
|
case "\xFF\xFF\xFF\xFF":
|
||
|
|
$iv = substr_replace($iv, "\x00\x00\x00\x00", -$j, 4);
|
||
|
|
break;
|
||
|
|
case "\x7F\xFF\xFF\xFF":
|
||
|
|
$iv = substr_replace($iv, "\x80\x00\x00\x00", -$j, 4);
|
||
|
|
break 2;
|
||
|
|
default:
|
||
|
|
extract(unpack('Ncount', $temp));
|
||
|
|
$iv = substr_replace($iv, pack('N', $count + 1), -$j, 4);
|
||
|
|
break 2;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return $xor;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Encrypts a message.
|
||
|
|
*
|
||
|
|
* @access public
|
||
|
|
* @param String $plaintext
|
||
|
|
*/
|
||
|
|
function encrypt($plaintext)
|
||
|
|
{
|
||
|
|
if ($this->paddable) {
|
||
|
|
$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 $ciphertext;
|
||
|
|
}
|
||
|
|
|
||
|
|
if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) {
|
||
|
|
if ($this->enchanged) {
|
||
|
|
if (!isset($this->enmcrypt)) {
|
||
|
|
$this->enmcrypt = mcrypt_module_open(MCRYPT_3DES, '', $this->mode, '');
|
||
|
|
}
|
||
|
|
mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
|
||
|
|
if ($this->mode != 'ncfb') {
|
||
|
|
$this->enchanged = false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if ($this->mode != 'ncfb') {
|
||
|
|
$ciphertext = mcrypt_generic($this->enmcrypt, $plaintext);
|
||
|
|
} else {
|
||
|
|
if ($this->enchanged) {
|
||
|
|
$this->ecb = mcrypt_module_open(MCRYPT_3DES, '', MCRYPT_MODE_ECB, '');
|
||
|
|
mcrypt_generic_init($this->ecb, $this->key, "\0\0\0\0\0\0\0\0");
|
||
|
|
$this->enchanged = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (strlen($this->enbuffer)) {
|
||
|
|
$ciphertext = $plaintext ^ substr($this->encryptIV, strlen($this->enbuffer));
|
||
|
|
$this->enbuffer.= $ciphertext;
|
||
|
|
if (strlen($this->enbuffer) == 8) {
|
||
|
|
$this->encryptIV = $this->enbuffer;
|
||
|
|
$this->enbuffer = '';
|
||
|
|
mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
|
||
|
|
}
|
||
|
|
$plaintext = substr($plaintext, strlen($ciphertext));
|
||
|
|
} else {
|
||
|
|
$ciphertext = '';
|
||
|
|
}
|
||
|
|
|
||
|
|
$last_pos = strlen($plaintext) & 0xFFFFFFF8;
|
||
|
|
$ciphertext.= $last_pos ? mcrypt_generic($this->enmcrypt, substr($plaintext, 0, $last_pos)) : '';
|
||
|
|
|
||
|
|
if (strlen($plaintext) & 0x7) {
|
||
|
|
if (strlen($ciphertext)) {
|
||
|
|
$this->encryptIV = substr($ciphertext, -8);
|
||
|
|
}
|
||
|
|
$this->encryptIV = mcrypt_generic($this->ecb, $this->encryptIV);
|
||
|
|
$this->enbuffer = substr($plaintext, $last_pos) ^ $this->encryptIV;
|
||
|
|
$ciphertext.= $this->enbuffer;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!$this->continuousBuffer) {
|
||
|
|
mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
|
||
|
|
}
|
||
|
|
|
||
|
|
return $ciphertext;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (strlen($this->key) <= 8) {
|
||
|
|
$this->des[0]->mode = $this->mode;
|
||
|
|
|
||
|
|
return $this->des[0]->encrypt($plaintext);
|
||
|
|
}
|
||
|
|
|
||
|
|
$des = $this->des;
|
||
|
|
|
||
|
|
$buffer = &$this->enbuffer;
|
||
|
|
$continuousBuffer = $this->continuousBuffer;
|
||
|
|
$ciphertext = '';
|
||
|
|
switch ($this->mode) {
|
||
|
|
case CRYPT_DES_MODE_ECB:
|
||
|
|
for ($i = 0; $i < strlen($plaintext); $i+=8) {
|
||
|
|
$block = substr($plaintext, $i, 8);
|
||
|
|
// all of these _processBlock calls could, in theory, be put in a function - say Crypt_TripleDES::_ede_encrypt() or something.
|
||
|
|
// only problem with that: it would slow encryption and decryption down. $this->des would have to be called every time that
|
||
|
|
// function is called, instead of once for the whole string of text that's being encrypted, which would, in turn, make
|
||
|
|
// encryption and decryption take more time, per this:
|
||
|
|
//
|
||
|
|
// http://blog.libssh2.org/index.php?/archives/21-Compiled-Variables.html
|
||
|
|
$block = $des[0]->_processBlock($block, CRYPT_DES_ENCRYPT);
|
||
|
|
$block = $des[1]->_processBlock($block, CRYPT_DES_DECRYPT);
|
||
|
|
$block = $des[2]->_processBlock($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 = $des[0]->_processBlock($block, CRYPT_DES_ENCRYPT);
|
||
|
|
$block = $des[1]->_processBlock($block, CRYPT_DES_DECRYPT);
|
||
|
|
$block = $des[2]->_processBlock($block, CRYPT_DES_ENCRYPT);
|
||
|
|
$xor = $block;
|
||
|
|
$ciphertext.= $block;
|
||
|
|
}
|
||
|
|
if ($this->continuousBuffer) {
|
||
|
|
$this->encryptIV = $xor;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case CRYPT_DES_MODE_CTR:
|
||
|
|
$xor = $this->encryptIV;
|
||
|
|
if (strlen($buffer)) {
|
||
|
|
for ($i = 0; $i < strlen($plaintext); $i+=8) {
|
||
|
|
$block = substr($plaintext, $i, 8);
|
||
|
|
$key = $this->_generate_xor(8, $xor);
|
||
|
|
$key = $des[0]->_processBlock($key, CRYPT_DES_ENCRYPT);
|
||
|
|
$key = $des[1]->_processBlock($key, CRYPT_DES_DECRYPT);
|
||
|
|
$key = $des[2]->_processBlock($key, CRYPT_DES_ENCRYPT);
|
||
|
|
$buffer.= $key;
|
||
|
|
$key = $this->_string_shift($buffer, 8);
|
||
|
|
$ciphertext.= $block ^ $key;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
for ($i = 0; $i < strlen($plaintext); $i+=8) {
|
||
|
|
$block = substr($plaintext, $i, 8);
|
||
|
|
$key = $this->_generate_xor(8, $xor);
|
||
|
|
$key = $des[0]->_processBlock($key, CRYPT_DES_ENCRYPT);
|
||
|
|
$key = $des[1]->_processBlock($key, CRYPT_DES_DECRYPT);
|
||
|
|
$key = $des[2]->_processBlock($key, CRYPT_DES_ENCRYPT);
|
||
|
|
$ciphertext.= $block ^ $key;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if ($this->continuousBuffer) {
|
||
|
|
$this->encryptIV = $xor;
|
||
|
|
if ($start = strlen($plaintext) & 7) {
|
||
|
|
$buffer = substr($key, $start) . $buffer;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case CRYPT_DES_MODE_CFB:
|
||
|
|
if (!empty($buffer['xor'])) {
|
||
|
|
$ciphertext = $plaintext ^ $buffer['xor'];
|
||
|
|
$iv = $buffer['encrypted'] . $ciphertext;
|
||
|
|
$start = strlen($ciphertext);
|
||
|
|
$buffer['encrypted'].= $ciphertext;
|
||
|
|
$buffer['xor'] = substr($buffer['xor'], strlen($ciphertext));
|
||
|
|
} else {
|
||
|
|
$ciphertext = '';
|
||
|
|
$iv = $this->encryptIV;
|
||
|
|
$start = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
for ($i = $start; $i < strlen($plaintext); $i+=8) {
|
||
|
|
$block = substr($plaintext, $i, 8);
|
||
|
|
$iv = $des[0]->_processBlock($iv, CRYPT_DES_ENCRYPT);
|
||
|
|
$iv = $des[1]->_processBlock($iv, CRYPT_DES_DECRYPT);
|
||
|
|
$xor= $des[2]->_processBlock($iv, CRYPT_DES_ENCRYPT);
|
||
|
|
|
||
|
|
$iv = $block ^ $xor;
|
||
|
|
if ($continuousBuffer && strlen($iv) != 8) {
|
||
|
|
$buffer = array(
|
||
|
|
'encrypted' => $iv,
|
||
|
|
'xor' => substr($xor, strlen($iv))
|
||
|
|
);
|
||
|
|
}
|
||
|
|
$ciphertext.= $iv;
|
||
|
|
}
|
||
|
|
|
||
|
|
if ($this->continuousBuffer) {
|
||
|
|
$this->encryptIV = $iv;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case CRYPT_DES_MODE_OFB:
|
||
|
|
$xor = $this->encryptIV;
|
||
|
|
if (strlen($buffer)) {
|
||
|
|
for ($i = 0; $i < strlen($plaintext); $i+=8) {
|
||
|
|
$xor = $des[0]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT);
|
||
|
|
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$buffer.= $xor;
|
||
|
|
$key = $this->_string_shift($buffer, 8);
|
||
|
|
$ciphertext.= substr($plaintext, $i, 8) ^ $key;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
for ($i = 0; $i < strlen($plaintext); $i+=8) {
|
||
|
|
$xor = $des[0]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT);
|
||
|
|
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$ciphertext.= substr($plaintext, $i, 8) ^ $xor;
|
||
|
|
}
|
||
|
|
$key = $xor;
|
||
|
|
}
|
||
|
|
if ($this->continuousBuffer) {
|
||
|
|
$this->encryptIV = $xor;
|
||
|
|
if ($start = strlen($plaintext) & 7) {
|
||
|
|
$buffer = substr($key, $start) . $buffer;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
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);
|
||
|
|
}
|
||
|
|
|
||
|
|
if ($this->paddable) {
|
||
|
|
// 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($ciphertext) + 7) & 0xFFFFFFF8, chr(0));
|
||
|
|
}
|
||
|
|
|
||
|
|
if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) {
|
||
|
|
if ($this->dechanged) {
|
||
|
|
if (!isset($this->demcrypt)) {
|
||
|
|
$this->demcrypt = mcrypt_module_open(MCRYPT_3DES, '', $this->mode, '');
|
||
|
|
}
|
||
|
|
mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
|
||
|
|
if ($this->mode != 'ncfb') {
|
||
|
|
$this->dechanged = false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if ($this->mode != 'ncfb') {
|
||
|
|
$plaintext = mdecrypt_generic($this->demcrypt, $ciphertext);
|
||
|
|
} else {
|
||
|
|
if ($this->dechanged) {
|
||
|
|
$this->ecb = mcrypt_module_open(MCRYPT_3DES, '', MCRYPT_MODE_ECB, '');
|
||
|
|
mcrypt_generic_init($this->ecb, $this->key, "\0\0\0\0\0\0\0\0");
|
||
|
|
$this->dechanged = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (strlen($this->debuffer)) {
|
||
|
|
$plaintext = $ciphertext ^ substr($this->decryptIV, strlen($this->debuffer));
|
||
|
|
|
||
|
|
$this->debuffer.= substr($ciphertext, 0, strlen($plaintext));
|
||
|
|
if (strlen($this->debuffer) == 8) {
|
||
|
|
$this->decryptIV = $this->debuffer;
|
||
|
|
$this->debuffer = '';
|
||
|
|
mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
|
||
|
|
}
|
||
|
|
$ciphertext = substr($ciphertext, strlen($plaintext));
|
||
|
|
} else {
|
||
|
|
$plaintext = '';
|
||
|
|
}
|
||
|
|
|
||
|
|
$last_pos = strlen($ciphertext) & 0xFFFFFFF8;
|
||
|
|
$plaintext.= $last_pos ? mdecrypt_generic($this->demcrypt, substr($ciphertext, 0, $last_pos)) : '';
|
||
|
|
|
||
|
|
if (strlen($ciphertext) & 0x7) {
|
||
|
|
if (strlen($plaintext)) {
|
||
|
|
$this->decryptIV = substr($ciphertext, $last_pos - 8, 8);
|
||
|
|
}
|
||
|
|
$this->decryptIV = mcrypt_generic($this->ecb, $this->decryptIV);
|
||
|
|
$this->debuffer = substr($ciphertext, $last_pos);
|
||
|
|
$plaintext.= $this->debuffer ^ $this->decryptIV;
|
||
|
|
}
|
||
|
|
|
||
|
|
return $plaintext;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!$this->continuousBuffer) {
|
||
|
|
mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
|
||
|
|
}
|
||
|
|
|
||
|
|
return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (strlen($this->key) <= 8) {
|
||
|
|
$this->des[0]->mode = $this->mode;
|
||
|
|
$plaintext = $this->des[0]->decrypt($ciphertext);
|
||
|
|
return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
|
||
|
|
}
|
||
|
|
|
||
|
|
$des = $this->des;
|
||
|
|
|
||
|
|
$buffer = &$this->enbuffer;
|
||
|
|
$continuousBuffer = $this->continuousBuffer;
|
||
|
|
$plaintext = '';
|
||
|
|
switch ($this->mode) {
|
||
|
|
case CRYPT_DES_MODE_ECB:
|
||
|
|
for ($i = 0; $i < strlen($ciphertext); $i+=8) {
|
||
|
|
$block = substr($ciphertext, $i, 8);
|
||
|
|
$block = $des[2]->_processBlock($block, CRYPT_DES_DECRYPT);
|
||
|
|
$block = $des[1]->_processBlock($block, CRYPT_DES_ENCRYPT);
|
||
|
|
$block = $des[0]->_processBlock($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 = $des[2]->_processBlock($block, CRYPT_DES_DECRYPT);
|
||
|
|
$block = $des[1]->_processBlock($block, CRYPT_DES_ENCRYPT);
|
||
|
|
$block = $des[0]->_processBlock($block, CRYPT_DES_DECRYPT);
|
||
|
|
$plaintext.= $block ^ $xor;
|
||
|
|
$xor = $orig;
|
||
|
|
}
|
||
|
|
if ($this->continuousBuffer) {
|
||
|
|
$this->decryptIV = $xor;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case CRYPT_DES_MODE_CTR:
|
||
|
|
$xor = $this->decryptIV;
|
||
|
|
if (strlen($buffer)) {
|
||
|
|
for ($i = 0; $i < strlen($ciphertext); $i+=8) {
|
||
|
|
$block = substr($ciphertext, $i, 8);
|
||
|
|
$key = $this->_generate_xor(8, $xor);
|
||
|
|
$key = $des[0]->_processBlock($key, CRYPT_DES_ENCRYPT);
|
||
|
|
$key = $des[1]->_processBlock($key, CRYPT_DES_DECRYPT);
|
||
|
|
$key = $des[2]->_processBlock($key, CRYPT_DES_ENCRYPT);
|
||
|
|
$buffer.= $key;
|
||
|
|
$key = $this->_string_shift($buffer, 8);
|
||
|
|
$plaintext.= $block ^ $key;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
for ($i = 0; $i < strlen($ciphertext); $i+=8) {
|
||
|
|
$block = substr($ciphertext, $i, 8);
|
||
|
|
$key = $this->_generate_xor(8, $xor);
|
||
|
|
$key = $des[0]->_processBlock($key, CRYPT_DES_ENCRYPT);
|
||
|
|
$key = $des[1]->_processBlock($key, CRYPT_DES_DECRYPT);
|
||
|
|
$key = $des[2]->_processBlock($key, CRYPT_DES_ENCRYPT);
|
||
|
|
$plaintext.= $block ^ $key;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if ($this->continuousBuffer) {
|
||
|
|
$this->decryptIV = $xor;
|
||
|
|
if ($start = strlen($plaintext) & 7) {
|
||
|
|
$buffer = substr($key, $start) . $buffer;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case CRYPT_DES_MODE_CFB:
|
||
|
|
if (!empty($buffer['ciphertext'])) {
|
||
|
|
$plaintext = $ciphertext ^ substr($this->decryptIV, strlen($buffer['ciphertext']));
|
||
|
|
$buffer['ciphertext'].= substr($ciphertext, 0, strlen($plaintext));
|
||
|
|
if (strlen($buffer['ciphertext']) == 8) {
|
||
|
|
$xor = $des[0]->_processBlock($buffer['ciphertext'], CRYPT_DES_ENCRYPT);
|
||
|
|
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT);
|
||
|
|
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$buffer['ciphertext'] = '';
|
||
|
|
}
|
||
|
|
$start = strlen($plaintext);
|
||
|
|
$block = $this->decryptIV;
|
||
|
|
} else {
|
||
|
|
$plaintext = '';
|
||
|
|
$xor = $des[0]->_processBlock($this->decryptIV, CRYPT_DES_ENCRYPT);
|
||
|
|
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT);
|
||
|
|
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$start = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
for ($i = $start; $i < strlen($ciphertext); $i+=8) {
|
||
|
|
$block = substr($ciphertext, $i, 8);
|
||
|
|
$plaintext.= $block ^ $xor;
|
||
|
|
if ($continuousBuffer && strlen($block) != 8) {
|
||
|
|
$buffer['ciphertext'].= $block;
|
||
|
|
$block = $xor;
|
||
|
|
} else if (strlen($block) == 8) {
|
||
|
|
$xor = $des[0]->_processBlock($block, CRYPT_DES_ENCRYPT);
|
||
|
|
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT);
|
||
|
|
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if ($this->continuousBuffer) {
|
||
|
|
$this->decryptIV = $block;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case CRYPT_DES_MODE_OFB:
|
||
|
|
$xor = $this->decryptIV;
|
||
|
|
if (strlen($buffer)) {
|
||
|
|
for ($i = 0; $i < strlen($ciphertext); $i+=8) {
|
||
|
|
$xor = $des[0]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT);
|
||
|
|
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$buffer.= $xor;
|
||
|
|
$key = $this->_string_shift($buffer, 8);
|
||
|
|
$plaintext.= substr($ciphertext, $i, 8) ^ $key;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
for ($i = 0; $i < strlen($ciphertext); $i+=8) {
|
||
|
|
$xor = $des[0]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT);
|
||
|
|
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT);
|
||
|
|
$plaintext.= substr($ciphertext, $i, 8) ^ $xor;
|
||
|
|
}
|
||
|
|
$key = $xor;
|
||
|
|
}
|
||
|
|
if ($this->continuousBuffer) {
|
||
|
|
$this->decryptIV = $xor;
|
||
|
|
if ($start = strlen($ciphertext) & 7) {
|
||
|
|
$buffer = substr($key, $start) . $buffer;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return $this->paddable ? $this->_unpad($plaintext) : $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 Crypt_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 Crypt_TripleDES::disableContinuousBuffer()
|
||
|
|
* @access public
|
||
|
|
*/
|
||
|
|
function enableContinuousBuffer()
|
||
|
|
{
|
||
|
|
$this->continuousBuffer = true;
|
||
|
|
if ($this->mode == CRYPT_DES_MODE_3CBC) {
|
||
|
|
$this->des[0]->enableContinuousBuffer();
|
||
|
|
$this->des[1]->enableContinuousBuffer();
|
||
|
|
$this->des[2]->enableContinuousBuffer();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Treat consecutive packets as if they are a discontinuous buffer.
|
||
|
|
*
|
||
|
|
* The default behavior.
|
||
|
|
*
|
||
|
|
* @see Crypt_TripleDES::enableContinuousBuffer()
|
||
|
|
* @access public
|
||
|
|
*/
|
||
|
|
function disableContinuousBuffer()
|
||
|
|
{
|
||
|
|
$this->continuousBuffer = false;
|
||
|
|
$this->encryptIV = $this->iv;
|
||
|
|
$this->decryptIV = $this->iv;
|
||
|
|
|
||
|
|
if ($this->mode == CRYPT_DES_MODE_3CBC) {
|
||
|
|
$this->des[0]->disableContinuousBuffer();
|
||
|
|
$this->des[1]->disableContinuousBuffer();
|
||
|
|
$this->des[2]->disableContinuousBuffer();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 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 Crypt_TripleDES::disablePadding()
|
||
|
|
* @access public
|
||
|
|
*/
|
||
|
|
function enablePadding()
|
||
|
|
{
|
||
|
|
$this->padding = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Do not pad packets.
|
||
|
|
*
|
||
|
|
* @see Crypt_TripleDES::enablePadding()
|
||
|
|
* @access public
|
||
|
|
*/
|
||
|
|
function disablePadding()
|
||
|
|
{
|
||
|
|
$this->padding = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Pads a string
|
||
|
|
*
|
||
|
|
* Pads a string using the RSA PKCS padding standards so that its length is a multiple of the blocksize (8).
|
||
|
|
* 8 - (strlen($text) & 7) bytes are added, each of which is equal to chr(8 - (strlen($text) & 7)
|
||
|
|
*
|
||
|
|
* If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless
|
||
|
|
* and padding will, hence forth, be enabled.
|
||
|
|
*
|
||
|
|
* @see Crypt_TripleDES::_unpad()
|
||
|
|
* @access private
|
||
|
|
*/
|
||
|
|
function _pad($text)
|
||
|
|
{
|
||
|
|
$length = strlen($text);
|
||
|
|
|
||
|
|
if (!$this->padding) {
|
||
|
|
if (($length & 7) == 0) {
|
||
|
|
return $text;
|
||
|
|
} else {
|
||
|
|
user_error("The plaintext's length ($length) is not a multiple of the block size (8)", E_USER_NOTICE);
|
||
|
|
$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 is invalid the encryption key will be assumed to be wrong
|
||
|
|
* and false will be returned.
|
||
|
|
*
|
||
|
|
* @see Crypt_TripleDES::_pad()
|
||
|
|
* @access private
|
||
|
|
*/
|
||
|
|
function _unpad($text)
|
||
|
|
{
|
||
|
|
if (!$this->padding) {
|
||
|
|
return $text;
|
||
|
|
}
|
||
|
|
|
||
|
|
$length = ord($text[strlen($text) - 1]);
|
||
|
|
|
||
|
|
if (!$length || $length > 8) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
return substr($text, 0, -$length);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* String Shift
|
||
|
|
*
|
||
|
|
* Inspired by array_shift
|
||
|
|
*
|
||
|
|
* @param String $string
|
||
|
|
* @param optional Integer $index
|
||
|
|
* @return String
|
||
|
|
* @access private
|
||
|
|
*/
|
||
|
|
function _string_shift(&$string, $index = 1)
|
||
|
|
{
|
||
|
|
$substr = substr($string, 0, $index);
|
||
|
|
$string = substr($string, $index);
|
||
|
|
return $substr;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// vim: ts=4:sw=4:et:
|
||
|
|
// vim6: fdl=1:
|