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<?php |
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/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */ |
| 3 |
|
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/** |
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* Pure-PHP implementation of Triple DES. |
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* |
| 7 |
* 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: |
| 12 |
* <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'); |
| 19 |
* |
| 20 |
* $size = 10 * 1024; |
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* $plaintext = ''; |
| 22 |
* for ($i = 0; $i < $size; $i++) { |
| 23 |
* $plaintext.= 'a'; |
| 24 |
* } |
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* |
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* echo $des->decrypt($des->encrypt($plaintext)); |
| 27 |
* ?> |
| 28 |
* </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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* @link http://phpseclib.sourceforge.net |
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*/ |
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|
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/** |
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* Include Crypt_DES |
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*/ |
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if (!class_exists('Crypt_DES')) { |
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require_once('DES.php'); |
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} |
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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', -2); |
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|
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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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/** |
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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 extends Crypt_DES { |
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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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/** |
| 95 |
* 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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* |
| 100 |
* @param optional Integer $mode |
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* @return Crypt_TripleDES |
| 102 |
* @access public |
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*/ |
| 104 |
function Crypt_TripleDES($mode = CRYPT_DES_MODE_CBC) |
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{ |
| 106 |
if ( !defined('CRYPT_DES_MODE') ) { |
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switch (true) { |
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case extension_loaded('mcrypt') && in_array('tripledes', mcrypt_list_algorithms()): |
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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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|
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if ( $mode == CRYPT_DES_MODE_3CBC ) { |
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$this->mode = CRYPT_DES_MODE_3CBC; |
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$this->des = array( |
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new Crypt_DES(CRYPT_DES_MODE_CBC), |
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new Crypt_DES(CRYPT_DES_MODE_CBC), |
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new Crypt_DES(CRYPT_DES_MODE_CBC) |
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); |
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$this->paddable = true; |
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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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$this->des[2]->disablePadding(); |
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|
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return; |
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} |
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|
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switch ( CRYPT_DES_MODE ) { |
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case CRYPT_DES_MODE_MCRYPT: |
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switch ($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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$this->ecb = mcrypt_module_open(MCRYPT_3DES, '', MCRYPT_MODE_ECB, ''); |
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break; |
| 147 |
case CRYPT_DES_MODE_OFB: |
| 148 |
$this->mode = MCRYPT_MODE_NOFB; |
| 149 |
break; |
| 150 |
case CRYPT_DES_MODE_CBC: |
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default: |
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$this->paddable = true; |
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$this->mode = MCRYPT_MODE_CBC; |
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} |
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$this->enmcrypt = mcrypt_module_open(MCRYPT_3DES, '', $this->mode, ''); |
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$this->demcrypt = mcrypt_module_open(MCRYPT_3DES, '', $this->mode, ''); |
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|
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break; |
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default: |
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$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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|
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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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$this->des[2]->disablePadding(); |
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|
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switch ($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: |
| 183 |
$this->paddable = true; |
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$this->mode = CRYPT_DES_MODE_CBC; |
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} |
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if (function_exists('create_function') && is_callable('create_function')) { |
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$this->inline_crypt_setup(3); |
| 188 |
$this->use_inline_crypt = true; |
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} |
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} |
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} |
| 192 |
|
| 193 |
/** |
| 194 |
* Sets the key. |
| 195 |
* |
| 196 |
* Keys can be of any length. Triple DES, itself, can use 128-bit (eg. strlen($key) == 16) or |
| 197 |
* 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. |
| 200 |
* |
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* If the key is not explicitly set, it'll be assumed to be all zero's. |
| 202 |
* |
| 203 |
* @access public |
| 204 |
* @param String $key |
| 205 |
*/ |
| 206 |
function setKey($key) |
| 207 |
{ |
| 208 |
$length = strlen($key); |
| 209 |
if ($length > 8) { |
| 210 |
$key = str_pad($key, 24, chr(0)); |
| 211 |
// if $key is between 64 and 128-bits, use the first 64-bits as the last, per this: |
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// http://php.net/function.mcrypt-encrypt#47973 |
| 213 |
//$key = $length <= 16 ? substr_replace($key, substr($key, 0, 8), 16) : substr($key, 0, 24); |
| 214 |
} else { |
| 215 |
$key = str_pad($key, 8, chr(0)); |
| 216 |
} |
| 217 |
$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($key, 16, 8)); |
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|
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// Merge the three DES-1-dim-key-arrays for 3DES-inline-en/decrypting |
| 226 |
if ($this->use_inline_crypt && $this->mode != CRYPT_DES_MODE_3CBC) { |
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$this->keys = array( |
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CRYPT_DES_ENCRYPT_1DIM => array_merge( |
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$this->des[0]->keys[CRYPT_DES_ENCRYPT_1DIM], |
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$this->des[1]->keys[CRYPT_DES_DECRYPT_1DIM], |
| 231 |
$this->des[2]->keys[CRYPT_DES_ENCRYPT_1DIM] |
| 232 |
), |
| 233 |
CRYPT_DES_DECRYPT_1DIM => array_merge( |
| 234 |
$this->des[2]->keys[CRYPT_DES_DECRYPT_1DIM], |
| 235 |
$this->des[1]->keys[CRYPT_DES_ENCRYPT_1DIM], |
| 236 |
$this->des[0]->keys[CRYPT_DES_DECRYPT_1DIM] |
| 237 |
), |
| 238 |
); |
| 239 |
} |
| 240 |
} |
| 241 |
$this->enchanged = $this->dechanged = true; |
| 242 |
} |
| 243 |
|
| 244 |
/** |
| 245 |
* Sets the password. |
| 246 |
* |
| 247 |
* Depending on what $method is set to, setPassword()'s (optional) parameters are as follows: |
| 248 |
* {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2}: |
| 249 |
* $hash, $salt, $method |
| 250 |
* |
| 251 |
* @param String $password |
| 252 |
* @param optional String $method |
| 253 |
* @access public |
| 254 |
*/ |
| 255 |
function setPassword($password, $method = 'pbkdf2') |
| 256 |
{ |
| 257 |
$key = ''; |
| 258 |
|
| 259 |
switch ($method) { |
| 260 |
default: // 'pbkdf2' |
| 261 |
list(, , $hash, $salt, $count) = func_get_args(); |
| 262 |
if (!isset($hash)) { |
| 263 |
$hash = 'sha1'; |
| 264 |
} |
| 265 |
// WPA and WPA2 use the SSID as the salt |
| 266 |
if (!isset($salt)) { |
| 267 |
$salt = 'phpseclib'; |
| 268 |
} |
| 269 |
// RFC2898#section-4.2 uses 1,000 iterations by default |
| 270 |
// WPA and WPA2 use 4,096. |
| 271 |
if (!isset($count)) { |
| 272 |
$count = 1000; |
| 273 |
} |
| 274 |
|
| 275 |
if (!class_exists('Crypt_Hash')) { |
| 276 |
require_once('Crypt/Hash.php'); |
| 277 |
} |
| 278 |
|
| 279 |
$i = 1; |
| 280 |
while (strlen($key) < 24) { // $dkLen == 24 |
| 281 |
$hmac = new Crypt_Hash(); |
| 282 |
$hmac->setHash($hash); |
| 283 |
$hmac->setKey($password); |
| 284 |
$f = $u = $hmac->hash($salt . pack('N', $i++)); |
| 285 |
for ($j = 2; $j <= $count; $j++) { |
| 286 |
$u = $hmac->hash($u); |
| 287 |
$f^= $u; |
| 288 |
} |
| 289 |
$key.= $f; |
| 290 |
} |
| 291 |
} |
| 292 |
|
| 293 |
$this->setKey($key); |
| 294 |
} |
| 295 |
|
| 296 |
/** |
| 297 |
* Sets the initialization vector. (optional) |
| 298 |
* |
| 299 |
* SetIV is not required when CRYPT_DES_MODE_ECB is being used. If not explictly set, it'll be assumed |
| 300 |
* to be all zero's. |
| 301 |
* |
| 302 |
* @access public |
| 303 |
* @param String $iv |
| 304 |
*/ |
| 305 |
function setIV($iv) |
| 306 |
{ |
| 307 |
$this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($iv, 0, 8), 8, chr(0)); |
| 308 |
if ($this->mode == CRYPT_DES_MODE_3CBC) { |
| 309 |
$this->des[0]->setIV($iv); |
| 310 |
$this->des[1]->setIV($iv); |
| 311 |
$this->des[2]->setIV($iv); |
| 312 |
} |
| 313 |
$this->enchanged = $this->dechanged = true; |
| 314 |
} |
| 315 |
|
| 316 |
/** |
| 317 |
* Encrypts a message. |
| 318 |
* |
| 319 |
* @access public |
| 320 |
* @param String $plaintext |
| 321 |
*/ |
| 322 |
function encrypt($plaintext) |
| 323 |
{ |
| 324 |
if ($this->paddable) { |
| 325 |
$plaintext = $this->_pad($plaintext); |
| 326 |
} |
| 327 |
|
| 328 |
// if the key is smaller then 8, do what we'd normally do |
| 329 |
if ($this->mode == CRYPT_DES_MODE_3CBC && strlen($this->key) > 8) { |
| 330 |
$ciphertext = $this->des[2]->encrypt($this->des[1]->decrypt($this->des[0]->encrypt($plaintext))); |
| 331 |
|
| 332 |
return $ciphertext; |
| 333 |
} |
| 334 |
|
| 335 |
if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) { |
| 336 |
if ($this->enchanged) { |
| 337 |
mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV); |
| 338 |
if ($this->mode == 'ncfb') { |
| 339 |
mcrypt_generic_init($this->ecb, $this->key, "\0\0\0\0\0\0\0\0"); |
| 340 |
} |
| 341 |
$this->enchanged = false; |
| 342 |
} |
| 343 |
|
| 344 |
if ($this->mode != 'ncfb' || !$this->continuousBuffer) { |
| 345 |
$ciphertext = mcrypt_generic($this->enmcrypt, $plaintext); |
| 346 |
} else { |
| 347 |
$iv = &$this->encryptIV; |
| 348 |
$pos = &$this->enbuffer['pos']; |
| 349 |
$len = strlen($plaintext); |
| 350 |
$ciphertext = ''; |
| 351 |
$i = 0; |
| 352 |
if ($pos) { |
| 353 |
$orig_pos = $pos; |
| 354 |
$max = 8 - $pos; |
| 355 |
if ($len >= $max) { |
| 356 |
$i = $max; |
| 357 |
$len-= $max; |
| 358 |
$pos = 0; |
| 359 |
} else { |
| 360 |
$i = $len; |
| 361 |
$pos+= $len; |
| 362 |
$len = 0; |
| 363 |
} |
| 364 |
$ciphertext = substr($iv, $orig_pos) ^ $plaintext; |
| 365 |
$iv = substr_replace($iv, $ciphertext, $orig_pos, $i); |
| 366 |
$this->enbuffer['enmcrypt_init'] = true; |
| 367 |
} |
| 368 |
if ($len >= 8) { |
| 369 |
if ($this->enbuffer['enmcrypt_init'] === false || $len > 950) { |
| 370 |
if ($this->enbuffer['enmcrypt_init'] === true) { |
| 371 |
mcrypt_generic_init($this->enmcrypt, $this->key, $iv); |
| 372 |
$this->enbuffer['enmcrypt_init'] = false; |
| 373 |
} |
| 374 |
$ciphertext.= mcrypt_generic($this->enmcrypt, substr($plaintext, $i, $len - $len % 8)); |
| 375 |
$iv = substr($ciphertext, -8); |
| 376 |
$i = strlen($ciphertext); |
| 377 |
$len%= 8; |
| 378 |
} else { |
| 379 |
while ($len >= 8) { |
| 380 |
$iv = mcrypt_generic($this->ecb, $iv) ^ substr($plaintext, $i, 8); |
| 381 |
$ciphertext.= $iv; |
| 382 |
$len-= 8; |
| 383 |
$i+= 8; |
| 384 |
} |
| 385 |
} |
| 386 |
} |
| 387 |
if ($len) { |
| 388 |
$iv = mcrypt_generic($this->ecb, $iv); |
| 389 |
$block = $iv ^ substr($plaintext, $i); |
| 390 |
$iv = substr_replace($iv, $block, 0, $len); |
| 391 |
$ciphertext.= $block; |
| 392 |
$pos = $len; |
| 393 |
} |
| 394 |
return $ciphertext; |
| 395 |
} |
| 396 |
|
| 397 |
if (!$this->continuousBuffer) { |
| 398 |
mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV); |
| 399 |
} |
| 400 |
|
| 401 |
return $ciphertext; |
| 402 |
} |
| 403 |
|
| 404 |
if (strlen($this->key) <= 8) { |
| 405 |
$this->des[0]->mode = $this->mode; |
| 406 |
|
| 407 |
return $this->des[0]->encrypt($plaintext); |
| 408 |
} |
| 409 |
|
| 410 |
if ($this->use_inline_crypt) { |
| 411 |
$inline = $this->inline_crypt; |
| 412 |
return $inline('encrypt', $this, $plaintext); |
| 413 |
} |
| 414 |
|
| 415 |
$des = $this->des; |
| 416 |
|
| 417 |
$buffer = &$this->enbuffer; |
| 418 |
$continuousBuffer = $this->continuousBuffer; |
| 419 |
$ciphertext = ''; |
| 420 |
switch ($this->mode) { |
| 421 |
case CRYPT_DES_MODE_ECB: |
| 422 |
for ($i = 0; $i < strlen($plaintext); $i+=8) { |
| 423 |
$block = substr($plaintext, $i, 8); |
| 424 |
// all of these _processBlock calls could, in theory, be put in a function - say Crypt_TripleDES::_ede_encrypt() or something. |
| 425 |
// only problem with that: it would slow encryption and decryption down. $this->des would have to be called every time that |
| 426 |
// function is called, instead of once for the whole string of text that's being encrypted, which would, in turn, make |
| 427 |
// encryption and decryption take more time, per this: |
| 428 |
// |
| 429 |
// http://blog.libssh2.org/index.php?/archives/21-Compiled-Variables.html |
| 430 |
$block = $des[0]->_processBlock($block, CRYPT_DES_ENCRYPT); |
| 431 |
$block = $des[1]->_processBlock($block, CRYPT_DES_DECRYPT); |
| 432 |
$block = $des[2]->_processBlock($block, CRYPT_DES_ENCRYPT); |
| 433 |
$ciphertext.= $block; |
| 434 |
} |
| 435 |
break; |
| 436 |
case CRYPT_DES_MODE_CBC: |
| 437 |
$xor = $this->encryptIV; |
| 438 |
for ($i = 0; $i < strlen($plaintext); $i+=8) { |
| 439 |
$block = substr($plaintext, $i, 8) ^ $xor; |
| 440 |
$block = $des[0]->_processBlock($block, CRYPT_DES_ENCRYPT); |
| 441 |
$block = $des[1]->_processBlock($block, CRYPT_DES_DECRYPT); |
| 442 |
$block = $des[2]->_processBlock($block, CRYPT_DES_ENCRYPT); |
| 443 |
$xor = $block; |
| 444 |
$ciphertext.= $block; |
| 445 |
} |
| 446 |
if ($this->continuousBuffer) { |
| 447 |
$this->encryptIV = $xor; |
| 448 |
} |
| 449 |
break; |
| 450 |
case CRYPT_DES_MODE_CTR: |
| 451 |
$xor = $this->encryptIV; |
| 452 |
if (strlen($buffer['encrypted'])) { |
| 453 |
for ($i = 0; $i < strlen($plaintext); $i+=8) { |
| 454 |
$block = substr($plaintext, $i, 8); |
| 455 |
if (strlen($block) > strlen($buffer['encrypted'])) { |
| 456 |
$key = $this->_generate_xor($xor); |
| 457 |
$key = $des[0]->_processBlock($key, CRYPT_DES_ENCRYPT); |
| 458 |
$key = $des[1]->_processBlock($key, CRYPT_DES_DECRYPT); |
| 459 |
$key = $des[2]->_processBlock($key, CRYPT_DES_ENCRYPT); |
| 460 |
$buffer['encrypted'].= $key; |
| 461 |
} |
| 462 |
$key = $this->_string_shift($buffer['encrypted']); |
| 463 |
$ciphertext.= $block ^ $key; |
| 464 |
} |
| 465 |
} else { |
| 466 |
for ($i = 0; $i < strlen($plaintext); $i+=8) { |
| 467 |
$block = substr($plaintext, $i, 8); |
| 468 |
$key = $this->_generate_xor($xor); |
| 469 |
$key = $des[0]->_processBlock($key, CRYPT_DES_ENCRYPT); |
| 470 |
$key = $des[1]->_processBlock($key, CRYPT_DES_DECRYPT); |
| 471 |
$key = $des[2]->_processBlock($key, CRYPT_DES_ENCRYPT); |
| 472 |
$ciphertext.= $block ^ $key; |
| 473 |
} |
| 474 |
} |
| 475 |
if ($this->continuousBuffer) { |
| 476 |
$this->encryptIV = $xor; |
| 477 |
if ($start = strlen($plaintext) & 7) { |
| 478 |
$buffer['encrypted'] = substr($key, $start) . $buffer['encrypted']; |
| 479 |
} |
| 480 |
} |
| 481 |
break; |
| 482 |
case CRYPT_DES_MODE_CFB: |
| 483 |
if (strlen($buffer['xor'])) { |
| 484 |
$ciphertext = $plaintext ^ $buffer['xor']; |
| 485 |
$iv = $buffer['encrypted'] . $ciphertext; |
| 486 |
$start = strlen($ciphertext); |
| 487 |
$buffer['encrypted'].= $ciphertext; |
| 488 |
$buffer['xor'] = substr($buffer['xor'], strlen($ciphertext)); |
| 489 |
} else { |
| 490 |
$ciphertext = ''; |
| 491 |
$iv = $this->encryptIV; |
| 492 |
$start = 0; |
| 493 |
} |
| 494 |
|
| 495 |
for ($i = $start; $i < strlen($plaintext); $i+=8) { |
| 496 |
$block = substr($plaintext, $i, 8); |
| 497 |
$iv = $des[0]->_processBlock($iv, CRYPT_DES_ENCRYPT); |
| 498 |
$iv = $des[1]->_processBlock($iv, CRYPT_DES_DECRYPT); |
| 499 |
$xor= $des[2]->_processBlock($iv, CRYPT_DES_ENCRYPT); |
| 500 |
|
| 501 |
$iv = $block ^ $xor; |
| 502 |
if ($continuousBuffer && strlen($iv) != 8) { |
| 503 |
$buffer = array( |
| 504 |
'encrypted' => $iv, |
| 505 |
'xor' => substr($xor, strlen($iv)) |
| 506 |
); |
| 507 |
} |
| 508 |
$ciphertext.= $iv; |
| 509 |
} |
| 510 |
|
| 511 |
if ($this->continuousBuffer) { |
| 512 |
$this->encryptIV = $iv; |
| 513 |
} |
| 514 |
break; |
| 515 |
case CRYPT_DES_MODE_OFB: |
| 516 |
$xor = $this->encryptIV; |
| 517 |
if (strlen($buffer['xor'])) { |
| 518 |
for ($i = 0; $i < strlen($plaintext); $i+=8) { |
| 519 |
$block = substr($plaintext, $i, 8); |
| 520 |
if (strlen($block) > strlen($buffer['xor'])) { |
| 521 |
$xor = $des[0]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 522 |
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT); |
| 523 |
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 524 |
$buffer['xor'].= $xor; |
| 525 |
} |
| 526 |
$key = $this->_string_shift($buffer['xor']); |
| 527 |
$ciphertext.= $block ^ $key; |
| 528 |
} |
| 529 |
} else { |
| 530 |
for ($i = 0; $i < strlen($plaintext); $i+=8) { |
| 531 |
$xor = $des[0]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 532 |
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT); |
| 533 |
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 534 |
$ciphertext.= substr($plaintext, $i, 8) ^ $xor; |
| 535 |
} |
| 536 |
$key = $xor; |
| 537 |
} |
| 538 |
if ($this->continuousBuffer) { |
| 539 |
$this->encryptIV = $xor; |
| 540 |
if ($start = strlen($plaintext) & 7) { |
| 541 |
$buffer['xor'] = substr($key, $start) . $buffer['xor']; |
| 542 |
} |
| 543 |
} |
| 544 |
} |
| 545 |
|
| 546 |
return $ciphertext; |
| 547 |
} |
| 548 |
|
| 549 |
/** |
| 550 |
* Decrypts a message. |
| 551 |
* |
| 552 |
* @access public |
| 553 |
* @param String $ciphertext |
| 554 |
*/ |
| 555 |
function decrypt($ciphertext) |
| 556 |
{ |
| 557 |
if ($this->mode == CRYPT_DES_MODE_3CBC && strlen($this->key) > 8) { |
| 558 |
$plaintext = $this->des[0]->decrypt($this->des[1]->encrypt($this->des[2]->decrypt($ciphertext))); |
| 559 |
|
| 560 |
return $this->_unpad($plaintext); |
| 561 |
} |
| 562 |
|
| 563 |
if ($this->paddable) { |
| 564 |
// we pad with chr(0) since that's what mcrypt_generic does. to quote from http://php.net/function.mcrypt-generic : |
| 565 |
// "The data is padded with "\0" to make sure the length of the data is n * blocksize." |
| 566 |
$ciphertext = str_pad($ciphertext, (strlen($ciphertext) + 7) & 0xFFFFFFF8, chr(0)); |
| 567 |
} |
| 568 |
|
| 569 |
if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) { |
| 570 |
if ($this->dechanged) { |
| 571 |
mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV); |
| 572 |
if ($this->mode == 'ncfb') { |
| 573 |
mcrypt_generic_init($this->ecb, $this->key, "\0\0\0\0\0\0\0\0"); |
| 574 |
} |
| 575 |
$this->dechanged = false; |
| 576 |
} |
| 577 |
|
| 578 |
if ($this->mode != 'ncfb' || !$this->continuousBuffer) { |
| 579 |
$plaintext = mdecrypt_generic($this->demcrypt, $ciphertext); |
| 580 |
} else { |
| 581 |
$iv = &$this->decryptIV; |
| 582 |
$pos = &$this->debuffer['pos']; |
| 583 |
$len = strlen($ciphertext); |
| 584 |
$plaintext = ''; |
| 585 |
$i = 0; |
| 586 |
if ($pos) { |
| 587 |
$orig_pos = $pos; |
| 588 |
$max = 8 - $pos; |
| 589 |
if ($len >= $max) { |
| 590 |
$i = $max; |
| 591 |
$len-= $max; |
| 592 |
$pos = 0; |
| 593 |
} else { |
| 594 |
$i = $len; |
| 595 |
$pos+= $len; |
| 596 |
$len = 0; |
| 597 |
} |
| 598 |
$plaintext = substr($iv, $orig_pos) ^ $ciphertext; |
| 599 |
$iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i); |
| 600 |
} |
| 601 |
if ($len >= 8) { |
| 602 |
$cb = substr($ciphertext, $i, $len - $len % 8); |
| 603 |
$plaintext.= mcrypt_generic($this->ecb, $iv . $cb) ^ $cb; |
| 604 |
$iv = substr($cb, -8); |
| 605 |
$len%= 8; |
| 606 |
} |
| 607 |
if ($len) { |
| 608 |
$iv = mcrypt_generic($this->ecb, $iv); |
| 609 |
$cb = substr($ciphertext, -$len); |
| 610 |
$plaintext.= $iv ^ $cb; |
| 611 |
$iv = substr_replace($iv, $cb, 0, $len); |
| 612 |
$pos = $len; |
| 613 |
} |
| 614 |
return $plaintext; |
| 615 |
} |
| 616 |
|
| 617 |
if (!$this->continuousBuffer) { |
| 618 |
mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV); |
| 619 |
} |
| 620 |
|
| 621 |
return $this->paddable ? $this->_unpad($plaintext) : $plaintext; |
| 622 |
} |
| 623 |
|
| 624 |
if (strlen($this->key) <= 8) { |
| 625 |
$this->des[0]->mode = $this->mode; |
| 626 |
$plaintext = $this->des[0]->decrypt($ciphertext); |
| 627 |
return $this->paddable ? $this->_unpad($plaintext) : $plaintext; |
| 628 |
} |
| 629 |
|
| 630 |
if ($this->use_inline_crypt) { |
| 631 |
$inline = $this->inline_crypt; |
| 632 |
return $inline('decrypt', $this, $ciphertext); |
| 633 |
} |
| 634 |
|
| 635 |
$des = $this->des; |
| 636 |
|
| 637 |
$buffer = &$this->debuffer; |
| 638 |
$continuousBuffer = $this->continuousBuffer; |
| 639 |
$plaintext = ''; |
| 640 |
switch ($this->mode) { |
| 641 |
case CRYPT_DES_MODE_ECB: |
| 642 |
for ($i = 0; $i < strlen($ciphertext); $i+=8) { |
| 643 |
$block = substr($ciphertext, $i, 8); |
| 644 |
$block = $des[2]->_processBlock($block, CRYPT_DES_DECRYPT); |
| 645 |
$block = $des[1]->_processBlock($block, CRYPT_DES_ENCRYPT); |
| 646 |
$block = $des[0]->_processBlock($block, CRYPT_DES_DECRYPT); |
| 647 |
$plaintext.= $block; |
| 648 |
} |
| 649 |
break; |
| 650 |
case CRYPT_DES_MODE_CBC: |
| 651 |
$xor = $this->decryptIV; |
| 652 |
for ($i = 0; $i < strlen($ciphertext); $i+=8) { |
| 653 |
$orig = $block = substr($ciphertext, $i, 8); |
| 654 |
$block = $des[2]->_processBlock($block, CRYPT_DES_DECRYPT); |
| 655 |
$block = $des[1]->_processBlock($block, CRYPT_DES_ENCRYPT); |
| 656 |
$block = $des[0]->_processBlock($block, CRYPT_DES_DECRYPT); |
| 657 |
$plaintext.= $block ^ $xor; |
| 658 |
$xor = $orig; |
| 659 |
} |
| 660 |
if ($this->continuousBuffer) { |
| 661 |
$this->decryptIV = $xor; |
| 662 |
} |
| 663 |
break; |
| 664 |
case CRYPT_DES_MODE_CTR: |
| 665 |
$xor = $this->decryptIV; |
| 666 |
if (strlen($buffer['ciphertext'])) { |
| 667 |
for ($i = 0; $i < strlen($ciphertext); $i+=8) { |
| 668 |
$block = substr($ciphertext, $i, 8); |
| 669 |
if (strlen($block) > strlen($buffer['ciphertext'])) { |
| 670 |
$key = $this->_generate_xor($xor); |
| 671 |
$key = $des[0]->_processBlock($key, CRYPT_DES_ENCRYPT); |
| 672 |
$key = $des[1]->_processBlock($key, CRYPT_DES_DECRYPT); |
| 673 |
$key = $des[2]->_processBlock($key, CRYPT_DES_ENCRYPT); |
| 674 |
$buffer['ciphertext'].= $key; |
| 675 |
} |
| 676 |
$key = $this->_string_shift($buffer['ciphertext']); |
| 677 |
$plaintext.= $block ^ $key; |
| 678 |
} |
| 679 |
} else { |
| 680 |
for ($i = 0; $i < strlen($ciphertext); $i+=8) { |
| 681 |
$block = substr($ciphertext, $i, 8); |
| 682 |
$key = $this->_generate_xor($xor); |
| 683 |
$key = $des[0]->_processBlock($key, CRYPT_DES_ENCRYPT); |
| 684 |
$key = $des[1]->_processBlock($key, CRYPT_DES_DECRYPT); |
| 685 |
$key = $des[2]->_processBlock($key, CRYPT_DES_ENCRYPT); |
| 686 |
$plaintext.= $block ^ $key; |
| 687 |
} |
| 688 |
} |
| 689 |
if ($this->continuousBuffer) { |
| 690 |
$this->decryptIV = $xor; |
| 691 |
if ($start = strlen($plaintext) & 7) { |
| 692 |
$buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext']; |
| 693 |
} |
| 694 |
} |
| 695 |
break; |
| 696 |
case CRYPT_DES_MODE_CFB: |
| 697 |
if (strlen($buffer['ciphertext'])) { |
| 698 |
$plaintext = $ciphertext ^ substr($this->decryptIV, strlen($buffer['ciphertext'])); |
| 699 |
$buffer['ciphertext'].= substr($ciphertext, 0, strlen($plaintext)); |
| 700 |
if (strlen($buffer['ciphertext']) != 8) { |
| 701 |
$block = $this->decryptIV; |
| 702 |
} else { |
| 703 |
$block = $buffer['ciphertext']; |
| 704 |
$xor = $des[0]->_processBlock($buffer['ciphertext'], CRYPT_DES_ENCRYPT); |
| 705 |
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT); |
| 706 |
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 707 |
$buffer['ciphertext'] = ''; |
| 708 |
} |
| 709 |
$start = strlen($plaintext); |
| 710 |
} else { |
| 711 |
$plaintext = ''; |
| 712 |
$xor = $des[0]->_processBlock($this->decryptIV, CRYPT_DES_ENCRYPT); |
| 713 |
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT); |
| 714 |
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 715 |
$start = 0; |
| 716 |
} |
| 717 |
|
| 718 |
for ($i = $start; $i < strlen($ciphertext); $i+=8) { |
| 719 |
$block = substr($ciphertext, $i, 8); |
| 720 |
$plaintext.= $block ^ $xor; |
| 721 |
if ($continuousBuffer && strlen($block) != 8) { |
| 722 |
$buffer['ciphertext'].= $block; |
| 723 |
$block = $xor; |
| 724 |
} else if (strlen($block) == 8) { |
| 725 |
$xor = $des[0]->_processBlock($block, CRYPT_DES_ENCRYPT); |
| 726 |
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT); |
| 727 |
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 728 |
} |
| 729 |
} |
| 730 |
if ($this->continuousBuffer) { |
| 731 |
$this->decryptIV = $block; |
| 732 |
} |
| 733 |
break; |
| 734 |
case CRYPT_DES_MODE_OFB: |
| 735 |
$xor = $this->decryptIV; |
| 736 |
if (strlen($buffer['xor'])) { |
| 737 |
for ($i = 0; $i < strlen($ciphertext); $i+=8) { |
| 738 |
$block = substr($ciphertext, $i, 8); |
| 739 |
if (strlen($block) > strlen($buffer['xor'])) { |
| 740 |
$xor = $des[0]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 741 |
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT); |
| 742 |
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 743 |
$buffer['xor'].= $xor; |
| 744 |
} |
| 745 |
$key = $this->_string_shift($buffer['xor']); |
| 746 |
$plaintext.= $block ^ $key; |
| 747 |
} |
| 748 |
} else { |
| 749 |
for ($i = 0; $i < strlen($ciphertext); $i+=8) { |
| 750 |
$xor = $des[0]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 751 |
$xor = $des[1]->_processBlock($xor, CRYPT_DES_DECRYPT); |
| 752 |
$xor = $des[2]->_processBlock($xor, CRYPT_DES_ENCRYPT); |
| 753 |
$plaintext.= substr($ciphertext, $i, 8) ^ $xor; |
| 754 |
} |
| 755 |
$key = $xor; |
| 756 |
} |
| 757 |
if ($this->continuousBuffer) { |
| 758 |
$this->decryptIV = $xor; |
| 759 |
if ($start = strlen($ciphertext) & 7) { |
| 760 |
$buffer['xor'] = substr($key, $start) . $buffer['xor']; |
| 761 |
} |
| 762 |
} |
| 763 |
} |
| 764 |
|
| 765 |
return $this->paddable ? $this->_unpad($plaintext) : $plaintext; |
| 766 |
} |
| 767 |
|
| 768 |
/** |
| 769 |
* Treat consecutive "packets" as if they are a continuous buffer. |
| 770 |
* |
| 771 |
* Say you have a 16-byte plaintext $plaintext. Using the default behavior, the two following code snippets |
| 772 |
* will yield different outputs: |
| 773 |
* |
| 774 |
* <code> |
| 775 |
* echo $des->encrypt(substr($plaintext, 0, 8)); |
| 776 |
* echo $des->encrypt(substr($plaintext, 8, 8)); |
| 777 |
* </code> |
| 778 |
* <code> |
| 779 |
* echo $des->encrypt($plaintext); |
| 780 |
* </code> |
| 781 |
* |
| 782 |
* The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates |
| 783 |
* another, as demonstrated with the following: |
| 784 |
* |
| 785 |
* <code> |
| 786 |
* $des->encrypt(substr($plaintext, 0, 8)); |
| 787 |
* echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8))); |
| 788 |
* </code> |
| 789 |
* <code> |
| 790 |
* echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8))); |
| 791 |
* </code> |
| 792 |
* |
| 793 |
* With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different |
| 794 |
* outputs. The reason is due to the fact that the initialization vector's change after every encryption / |
| 795 |
* decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. |
| 796 |
* |
| 797 |
* Put another way, when the continuous buffer is enabled, the state of the Crypt_DES() object changes after each |
| 798 |
* encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that |
| 799 |
* continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), |
| 800 |
* however, they are also less intuitive and more likely to cause you problems. |
| 801 |
* |
| 802 |
* @see Crypt_TripleDES::disableContinuousBuffer() |
| 803 |
* @access public |
| 804 |
*/ |
| 805 |
function enableContinuousBuffer() |
| 806 |
{ |
| 807 |
$this->continuousBuffer = true; |
| 808 |
if ($this->mode == CRYPT_DES_MODE_3CBC) { |
| 809 |
$this->des[0]->enableContinuousBuffer(); |
| 810 |
$this->des[1]->enableContinuousBuffer(); |
| 811 |
$this->des[2]->enableContinuousBuffer(); |
| 812 |
} |
| 813 |
} |
| 814 |
|
| 815 |
/** |
| 816 |
* Treat consecutive packets as if they are a discontinuous buffer. |
| 817 |
* |
| 818 |
* The default behavior. |
| 819 |
* |
| 820 |
* @see Crypt_TripleDES::enableContinuousBuffer() |
| 821 |
* @access public |
| 822 |
*/ |
| 823 |
function disableContinuousBuffer() |
| 824 |
{ |
| 825 |
$this->continuousBuffer = false; |
| 826 |
$this->encryptIV = $this->iv; |
| 827 |
$this->decryptIV = $this->iv; |
| 828 |
$this->enchanged = true; |
| 829 |
$this->dechanged = true; |
| 830 |
$this->enbuffer = array('encrypted' => '', 'xor' => '', 'pos' => 0, 'enmcrypt_init' => true); |
| 831 |
$this->debuffer = array('ciphertext' => '', 'xor' => '', 'pos' => 0, 'demcrypt_init' => true); |
| 832 |
|
| 833 |
if ($this->mode == CRYPT_DES_MODE_3CBC) { |
| 834 |
$this->des[0]->disableContinuousBuffer(); |
| 835 |
$this->des[1]->disableContinuousBuffer(); |
| 836 |
$this->des[2]->disableContinuousBuffer(); |
| 837 |
} |
| 838 |
} |
| 839 |
} |
| 840 |
|
| 841 |
// vim: ts=4:sw=4:et: |
| 842 |
// vim6: fdl=1: |
| 843 |
|
