diff options
author | James Walker <walkah@walkah.net> | 2010-03-12 20:01:34 -0500 |
---|---|---|
committer | James Walker <walkah@walkah.net> | 2010-03-12 20:01:34 -0500 |
commit | 520faaf67d7bd7bb0a87322d3f2e244c22d0c994 (patch) | |
tree | 283f77bdd779b38a0f3ab299278665d4b5459887 /plugins/OStatus/extlib/Crypt/TripleDES.php | |
parent | c5bb41176ee246369e05b932f031f40e38087f23 (diff) |
updating phpseclib to latest cvs - fixes a bunch of key generation issues
Diffstat (limited to 'plugins/OStatus/extlib/Crypt/TripleDES.php')
-rw-r--r-- | plugins/OStatus/extlib/Crypt/TripleDES.php | 1291 |
1 files changed, 689 insertions, 602 deletions
diff --git a/plugins/OStatus/extlib/Crypt/TripleDES.php b/plugins/OStatus/extlib/Crypt/TripleDES.php index 03050e5d6..9d054086a 100644 --- a/plugins/OStatus/extlib/Crypt/TripleDES.php +++ b/plugins/OStatus/extlib/Crypt/TripleDES.php @@ -1,603 +1,690 @@ -<?php
-/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
-
-/**
- * Pure-PHP implementation of Triple DES.
- *
- * Uses mcrypt, if available, and an internal implementation, otherwise. Operates in the EDE3 mode (encrypt-decrypt-encrypt).
- *
- * PHP versions 4 and 5
- *
- * Here's a short example of how to use this library:
- * <code>
- * <?php
- * include('Crypt/TripleDES.php');
- *
- * $des = new Crypt_TripleDES();
- *
- * $des->setKey('abcdefghijklmnopqrstuvwx');
- *
- * $size = 10 * 1024;
- * $plaintext = '';
- * for ($i = 0; $i < $size; $i++) {
- * $plaintext.= 'a';
- * }
- *
- * echo $des->decrypt($des->encrypt($plaintext));
- * ?>
- * </code>
- *
- * LICENSE: This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- *
- * @category Crypt
- * @package Crypt_TripleDES
- * @author Jim Wigginton <terrafrost@php.net>
- * @copyright MMVII Jim Wigginton
- * @license http://www.gnu.org/licenses/lgpl.txt
- * @version $Id: TripleDES.php,v 1.9 2009/11/23 19:06:07 terrafrost Exp $
- * @link http://phpseclib.sourceforge.net
- */
-
-/**
- * Include Crypt_DES
- */
-require_once 'DES.php';
-
-/**
- * Encrypt / decrypt using inner chaining
- *
- * Inner chaining is used by SSH-1 and is generally considered to be less secure then outer chaining (CRYPT_DES_MODE_CBC3).
- */
-define('CRYPT_DES_MODE_3CBC', 3);
-
-/**
- * Encrypt / decrypt using outer chaining
- *
- * Outer chaining is used by SSH-2 and when the mode is set to CRYPT_DES_MODE_CBC.
- */
-define('CRYPT_DES_MODE_CBC3', CRYPT_DES_MODE_CBC);
-
-/**
- * Pure-PHP implementation of Triple DES.
- *
- * @author Jim Wigginton <terrafrost@php.net>
- * @version 0.1.0
- * @access public
- * @package Crypt_TerraDES
- */
-class Crypt_TripleDES {
- /**
- * The Three Keys
- *
- * @see Crypt_TripleDES::setKey()
- * @var String
- * @access private
- */
- var $key = "\0\0\0\0\0\0\0\0";
-
- /**
- * The Encryption Mode
- *
- * @see Crypt_TripleDES::Crypt_TripleDES()
- * @var Integer
- * @access private
- */
- var $mode = CRYPT_DES_MODE_CBC;
-
- /**
- * Continuous Buffer status
- *
- * @see Crypt_TripleDES::enableContinuousBuffer()
- * @var Boolean
- * @access private
- */
- var $continuousBuffer = false;
-
- /**
- * Padding status
- *
- * @see Crypt_TripleDES::enablePadding()
- * @var Boolean
- * @access private
- */
- var $padding = true;
-
- /**
- * The Initialization Vector
- *
- * @see Crypt_TripleDES::setIV()
- * @var String
- * @access private
- */
- var $iv = "\0\0\0\0\0\0\0\0";
-
- /**
- * A "sliding" Initialization Vector
- *
- * @see Crypt_TripleDES::enableContinuousBuffer()
- * @var String
- * @access private
- */
- var $encryptIV = "\0\0\0\0\0\0\0\0";
-
- /**
- * A "sliding" Initialization Vector
- *
- * @see Crypt_TripleDES::enableContinuousBuffer()
- * @var String
- * @access private
- */
- var $decryptIV = "\0\0\0\0\0\0\0\0";
-
- /**
- * MCrypt parameters
- *
- * @see Crypt_TripleDES::setMCrypt()
- * @var Array
- * @access private
- */
- var $mcrypt = array('', '');
-
- /**
- * The Crypt_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 $mode
- * @return Crypt_TripleDES
- * @access public
- */
- function Crypt_TripleDES($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 Crypt_DES(CRYPT_DES_MODE_CBC),
- new Crypt_DES(CRYPT_DES_MODE_CBC),
- new Crypt_DES(CRYPT_DES_MODE_CBC)
- );
-
- // we're going to be doing the padding, ourselves, so disable it in the Crypt_DES objects
- $this->des[0]->disablePadding();
- $this->des[1]->disablePadding();
- $this->des[2]->disablePadding();
-
- return;
- }
-
- switch ( CRYPT_DES_MODE ) {
- case CRYPT_DES_MODE_MCRYPT:
- switch ($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 Crypt_DES(CRYPT_DES_MODE_ECB),
- new Crypt_DES(CRYPT_DES_MODE_ECB),
- new Crypt_DES(CRYPT_DES_MODE_ECB)
- );
-
- // we're going to be doing the padding, ourselves, so disable it in the Crypt_DES objects
- $this->des[0]->disablePadding();
- $this->des[1]->disablePadding();
- $this->des[2]->disablePadding();
-
- switch ($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 $key
- */
- function setKey($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:
- $this->des[0]->setKey(substr($key, 0, 8));
- $this->des[1]->setKey(substr($key, 8, 8));
- $this->des[2]->setKey(substr($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 $iv
- */
- function setIV($iv)
- {
- $this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($iv, 0, 8), 8, chr(0));
- if ($this->mode == CRYPT_DES_MODE_3CBC) {
- $this->des[0]->setIV($iv);
- $this->des[1]->setIV($iv);
- $this->des[2]->setIV($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 $mode_directory
- */
- function setMCrypt($algorithm_directory = '', $mode_directory = '')
- {
- $this->mcrypt = array($algorithm_directory, $mode_directory);
- if ( $this->mode == CRYPT_DES_MODE_3CBC ) {
- $this->des[0]->setMCrypt($algorithm_directory, $mode_directory);
- $this->des[1]->setMCrypt($algorithm_directory, $mode_directory);
- $this->des[2]->setMCrypt($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 = $this->des[0]->_processBlock($block, CRYPT_DES_ENCRYPT);
- $block = $this->des[1]->_processBlock($block, CRYPT_DES_DECRYPT);
- $block = $this->des[2]->_processBlock($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 = $this->des[0]->_processBlock($block, CRYPT_DES_ENCRYPT);
- $block = $this->des[1]->_processBlock($block, CRYPT_DES_DECRYPT);
- $block = $this->des[2]->_processBlock($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 = $this->des[2]->_processBlock($block, CRYPT_DES_DECRYPT);
- $block = $this->des[1]->_processBlock($block, CRYPT_DES_ENCRYPT);
- $block = $this->des[0]->_processBlock($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 = $this->des[2]->_processBlock($block, CRYPT_DES_DECRYPT);
- $block = $this->des[1]->_processBlock($block, CRYPT_DES_ENCRYPT);
- $block = $this->des[0]->_processBlock($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 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, padding will be, hence forth, disabled.
- *
- * @see Crypt_TripleDES::_pad()
- * @access private
- */
- function _unpad($text)
- {
- if (!$this->padding) {
- return $text;
- }
-
- $length = ord($text[strlen($text) - 1]);
-
- if (!$length || $length > 8) {
- user_error("The number of bytes reported as being padded ($length) is invalid (block size = 8)", E_USER_NOTICE);
- $this->padding = false;
- return $text;
- }
-
- return substr($text, 0, -$length);
- }
-}
-
-// vim: ts=4:sw=4:et:
+<?php +/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */ + +/** + * Pure-PHP implementation of Triple DES. + * + * Uses mcrypt, if available, and an internal implementation, otherwise. Operates in the EDE3 mode (encrypt-decrypt-encrypt). + * + * PHP versions 4 and 5 + * + * Here's a short example of how to use this library: + * <code> + * <?php + * include('Crypt/TripleDES.php'); + * + * $des = new Crypt_TripleDES(); + * + * $des->setKey('abcdefghijklmnopqrstuvwx'); + * + * $size = 10 * 1024; + * $plaintext = ''; + * for ($i = 0; $i < $size; $i++) { + * $plaintext.= 'a'; + * } + * + * echo $des->decrypt($des->encrypt($plaintext)); + * ?> + * </code> + * + * LICENSE: This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + * @category Crypt + * @package Crypt_TripleDES + * @author Jim Wigginton <terrafrost@php.net> + * @copyright MMVII Jim Wigginton + * @license http://www.gnu.org/licenses/lgpl.txt + * @version $Id: TripleDES.php,v 1.13 2010/02/26 03:40:25 terrafrost Exp $ + * @link http://phpseclib.sourceforge.net + */ + +/** + * Include Crypt_DES + */ +require_once 'DES.php'; + +/** + * Encrypt / decrypt using inner chaining + * + * Inner chaining is used by SSH-1 and is generally considered to be less secure then outer chaining (CRYPT_DES_MODE_CBC3). + */ +define('CRYPT_DES_MODE_3CBC', 3); + +/** + * Encrypt / decrypt using outer chaining + * + * Outer chaining is used by SSH-2 and when the mode is set to CRYPT_DES_MODE_CBC. + */ +define('CRYPT_DES_MODE_CBC3', CRYPT_DES_MODE_CBC); + +/** + * Pure-PHP implementation of Triple DES. + * + * @author Jim Wigginton <terrafrost@php.net> + * @version 0.1.0 + * @access public + * @package Crypt_TerraDES + */ +class Crypt_TripleDES { + /** + * The Three Keys + * + * @see Crypt_TripleDES::setKey() + * @var String + * @access private + */ + var $key = "\0\0\0\0\0\0\0\0"; + + /** + * The Encryption Mode + * + * @see Crypt_TripleDES::Crypt_TripleDES() + * @var Integer + * @access private + */ + var $mode = CRYPT_DES_MODE_CBC; + + /** + * Continuous Buffer status + * + * @see Crypt_TripleDES::enableContinuousBuffer() + * @var Boolean + * @access private + */ + var $continuousBuffer = false; + + /** + * Padding status + * + * @see Crypt_TripleDES::enablePadding() + * @var Boolean + * @access private + */ + var $padding = true; + + /** + * The Initialization Vector + * + * @see Crypt_TripleDES::setIV() + * @var String + * @access private + */ + var $iv = "\0\0\0\0\0\0\0\0"; + + /** + * A "sliding" Initialization Vector + * + * @see Crypt_TripleDES::enableContinuousBuffer() + * @var String + * @access private + */ + var $encryptIV = "\0\0\0\0\0\0\0\0"; + + /** + * A "sliding" Initialization Vector + * + * @see Crypt_TripleDES::enableContinuousBuffer() + * @var String + * @access private + */ + var $decryptIV = "\0\0\0\0\0\0\0\0"; + + /** + * The Crypt_DES objects + * + * @var Array + * @access private + */ + var $des; + + /** + * mcrypt resource for encryption + * + * The mcrypt resource can be recreated every time something needs to be created or it can be created just once. + * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode. + * + * @see Crypt_AES::encrypt() + * @var String + * @access private + */ + var $enmcrypt; + + /** + * mcrypt resource for decryption + * + * The mcrypt resource can be recreated every time something needs to be created or it can be created just once. + * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode. + * + * @see Crypt_AES::decrypt() + * @var String + * @access private + */ + var $demcrypt; + + /** + * Does the (en|de)mcrypt resource need to be (re)initialized? + * + * @see setKey() + * @see setIV() + * @var Boolean + * @access private + */ + var $changed = true; + + /** + * 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 $mode + * @return Crypt_TripleDES + * @access public + */ + function Crypt_TripleDES($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 Crypt_DES(CRYPT_DES_MODE_CBC), + new Crypt_DES(CRYPT_DES_MODE_CBC), + new Crypt_DES(CRYPT_DES_MODE_CBC) + ); + + // we're going to be doing the padding, ourselves, so disable it in the Crypt_DES objects + $this->des[0]->disablePadding(); + $this->des[1]->disablePadding(); + $this->des[2]->disablePadding(); + + return; + } + + switch ( CRYPT_DES_MODE ) { + case CRYPT_DES_MODE_MCRYPT: + switch ($mode) { + case CRYPT_DES_MODE_ECB: + $this->mode = MCRYPT_MODE_ECB; + break; + case CRYPT_DES_MODE_CTR: + $this->mode = 'ctr'; + break; + case CRYPT_DES_MODE_CBC: + default: + $this->mode = MCRYPT_MODE_CBC; + } + + break; + default: + $this->des = array( + new Crypt_DES(CRYPT_DES_MODE_ECB), + new Crypt_DES(CRYPT_DES_MODE_ECB), + new Crypt_DES(CRYPT_DES_MODE_ECB) + ); + + // we're going to be doing the padding, ourselves, so disable it in the Crypt_DES objects + $this->des[0]->disablePadding(); + $this->des[1]->disablePadding(); + $this->des[2]->disablePadding(); + + switch ($mode) { + case CRYPT_DES_MODE_ECB: + case CRYPT_DES_MODE_CTR: + 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 $key + */ + function setKey($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: + $this->des[0]->setKey(substr($key, 0, 8)); + $this->des[1]->setKey(substr($key, 8, 8)); + $this->des[2]->setKey(substr($key, 16, 8)); + } + $this->changed = true; + } + + /** + * 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) + { + $this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($iv, 0, 8), 8, chr(0)); + if ($this->mode == CRYPT_DES_MODE_3CBC) { + $this->des[0]->setIV($iv); + $this->des[1]->setIV($iv); + $this->des[2]->setIV($iv); + } + $this->changed = 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_DES::decrypt() + * @see Crypt_DES::encrypt() + * @access public + * @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->mode != CRYPT_DES_MODE_CTR && $this->mode != 'ctr') { + $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->changed) { + if (!isset($this->enmcrypt)) { + $this->enmcrypt = mcrypt_module_open(MCRYPT_3DES, '', $this->mode, ''); + } + mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV); + $this->changed = false; + } + + $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext); + + if (!$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); + } + + // 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)); + + $des = $this->des; + + $ciphertext = ''; + switch ($this->mode) { + case CRYPT_DES_MODE_ECB: + for ($i = 0; $i < strlen($plaintext); $i+=8) { + $block = substr($plaintext, $i, 8); + $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 = $this->encryptIV; + for ($i = 0; $i < strlen($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); + $block = substr($plaintext, $i, 8); + $ciphertext.= $block ^ $key; + } + if ($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($ciphertext) + 7) & 0xFFFFFFF8, chr(0)); + + if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) { + if ($this->changed) { + if (!isset($this->demcrypt)) { + $this->demcrypt = mcrypt_module_open(MCRYPT_3DES, '', $this->mode, ''); + } + mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV); + $this->changed = false; + } + + $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext); + + if (!$this->continuousBuffer) { + mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV); + } + + return $this->mode != 'ctr' ? $this->_unpad($plaintext) : $plaintext; + } + + if (strlen($this->key) <= 8) { + $this->des[0]->mode = $this->mode; + + return $this->_unpad($this->des[0]->decrypt($plaintext)); + } + + $des = $this->des; + + $plaintext = ''; + switch ($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 = $this->decryptIV; + for ($i = 0; $i < strlen($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); + $block = substr($ciphertext, $i, 8); + $plaintext.= $block ^ $key; + } + if ($this->continuousBuffer) { + $this->decryptIV = $xor; + } + } + + return $this->mode != CRYPT_DES_MODE_CTR ? $this->_unpad($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); + } +} + +// vim: ts=4:sw=4:et: // vim6: fdl=1:
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