View file File name : TripleDES.php Content :<?php /** * 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: Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. * * @category Crypt * @package Crypt_TripleDES * @author Jim Wigginton <terrafrost@php.net> * @copyright 2007 Jim Wigginton * @license http://www.opensource.org/licenses/mit-license.html MIT License * @link http://phpseclib.sourceforge.net */ /** * Include Crypt_DES */ if (!class_exists('Crypt_DES')) { include_once 'DES.php'; } /**#@+ * @access public * @see self::Crypt_TripleDES() */ /** * 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_MODE_3CBC', -2); /** * BC version of the above. */ define('CRYPT_DES_MODE_3CBC', -2); /** * 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_MODE_CBC3', CRYPT_MODE_CBC); /** * BC version of the above. */ define('CRYPT_DES_MODE_CBC3', CRYPT_MODE_CBC3); /**#@-*/ /** * Pure-PHP implementation of Triple DES. * * @package Crypt_TripleDES * @author Jim Wigginton <terrafrost@php.net> * @access public */ class Crypt_TripleDES extends Crypt_DES { /** * Key Length (in bytes) * * @see Crypt_TripleDES::setKeyLength() * @var int * @access private */ var $key_length = 24; /** * The default salt used by setPassword() * * @see Crypt_Base::password_default_salt * @see Crypt_Base::setPassword() * @var string * @access private */ var $password_default_salt = 'phpseclib'; /** * The namespace used by the cipher for its constants. * * @see Crypt_DES::const_namespace * @see Crypt_Base::const_namespace * @var string * @access private */ var $const_namespace = 'DES'; /** * The mcrypt specific name of the cipher * * @see Crypt_DES::cipher_name_mcrypt * @see Crypt_Base::cipher_name_mcrypt * @var string * @access private */ var $cipher_name_mcrypt = 'tripledes'; /** * Optimizing value while CFB-encrypting * * @see Crypt_Base::cfb_init_len * @var int * @access private */ var $cfb_init_len = 750; /** * max possible size of $key * * @see self::setKey() * @see Crypt_DES::setKey() * @var string * @access private */ var $key_length_max = 24; /** * Internal flag whether using CRYPT_DES_MODE_3CBC or not * * @var bool * @access private */ var $mode_3cbc; /** * The Crypt_DES objects * * Used only if $mode_3cbc === true * * @var array * @access private */ var $des; /** * Default Constructor. * * Determines whether or not the mcrypt extension should be used. * * $mode could be: * * - CRYPT_DES_MODE_ECB * * - CRYPT_DES_MODE_CBC * * - CRYPT_DES_MODE_CTR * * - CRYPT_DES_MODE_CFB * * - CRYPT_DES_MODE_OFB * * - CRYPT_DES_MODE_3CBC * * If not explicitly set, CRYPT_DES_MODE_CBC will be used. * * @see Crypt_DES::Crypt_DES() * @see Crypt_Base::Crypt_Base() * @param int $mode * @access public */ function __construct($mode = CRYPT_MODE_CBC) { switch ($mode) { // In case of CRYPT_DES_MODE_3CBC, we init as CRYPT_DES_MODE_CBC // and additional flag us internally as 3CBC case CRYPT_DES_MODE_3CBC: parent::Crypt_Base(CRYPT_MODE_CBC); $this->mode_3cbc = true; // This three $des'es will do the 3CBC work (if $key > 64bits) $this->des = array( new Crypt_DES(CRYPT_MODE_CBC), new Crypt_DES(CRYPT_MODE_CBC), new Crypt_DES(CRYPT_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(); $this->des[2]->disablePadding(); break; // If not 3CBC, we init as usual default: parent::__construct($mode); } } /** * PHP4 compatible Default Constructor. * * @see self::__construct() * @param int $mode * @access public */ function Crypt_TripleDES($mode = CRYPT_MODE_CBC) { $this->__construct($mode); } /** * Test for engine validity * * This is mainly just a wrapper to set things up for Crypt_Base::isValidEngine() * * @see Crypt_Base::Crypt_Base() * @param int $engine * @access public * @return bool */ function isValidEngine($engine) { if ($engine == CRYPT_ENGINE_OPENSSL) { $this->cipher_name_openssl_ecb = 'des-ede3'; $mode = $this->_openssl_translate_mode(); $this->cipher_name_openssl = $mode == 'ecb' ? 'des-ede3' : 'des-ede3-' . $mode; } return parent::isValidEngine($engine); } /** * Sets the initialization vector. (optional) * * SetIV is not required when CRYPT_DES_MODE_ECB is being used. If not explicitly set, it'll be assumed * to be all zero's. * * @see Crypt_Base::setIV() * @access public * @param string $iv */ function setIV($iv) { parent::setIV($iv); if ($this->mode_3cbc) { $this->des[0]->setIV($iv); $this->des[1]->setIV($iv); $this->des[2]->setIV($iv); } } /** * Sets the key length. * * Valid key lengths are 64, 128 and 192 * * @see Crypt_Base:setKeyLength() * @access public * @param int $length */ function setKeyLength($length) { $length >>= 3; switch (true) { case $length <= 8: $this->key_length = 8; break; case $length <= 16: $this->key_length = 16; break; default: $this->key_length = 24; } parent::setKeyLength($length); } /** * 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 null bytes. * * @access public * @see Crypt_DES::setKey() * @see Crypt_Base::setKey() * @param string $key */ function setKey($key) { $length = $this->explicit_key_length ? $this->key_length : strlen($key); if ($length > 8) { $key = str_pad(substr($key, 0, 24), 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); } else { $key = str_pad($key, 8, chr(0)); } parent::setKey($key); // And in case of CRYPT_DES_MODE_3CBC: // if key <= 64bits we not need the 3 $des to work, // because we will then act as regular DES-CBC with just a <= 64bit key. // So only if the key > 64bits (> 8 bytes) we will call setKey() for the 3 $des. if ($this->mode_3cbc && $length > 8) { $this->des[0]->setKey(substr($key, 0, 8)); $this->des[1]->setKey(substr($key, 8, 8)); $this->des[2]->setKey(substr($key, 16, 8)); } } /** * Encrypts a message. * * @see Crypt_Base::encrypt() * @access public * @param string $plaintext * @return string $cipertext */ function encrypt($plaintext) { // parent::en/decrypt() is able to do all the work for all modes and keylengths, // except for: CRYPT_MODE_3CBC (inner chaining CBC) with a key > 64bits // if the key is smaller then 8, do what we'd normally do if ($this->mode_3cbc && strlen($this->key) > 8) { return $this->des[2]->encrypt( $this->des[1]->decrypt( $this->des[0]->encrypt( $this->_pad($plaintext) ) ) ); } return parent::encrypt($plaintext); } /** * Decrypts a message. * * @see Crypt_Base::decrypt() * @access public * @param string $ciphertext * @return string $plaintext */ function decrypt($ciphertext) { if ($this->mode_3cbc && strlen($this->key) > 8) { return $this->_unpad( $this->des[0]->decrypt( $this->des[1]->encrypt( $this->des[2]->decrypt( str_pad($ciphertext, (strlen($ciphertext) + 7) & 0xFFFFFFF8, "\0") ) ) ) ); } return parent::decrypt($ciphertext); } /** * 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($plaintext, 8, 8))); * </code> * * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different * outputs. The reason is due to the fact that the initialization vector's change after every encryption / * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. * * Put another way, when the continuous buffer is enabled, the state of the Crypt_DES() object changes after each * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), * however, they are also less intuitive and more likely to cause you problems. * * @see Crypt_Base::enableContinuousBuffer() * @see self::disableContinuousBuffer() * @access public */ function enableContinuousBuffer() { parent::enableContinuousBuffer(); if ($this->mode_3cbc) { $this->des[0]->enableContinuousBuffer(); $this->des[1]->enableContinuousBuffer(); $this->des[2]->enableContinuousBuffer(); } } /** * Treat consecutive packets as if they are a discontinuous buffer. * * The default behavior. * * @see Crypt_Base::disableContinuousBuffer() * @see self::enableContinuousBuffer() * @access public */ function disableContinuousBuffer() { parent::disableContinuousBuffer(); if ($this->mode_3cbc) { $this->des[0]->disableContinuousBuffer(); $this->des[1]->disableContinuousBuffer(); $this->des[2]->disableContinuousBuffer(); } } /** * Creates the key schedule * * @see Crypt_DES::_setupKey() * @see Crypt_Base::_setupKey() * @access private */ function _setupKey() { switch (true) { // if $key <= 64bits we configure our internal pure-php cipher engine // to act as regular [1]DES, not as 3DES. mcrypt.so::tripledes does the same. case strlen($this->key) <= 8: $this->des_rounds = 1; break; // otherwise, if $key > 64bits, we configure our engine to work as 3DES. default: $this->des_rounds = 3; // (only) if 3CBC is used we have, of course, to setup the $des[0-2] keys also separately. if ($this->mode_3cbc) { $this->des[0]->_setupKey(); $this->des[1]->_setupKey(); $this->des[2]->_setupKey(); // because $des[0-2] will, now, do all the work we can return here // not need unnecessary stress parent::_setupKey() with our, now unused, $key. return; } } // setup our key parent::_setupKey(); } /** * Sets the internal crypt engine * * @see Crypt_Base::Crypt_Base() * @see Crypt_Base::setPreferredEngine() * @param int $engine * @access public * @return int */ function setPreferredEngine($engine) { if ($this->mode_3cbc) { $this->des[0]->setPreferredEngine($engine); $this->des[1]->setPreferredEngine($engine); $this->des[2]->setPreferredEngine($engine); } return parent::setPreferredEngine($engine); } }