EVOLUTION-MANAGER
Edit File: TripleDES.php
<?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 version 5 * * Here's a short example of how to use this library: * <code> * <?php * include 'vendor/autoload.php'; * * $des = new \phpseclib\Crypt\TripleDES(); * * $des->setKey('abcdefghijklmnopqrstuvwx'); * * $size = 10 * 1024; * $plaintext = ''; * for ($i = 0; $i < $size; $i++) { * $plaintext.= 'a'; * } * * echo $des->decrypt($des->encrypt($plaintext)); * ?> * </code> * * @category Crypt * @package 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 */ namespace phpseclib\Crypt; defined("ABSPATH") or die(""); use phpseclib\Crypt\Base; use phpseclib\Crypt\DES; /** * Pure-PHP implementation of Triple DES. * * @package TripleDES * @author Jim Wigginton <terrafrost@php.net> * @access public */ class TripleDES extends DES { /** * Encrypt / decrypt using inner chaining * * Inner chaining is used by SSH-1 and is generally considered to be less secure then outer chaining (self::MODE_CBC3). */ const MODE_3CBC = -2; /** * Encrypt / decrypt using outer chaining * * Outer chaining is used by SSH-2 and when the mode is set to \phpseclib\Crypt\Base::MODE_CBC. */ const MODE_CBC3 = Base::MODE_CBC; /** * The default password key_size used by setPassword() * * @see \phpseclib\Crypt\DES::password_key_size * @see \phpseclib\Crypt\Base::password_key_size * @see \phpseclib\Crypt\Base::setPassword() * @var Integer * @access private */ var $password_key_size = 24; /** * The default salt used by setPassword() * * @see \phpseclib\Crypt\Base::password_default_salt * @see \phpseclib\Crypt\Base::setPassword() * @var String * @access private */ var $password_default_salt = 'phpseclib'; /** * The mcrypt specific name of the cipher * * @see \phpseclib\Crypt\DES::cipher_name_mcrypt * @see \phpseclib\Crypt\Base::cipher_name_mcrypt * @var String * @access private */ var $cipher_name_mcrypt = 'tripledes'; /** * Optimizing value while CFB-encrypting * * @see \phpseclib\Crypt\Base::cfb_init_len * @var Integer * @access private */ var $cfb_init_len = 750; /** * max possible size of $key * * @see \phpseclib\Crypt\TripleDES::setKey() * @see \phpseclib\Crypt\DES::setKey() * @var String * @access private */ var $key_size_max = 24; /** * Internal flag whether using self::MODE_3CBC or not * * @var Boolean * @access private */ var $mode_3cbc; /** * The \phpseclib\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: * * - \phpseclib\Crypt\Base::MODE_ECB * * - \phpseclib\Crypt\Base::MODE_CBC * * - \phpseclib\Crypt\Base::MODE_CTR * * - \phpseclib\Crypt\Base::MODE_CFB * * - \phpseclib\Crypt\Base::MODE_OFB * * - \phpseclib\Crypt\TripleDES::MODE_3CBC * * If not explicitly set, \phpseclib\Crypt\Base::MODE_CBC will be used. * * @see \phpseclib\Crypt\DES::__construct() * @see \phpseclib\Crypt\Base::__construct() * @param optional Integer $mode * @access public */ function __construct($mode = Base::MODE_CBC) { switch ($mode) { // In case of self::MODE_3CBC, we init as CRYPT_DES_MODE_CBC // and additional flag us internally as 3CBC case self::MODE_3CBC: parent::__construct(Base::MODE_CBC); $this->mode_3cbc = true; // This three $des'es will do the 3CBC work (if $key > 64bits) $this->des = array( new DES(Base::MODE_CBC), new DES(Base::MODE_CBC), new DES(Base::MODE_CBC), ); // we're going to be doing the padding, ourselves, so disable it in the \phpseclib\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); } } /** * Test for engine validity * * This is mainly just a wrapper to set things up for \phpseclib\Crypt\Base::isValidEngine() * * @see \phpseclib\Crypt\Base::Crypt_Base() * @param Integer $engine * @access public * @return Boolean */ function isValidEngine($engine) { if ($engine == self::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 \phpseclib\Crypt\Base::MODE_ECB is being used. If not explicitly set, it'll be assumed * to be all zero's. * * @see \phpseclib\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. * * 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 \phpseclib\Crypt\DES::setKey() * @see \phpseclib\Crypt\Base::setKey() * @param String $key */ function setKey($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 self::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 \phpseclib\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: self::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 \phpseclib\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($plaintext, 8, 8))); * </code> * * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different * outputs. The reason is due to the fact that the initialization vector's change after every encryption / * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. * * Put another way, when the continuous buffer is enabled, the state of the \phpseclib\Crypt\DES() object changes after each * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), * however, they are also less intuitive and more likely to cause you problems. * * @see \phpseclib\Crypt\Base::enableContinuousBuffer() * @see \phpseclib\Crypt\TripleDES::disableContinuousBuffer() * @access public */ function enableContinuousBuffer() { parent::enableContinuousBuffer(); if ($this->mode_3cbc) { $this->des[0]->enableContinuousBuffer(); $this->des[1]->enableContinuousBuffer(); $this->des[2]->enableContinuousBuffer(); } } /** * Treat consecutive packets as if they are a discontinuous buffer. * * The default behavior. * * @see \phpseclib\Crypt\Base::disableContinuousBuffer() * @see \phpseclib\Crypt\TripleDES::enableContinuousBuffer() * @access public */ function disableContinuousBuffer() { parent::disableContinuousBuffer(); if ($this->mode_3cbc) { $this->des[0]->disableContinuousBuffer(); $this->des[1]->disableContinuousBuffer(); $this->des[2]->disableContinuousBuffer(); } } /** * Creates the key schedule * * @see \phpseclib\Crypt\DES::_setupKey() * @see \phpseclib\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 \phpseclib\Crypt\Base::Crypt_Base() * @see \phpseclib\Crypt\Base::setPreferredEngine() * @param Integer $engine * @access public * @return Integer */ function setPreferredEngine($engine) { if ($this->mode_3cbc) { $this->des[0]->setPreferredEngine($engine); $this->des[1]->setPreferredEngine($engine); $this->des[2]->setPreferredEngine($engine); } return parent::setPreferredEngine($engine); } }