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Diffstat (limited to 'phpsec/Crypt/RC4.php')
| -rw-r--r-- | phpsec/Crypt/RC4.php | 493 |
1 files changed, 0 insertions, 493 deletions
diff --git a/phpsec/Crypt/RC4.php b/phpsec/Crypt/RC4.php deleted file mode 100644 index 6f82b2413..000000000 --- a/phpsec/Crypt/RC4.php +++ /dev/null @@ -1,493 +0,0 @@ -<?php
-/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
-
-/**
- * Pure-PHP implementation of RC4.
- *
- * Uses mcrypt, if available, and an internal implementation, otherwise.
- *
- * PHP versions 4 and 5
- *
- * Useful resources are as follows:
- *
- * - {@link http://www.mozilla.org/projects/security/pki/nss/draft-kaukonen-cipher-arcfour-03.txt ARCFOUR Algorithm}
- * - {@link http://en.wikipedia.org/wiki/RC4 - Wikipedia: RC4}
- *
- * RC4 is also known as ARCFOUR or ARC4. The reason is elaborated upon at Wikipedia. This class is named RC4 and not
- * ARCFOUR or ARC4 because RC4 is how it is refered to in the SSH1 specification.
- *
- * Here's a short example of how to use this library:
- * <code>
- * <?php
- * include('Crypt/RC4.php');
- *
- * $rc4 = new Crypt_RC4();
- *
- * $rc4->setKey('abcdefgh');
- *
- * $size = 10 * 1024;
- * $plaintext = '';
- * for ($i = 0; $i < $size; $i++) {
- * $plaintext.= 'a';
- * }
- *
- * echo $rc4->decrypt($rc4->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_RC4
- * @author Jim Wigginton <terrafrost@php.net>
- * @copyright MMVII Jim Wigginton
- * @license http://www.gnu.org/licenses/lgpl.txt
- * @version $Id: RC4.php,v 1.8 2009/06/09 04:00:38 terrafrost Exp $
- * @link http://phpseclib.sourceforge.net
- */
-
-/**#@+
- * @access private
- * @see Crypt_RC4::Crypt_RC4()
- */
-/**
- * Toggles the internal implementation
- */
-define('CRYPT_RC4_MODE_INTERNAL', 1);
-/**
- * Toggles the mcrypt implementation
- */
-define('CRYPT_RC4_MODE_MCRYPT', 2);
-/**#@-*/
-
-/**#@+
- * @access private
- * @see Crypt_RC4::_crypt()
- */
-define('CRYPT_RC4_ENCRYPT', 0);
-define('CRYPT_RC4_DECRYPT', 1);
-/**#@-*/
-
-/**
- * Pure-PHP implementation of RC4.
- *
- * @author Jim Wigginton <terrafrost@php.net>
- * @version 0.1.0
- * @access public
- * @package Crypt_RC4
- */
-class Crypt_RC4 {
- /**
- * The Key
- *
- * @see Crypt_RC4::setKey()
- * @var String
- * @access private
- */
- var $key = "\0";
-
- /**
- * The Key Stream for encryption
- *
- * If CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT, this will be equal to the mcrypt object
- *
- * @see Crypt_RC4::setKey()
- * @var Array
- * @access private
- */
- var $encryptStream = false;
-
- /**
- * The Key Stream for decryption
- *
- * If CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT, this will be equal to the mcrypt object
- *
- * @see Crypt_RC4::setKey()
- * @var Array
- * @access private
- */
- var $decryptStream = false;
-
- /**
- * The $i and $j indexes for encryption
- *
- * @see Crypt_RC4::_crypt()
- * @var Integer
- * @access private
- */
- var $encryptIndex = 0;
-
- /**
- * The $i and $j indexes for decryption
- *
- * @see Crypt_RC4::_crypt()
- * @var Integer
- * @access private
- */
- var $decryptIndex = 0;
-
- /**
- * MCrypt parameters
- *
- * @see Crypt_RC4::setMCrypt()
- * @var Array
- * @access private
- */
- var $mcrypt = array('', '');
-
- /**
- * The Encryption Algorithm
- *
- * Only used if CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT. Only possible values are MCRYPT_RC4 or MCRYPT_ARCFOUR.
- *
- * @see Crypt_RC4::Crypt_RC4()
- * @var Integer
- * @access private
- */
- var $mode;
-
- /**
- * Default Constructor.
- *
- * Determines whether or not the mcrypt extension should be used.
- *
- * @param optional Integer $mode
- * @return Crypt_RC4
- * @access public
- */
- function Crypt_RC4()
- {
- if ( !defined('CRYPT_RC4_MODE') ) {
- switch (true) {
- case extension_loaded('mcrypt') && (defined('MCRYPT_ARCFOUR') || defined('MCRYPT_RC4')):
- // i'd check to see if rc4 was supported, by doing in_array('arcfour', 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_RC4_MODE', CRYPT_RC4_MODE_MCRYPT);
- break;
- default:
- define('CRYPT_RC4_MODE', CRYPT_RC4_MODE_INTERNAL);
- }
- }
-
- switch ( CRYPT_RC4_MODE ) {
- case CRYPT_RC4_MODE_MCRYPT:
- switch (true) {
- case defined('MCRYPT_ARCFOUR'):
- $this->mode = MCRYPT_ARCFOUR;
- break;
- case defined('MCRYPT_RC4');
- $this->mode = MCRYPT_RC4;
- }
- }
- }
-
- /**
- * Sets the key.
- *
- * Keys can be between 1 and 256 bytes long. If they are longer then 256 bytes, the first 256 bytes will
- * be used. If no key is explicitly set, it'll be assumed to be a single null byte.
- *
- * @access public
- * @param String $key
- */
- function setKey($key)
- {
- $this->key = $key;
-
- if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
- return;
- }
-
- $keyLength = strlen($key);
- $keyStream = array();
- for ($i = 0; $i < 256; $i++) {
- $keyStream[$i] = $i;
- }
- $j = 0;
- for ($i = 0; $i < 256; $i++) {
- $j = ($j + $keyStream[$i] + ord($key[$i % $keyLength])) & 255;
- $temp = $keyStream[$i];
- $keyStream[$i] = $keyStream[$j];
- $keyStream[$j] = $temp;
- }
-
- $this->encryptIndex = $this->decryptIndex = array(0, 0);
- $this->encryptStream = $this->decryptStream = $keyStream;
- }
-
- /**
- * Dummy function.
- *
- * Some protocols, such as WEP, prepend an "initialization vector" to the key, effectively creating a new key [1].
- * If you need to use an initialization vector in this manner, feel free to prepend it to the key, yourself, before
- * calling setKey().
- *
- * [1] WEP's initialization vectors (IV's) are used in a somewhat insecure way. Since, in that protocol,
- * the IV's are relatively easy to predict, an attack described by
- * {@link http://www.drizzle.com/~aboba/IEEE/rc4_ksaproc.pdf Scott Fluhrer, Itsik Mantin, and Adi Shamir}
- * can be used to quickly guess at the rest of the key. The following links elaborate:
- *
- * {@link http://www.rsa.com/rsalabs/node.asp?id=2009 http://www.rsa.com/rsalabs/node.asp?id=2009}
- * {@link http://en.wikipedia.org/wiki/Related_key_attack http://en.wikipedia.org/wiki/Related_key_attack}
- *
- * @param String $iv
- * @see Crypt_RC4::setKey()
- * @access public
- */
- function setIV($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 = '')
- {
- if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
- $this->mcrypt = array($algorithm_directory, $mode_directory);
- $this->_closeMCrypt();
- }
- }
-
- /**
- * Encrypts a message.
- *
- * @see Crypt_RC4::_crypt()
- * @access public
- * @param String $plaintext
- */
- function encrypt($plaintext)
- {
- return $this->_crypt($plaintext, CRYPT_RC4_ENCRYPT);
- }
-
- /**
- * Decrypts a message.
- *
- * $this->decrypt($this->encrypt($plaintext)) == $this->encrypt($this->encrypt($plaintext)).
- * Atleast if the continuous buffer is disabled.
- *
- * @see Crypt_RC4::_crypt()
- * @access public
- * @param String $ciphertext
- */
- function decrypt($ciphertext)
- {
- return $this->_crypt($ciphertext, CRYPT_RC4_DECRYPT);
- }
-
- /**
- * Encrypts or decrypts a message.
- *
- * @see Crypt_RC4::encrypt()
- * @see Crypt_RC4::decrypt()
- * @access private
- * @param String $text
- * @param Integer $mode
- */
- function _crypt($text, $mode)
- {
- if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
- $keyStream = $mode == CRYPT_RC4_ENCRYPT ? 'encryptStream' : 'decryptStream';
-
- if ($this->$keyStream === false) {
- $this->$keyStream = mcrypt_module_open($this->mode, $this->mcrypt[0], MCRYPT_MODE_STREAM, $this->mcrypt[1]);
- mcrypt_generic_init($this->$keyStream, $this->key, '');
- } else if (!$this->continuousBuffer) {
- mcrypt_generic_init($this->$keyStream, $this->key, '');
- }
- $newText = mcrypt_generic($this->$keyStream, $text);
- if (!$this->continuousBuffer) {
- mcrypt_generic_deinit($this->$keyStream);
- }
-
- return $newText;
- }
-
- if ($this->encryptStream === false) {
- $this->setKey($this->key);
- }
-
- switch ($mode) {
- case CRYPT_RC4_ENCRYPT:
- $keyStream = $this->encryptStream;
- list($i, $j) = $this->encryptIndex;
- break;
- case CRYPT_RC4_DECRYPT:
- $keyStream = $this->decryptStream;
- list($i, $j) = $this->decryptIndex;
- }
-
- $newText = '';
- for ($k = 0; $k < strlen($text); $k++) {
- $i = ($i + 1) & 255;
- $j = ($j + $keyStream[$i]) & 255;
- $temp = $keyStream[$i];
- $keyStream[$i] = $keyStream[$j];
- $keyStream[$j] = $temp;
- $temp = $keyStream[($keyStream[$i] + $keyStream[$j]) & 255];
- $newText.= chr(ord($text[$k]) ^ $temp);
- }
-
- if ($this->continuousBuffer) {
- switch ($mode) {
- case CRYPT_RC4_ENCRYPT:
- $this->encryptStream = $keyStream;
- $this->encryptIndex = array($i, $j);
- break;
- case CRYPT_RC4_DECRYPT:
- $this->decryptStream = $keyStream;
- $this->decryptIndex = array($i, $j);
- }
- }
-
- return $newText;
- }
-
- /**
- * 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 $rc4->encrypt(substr($plaintext, 0, 8));
- * echo $rc4->encrypt(substr($plaintext, 8, 8));
- * </code>
- * <code>
- * echo $rc4->encrypt($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>
- * $rc4->encrypt(substr($plaintext, 0, 8));
- * echo $rc4->decrypt($des->encrypt(substr($plaintext, 8, 8)));
- * </code>
- * <code>
- * echo $rc4->decrypt($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_RC4::disableContinuousBuffer()
- * @access public
- */
- function enableContinuousBuffer()
- {
- $this->continuousBuffer = true;
- }
-
- /**
- * Treat consecutive packets as if they are a discontinuous buffer.
- *
- * The default behavior.
- *
- * @see Crypt_RC4::enableContinuousBuffer()
- * @access public
- */
- function disableContinuousBuffer()
- {
- if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_INTERNAL ) {
- $this->encryptIndex = $this->decryptIndex = array(0, 0);
- $this->setKey($this->key);
- }
-
- $this->continuousBuffer = false;
- }
-
- /**
- * Dummy function.
- *
- * Since RC4 is a stream cipher and not a block cipher, no padding is necessary. The only reason this function is
- * included is so that you can switch between a block cipher and a stream cipher transparently.
- *
- * @see Crypt_RC4::disablePadding()
- * @access public
- */
- function enablePadding()
- {
- }
-
- /**
- * Dummy function.
- *
- * @see Crypt_RC4::enablePadding()
- * @access public
- */
- function disablePadding()
- {
- }
-
- /**
- * Class destructor.
- *
- * Will be called, automatically, if you're using PHP5. If you're using PHP4, call it yourself. Only really
- * needs to be called if mcrypt is being used.
- *
- * @access public
- */
- function __destruct()
- {
- if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
- $this->_closeMCrypt();
- }
- }
-
- /**
- * Properly close the MCrypt objects.
- *
- * @access prviate
- */
- function _closeMCrypt()
- {
- if ( $this->encryptStream !== false ) {
- if ( $this->continuousBuffer ) {
- mcrypt_generic_deinit($this->encryptStream);
- }
-
- mcrypt_module_close($this->encryptStream);
-
- $this->encryptStream = false;
- }
-
- if ( $this->decryptStream !== false ) {
- if ( $this->continuousBuffer ) {
- mcrypt_generic_deinit($this->decryptStream);
- }
-
- mcrypt_module_close($this->decryptStream);
-
- $this->decryptStream = false;
- }
- }
-}
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