mirror of
https://github.com/danog/tgseclib.git
synced 2024-12-11 16:49:41 +01:00
727dba5905
These lines served some purpose on SVN, but are now useless on Git. They actually do harm as they might make people think their files are older than they actually are.
518 lines
16 KiB
PHP
518 lines
16 KiB
PHP
<?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 referred 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: 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_RC4
|
|
* @author Jim Wigginton <terrafrost@php.net>
|
|
* @copyright MMVII Jim Wigginton
|
|
* @license http://www.opensource.org/licenses/mit-license.html MIT License
|
|
* @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;
|
|
|
|
/**
|
|
* 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;
|
|
|
|
/**
|
|
* Continuous Buffer status
|
|
*
|
|
* @see Crypt_RC4::enableContinuousBuffer()
|
|
* @var Boolean
|
|
* @access private
|
|
*/
|
|
var $continuousBuffer = false;
|
|
|
|
/**
|
|
* Default Constructor.
|
|
*
|
|
* Determines whether or not the mcrypt extension should be used.
|
|
*
|
|
* @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')) && in_array('arcfour', mcrypt_list_algorithms()):
|
|
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;
|
|
}
|
|
$this->encryptStream = mcrypt_module_open($this->mode, '', MCRYPT_MODE_STREAM, '');
|
|
$this->decryptStream = mcrypt_module_open($this->mode, '', MCRYPT_MODE_STREAM, '');
|
|
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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 = $key;
|
|
|
|
if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
|
|
mcrypt_generic_init($this->encryptStream, $this->key, '');
|
|
mcrypt_generic_init($this->decryptStream, $this->key, '');
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* Sets the password.
|
|
*
|
|
* Depending on what $method is set to, setPassword()'s (optional) parameters are as follows:
|
|
* {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2}:
|
|
* $hash, $salt, $count, $dkLen
|
|
*
|
|
* @param String $password
|
|
* @param optional String $method
|
|
* @access public
|
|
*/
|
|
function setPassword($password, $method = 'pbkdf2')
|
|
{
|
|
$key = '';
|
|
|
|
switch ($method) {
|
|
default: // 'pbkdf2'
|
|
list(, , $hash, $salt, $count) = func_get_args();
|
|
if (!isset($hash)) {
|
|
$hash = 'sha1';
|
|
}
|
|
// WPA and WPA2 use the SSID as the salt
|
|
if (!isset($salt)) {
|
|
$salt = 'phpseclib/salt';
|
|
}
|
|
// RFC2898#section-4.2 uses 1,000 iterations by default
|
|
// WPA and WPA2 use 4,096.
|
|
if (!isset($count)) {
|
|
$count = 1000;
|
|
}
|
|
if (!isset($dkLen)) {
|
|
$dkLen = 128;
|
|
}
|
|
|
|
if (!class_exists('Crypt_Hash')) {
|
|
require_once('Crypt/Hash.php');
|
|
}
|
|
|
|
$i = 1;
|
|
while (strlen($key) < $dkLen) {
|
|
//$dk.= $this->_pbkdf($password, $salt, $count, $i++);
|
|
$hmac = new Crypt_Hash();
|
|
$hmac->setHash($hash);
|
|
$hmac->setKey($password);
|
|
$f = $u = $hmac->hash($salt . pack('N', $i++));
|
|
for ($j = 2; $j <= $count; $j++) {
|
|
$u = $hmac->hash($u);
|
|
$f^= $u;
|
|
}
|
|
$key.= $f;
|
|
}
|
|
}
|
|
|
|
$this->setKey(substr($key, 0, $dkLen));
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* 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->continuousBuffer) {
|
|
mcrypt_generic_init($this->$keyStream, $this->key, '');
|
|
}
|
|
|
|
return mcrypt_generic($this->$keyStream, $text);
|
|
}
|
|
|
|
if ($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($plaintext, 8, 8)));
|
|
* </code>
|
|
*
|
|
* With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different
|
|
* outputs. The reason is due to the fact that the initialization vector's change after every encryption /
|
|
* decryption round when the continuous buffer is enabled. When it's disabled, they remain constant.
|
|
*
|
|
* Put another way, when the continuous buffer is enabled, the state of the Crypt_DES() object changes after each
|
|
* encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that
|
|
* continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them),
|
|
* however, they are also less intuitive and more likely to cause you problems.
|
|
*
|
|
* @see Crypt_RC4::disableContinuousBuffer()
|
|
* @access public
|
|
*/
|
|
function enableContinuousBuffer()
|
|
{
|
|
if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
|
|
mcrypt_generic_init($this->encryptStream, $this->key, '');
|
|
mcrypt_generic_init($this->decryptStream, $this->key, '');
|
|
}
|
|
|
|
$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->encryptStream = $this->decryptStream = false;
|
|
}
|
|
|
|
$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 ) {
|
|
$this->_closeMCrypt();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Properly close the MCrypt objects.
|
|
*
|
|
* @access prviate
|
|
*/
|
|
function _closeMCrypt()
|
|
{
|
|
mcrypt_module_close($this->encryptStream);
|
|
mcrypt_module_close($this->decryptStream);
|
|
}
|
|
}
|
|
|
|
// vim: ts=4:sw=4:et:
|
|
// vim6: fdl=1:
|