php实现的rc4加密解密类定义与用法示例


Posted in PHP onAugust 16, 2018

本文实例讲述了php实现的rc4加密解密类。分享给大家供大家参考,具体如下:

class.rc4crypt.php文件:

<?php
/* 
 * By julying.com
 */
define('CRYPT_RC4_MODE_INTERNAL', 1);
define('CRYPT_RC4_MODE_MCRYPT', 2);
define('CRYPT_RC4_ENCRYPT', 0);
define('CRYPT_RC4_DECRYPT', 1);
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
  */
 var $continuousBuffer ;
 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 self::toHex($this->_crypt($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)
 {
  $ciphertext = self::fromHex($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);
   $this->decryptStream = false;
  }
 }
 // @function fromHex 把十六进制数转换成字符串
 function toHex($sa , $len = 0){
  $buf = "";
  if( $len == 0 )
   $len = strlen($sa) ;
  for ($i = 0; $i < $len; $i++)
  {
   $val = dechex(ord($sa{$i}));  
   if(strlen($val)< 2) 
    $val = "0".$val;
   $buf .= $val;
  }
  return $buf;
 }
 // @function fromHex 把十六进制数转换成字符串 
 function fromHex($sa){
  $buf = "";
  $len = strlen($sa) ;
  for($i = 0; $i < $len; $i += 2){
   $val = chr(hexdec(substr($sa, $i, 2)));
   $buf .= $val;
  }
  return $buf;
 }
}

使用方法:

include('class.rc4crypt.php');
$rc4 = new Crypt_RC4();
$rc4 -> setKey('21sd54a1w5q');
$text = '3water.com';
echo $x = $rc4->encrypt($text);//加密
echo '<br />';
echo $rc4->decrypt( $x) ;//解密

运行结果:

7907bb7c6694f179e9642ebd
3water.com

PHP 相关文章推荐
php self,$this,const,static,-&amp;gt;的使用
Oct 22 PHP
PHP Memcached + APC + 文件缓存封装实现代码
Mar 11 PHP
PHP Undefined index报错的修复方法
Jul 17 PHP
PHP的异常处理类Exception的使用及说明
Jun 13 PHP
php笔记之:初探PHPcms模块开发介绍
Apr 26 PHP
php5.3提示Function ereg() is deprecated Error问题解决方法
Nov 12 PHP
PHP中的事务使用实例
May 26 PHP
PHP翻页跳转功能实现方法
Nov 30 PHP
php获取文件后缀的9种方法
Mar 22 PHP
php面向对象编程self和static的区别
May 08 PHP
Yii框架中sphinx索引配置方法解析
Oct 18 PHP
浅谈PHP SHA1withRSA加密生成签名及验签
Mar 18 PHP
Laravel框架实现定时发布任务的方法
Aug 16 #PHP
Laravel框架使用monolog_mysql实现将系统日志信息保存到mysql数据库的方法
Aug 16 #PHP
Laravel中的chunk组块结果集处理与注意问题
Aug 15 #PHP
PHP curl批处理及多请求并发实现方法分析
Aug 15 #PHP
php使用curl_init()和curl_multi_init()多线程的速度比较详解
Aug 15 #PHP
php使用curl获取header检测开启GZip压缩的方法
Aug 15 #PHP
深入研究PHP中的preg_replace和代码执行
Aug 15 #PHP
You might like
深入解析php模板技术原理【一】
2008/01/10 PHP
用php将任何格式视频转为flv的代码
2009/09/03 PHP
php数据库的增删改查 php与javascript之间的交互
2017/08/31 PHP
PHP递归实现汉诺塔问题的方法示例
2017/11/25 PHP
网上应用的一个不错common.js脚本
2007/08/08 Javascript
JavaScript 获取任一float型小数点后两位的小数
2014/06/30 Javascript
解决js下referer兼容各大浏览器的方法
2014/11/03 Javascript
Vue.JS入门教程之事件监听
2016/12/01 Javascript
Vue.js学习之计算属性
2017/01/22 Javascript
JSON与js对象序列化实例详解
2017/03/16 Javascript
详解AngularJS1.6版本中ui-router路由中/#!/的解决方法
2017/05/22 Javascript
解决vue-cli单页面手机应用input点击手机端虚拟键盘弹出盖住input问题
2018/08/25 Javascript
解决layui弹出层layer的area过大被遮挡的问题
2019/09/21 Javascript
JS+html5实现异步上传图片显示上传文件进度条功能示例
2019/11/09 Javascript
在Vue中使用mockjs代码实例
2020/11/25 Vue.js
python基础教程之序列详解
2014/08/29 Python
python urllib urlopen()对象方法/代理的补充说明
2017/06/29 Python
浅谈Tensorflow由于版本问题出现的几种错误及解决方法
2018/06/13 Python
django用户登录和注销的实现方法
2018/07/16 Python
pandas pivot_table() 按日期分多列数据的方法
2018/11/16 Python
浅谈Scrapy网络爬虫框架的工作原理和数据采集
2019/02/07 Python
Django REST framework 分页的实现代码
2019/06/19 Python
Python实现企业微信机器人每天定时发消息实例
2020/02/25 Python
Python利用FFT进行简单滤波的实现
2020/02/26 Python
使用Python合成图片的实现代码(图片添加个性化文本,图片上叠加其他图片)
2020/04/30 Python
用Python制作音乐海报
2021/01/26 Python
美国隐形眼镜零售商:LensPure
2019/03/10 全球购物
Viking Direct爱尔兰:办公用品和家具
2019/11/21 全球购物
Shopping happy life西班牙:以最优惠的价格提供最好的时尚配饰
2020/03/13 全球购物
JSF如何进行表格处理及取值
2012/08/06 面试题
搬家公司的创业计划书
2014/01/01 职场文书
求职信模板怎么做
2014/01/26 职场文书
排查整治工作方案
2014/06/09 职场文书
电子商务求职信
2014/06/15 职场文书
小学生2014国庆节演讲稿:祖国在我心中
2014/09/21 职场文书
助学金申请书该怎么写?
2019/07/16 职场文书