php对称加密算法的例子

分享下php对称加密算法的实现代码。

KEY 是之前定义的常量

Mcrypt::encrypt();

Mcrypt::decrypt();



defined('ROOT') or exit('Access Denied');

class Mcrypt{



public static function encrypt($code){

return base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5(KEY), $code, MCRYPT_MODE_ECB, mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND)));

}



public static function decrypt($code){

return mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5(KEY), base64_decode($code), MCRYPT_MODE_ECB, mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND));

}

}

常用对称加密算法（DES/AES）类

xcrypt.php

/** 

* 常用对称加密算法类 

* 支持密钥：64/128/256 bit（字节长度8/16/32） 

* 支持算法：DES/AES（根据密钥长度自动匹配使用：DES:64bit AES:128/256bit） 

* 支持模式：CBC/ECB/OFB/CFB 

* 密文编码：base64字符串/十六进制字符串/二进制字符串流 

* 填充方式: PKCS5Padding（DES） 

* 

* @author: linvo 

* @version: 1.0.0 

* @date: 2013/1/10 

*/ 

class Xcrypt{



private $mcrypt; 

private $key; 

private $mode; 

private $iv; 

private $blocksize;



/** 

* 构造函数 

* 

* @param string 密钥 

* @param string 模式 

* @param string 向量（"off":不使用 / "auto":自动 / 其他:指定值，长度同密钥） 

*/ 

public function __construct($key, $mode = 'cbc', $iv = "off"){ 

switch (strlen($key)){ 

case 8: 

$this->mcrypt = MCRYPT_DES; 

break; 

case 16: 

$this->mcrypt = MCRYPT_RIJNDAEL_128; 

break; 

case 32: 

$this->mcrypt = MCRYPT_RIJNDAEL_256; 

break; 

default: 

die("Key size must be 8/16/32"); 

} www.jbxue.com



$this->key = $key;



switch (strtolower($mode)){ 

case 'ofb': 

$this->mode = MCRYPT_MODE_OFB; 

if ($iv == 'off') die('OFB must give a IV'); //OFB必须有向量 

break; 

case 'cfb': 

$this->mode = MCRYPT_MODE_CFB; 

if ($iv == 'off') die('CFB must give a IV'); //CFB必须有向量 

break; 

case 'ecb': 

$this->mode = MCRYPT_MODE_ECB; 

$iv = 'off'; //ECB不需要向量 

break; 

case 'cbc': 

default: 

$this->mode = MCRYPT_MODE_CBC; 

}



switch (strtolower($iv)){ 

case "off": 

$this->iv = null; 

break; 

case "auto": 

$source = PHP_OS=='WINNT' ? MCRYPT_RAND : MCRYPT_DEV_RANDOM; 

$this->iv = mcrypt_create_iv(mcrypt_get_block_size($this->mcrypt, $this->mode), $source); 

break; 

default: 

$this->iv = $iv; 

} 

}



/** 

* 获取向量值 

* @param string 向量值编码（base64/hex/bin） 

* @return string 向量值 

*/  www.jbxue.com

public function getIV($code = 'base64'){ 

switch ($code){ 

case 'base64': 

$ret = base64_encode($this->iv); 

break; 

case 'hex': 

$ret = bin2hex($this->iv); 

break; 

case 'bin': 

default: 

$ret = $this->iv; 

} 

return $ret; 

} 



/** 

* 加密 

* @param string 明文 

* @param string 密文编码（base64/hex/bin） 

* @return string 密文 

*/ 

public function encrypt($str, $code = 'base64'){ 

if ($this->mcrypt == MCRYPT_DES) $str = $this->_pkcs5Pad($str);



if (isset($this->iv)) { 

$result = mcrypt_encrypt($this->mcrypt, $this->key, $str, $this->mode, $this->iv); 

} else { 

@$result = mcrypt_encrypt($this->mcrypt, $this->key, $str, $this->mode); 

}



switch ($code){ 

case 'base64': 

$ret = base64_encode($result); 

break; 

case 'hex': 

$ret = bin2hex($result); 

break; 

case 'bin': 

default: 

$ret = $result; 

}



return $ret;



}



/** 

* 解密 

* @param string 密文 

* @param string 密文编码（base64/hex/bin） 

* @return string 明文 

*/ 

public function decrypt($str, $code = "base64"){ 

$ret = false;



switch ($code){ 

case 'base64': 

$str = base64_decode($str); 

break; 

case 'hex': 

$str = $this->_hex2bin($str); 

break; 

case 'bin': 

default: 

}



if ($str !== false){ 

if (isset($this->iv)) { 

$ret = mcrypt_decrypt($this->mcrypt, $this->key, $str, $this->mode, $this->iv); 

} else { 

@$ret = mcrypt_decrypt($this->mcrypt, $this->key, $str, $this->mode); 

} 

if ($this->mcrypt == MCRYPT_DES) $ret = $this->_pkcs5Unpad($ret); 

$ret = trim($ret); 

}



return $ret; 

}



private function _pkcs5Pad($text){ 

$this->blocksize = mcrypt_get_block_size($this->mcrypt, $this->mode); 

$pad = $this->blocksize - (strlen($text) % $this->blocksize); 

return $text . str_repeat(chr($pad), $pad); 

}



private function _pkcs5Unpad($text){ 

$pad = ord($text{strlen($text) - 1}); 

if ($pad > strlen($text)) return false; 

if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) return false; 

$ret = substr($text, 0, -1 * $pad); 

return $ret; 

}



private function _hex2bin($hex = false){ 

$ret = $hex !== false && preg_match('/^[0-9a-fA-F]+$/i', $hex) ? pack("H*", $hex) : false; 

return $ret; 

} 

} 

上面php加密算法类的使用方法

<?php 

header('Content-Type:text/html;Charset=utf-8;');



include "xcrypt.php";



echo '<pre>'; 

$a = isset($_GET['a']) ? $_GET['a'] : '测试123';



//密钥 

$key = '12345678123456781234567812345678'; //256 bit 

$key = '1234567812345678'; //128 bit 

$key = '12345678'; //64 bit



//设置模式和IV 

$m = new Xcrypt($key, 'cbc', 'auto');



//获取向量值 

echo '向量：'; 

var_dump($m->getIV());



//加密 

$b = $m->encrypt($a, 'base64'); 

//解密 

$c = $m->decrypt($b, 'base64');



echo '加密后：'; 

var_dump($b); 

echo '解密后：'; 

var_dump($c); 

echo '</pre>';