php對稱加密算法（DES/AES）類代碼

/**


常用對稱加密算法類
支持密鑰：64/128/256 bit（字節長度8/16/32）
支持算法：DES/AES（根據密鑰長度自動匹配使用：DES:64bit AES:128/256bit）
支持模式：CBC/ECB/OFB/CFB
密文編碼：base64字符串/十六進制字符串/二進制字符串流
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;
/**

構造函數
*
@param string 密鑰
@param string 模式
@param string 向量（"off":不使用 / "auto":自動 / 其他:指定值，長度同密鑰）
*/ 
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"); 

}
$this->key = $key;
switch (strtolower($mode)){ 
 case 'ofb':

 $this->mode = MCRYPT_MODE_OFB; 
 if ($iv == 'off') die('OFB must give a IV'); //OFB必須有向量 
 break; 

case 'cfb':

 $this->mode = MCRYPT_MODE_CFB; 
 if ($iv == 'off') die('CFB must give a IV'); //CFB必須有向量 
 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; 

}





} 


/**
 * 獲取向量值
 * @param string 向量值編碼（base64/hex/bin）
 * @return string 向量值
 */ 
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 密文編碼（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 密文編碼（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); 
    } 

    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; 
} 




} 
 </pre> 使用示例：
<?php 
header('Content-Type:text/html;Charset=utf-8;');

include "xcrypt.php";
echo '<pre>'; 
////////////////////////////////////// 
$a = isset($_GET['a']) ? $_GET['a'] : '測試123';
//密鑰 
$key = '12345678123456781234567812345678'; //256 bit 
$key = '1234567812345678'; //128 bit 
$key = '12345678'; //64 bit
//設置模式和IV 
$m = new Xcrypt($key, 'cbc', 'auto');
//獲取向量值 
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>';  </pre>