php对称加密算法示例_php实例

KEY 是之前定义的常量

代码如下:

Mcrypt::encrypt();
Mcrypt::decrypt();

代码如下:

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

代码如下:

/**
* 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");
}

$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
*/
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;
}
}

上面类的使用方法

代码如下:

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

include "xcrypt.php";

echo '

';    
$a = isset($_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 '