php对称加密算法示例

  php对称加密算法

  KEY 是之前定义的常量

  

复制代码 代码如下:

  Mcrypt::encrypt();

  Mcrypt::decrypt();

  

复制代码 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

  

复制代码 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

  

复制代码 代码如下:

  <?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>';