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本文实例讲述了PHP实现的DES加密解密类定义与用法。分享给大家供大家参考，具体如下：

今天写App接口的时候需要传递加密数据给APP端，于是就写了下面的DES加密类，亲测正确代码如下

class CryptDes {
  function __construct(){
    $this->key = 'codelovers'; //密钥
    $this->iv = '15548632'; //偏移量
  }
  /*
   * 加密
   */
  function encrypt($input){
    $size = mcrypt_get_block_size(MCRYPT_DES,MCRYPT_MODE_CBC); //3DES加密将MCRYPT_DES改为MCRYPT_3DES
    $input = $this->pkcs5_pad($input, $size); //如果采用PaddingPKCS7，请更换成PaddingPKCS7方法。
    $key = str_pad($this->key,8,'0'); //3DES加密将8改为24
    $td = mcrypt_module_open(MCRYPT_DES, '', MCRYPT_MODE_CBC, '');
    if( $this->iv == '' )
    {
      $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
    }
    else
    {
      $iv = $this->iv;
    }
    @mcrypt_generic_init($td, $key, $iv);
    $data = mcrypt_generic($td, $input);
    mcrypt_generic_deinit($td);
    mcrypt_module_close($td);
    $data = base64_encode($data);//如需转换二进制可改成 bin2hex 转换
    return $data;
  }
  /*
   * 解密
   */
  function decrypt($encrypted){
    $encrypted = base64_decode($encrypted); //如需转换二进制可改成 bin2hex 转换
    $key = str_pad($this->key,8,'0'); //3DES加密将8改为24
    $td = mcrypt_module_open(MCRYPT_DES,'',MCRYPT_MODE_CBC,'');//3DES加密将MCRYPT_DES改为MCRYPT_3DES
    if( $this->iv == '' )
    {
      $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
    }
    else
    {
      $iv = $this->iv;
    }
    $ks = mcrypt_enc_get_key_size($td);
    @mcrypt_generic_init($td, $key, $iv);
    $decrypted = mdecrypt_generic($td, $encrypted);
    mcrypt_generic_deinit($td);
    mcrypt_module_close($td);
    $y=$this->pkcs5_unpad($decrypted);
    return $y;
  }
  function pkcs5_pad ($text, $blocksize) {
    $pad = $blocksize - (strlen($text) % $blocksize);
    return $text . str_repeat(chr($pad), $pad);
  }
  function pkcs5_unpad($text){
    $pad = ord($text{strlen($text)-1});
    if ($pad > strlen($text)) {
      return false;
    }
    if (strspn($text, chr($pad), strlen($text) - $pad) != $pad){
      return false;
    }
    return substr($text, 0, -1 * $pad);
  }
  function PaddingPKCS7($data) {
    $block_size = mcrypt_get_block_size(MCRYPT_DES, MCRYPT_MODE_CBC);//3DES加密将MCRYPT_DES改为MCRYPT_3DES
    $padding_char = $block_size - (strlen($data) % $block_size);
    $data .= str_repeat(chr($padding_char),$padding_char);
    return $data;
  }
}

用法如下：

$str = 'www.jb51.net';
$des = new CryptDes();
$mres = $des->encrypt($str); //加密
echo $mres."<br/>";
$jres = $des->decrypt($mres); //解密
echo $jres."<br/>";

运行结果：