<?php

class DES

{

  var $key;

  var $iv; //偏移量

  function DES($key = '11001100', $iv=0 ) {

  //key长度8例如:1234abcd

    $this->key = $key;

    if( $iv == 0 ) {

      $this->iv = $key; //默认以$key 作为 iv

    } else {

      $this->iv = $iv; //mcrypt_create_iv ( mcrypt_get_block_size (MCRYPT_DES, MCRYPT_MODE_CBC), MCRYPT_DEV_RANDOM );

    }

  }

  function encrypt($str) {

  //加密，返回大写十六进制字符串

    $size = mcrypt_get_block_size ( MCRYPT_DES, MCRYPT_MODE_CBC );

    $str = $this->pkcs5Pad ( $str, $size );

    return strtoupper( bin2hex( mcrypt_cbc(MCRYPT_DES, $this->key, $str, MCRYPT_ENCRYPT, $this->iv ) ) );

  }

  function decrypt($str) {

  //解密

    $strBin = $this->hex2bin( strtolower( $str ) );

    $str = mcrypt_cbc( MCRYPT_DES, $this->key, $strBin, MCRYPT_DECRYPT, $this->iv );

    $str = $this->pkcs5Unpad( $str );

    return $str;

  }

  function hex2bin($hexData) {

    $binData = "";

    for($i = 0; $i < strlen ( $hexData ); $i += 2) {

      $binData .= chr ( hexdec ( substr ( $hexData, $i, 2 ) ) );

    }

    return $binData;

  }

  function pkcs5Pad($text, $blocksize) {

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

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

  }

  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;

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

  }

}

?>

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Security.Cryptography;

using System.Text;

namespace WindowsFormsApplication1

{

  /// <summary>

  /// DES加密解密字符串

  /// </summary>

  public class DesEncryption

  {

    /// <summary>

    /// DES加密字符串

    /// </summary>

    /// <param name="encryptString">待加密的字符串</param>

    /// <param name="encryptKey">加密密钥,要求为8位</param>

    /// <returns>加密成功返回加密后的字符串，失败返回null</returns>

    public static string EncryptDES(string encryptString, string encryptKey = "")

    {

      try

      {

        byte[] rgbKey = ASCIIEncoding.ASCII.GetBytes(encryptKey.Substring(, ));

        byte[] rgbIV = rgbKey;

        byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);

        DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();

        MemoryStream mStream = new MemoryStream();

        CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);

        cStream.Write(inputByteArray, , inputByteArray.Length);

        cStream.FlushFinalBlock();

        StringBuilder ret = new StringBuilder();

        foreach (byte b in mStream.ToArray())

        {

          ret.AppendFormat("{0:X2}", b);

        }

        ret.ToString();

        return ret.ToString();

      }

      catch

      {

        return null;

      }

    }

    /// <summary>

    /// DES解密字符串

    /// </summary>

    /// <param name="decryptString">待解密的字符串</param>

    /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>

    /// <returns>解密成功返回解密后的字符串，失败返回null</returns>

    public static string DecryptDES(string decryptString, string decryptKey = "")

    {

      try

      {

        byte[] rgbKey = ASCIIEncoding.ASCII.GetBytes(decryptKey);

        byte[] rgbIV = rgbKey;

        byte[] inputByteArray = new byte[decryptString.Length / ];

        for (int x = ; x < decryptString.Length / ; x++)

        {

          int i = (Convert.ToInt32(decryptString.Substring(x * , ), ));

          inputByteArray[x] = (byte)i;

        }

        DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();

        MemoryStream mStream = new MemoryStream();

        CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);

        cStream.Write(inputByteArray, , inputByteArray.Length);

        cStream.FlushFinalBlock();

        return Encoding.UTF8.GetString(mStream.ToArray());

      }

      catch

      {

        return null;

      }

    }

  }

}