using System;

using System.Text;

using System.IO;

using System.Security.Cryptography;

public partial class _Default : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        Response.Write("<a href = " + "http://www.baidu.com?" + Encode("id=12345&name=jack", "jiamikey") + ">" + "http://www.baidu.com?" + Encode("id=12345&name=jack", "jiamikey") + "</a>");

        Response.Write("<BR/>------------------------------------------------------<BR/>");

        Response.Write("<a href = " + "http://www.baidu.com?" + Encode(Encode("id=12345&name=jack", "jiamikey"), "jiamikey") + ">" + "http://www.baidu.com?id=12345&name=jack" + "</a>");

    }

    /// <summary>

    /// 加密

    /// </summary>

    /// <param name="str"></param>

    /// <param name="key"></param>

    /// <returns></returns>

    public static string Encode(string str, string key)

    {

        DESCryptoServiceProvider provider = new DESCryptoServiceProvider();

        provider.Key = Encoding.ASCII.GetBytes(key.Substring(, ));

        provider.IV = Encoding.ASCII.GetBytes(key.Substring(, ));

        byte[] bytes = Encoding.GetEncoding("GB2312").GetBytes(str);

        MemoryStream stream = new MemoryStream();

        CryptoStream stream2 = new CryptoStream(stream, provider.CreateEncryptor(), CryptoStreamMode.Write);

        stream2.Write(bytes, , bytes.Length);

        stream2.FlushFinalBlock();

        StringBuilder builder = new StringBuilder();

        foreach (byte num in stream.ToArray())

        {

            builder.AppendFormat("{0:X2}", num);

        }

        stream.Close();

        return builder.ToString();

    }

    /// <summary>

    /// Des 解密 GB2312

    /// </summary>

    /// <param name="str">Desc string</param>

    /// <param name="key">Key ,必须为8位 </param>

    /// <returns></returns>

    public static string Decode(string str, string key)

    {

        DESCryptoServiceProvider provider = new DESCryptoServiceProvider();

        provider.Key = Encoding.ASCII.GetBytes(key.Substring(, ));

        provider.IV = Encoding.ASCII.GetBytes(key.Substring(, ));

        byte[] buffer = new byte[str.Length / ];

        for (int i = ; i < (str.Length / ); i++)

        {

            int num2 = Convert.ToInt32(str.Substring(i * , ), 0x10);

            buffer[i] = (byte)num2;

        }

        MemoryStream stream = new MemoryStream();

        CryptoStream stream2 = new CryptoStream(stream, provider.CreateDecryptor(), CryptoStreamMode.Write);

        stream2.Write(buffer, , buffer.Length);

        stream2.FlushFinalBlock();

        stream.Close();

        return Encoding.GetEncoding("GB2312").GetString(stream.ToArray());

    }

}