Cookie写记住我和自动登录并加密cookie

前台

   
   


   

   

    用户名：
   

    密码：
   

    记住我:
    自动登录：
   

       
   

   

后台

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Cryptography;
using System.Text;
using System.IO;

namespace js
{
    public partial class jsdenglu : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                if (Request.Cookies["username"] != null && Request.Cookies["password"] == null)
                {
                    txtusername.Text = Request.Cookies["username"].Value;
                }
                if (Request.Cookies["username"] != null && Request.Cookies["password"] != null)
                {
                    txtusername.Text = Request.Cookies["username"].Value;
                    txtpasswrod.Text = Request.Cookies["password"].Value;
                }
            }
        }

        protected void btnsave_Click(object sender, EventArgs e)
        {
            if (ckme.Checked==true)
            {
                HttpCookie cookieme = new HttpCookie("username");
                cookieme.Value = txtusername.Text;
                cookieme.Expires = DateTime.Now.AddDays(7);
                Response.Cookies.Add(cookieme);
            }
            if (ckdeng.Checked == true)
            {
                HttpCookie cookieusername = new HttpCookie("username");
                cookieusername.Value = txtusername.Text;
                cookieusername.Expires = DateTime.Now.AddDays(7);
                Response.Cookies.Add(cookieusername);
                HttpCookie cookiepassword = new HttpCookie("password");
                cookiepassword.Value = txtpasswrod.Text;
                cookiepassword.Expires = DateTime.Now.AddDays(7);
                Response.Cookies.Add(cookiepassword);
            }
            Response.Write("");
        }
        //加密
        public static string Encode(string str, string key)
        {
            try
            {
                DESCryptoServiceProvider provider = new DESCryptoServiceProvider

();
                provider.Key = Encoding.ASCII.GetBytes(key.Substring(0, 8));
                provider.IV = Encoding.ASCII.GetBytes(key.Substring(0, 8));
                byte[] bytes = Encoding.GetEncoding("GB2312").GetBytes(str);
                MemoryStream stream = new MemoryStream();
                CryptoStream stream2 = new CryptoStream(stream,

provider.CreateEncryptor(), CryptoStreamMode.Write);
                stream2.Write(bytes, 0, bytes.Length);
                stream2.FlushFinalBlock();
                StringBuilder builder = new StringBuilder();
                foreach (byte num in stream.ToArray())
                {
                    builder.AppendFormat("{0:X2}", num);
                }
                stream.Close();
                return builder.ToString();
            }
            catch
            {
                return "不是用Encrypt加密的字符串,加密失败!";
            }
        }
        //解密
        public static string Decode(string str, string key)
        {
            try
            {
                DESCryptoServiceProvider provider = new DESCryptoServiceProvider

();
                provider.Key = Encoding.ASCII.GetBytes(key.Substring(0, 8));
                provider.IV = Encoding.ASCII.GetBytes(key.Substring(0, 8));
                byte[] buffer = new byte[str.Length / 2];
                for (int i = 0; i < (str.Length / 2); i++)
                {
                    int num2 = Convert.ToInt32(str.Substring(i * 2, 2), 0x10);
                    buffer[i] = (byte)num2;
                }
                MemoryStream stream = new MemoryStream();
                CryptoStream stream2 = new CryptoStream(stream,

provider.CreateDecryptor(), CryptoStreamMode.Write);
                stream2.Write(buffer, 0, buffer.Length);
                stream2.FlushFinalBlock();
                stream.Close();
                return Encoding.GetEncoding("GB2312").GetString(stream.ToArray

());
            }
            catch
            {
                return "不是用Encrypt加密的字符串,解密失败!";
            }

        }
    }
}