C#实现数据包加密与解密实例详解

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Threading;using System.Net;using System.Net.Sockets;using System.Net.NetworkInformation;using System.Security.Cryptography;using System.IO;namespace EncryptDataReport{  public partial class Form1 : Form  {    public Form1()    {      InitializeComponent();    }    #region 定义全局对象及变量    private IPEndPoint Server;//服务器端    private IPEndPoint Client;//客户端    private Socket mySocket;//套接字    private EndPoint ClientIP;//IP地址    byte[] buffer, data;//接收缓存    bool blFlag = true;//标识是否第一次发送信息    bool ISPort = false;//判断端口打开    int SendNum1, ReceiveNum1, DisNum1; //记录窗体加载时的已发送/已接收/丢失的数据报    int SendNum2, ReceiveNum2, DisNum2; //记录当前已发送/已接收/丢失的数据报    int SendNum3, ReceiveNum3, DisNum3; //缓存已发送/已接收/丢失的数据报    int port;//端口号    #endregion    //异步接收信息    private void StartLister(IAsyncResult IAResult)    {      int Num = mySocket.EndReceiveFrom(IAResult, ref ClientIP);      string strInfo = Encoding.Unicode.GetString(buffer, 0, Num);      rtbContent.AppendText("用户" + ClientIP.ToString());      rtbContent.AppendText("：");      rtbContent.AppendText("/r/n");      rtbContent.AppendText(DecryptDES(strInfo, "mrsoftxk"));//对接收到的信息进行解密      rtbContent.AppendText("/r/n");      mySocket.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref ClientIP, new AsyncCallback(StartLister), null);    }    //初始化已发送、已接收和丢失的数据报    private void Form1_Load(object sender, EventArgs e)    {      if (blFlag == true)      {        IPGlobalProperties NetInfo = IPGlobalProperties.GetIPGlobalProperties();        UdpStatistics myUdpStat = null;        myUdpStat = NetInfo.GetUdpIPv4Statistics();        SendNum1 = Int32.Parse(myUdpStat.DatagramsSent.ToString());        ReceiveNum1 = Int32.Parse(myUdpStat.DatagramsReceived.ToString());        DisNum1 = Int32.Parse(myUdpStat.IncomingDatagramsDiscarded.ToString());      }    }    //设置端口号    private void button4_Click(object sender, EventArgs e)    {      try      {        port = Convert.ToInt32(textBox4.Text);        CheckForIllegalCrossThreadCalls = false;        buffer = new byte[1024];        data = new byte[1024];        Server = new IPEndPoint(IPAddress.Any, port);        Client = new IPEndPoint(IPAddress.Broadcast, port);        ClientIP = (EndPoint)Server;        mySocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);        mySocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);        mySocket.Bind(Server);        mySocket.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref ClientIP, new AsyncCallback(StartLister), null);        ISPort = true;//打开指定端口号      }      catch { }    }    //发送信息    private void button2_Click(object sender, EventArgs e)    {      if (ISPort == true)//判断是否有打开的端口号      {        IPGlobalProperties NetInfo = IPGlobalProperties.GetIPGlobalProperties();        UdpStatistics myUdpStat = null;        myUdpStat = NetInfo.GetUdpIPv4Statistics();        try        {          if (blFlag == false)//非第一次发送          {            SendNum2 = Int32.Parse(myUdpStat.DatagramsSent.ToString());            ReceiveNum2 = Int32.Parse(myUdpStat.DatagramsReceived.ToString());            DisNum2 = Int32.Parse(myUdpStat.IncomingDatagramsDiscarded.ToString());            textBox1.Text = Convert.ToString(SendNum2 - SendNum3);            textBox2.Text = Convert.ToString(ReceiveNum2 - ReceiveNum3);            textBox3.Text = Convert.ToString(DisNum2 - DisNum3);          }          SendNum2 = Int32.Parse(myUdpStat.DatagramsSent.ToString());          ReceiveNum2 = Int32.Parse(myUdpStat.DatagramsReceived.ToString());          DisNum2 = Int32.Parse(myUdpStat.IncomingDatagramsDiscarded.ToString());          SendNum3 = SendNum2; //记录本次的发送数据报          ReceiveNum3 = ReceiveNum2;//记录本次的接收数据报          DisNum3 = DisNum2; //记录本次的丢失数据报          if (blFlag == true)//第一次发送          {            textBox1.Text = Convert.ToString(SendNum2 - SendNum1);            textBox2.Text = Convert.ToString(ReceiveNum2 - ReceiveNum1);            textBox3.Text = Convert.ToString(DisNum2 - DisNum1);            blFlag = false;          }        }        catch (Exception ex)        {          MessageBox.Show(ex.Message, "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information);        }        string str = EncryptDES(rtbSend.Text, "mrsoftxk");//加密要发送的信息        data = Encoding.Unicode.GetBytes(str);        mySocket.SendTo(data, data.Length, SocketFlags.None, Client);        rtbSend.Text = "";      }      else      {        MessageBox.Show("请首先打开端口！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);        button4.Focus();      }    }    //清屏    private void button1_Click(object sender, EventArgs e)    {      rtbContent.Clear();    }    //退出    private void button3_Click(object sender, EventArgs e)    {      Application.Exit();    }    //按<Ctrl+Enter>组合键发送信息    private void rtbSend_KeyDown(object sender, KeyEventArgs e)    {      //当同时按下Ctrl和Enter时，发送消息      if (e.Control && e.KeyValue == 13)      {        e.Handled = true;        button2_Click(this, null);      }    }    //聊天记录随时滚动    private void rtbContent_TextChanged(object sender, EventArgs e)    {      rtbContent.ScrollToCaret();    }    private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };//密钥    #region DES加密字符串    ///<summary>      ///DES加密字符串      ///</summary>      ///<param name="str">待加密的字符串</param>      ///<param name="key">加密密钥,要求为8位</param>      ///<returns>加密成功返回加密后的字符串，失败返回源字符串</returns>      public string EncryptDES(string str, string key)    {      try      {        byte[] rgbKey = Encoding.UTF8.GetBytes(key.Substring(0, 8));        byte[] rgbIV = Keys;        byte[] inputByteArray = Encoding.UTF8.GetBytes(str);        DESCryptoServiceProvider myDES = new DESCryptoServiceProvider();        MemoryStream MStream = new MemoryStream();        CryptoStream CStream = new CryptoStream(MStream, myDES.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);        CStream.Write(inputByteArray, 0, inputByteArray.Length);        CStream.FlushFinalBlock();        return Convert.ToBase64String(MStream.ToArray());      }      catch      {        return str;      }    }    #endregion    #region DES解密字符串    ///<summary>      ///DES解密字符串      ///</summary>      ///<param name="str">待解密的字符串</param>      ///<param name="key">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，失败返源字符串</returns>      public string DecryptDES(string str, string key)    {      try      {        byte[] rgbKey = Encoding.UTF8.GetBytes(key);        byte[] rgbIV = Keys;        byte[] inputByteArray = Convert.FromBase64String(str);        DESCryptoServiceProvider myDES = new DESCryptoServiceProvider();        MemoryStream MStream = new MemoryStream();        CryptoStream CStream = new CryptoStream(MStream, myDES.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);        CStream.Write(inputByteArray, 0, inputByteArray.Length);        CStream.FlushFinalBlock();        return Encoding.UTF8.GetString(MStream.ToArray());      }      catch      {        return str;      }    }    #endregion  }}