在很多项目中，为了安全安全考虑，需要对数据包进行加密处理，本文实例所述的即为C#加密代码，在应用开发中有很大的实用价值。说起数据包加密，其实对C#编程者来说，应该是一个基础的技巧，是进行C#程序设计人员必须要掌握的技能。
C#实现加密功能的核心代码如下：
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
///
///DES加密字符串
///
///待加密的字符串
///加密密钥,要求为8位
///加密成功返回加密后的字符串，失败返回源字符串
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
///
///DES解密字符串
///
///待解密的字符串
///解密密钥,要求为8位,和加密密钥相同
///解密成功返回解密后的字符串，失败返源字符串
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
}
}
本例备有详细的注释，对于开发者而言应该不难理解，读者可以根据自身项目需要改进本例代码以符合自身应用需求。