混合加密网络聊天传输程序（聊天消息加密解密）

【实例简介】

混合加密网络聊天传输程序

【实例截图】

【核心代码】

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.Net;
using System.Net.Sockets;
using System.IO;
using System.Security.Cryptography;
using System.Threading;

namespace 加密程序__服务器端
{
    public partial class Form1 : Form
    {
        private Socket socket;//监听套接字
        private Socket clientSocket;//通信套接字
        private Thread thread;
        private string SAKey;

        private RSACryptoServiceProvider rsa;
        private byte[] SAIV = { 0xFE, 0xA1, 0x23, 0x4E, 0xBC, 0x1B, 0x32, 0xEF };

        public Form1()
        {
            InitializeComponent();
            CheckForIllegalCrossThreadCalls = false;
            this.listBoxState.Items.Clear();//状态栏清空
            this.richTextBoxAccept.Text = "";//接收栏清空
            this.txtSend.Text = "";//发送栏清空
        }

        private void btnStart_Click(object sender, EventArgs e)//开始监听（建立连接-->获得客户端公钥-->加密对称密钥并发送）
        {
            try
            {
                SAKey = this.txtpwd.Text;//输入对称加密密钥
                if (SAKey.Length != 8)
                {
                    MessageBox.Show("请输入8位密码");
                    this.Close();
                }


                IPEndPoint server = new IPEndPoint(IPAddress.Parse(this.textBoxIP.Text), Int32.Parse(this.textBoxPort.Text));//端点
                this.socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                this.socket.Bind(server);
                this.socket.Listen(10);
                this.clientSocket = socket.Accept();
                this.listBoxState.Items.Add("与客户"   clientSocket.RemoteEndPoint.ToString()   "建立连接");//Tcp建立连接
                this.btnStart.Enabled = false;
                getClientPublicKey();//接收客户端发来RSA公钥
                encryptAndSendSymmetricKey();//加密DES对称密钥 并发送
            }
            catch
            {
                MessageBox.Show("");

            }

            thread = new Thread(new ThreadStart(AcceptMessage));//接收信息
            thread.Start();
        }

        private void btnStop_Click(object sender, EventArgs e)//停止监听
        {
            try
            {
                this.socket.Shutdown(SocketShutdown.Both);//在套接字上停止发送和接收
                this.socket.Close();//关闭监听套接字
                this.clientSocket.Close();//关闭通信套接字
                this.thread.Abort();//终止线程
                this.btnStart.Enabled = true;
                this.btnStop.Enabled = false;
            }
            catch (Exception ee)
            {

                MessageBox.Show(ee.Message);
            }
        }

        private void btnSend_Click(object sender, EventArgs e)//发送
        {
            try
            {
                if (this.txtSend.Text == "")
                {
                    MessageBox.Show("无法送信息");
                    return;
                }
                string str = EncryptDES(this.txtSend.Text);//DES加密
                TransData.SendVarData(clientSocket, Encoding.UTF8.GetBytes(str));//发送加密的信息
                this.richTextBoxAccept.AppendText("发送:"   this.txtSend.Text   Environment.NewLine);//显示
                this.txtSend.Text = "";//清空

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void getClientPublicKey()//获得客户端公钥
        {
            Byte[] message = TransData.ReceiveVarData(clientSocket);

            this.rsa = new RSACryptoServiceProvider();
            this.rsa.KeySize = 1024;
            this.rsa.FromXmlString(Encoding.UTF8.GetString(message));
        }

        private void encryptAndSendSymmetricKey()//加密对称密钥 并发送
        {


            byte[] symKeyEncrypted = rsa.Encrypt(Encoding.UTF8.GetBytes(SAKey), false);
            byte[] symIVEncrypted = rsa.Encrypt(SAIV, false);

            TransData.SendVarData(clientSocket, symKeyEncrypted);
            TransData.SendVarData(clientSocket, symIVEncrypted);
        }


        private string DecryptDES(string decryptString)//DES解密字符串
        {
            if (decryptString == "")
                return "";
            try
            {

                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream ms = new MemoryStream();

                CryptoStream cs = new CryptoStream(ms, DCSP.CreateDecryptor(Encoding.UTF8.GetBytes(this.SAKey),
                    this.SAIV), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                return Encoding.UTF8.GetString(ms.ToArray());
            }
            catch (Exception ee)
            {
                MessageBox.Show(ee.Message);
                return decryptString;
            }
        }

        public string EncryptDES(string encryptString)//DES加密字符串
        {
            try
            {

                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, DCSP.CreateEncryptor(Encoding.UTF8.GetBytes(this.SAKey),
                    this.SAIV), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                return Convert.ToBase64String(ms.ToArray());

            }
            catch (Exception ee)
            {
                MessageBox.Show(ee.Message);
                return encryptString;
            }
        }

        private void AcceptMessage()//接收信息
        {
            while (true)
            {

                try
                {
                    byte[] message = TransData.ReceiveVarData(this.clientSocket);

                    string str = Encoding.UTF8.GetString(message);
                    this.richTextBoxAccept.AppendText("收到："   this.DecryptDES(str)   Environment.NewLine);//接收信息并解密

                }
                catch (Exception ee)
                {
                    MessageBox.Show(ee.Message);
                    break;
                }
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.Close();
        }


    }
}
//信息对称加密 EncryptDES(string encryptString)

//对称加密密钥 使用RSA非对称发送
//所以服务器需要客户端公钥 getClientPublicKey()，然后加密对称密钥发送给客户端  encryptAndSendSymmetricKey

//服务器要通过接收到的信息（客户端通过收到的对称密钥[服务器本身就有]加密过的密文）进行对称解密