如何在发送到服务器时加密我的消息？

Question

我想从客户端发送到服务器时加密我的消息，我该怎么办？

客户

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.Sockets;
using System.Threading;

namespace SocketClient
{
    public partial class SocketClient : Form
    {
        System.Net.Sockets.TcpClient clientSocket = new System.Net.Sockets.TcpClient();
        NetworkStream serverStream = default(NetworkStream);
        string readData = null;

        public SocketClient()
        {
            InitializeComponent();
        }

        private void getMessage()
        {
            while (true)
            {
                serverStream = clientSocket.GetStream();
                int buffSize = 0;
                byte[] inStream = new byte[10025];
                buffSize = clientSocket.ReceiveBufferSize;
                serverStream.Read(inStream, 0, buffSize);
                string returndata = System.Text.Encoding.ASCII.GetString(inStream);
                readData = "" + returndata;
                msg();
            }
        }

        private void msg()
        {
            if (this.InvokeRequired)
                this.Invoke(new MethodInvoker(msg));
            else
                textDisplay.Text = textDisplay.Text + Environment.NewLine + " >> " + readData;
        }

        private void buttonConnect_Click(object sender, EventArgs e)
        {
            readData = "Connected to NYP Chat Server ...";
            msg();
            //clientSocket.Connect("127.0.0.1", 8888);
            clientSocket.Connect(textIP.Text, Convert.ToInt32(textPort.Text));
            serverStream = clientSocket.GetStream();

            byte[] outStream = System.Text.Encoding.ASCII.GetBytes(textName.Text + "$");
            serverStream.Write(outStream, 0, outStream.Length);
            serverStream.Flush();

            Thread ctThread = new Thread(getMessage);
            ctThread.Start();
        }

        private void buttonSend_Click(object sender, EventArgs e)
        {
            // Show msg box if no server is connected
            if (serverStream == null)
            {
                MessageBox.Show("Please connect to a server first!");
                return;
            }

            // Send text
            byte[] outStream = System.Text.Encoding.ASCII.GetBytes(textSend.Text + "$");
            serverStream.Write(outStream, 0, outStream.Length);
            serverStream.Flush();

            // Clear text
            textSend.Text = "";
        }

        private void textDisplay_TextChanged(object sender, EventArgs e)
        {
            textDisplay.SelectionStart = textDisplay.Text.Length;
            textDisplay.ScrollToCaret();
            textDisplay.Refresh();
        }

        private void textSend_TextChanged(object sender, EventArgs e)
        {
            buttonSend.Enabled = !string.IsNullOrEmpty(textSend.Text);
        }
    }
}

服务器

using System;
using System.Threading;
using System.Net.Sockets;
using System.Text;
using System.Collections;

namespace ConsoleApplication1
{
    class Program
    {
        public static Hashtable clientsList = new Hashtable();

        static void Main(string[] args)
        {
            //TcpListener serverSocket = new TcpListener(portFromAppConfig);

            TcpListener serverSocket = new TcpListener(9999);
            TcpClient clientSocket = default(TcpClient);
            int counter = 0;

            serverSocket.Start();
            Console.WriteLine("Welcome to NYP Chat Server ");
            counter = 0;
            while ((true))
            {
                counter += 1;
                clientSocket = serverSocket.AcceptTcpClient();

                byte[] bytesFrom = new byte[10025];
                string dataFromClient = null;

                NetworkStream networkStream = clientSocket.GetStream();
                networkStream.Read(bytesFrom, 0, (int)clientSocket.ReceiveBufferSize);
                dataFromClient = System.Text.Encoding.ASCII.GetString(bytesFrom);
                dataFromClient = dataFromClient.Substring(0, dataFromClient.IndexOf("$"));

                clientsList.Add(dataFromClient, clientSocket);

                broadcast(dataFromClient + " Connected ", dataFromClient, false);

                Console.WriteLine(dataFromClient + " has join the chat room ");
                handleClient client = new handleClient();
                client.startClient(clientSocket, dataFromClient, clientsList);
            }

            clientSocket.Close();
            serverSocket.Stop();
            Console.WriteLine("exit");
            Console.ReadLine();
        }

        public static void broadcast(string msg, string uName, bool flag)
        {
            foreach (DictionaryEntry Item in clientsList)
            {
                TcpClient broadcastSocket;
                broadcastSocket = (TcpClient)Item.Value;
                NetworkStream broadcastStream = broadcastSocket.GetStream();
                Byte[] broadcastBytes = null;

                if (flag == true)
                {
                    broadcastBytes = Encoding.ASCII.GetBytes(uName + " says : " + msg);
                }
                else
                {
                    broadcastBytes = Encoding.ASCII.GetBytes(msg);
                }

                broadcastStream.Write(broadcastBytes, 0, broadcastBytes.Length);
                broadcastStream.Flush();
            }
        }  //end broadcast function
    }//end Main class


    public class handleClient
    {
        TcpClient clientSocket;
        string clNo;
        Hashtable clientsList;

        public void startClient(TcpClient inClientSocket, string clineNo, Hashtable cList)
        {
            this.clientSocket = inClientSocket;
            this.clNo = clineNo;
            this.clientsList = cList;
            Thread ctThread = new Thread(doChat);
            ctThread.Start();
        }

        private void doChat()
        {
            int requestCount = 0;
            byte[] bytesFrom = new byte[10025];
            string dataFromClient = null;
            Byte[] sendBytes = null;
            string serverResponse = null;
            string rCount = null;
            requestCount = 0;

            while ((true))
            {
                try
                {
                    requestCount = requestCount + 1;
                    NetworkStream networkStream = clientSocket.GetStream();
                    networkStream.Read(bytesFrom, 0, (int)clientSocket.ReceiveBufferSize);
                    dataFromClient = System.Text.Encoding.ASCII.GetString(bytesFrom);
                    dataFromClient = dataFromClient.Substring(0, dataFromClient.IndexOf("$"));
                    Console.WriteLine("From client - " + clNo + " : " + dataFromClient);
                    rCount = Convert.ToString(requestCount);

                    Program.broadcast(dataFromClient, clNo, true);
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.ToString());
                }
            }//end while
        }//end doChat
    } //end class handleClient
}//end namespace

Answer 1

绝对最简单的方法是翻录您编写的所有代码并使用WCF。

下一个最简单的方法是使用安全流而不是原始网络流，如SslStream或NegotiateStream 。 Secure Streams Sample上有一个完整的示例，它显示了NTLM / Kerberos和SChannel协议（也称为SSL / TLS）的客户端和服务器。

你绝对不应该做的一件事是编写自己的加密。 加密消息是微不足道的，你会在网上找到无数的样本。 但是创建一个密钥交换协议，所以你实际上有一些东西需要加密，这是加密中最难的任务之一。 使用业界公认的密钥交换方案之一，如Kerberos或SSL / TLS，这些已经在我链接的两个流类中实现。

Answer 2

C＃为加密System.Security.Cryptography提供了一个命名空间...为了开始你可以检查出来......或者尝试实现像Vernamm这样最简单，最容易实现的加密算法。 或者，如果您想要完全安全，则应使用System.Security.Cryptography命名空间System.Security.Cryptography.X509Certificates命名空间。