向聊天客户端添加安全性

Question

所以这是我的基本聊天程序，它允许用户添加自己的IP并接收IP，以及用于通信的自定义端口。

在windows窗体设计中我有：

文本框--textLocalIp

文本框--textLocalPort

文本框--textFriendIp

文本框--textFriendPort

文本框--text消息

列表框--listMessage

按钮---启动

按钮---发送

所以这是一个非常基本的客户端，但我想要帮助的是使其安全/更安全，因为现在的安全性不好。

也许就像一个有不同IP的隧道，这样你就不必知道接收者的IP，只需要知道他们提供的IP，然后发送给他们或其他什么？

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using System.Net;
using System.Net.Sockets;

namespace Client
{
public partial class Form1 : Form
{
Socket sck;
EndPoint epLocal, epRemote;
public Form1()
{
InitializeComponent();
sck = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
sck.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
textLocalIp.Text = GetLocalIP();
textFriendIp.Text = GetLocalIP();
}
private string GetLocalIP()
{
IPHostEntry host;
host = Dns.GetHostEntry(Dns.GetHostName());
foreach (IPAddress ip in host.AddressList)
{
if (ip.AddressFamily == AddressFamily.InterNetwork)
{
return ip.ToString();
}
}
return "127.0.0.1";
}

private void MessageCallBack(IAsyncResult aResult)
{
try
{
int size = sck.EndReceiveFrom(aResult, ref epRemote);
if (size > 0)
{
byte[] recievedData = new byte[1464];
recievedData = (byte[])aResult.AsyncState;
ASCIIEncoding eEncoding = new ASCIIEncoding();
string receivedMessage = eEncoding.GetString(recievedData);
listMessage.Items.Add("Sender: "+receivedMessage);
}
byte[] buffer = new byte[1500];
sck.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref epRemote, new AsyncCallback(MessageCallBack), buffer);
}
catch (Exception exp)
{
MessageBox.Show(exp.ToString());
}
}
private void button1_Click(object sender, EventArgs e)
{
try
{
System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
byte[] msg = new byte[1500];
msg = enc.GetBytes(textMessage.Text);
sck.Send(msg);
listMessage.Items.Add("Local:" + textMessage.Text);
textMessage.Clear();
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
private void start_Click(object sender, EventArgs e)
{
try
{
epLocal = new IPEndPoint(IPAddress.Parse(textLocalIp.Text), Convert.ToInt32(textLocalPort.Text));
sck.Bind(epLocal);
epRemote = new IPEndPoint(IPAddress.Parse(textFriendIp.Text), Convert.ToInt32(textFriendPort.Text));
sck.Connect(epRemote);
byte[] buffer = new byte[1500];
sck.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref epRemote, new AsyncCallback(MessageCallBack), buffer);
start.Text = "Connected";
start.Enabled = false;
send.Enabled = true;
textMessage.Focus();
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}

Answer 1

使用通道实现套接字通信安全性更加困难。所以我建议你加密IP和传输内容。

对于IP加密，可以将TextBox的Passwordchar属性设置为*。

对于传输内容，可以使用加密算法对其进行加密。

以下代码实现了服务器和多个客户端之间的通信，您可以在此基础上执行加密。

服务器：

namespace Server
{
class Program
{
private static byte[] result = new byte[1024];
private static int myProt = 8885; 
static Socket serverSocket;
static void Main(string[] args)
{

serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
serverSocket.Bind(new IPEndPoint(IPAddress.Any, myProt)); 
serverSocket.Listen(10); //Set up to 10 queued connection requests
Console.WriteLine("Start listening {0} successfully", serverSocket.LocalEndPoint.ToString());      
Thread myThread = new Thread(ListenClientConnect);
myThread.Start();
Console.ReadLine();
}
/// <summary>
/// Listen for Client connections
/// </summary>
private static void ListenClientConnect()
{
while (true)
{
Socket clientSocket = serverSocket.Accept();
clientSocket.Send(Encoding.ASCII.GetBytes("Server Say Hello"));
Thread receiveThread = new Thread(ReceiveMessage);
receiveThread.Start(clientSocket);
}
}
/// <summary>
/// receive data
/// </summary>
/// <param name="clientSocket"></param>
private static void ReceiveMessage(object clientSocket)
{
Socket myClientSocket = (Socket)clientSocket;
while (true)
{
try
{

int receiveNumber = myClientSocket.Receive(result);
Console.WriteLine("Receive client {0} message {1}", myClientSocket.RemoteEndPoint.ToString(), Encoding.ASCII.GetString(result, 0, receiveNumber));
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
myClientSocket.Shutdown(SocketShutdown.Both);
myClientSocket.Close();
break;
}
}
}
}
}

客户：

namespace Client
{
class Program
{
private static byte[] result = new byte[1024];
static void Main(string[] args)
{

IPAddress ip = IPAddress.Parse("127.0.0.1");
Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
clientSocket.Connect(new IPEndPoint(ip, 8885)); 
Console.WriteLine("Successfully connected to the server");
}
catch
{
Console.WriteLine("Failed to connect to the server, please press Enter to exit!");
return;
}
//Receive data through clientSocket
int receiveLength = clientSocket.Receive(result);
Console.WriteLine("Server：{0}", Encoding.ASCII.GetString(result, 0, receiveLength));
//Send data through clientSocket
for (int i = 0; i <3; i++)
{
try
{
Thread.Sleep(1000); 
string sendMessage = "client send Message Hellp" + DateTime.Now;
clientSocket.Send(Encoding.ASCII.GetBytes(sendMessage));
Console.WriteLine("Client：{0}" + sendMessage);
}
catch
{
clientSocket.Shutdown(SocketShutdown.Both);
clientSocket.Close();
break;
}
}
Console.WriteLine("After sending, press Enter to exit");
Console.ReadLine();
}
}
}