C# WebSocket模拟发送接收

怼烎@ 2022-04-04 04:28 687阅读 0赞

WebSocket服务端 C\#示例代码

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Net.Sockets;
    using System.Net;
    using System.Threading;
    using System.Text.RegularExpressions;
    using System.Security.Cryptography;
    
    namespace WebSocketDemo
    {
        class Program
        {
            static void Main(string[] args)
            {
                int port = 10;
                byte[] buffer = new byte[1024];
    
                IPEndPoint localEP = new IPEndPoint(IPAddress.Any, port);
                Socket listener = new Socket(localEP.Address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
    
                try
                {
                    listener.Bind(localEP);
                    listener.Listen(10);
    
                    Console.WriteLine("等待客户端连接....");
                    Socket sc = listener.Accept();//接受一个连接
                    Console.WriteLine("接受到了客户端：" + sc.RemoteEndPoint.ToString() + "连接....");
    
                    //握手
                    int length = sc.Receive(buffer);//接受客户端握手信息
                    sc.Send(PackHandShakeData(GetSecKeyAccetp(buffer, length)));
                    Console.WriteLine("已经发送握手协议了....");
    
                    //接受客户端数据
                    Console.WriteLine("等待客户端数据....");
                    length = sc.Receive(buffer);//接受客户端信息
                    string clientMsg = AnalyticData(buffer, length);
                    Console.WriteLine("接受到客户端数据：" + clientMsg);
    
                    //发送数据
                    string sendMsg = "您好，" + clientMsg;
                    Console.WriteLine("发送数据：“" + sendMsg + "” 至客户端....");
                    sc.Send(PackData(sendMsg));
    
                    Console.WriteLine("演示Over!");
    
                }
                catch (Exception e)
                {
                    Console.WriteLine(e.ToString());
                }
            }
            /// <summary>
            /// 打包握手信息
            /// </summary>
            /// <param name="secKeyAccept"></param>
            /// <returns></returns>
            private static byte[] PackHandShakeData(string secKeyAccept)
            {
                var responseBuilder = new StringBuilder();
                responseBuilder.Append("HTTP/1.1 101 Switching Protocols" + Environment.NewLine);
                responseBuilder.Append("Upgrade: websocket" + Environment.NewLine);
                responseBuilder.Append("Connection: Upgrade" + Environment.NewLine);
                responseBuilder.Append("Sec-WebSocket-Accept: " + secKeyAccept + Environment.NewLine + Environment.NewLine);
                //如果把上一行换成下面两行，才是thewebsocketprotocol-17协议，但居然握手不成功，目前仍没弄明白！
                //responseBuilder.Append("Sec-WebSocket-Accept: " + secKeyAccept + Environment.NewLine);
                //responseBuilder.Append("Sec-WebSocket-Protocol: chat" + Environment.NewLine);
    
                return Encoding.UTF8.GetBytes(responseBuilder.ToString());
            }
    
            /// <summary>
            /// 生成Sec-WebSocket-Accept
            /// </summary>
            /// <param name="handShakeText">客户端握手信息</param>
            /// <returns>Sec-WebSocket-Accept</returns>
            private static string GetSecKeyAccetp(byte[] handShakeBytes, int bytesLength)
            {
                string handShakeText = Encoding.UTF8.GetString(handShakeBytes, 0, bytesLength);
                string key = string.Empty;
                Regex r = new Regex(@"Sec\-WebSocket\-Key:(.*?)\r\n");
                Match m = r.Match(handShakeText);
                if (m.Groups.Count != 0)
                {
                    key = Regex.Replace(m.Value, @"Sec\-WebSocket\-Key:(.*?)\r\n", "$1").Trim();
                }
                byte[] encryptionString = SHA1.Create().ComputeHash(Encoding.ASCII.GetBytes(key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"));
                return Convert.ToBase64String(encryptionString);
            }
    
            /// <summary>
            /// 解析客户端数据包
            /// </summary>
            /// <param name="recBytes">服务器接收的数据包</param>
            /// <param name="recByteLength">有效数据长度</param>
            /// <returns></returns>
            private static string AnalyticData(byte[] recBytes, int recByteLength)
            {
                if (recByteLength < 2) { return string.Empty; }
    
                bool fin = (recBytes[0] & 0x80) == 0x80; // 1bit，1表示最后一帧  
                if (!fin)
                {
                    return string.Empty;// 超过一帧暂不处理 
                }
    
                bool mask_flag = (recBytes[1] & 0x80) == 0x80; // 是否包含掩码  
                if (!mask_flag)
                {
                    return string.Empty;// 不包含掩码的暂不处理
                }
    
                int payload_len = recBytes[1] & 0x7F; // 数据长度  
    
                byte[] masks = new byte[4];
                byte[] payload_data;
    
                if (payload_len == 126)
                {
                    Array.Copy(recBytes, 4, masks, 0, 4);
                    payload_len = (UInt16)(recBytes[2] << 8 | recBytes[3]);
                    payload_data = new byte[payload_len];
                    Array.Copy(recBytes, 8, payload_data, 0, payload_len);
    
                }
                else if (payload_len == 127)
                {
                    Array.Copy(recBytes, 10, masks, 0, 4);
                    byte[] uInt64Bytes = new byte[8];
                    for (int i = 0; i < 8; i++)
                    {
                        uInt64Bytes[i] = recBytes[9 - i];
                    }
                    UInt64 len = BitConverter.ToUInt64(uInt64Bytes, 0);
    
                    payload_data = new byte[len];
                    for (UInt64 i = 0; i < len; i++)
                    {
                        payload_data[i] = recBytes[i + 14];
                    }
                }
                else
                {
                    Array.Copy(recBytes, 2, masks, 0, 4);
                    payload_data = new byte[payload_len];
                    Array.Copy(recBytes, 6, payload_data, 0, payload_len);
    
                }
    
                for (var i = 0; i < payload_len; i++)
                {
                    payload_data[i] = (byte)(payload_data[i] ^ masks[i % 4]);
                }
    
                return Encoding.UTF8.GetString(payload_data);
            }
    
    
            /// <summary>
            /// 打包服务器数据
            /// </summary>
            /// <param name="message">数据</param>
            /// <returns>数据包</returns>
            private static byte[] PackData(string message)
            {
                byte[] contentBytes = null;
                byte[] temp = Encoding.UTF8.GetBytes(message);
    
                if (temp.Length < 126)
                {
                    contentBytes = new byte[temp.Length + 2];
                    contentBytes[0] = 0x81;
                    contentBytes[1] = (byte)temp.Length;
                    Array.Copy(temp, 0, contentBytes, 2, temp.Length);
                }
                else if (temp.Length < 0xFFFF)
                {
                    contentBytes = new byte[temp.Length + 4];
                    contentBytes[0] = 0x81;
                    contentBytes[1] = 126;
                    contentBytes[2] = (byte)(temp.Length & 0xFF);
                    contentBytes[3] = (byte)(temp.Length >> 8 & 0xFF);
                    Array.Copy(temp, 0, contentBytes, 4, temp.Length);
                }
                else
                {
                    // 暂不处理超长内容  
                }
    
                return contentBytes;
            }  
        }
    }

HTML5 客户端示例代码

<!DOCTYPE html>
    <html>
    <head>
    <meta charset="utf-8" />
    <title>WebSockets客户端示例</title>
    </head>
    <script>
    var webSocket;
    function connect()
    {
        try
        {
            var readyState = new Array("正在连接","已建立连接","正在关闭连接","已关闭连接");
            var host = "ws://localhost:10";
            webSocket = new WebSocket(host);
            var message = document.getElementById("message");
            message.innerHTML +="<p>Socket状态：" + readyState[webSocket.readyState] + "</p>";
            webSocket.onopen = function()
            {
                message.innerHTML += "<p>Socket状态：" + readyState[webSocket.readyState] + "</p>";
            }
            webSocket.onmessage = function(msg)
            {
                message.innerHTML +="<p>接收信息：" + msg.data + "</p>";
            }
            webSocket.onclose=function()
            {
                message.innerHTML +="<p>Socket状态：" + readyState[webSocket.readyState] + "</p>";
            }
        }
        catch(exception)
        {
            message.innerHTML += "<p>有错误发生</p>";
        }
    }
    function send()
    {
        var text = document.getElementById("text").value;
        var message = document.getElementById("message");
        if(text == "")
        {
            message.innerHTML += "<p>请输入一些文字</p>";
            return ;
        }
        try
        {
            webSocket.send(text);
            message.innerHTML += "<p>发送数据：" +text + "</p>";
        }
        catch(exception)
        {
            message.innerHTML += "<p>发送数据出错</p>";
        }
        document.getElementById("text").value="";
    }
    function disconnect()
    {
        webSocket.close();
    }
    </script>
    <body>
    <h1>WebSocket客户端示例</h1>
    <div id="message"></div>
    <p>请输入一些文字</p>
    <input id="text" type="text">
    <button id="connect" onClick="connect();">建立连接</button>
    <button id="send" onClick="send();">发送数据</button>
    <button id="disconnect" onClick="disconnect();">断开连接</button>
    </body>
    </html>