websocket协议
什么是websocket协议
websocket协议类似于http协议
http ：数据按 \r\n 分割，请求头和请求体按 \r\n\r\n 分割 是短连接、无状态基于tcp协议
websocket：数据按 \r\n分割，创建连接后不断开，创建连接是需要先验证，发送数据时要加密
websocket本质
1、创建一个建立连接之后不断开的socket
2、创建连接（握手）
-客户端向服务端发送请求
-服务端获取请求头中的Sec-WebSocket-key的值，将此值+magic_string(魔法字符串)进行hashlib和base64加密
-构造响应头，里面包含Sec-WebSocket-Accept: 加密后的值
-返送给客户端
-客户端再拿到加密的数据，解密进行验证
3、连接建立成功后：建立双工通道（同一时间，即可发送数据也可接受数据），进行数据通信
-发送的数据都是加密的，解密后，根据payload_len的值获取内容（payload_len的值相当于报头）
-payload_len <=125
-payload_len ==126
-payload_len ==127
-将获取的内容分为
-mask_key
-数据
根据mask_key和数据进行位运算，最后解析出数据
示例：
参考：http://www.cnblogs.com/wupeiqi/p/6558766.html import socket import base64 import hashlib def get_headers(data): """ 将请求头格式化成字典 :param data: :return: """ header_dict = {} data = str(data, encoding='utf-8') header, body = data.split('\r\n\r\n', 1) header_list = header.split('\r\n') for i in range(0, len(header_list)): if i == 0: if len(header_list[i].split(' ')) == 3: header_dict['method'], header_dict['url'], header_dict['protocol'] = header_list[i].split(' ') else: k, v = header_list[i].split(':', 1) header_dict[k] = v.strip() return header_dict def send_msg(conn, msg_bytes): """ WebSocket服务端向客户端发送消息 :param conn: 客户端连接到服务器端的socket对象,即： conn,address = socket.accept() :param msg_bytes: 向客户端发送的字节 :return: """ import struct token = b"\x81" length = len(msg_bytes) if length < 126: token += struct.pack("B", length) elif length <= 0xFFFF: token += struct.pack("!BH", 126, length) else: token += struct.pack("!BQ", 127, length) msg = token + msg_bytes conn.send(msg) return True sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock.bind(('127.0.0.1', 8002)) sock.listen(5) # 等待用户连接 conn, address = sock.accept() data = conn.recv(8096) header_dict = get_headers(data) # 在验证环节对Sec-WebSocket-Key对应的值进行加密 magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11' value = header_dict['Sec-WebSocket-Key'] + magic_string ac = base64.b64encode(hashlib.sha1(value.encode('utf-8')).digest()) # 构造响应头 response_tpl = "HTTP/1.1 101 Switching Protocols\r\n" \ "Upgrade:websocket\r\n" \ "Connection: Upgrade\r\n" \ "Sec-WebSocket-Accept: %s\r\n" \ "WebSocket-Location: ws://127.0.0.1:8002\r\n\r\n" response = response_tpl %(str(ac,encoding='utf-8'),) conn.sendall(bytes(response,encoding='utf-8')) while True: # 用户发过来的加密的数据 info = conn.recv(8096) payload_len = info[1] & 127 if payload_len == 127: extend_payload_len = info[2:10] mask = info[10:14] decoded = info[14:] elif payload_len == 126: extend_payload_len = info[2:4] mask = info[4:8] decoded = info[8:] else: extend_payload_len = None mask = info[2:6] decoded = info[6:] bytes_list = bytearray() for i in range(len(decoded)): chunk = decoded[i] ^ mask[i % 4] bytes_list.append(chunk) body = str(bytes_list, encoding='utf-8') print(body) body = body + 'sb' send_msg(conn,bytes(body,encoding='utf-8'))
<!DOCTYPE html> <html lang="zh-cn"> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>Title</title> <style> .msg-item{ padding: 5px; border: 1px; margin: 0 5px; } </style> </head> <body> <h1>首页</h1> <div> <h2>发送消息</h2> <input id="msg" type="text" /> <input type="button" value="发送" onclick="sendMsg()"> <h2>接收消息</h2> <div id="container"> </div> </div> <script src="/static/jquery-3.3.1.min.js"></script> <script> ws = new WebSocket('ws://192.168.12.42:5000/test'); ws.onmessage = function (event) { var tag = document.createElement('div'); tag.className = 'msg-item'; tag.innerText = event.data; $('#container').append(tag); } function sendMsg() { ws.send($('#msg').val()); } </script> </body> </html>
待续.....
