websocket原理

import socket, base64, hashlib

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('127.0.0.1', 9527))
sock.listen(5)
# 获取客户端socket对象
conn, address = sock.accept()
# 获取客户端的【握手】信息
data = conn.recv(1024)
print(data)
"""
GET /ws HTTP/1.1\r\n
Host: 127.0.0.1:9527\r\n
Connection: Upgrade\r\n
Pragma: no-cache\r\n
Cache-Control: no-cache\r\n
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36\r\n
Upgrade: websocket\r\n
Origin: http://localhost:63342\r\n
Sec-WebSocket-Version: 13\r\n
Accept-Encoding: gzip, deflate, br\r\n
Accept-Language: zh-CN,zh;q=0.9\r\n
Cookie: session=a6f96c20-c59e-4f33-84d9-c664a2f29dfc\r\n
Sec-WebSocket-Key: MAZZU5DPIxWmhk/UWL2+BA==\r\n
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits\r\n\r\n
"""
# 以下动作是由websockethandler完成的
# magic string为：258EAFA5-E914-47DA-95CA-C5AB0DC85B11


def get_headers(data):
    header_dict = {}
    header_str = data.decode("utf8")
    for i in header_str.split("\r\n"):
        if str(i).startswith("Sec-WebSocket-Key"):
            header_dict["Sec-WebSocket-Key"] = i.split(":")[1].strip()

    return header_dict


headers = get_headers(data)  # 提取请求头信息
#
magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
#Sec-WebSocket-Key: MAZZU5DPIxWmhk/UWL2+BA==
value = headers['Sec-WebSocket-Key'] + magic_string
print(value)
ac = base64.b64encode(hashlib.sha1(value.encode('utf-8')).digest())

# 对请求头中的sec-websocket-key进行加密
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://127.0.0.1:9527\r\n\r\n"
print(ac.decode('utf-8'))
response_str = response_tpl % (ac.decode('utf-8'))
# 响应【握手】信息
conn.send(response_str.encode("utf8"))
#
while True:
    msg = conn.recv(8096)
    print(msg)