websocket的加密和解密

补充个小知识点：按位与运算

按位与运算是同位都为1才为1，有一个不为1就是0

websocket_hand

 import socket, base64, hashlib
 import websocket_jiemi
 import websocket_jiami

 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() # 阻塞

 # 获取客户端的【握手】信息
 data = conn.recv(2048)
 print(data)

 """
 b'
 GET / 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 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 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
 Sec-WebSocket-Key: tPWfDfGthkhhqfY4ZdT1yQ==\r\n
 Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits\r\n\r\n'
 """
 #
 # # magic string为：258EAFA5-E914-47DA-95CA-C5AB0DC85B11
 magic_string = '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

 # # 对请求头中的sec-websocket-key进行加密

 #
 value = headers['Sec-WebSocket-Key'] + magic_string  # jtl/vockZ8GRyadFVeiUTA==258EAFA5-E914-47DA-95CA-C5AB0DC85B11
 print(value)
 sha1_value = hashlib.sha1(value.encode('utf-8')).digest()
 print("sha1_value",sha1_value)
 ac = base64.b64encode(sha1_value)
 print("ac",ac)
 # ac  - sha1(sec+magic) - base64
 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"

 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)
     msg = websocket_jiemi.websocket_jiema(msg)

     # conn.send("123123123123".encode("utf8"))
     send_str = websocket_jiami.jiami("hello".encode("utf8"))
     print(send_str)
     conn.send(send_str)

websocket_jiami

 import struct
 # msg_bytes = "哎呀妈呀脑瓜疼".encode("utf8")
 def jiami(msg_bytes):
     token = b"\x81"
     length = len(msg_bytes)

     if length < 126:
         token += struct.pack("B", length) # \x85$
     elif length == 126:
         token += struct.pack("!BH", 126, length)
     else:
         token += struct.pack("!BQ", 127, length)

     msg = token + msg_bytes

     return msg

websocket_jiemi

 # b'\x81\x83\xceH\xb6\x85\xffz\x85'

 hashstr = b'\x81\x85$\xcb>\x14L\xaeRxK'
 # b'\x81
 # \x85$
 # \xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L
 # \xaeRxK\xcb>\x14L\xaeRxK
 # \xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK'

 # 将第二个字节也就是 \x83 第9-16位 进行与127进行位运算

 def websocket_jiema(hashstr):
     print(hashstr[1])
     payload = hashstr[1] & 127
     print(payload)

     if payload == 127:
         extend_payload_len = hashstr[2:10] #
         mask = hashstr[10:14]
         decoded = hashstr[14:]
     # 当位运算结果等于127时,则第3-10个字节为数据长度
     # 第11-14字节为mask 解密所需字符串
     # 则数据为第15字节至结尾
     #

     # b'\x81
     # \x85$    126
     # \xcb>\x14L 120
     # \xaeRxK\xcb>\x14L\xaeRxK
     # \xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK \xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK'

     if payload == 126:
         extend_payload_len = hashstr[2:4]
         mask = hashstr[4:8]
         decoded = hashstr[8:]
     # 当位运算结果等于126时,则第3-4个字节为数据长度
     # 第5-8字节为mask 解密所需字符串
     # 则数据为第9字节至结尾
     #
     #   b'\x81
     # \x85$ 5 len数据长度
     # \xcb>\x14L\xaeRxK'

     if payload <= 125:
         extend_payload_len = payload
         mask = hashstr[2:6]
         decoded = hashstr[6:]  #

     # 当位运算结果小于等于125时,则这个数字就是数据的长度
     # 第3-6字节为mask 解密所需字符串
     # 则数据为第7字节至结尾
     #
     str_byte = bytearray()
     #
     for i in range(len(decoded)):
         byte = decoded[i] ^ mask[i % 4]
         str_byte.append(byte)
     #
     return str_byte.decode("utf8")

my_socket

 <!DOCTYPE html>
 <html lang="en">
 <head>
     <meta charset="UTF-8">
     <title>Title</title>
 </head>
 <body>

 </body>
 <script>
     var ws = new WebSocket("ws://127.0.0.1:9527")
     ws.onmessage = function (data) {
         console.log(data.data)

     }
 </script>
 </html>