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

 1 import socket, base64, hashlib
 2 import websocket_jiemi
 3 import websocket_jiami
 4 
 5 sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 6 sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 7 sock.bind(('127.0.0.1', 9527))
 8 sock.listen(5)
 9 # 获取客户端socket对象
10 conn, address = sock.accept() # 阻塞
11 
12 # 获取客户端的【握手】信息
13 data = conn.recv(2048)
14 print(data)
15 
16 
17 """
18 b'
19 GET / HTTP/1.1\r\n
20 Host: 127.0.0.1:9527\r\n
21 Connection: Upgrade\r\n
22 Pragma: no-cache\r\n
23 Cache-Control: no-cache\r\n
24 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
25 Upgrade: websocket\r\n
26 Origin: http://localhost:63342\r\n
27 Sec-WebSocket-Version: 13\r\n
28 Accept-Encoding: gzip, deflate, br\r\n
29 Accept-Language: zh-CN,zh;q=0.9\r\n
30 Sec-WebSocket-Key: tPWfDfGthkhhqfY4ZdT1yQ==\r\n
31 Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits\r\n\r\n'
32 """
33 #
34 # # magic string为：258EAFA5-E914-47DA-95CA-C5AB0DC85B11
35 magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
36 #
37 #
38 def get_headers(data):
39     header_dict = {}
40     header_str = data.decode("utf8")
41     for i in header_str.split("\r\n"):
42         if str(i).startswith("Sec-WebSocket-Key"):
43             header_dict["Sec-WebSocket-Key"] = i.split(":")[1].strip()
44 
45     return header_dict
46 
47 headers = get_headers(data)  # 提取请求头信息
48 
49 # # 对请求头中的sec-websocket-key进行加密
50 
51 #
52 value = headers['Sec-WebSocket-Key']   magic_string  # jtl/vockZ8GRyadFVeiUTA==258EAFA5-E914-47DA-95CA-C5AB0DC85B11
53 print(value)
54 sha1_value = hashlib.sha1(value.encode('utf-8')).digest()
55 print("sha1_value",sha1_value)
56 ac = base64.b64encode(sha1_value)
57 print("ac",ac)
58 # ac  - sha1(sec magic) - base64
59 response_tpl = "HTTP/1.1 101 Switching Protocols\r\n" \
60                "Upgrade:websocket\r\n" \
61                "Connection: Upgrade\r\n" \
62                "Sec-WebSocket-Accept: %s\r\n" \
63                "WebSocket-Location: ws://127.0.0.1:9527\r\n\r\n"
64 
65 response_str = response_tpl % (ac.decode('utf-8'))
66 # 响应【握手】信息
67 conn.send(response_str.encode("utf8"))
68 
69 while True:
70     msg = conn.recv(8096)
71     msg = websocket_jiemi.websocket_jiema(msg)
72 
73     # conn.send("123123123123".encode("utf8"))
74     send_str = websocket_jiami.jiami("hello".encode("utf8"))
75     print(send_str)
76     conn.send(send_str)

websocket_jiami

 1 import struct
 2 # msg_bytes = "哎呀妈呀脑瓜疼".encode("utf8")
 3 def jiami(msg_bytes):
 4     token = b"\x81"
 5     length = len(msg_bytes)
 6 
 7     if length < 126:
 8         token  = struct.pack("B", length) # \x85$
 9     elif length == 126:
10         token  = struct.pack("!BH", 126, length)
11     else:
12         token  = struct.pack("!BQ", 127, length)
13 
14     msg = token   msg_bytes
15 
16     return msg

websocket_jiemi

 1 # b'\x81\x83\xceH\xb6\x85\xffz\x85'
 2 
 3 hashstr = b'\x81\x85$\xcb>\x14L\xaeRxK'
 4 # b'\x81
 5 # \x85$
 6 # \xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L
 7 # \xaeRxK\xcb>\x14L\xaeRxK
 8 # \xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK\xcb>\x14L\xaeRxK'
 9 
10 # 将第二个字节也就是 \x83 第9-16位 进行与127进行位运算
11 
12 def websocket_jiema(hashstr):
13     print(hashstr[1])
14     payload = hashstr[1] & 127
15     print(payload)
16 
17     if payload == 127:
18         extend_payload_len = hashstr[2:10] # 834473503
19         mask = hashstr[10:14]
20         decoded = hashstr[14:]
21     # 当位运算结果等于127时,则第3-10个字节为数据长度
22     # 第11-14字节为mask 解密所需字符串
23     # 则数据为第15字节至结尾
24     #
25 
26     # b'\x81
27     # \x85$    126
28     # \xcb>\x14L 120
29     # \xaeRxK\xcb>\x14L\xaeRxK
30     # \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'
31 
32 
33     if payload == 126:
34         extend_payload_len = hashstr[2:4]
35         mask = hashstr[4:8]
36         decoded = hashstr[8:]
37     # 当位运算结果等于126时,则第3-4个字节为数据长度
38     # 第5-8字节为mask 解密所需字符串
39     # 则数据为第9字节至结尾
40     #
41     #   b'\x81
42     # \x85$ 5 len数据长度
43     # \xcb>\x14L\xaeRxK'
44 
45     if payload <= 125:
46         extend_payload_len = payload
47         mask = hashstr[2:6]
48         decoded = hashstr[6:]  # 5
49 
50     # 当位运算结果小于等于125时,则这个数字就是数据的长度
51     # 第3-6字节为mask 解密所需字符串
52     # 则数据为第7字节至结尾
53     #
54     str_byte = bytearray()
55     #
56     for i in range(len(decoded)):
57         byte = decoded[i] ^ mask[i % 4]
58         str_byte.append(byte)
59     #
60     return str_byte.decode("utf8")

my_socket

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>Title</title>
 6 </head>
 7 <body>
 8 
 9 </body>
10 <script>
11     var ws = new WebSocket("ws://127.0.0.1:9527")
12     ws.onmessage = function (data) {
13         console.log(data.data)
14 
15     }
16 </script>
17 </html>