验证链接合法性(hmac)

Posted 2022-06-14 shachengcc1

一种类似于哈希的加密方式，

服务端建立连接后发送固定的随机数，客户端接收同样的随机数后，

使用这串字符串与客户端的密匙生成hmac数据返回服务端，

服务端自己也用hmac把随机数与服务端密匙生成数据

两个数据用hmac模块的比较即可。

服务端

 1 import hmac,os
 2 from socket import *
 3 
 4 secret_key = b‘just do it‘
 5 
 6 def conn_auth(conn):
 7     print(‘开始验证链接合法性‘)
 8     msg = os.urandom(32)
 9     conn.sendall(msg)
10     h = hmac.new(secret_key,msg)
11     digest = h.digest()
12     respone = conn.recv(len(digest))
13     return hmac.compare_digest(respone,digest)
14 
15 
16 def data_handler(conn,bufsize):
17     if not conn_auth(conn):
18         print(‘该链接不合法，关闭‘)
19         conn.close()
20         return
21     print(‘链接合法，开始通信‘)
22     while True:
23         data = conn.recv(bufsize)
24         if not data:break
25         conn.sendall(data.upper())
26 
27 
28 def server_handlse(ip_port,bufsize,backlog=5):
29     tcp_socket_server = socket(AF_INET,SOCK_STREAM)
30     tcp_socket_server.bind(ip_port)
31     tcp_socket_server.listen(backlog)
32     while 1:
33         conn,addr = tcp_socket_server.accept()
34         print(‘产生新连接‘)
35         data_handler(conn,bufsize)
36 
37 if __name__ == ‘__main__‘:
38     ip_port = (‘121.195.167.34‘,9999)
39     bufsize = 1024
40     server_handlse(ip_port,bufsize)

客户端

 1 import hmac
 2 from socket import *
 3 
 4 secret_key = ‘just do it‘.encode(‘utf-8‘)
 5 
 6 def conn_auth(conn):
 7     msg = conn.recv(32)
 8     h = hmac.new(secret_key,msg)
 9     digest = h.digest()
10     conn.sendall(digest)
11 
12 
13 
14 def client_handler(ip_port, bufsize):
15     tcp_socket_client = socket(AF_INET,SOCK_STREAM)
16     tcp_socket_client.connect(ip_port)
17 
18     conn_auth(tcp_socket_client)
19 
20     while True:
21         data = input(‘>>>:‘).strip()
22         if data == ‘quit‘:
23             break
24         else:
25             continue
26         tcp_socket_client.sendall(data.encode(‘utf-8‘))
27         respone = tcp_socket_client.recv(bufsize)
28         print(respone.decode(‘utf-8‘))
29     tcp_socket_client.close()
30 
31 if __name__ == ‘__main__‘:
32     ip_port = (‘121.195.167.34‘,9999)
33     bufsize = 1024
34     client_handler(ip_port,bufsize)

j