VII. Network Programming (hmac verify the legitimacy of the client module)

A. Verify the legitimacy of the client module hmac

Python's built hmac module implements the standard of Hmac algorithm,

It is calculated using a hash key for the message "hash",

Hmac algorithm is more secure than using the standard hash algorithm, because for the same message, different key will produce different hash.

import  os
aa=os.urandom(32)
print(type(aa),aa)
print("*******************************************************888")

import hmac
Message = B ' the Hello World ' 
Key = B ' Secret ' 
H = hmac.new (key, Message, digestmod = " MD5 " )
 # The first argument is the key key, the second argument is the string to be encrypted, The third parameter is a hash function 
Print (h.hexdigest ())

print("*******************************************************888")

Test to see whether the client is legitimate
Do not rely on login authentication
import hmac
H = hmac.new ()      #   SECRET_KEY you want bytes encrypted 
ciphertext h.digest = ()    # ciphertext Abstract # returned as binary data string value 
hmac.compare_digest ()   # comparative ciphertext another ciphertext

1. Verify the legitimacy of the client

server

import os
import hmac
import socket
secret_key=b'lover'
sk=socket.socket()
sk.bind(('127.0.0.1',8600))
sk.listen()

def chek(conn):
    msg = os.urandom (32 )
    conn.send(msg)
    h=hmac.new(secret_key,msg)
    dyke = h.digest ()

    client_dige=conn.recv(1024)

    return hmac.compare_digest(dige,client_dige)

conn,addr=sk.accept()

RES = Chek (Conn)
 IF RES:
     Print ( " legitimate customer terminal " )
    conn.close()
the else :
     Print ( " illegal customer service side " )
    conn.close()

client

import hmac
import socket
secret_key=b'lover'
sk=socket.socket()
sk.connect(('127.0.0.1',8600))

msg=sk.recv(1024)
h=hmac.new(secret_key,msg)
dyke = h.digest ()

sk.send (head)