client_crc.py

import socket 
import matplotlib.pyplot as plt


def xor(a, b): 
    result = [] 
    for i in range(1, len(b)): 
        if a[i] == b[i]: 
            result.append('0') 
        else: 
            result.append('1') 

    return ''.join(result) 

def mod2div(divident, divisor): 
    pick = len(divisor) 
    tmp = divident[0 : pick] 

    while pick < len(divident): 

        if tmp[0] == '1': 
            tmp = xor(divisor, tmp) + divident[pick] 

        else: 
            tmp = xor('0'*pick, tmp) + divident[pick] 
        pick += 1

    if tmp[0] == '1': 
        tmp = xor(divisor, tmp) 
    else: 
        tmp = xor('0'*pick, tmp) 

    checkword = tmp 
    return checkword 

def decodeData(data, key): 
    l_key = len(key) 
    appended_data = data + '0'*(l_key-1) 
    remainder = mod2div(appended_data, key) 
    return remainder 

s = socket.socket() 
print ("Socket successfully created") 
port = 65432
s.bind(('', port)) 
print ("socket binded to %s" % (port)) 
s.listen(5) 
print ("socket is listening") 


while True: 
    c, addr = s.accept() 
    print('Got connection from', addr) 
    data = c.recv(1024)
    print(data) 

    if not data: 
        break
    key = "1001"
    ans = decodeData(data, key) 
    print("Remainder after decoding is->"+ans) 
    temp = "0" * (len(key) - 1) 
    if ans == temp: 
        c.sendall("THANK you Data ->"+data + " Received No error FOUND") 
    else: 
        c.sendall("Error in data") 

    plot2(data, key)

    c.close() 

def plot2(inp1, inp2):
    plt.title("CLIENT")
    plt.ylabel("REMAINDER_rec")
    plt.plot(decodeData(inp1, inp2))
    plt.show()