OverTheWire.org - Vortex - Level 0 Writeup

Let's start with the requirements...
We have to

• connect to port 5842 of vortex.labs.overthewire.org
• read 4 integer numbers (4 byte each) in host byte order (i.e. little endian)
• Sum this numbers
• send it back (in the same host byte order
• read the reply that contains username and password

This can be done with some socket programming lines...
I'm a bit ashamed publishing this code cause it's badly written, but it took me short time and it works.

#!/usr/bin/env python3

import socket

HOST = '176.9.9.172'
PORT = 5842


with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.connect((HOST, PORT))
        data = s.recv(16)

        print('Received', repr(data))
        num1=data[0]+ data[1]*256 + data[2]*256*256 + data[3]*256*256*256
        num2=data[4]+ data[5]*256 + data[6]*256*256 + data[7]*256*256*256
        num3=data[8]+ data[9]*256 + data[10]*256*256 + data[11]*256*256*256
        num4=data[12]+ data[13]*256 + data[14]*256*256 + data[15]*256*256*256

        total=num1+num2+num3+num4

        byte1= total // (256*256*256)
        reminder1= total % (256*256*256)

        byte2= reminder1 // (256*256)
        reminder2= reminder1 % (256*256)

        byte3= reminder2 // (256)
        byte4= reminder2 % (256)
        reply=[byte4,byte3,byte2,byte1]

        reply2=bytes(reply)

        s.sendall(reply2)
        data=s.recv(128)

        print('Received', data)