(adsbygoogle = window.adsbygoogle || []).push({}); Hello, tonight I decided to make a tutorial on building a functional port scanner with the Python programming language. Let's get started...

Q&A

Q: What is a port scanner and what does it do?
A: A port scanner is a software application designed to probe a server or host for open ports. This is often used by administrators to verify security policies of their networks and by attackers to identify running services on a host with the view to compromise it. A port scan or portscan can be defined as a process that sends client requests to a range of server port addresses on a host, with the goal of finding an active port. While not a nefarious process in and of itself, it is one used by hackers to probe target machine services with the aim of exploiting a known vulnerability of that service.

Q: What is Python?
A: Leave...now....


Python 2.7.6 (2.7.x)

Required Modules:

    import os

import sys

from socket import * 

Color Functions (makes the script look more pro):

    W = '\033[0m'  # white (normal)

R = '\033[31m'  # red

G = '\033[32m'  # green

O = '\033[33m'  # orange

B = '\033[34m'  # blue

P = '\033[35m'  # purple

C = '\033[36m'  # cyan

GR = '\033[37m'  # gray

Main Function:

    if __name__ == '__main__':



    #used to clear terminal (Cmd Prompt) screen of previous uses

    os.system('clear' 

    #os.system('cls' if you're on windows



    #style or whatever

    print 40 * '-'

    print P + 'My Port Scanner ' + W + '//' + B + ' Made By XXXXX'

    print W + 40 * '-'

    target = raw_input('Target Domain/IP: '

    p_start=input("Start At Port: ")

    p_stop=input("Stop At Port: ")

    

    #resolves host name into ip

    targetIP = gethostbyname(target)



    print 'Starting scan on' + O, targetIP

    print W + 40 * '-'

Scan Function:

    

    for i in range(p_start, p_stop):

        s = socket(AF_INET, SOCK_STREAM)



        #connects to the ip of the resoved host name

        result = s.connect_ex((targetIP, i))

        

        #0 is the level code for 'true' or in this case 'open'

        if(result == 0) :

            print G + 'Port %d: OPEN' % (i,) + W

        

       #else will occur if the result comes back with the level code 1 or 'false'

	else:

	    print R + 'Port %d: CLOSED' % (i,) + W

        s.close()

Doesn't really seem like a tutorial, more of showing you how it works, but still I hope this helps. If you get a traceback error then please notify me so I can review the code. Also if you have improvements of this code, then please share!