nmap_port_scanner.py

#Use these commands in Kali to install required software:
#  sudo apt install python3-pip
#  pip install python-nmap

# Import nmap so we can use it for the scan
import nmap
# We need to create regular expressions to ensure that the input is correctly formatted.
import re

# Regular Expression Pattern to recognise IPv4 addresses.
ip_add_pattern = re.compile("^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$")
# Regular Expression Pattern to extract the number of ports you want to scan. 
# You have to specify <lowest_port_number>-<highest_port_number> (ex 10-100)
port_range_pattern = re.compile("([0-9]+)-([0-9]+)")
# Initialising the port numbers, will be using the variables later on.
port_min = 0
port_max = 65535

# This port scanner uses the Python nmap module.
# You'll need to install the following to get it work on Linux:
# Step 1: sudo apt install python3-pip
# Step 2: pip install python-nmap


# Basic user interface header
print(r"""______            _     _  ______                 _           _ 
|  _  \          (_)   | | | ___ \               | |         | |
| | | |__ ___   ___  __| | | |_/ / ___  _ __ ___ | |__   __ _| |
| | | / _` \ \ / / |/ _` | | ___ \/ _ \| '_ ` _ \| '_ \ / _` | |
| |/ / (_| |\ V /| | (_| | | |_/ / (_) | | | | | | |_) | (_| | |
|___/ \__,_| \_/ |_|\__,_| \____/ \___/|_| |_| |_|_.__/ \__,_|_|""")
print("\n****************************************************************")
print("\n* Copyright of David Bombal, 2021                              *")
print("\n* https://www.davidbombal.com                                  *")
print("\n* https://www.youtube.com/davidbombal                          *")
print("\n****************************************************************")

open_ports = []
# Ask user to input the ip address they want to scan.
while True:
    ip_add_entered = input("\nPlease enter the ip address that you want to scan: ")
    if ip_add_pattern.search(ip_add_entered):
        print(f"{ip_add_entered} is a valid ip address")
        break

while True:
    # You can scan 0-65535 ports. This scanner is basic and doesn't use multithreading so scanning 
    # all the ports is not advised.
    print("Please enter the range of ports you want to scan in format: <int>-<int> (ex would be 60-120)")
    port_range = input("Enter port range: ")
    port_range_valid = port_range_pattern.search(port_range.replace(" ",""))
    if port_range_valid:
        port_min = int(port_range_valid.group(1))
        port_max = int(port_range_valid.group(2))
        break

nm = nmap.PortScanner()
# We're looping over all of the ports in the specified range.
for port in range(port_min, port_max + 1):
    try:
        # The result is quite interesting to look at. You may want to inspect the dictionary it returns. 
        # It contains what was sent to the command line in addition to the port status we're after. 
        # For in nmap for port 80 and ip 10.0.0.2 you'd run: nmap -oX - -p 89 -sV 10.0.0.2
        result = nm.scan(ip_add_entered, str(port))
        # Uncomment following line and look at dictionary
        # print(result)
        # We extract the port status from the returned object
        port_status = (result['scan'][ip_add_entered]['tcp'][port]['state'])
        print(f"Port {port} is {port_status}")
    except:
        # We cannot scan some ports and this ensures the program doesn't crash when we try to scan them.
        print(f"Cannot scan port {port}.")