Python Ethical Hacking - MAC Address & How to Change(2)

FUNCTIONS

• Set of instructions to carry out a task.
• Can take input, and return a result.
• Make the code clearer, reusable, and more abstract.
• input() function prompts the user to enter the value.

Rewrite the Python script using the function style.

#!/usr/bin/env python

import subprocess
import optparse

def change_mac(interface, new_mac):
    print("[+] Changing MAC address for " + interface + " to " + new_mac)
    subprocess.call(["ifconfig", interface, "down"])
    subprocess.call(["ifconfig", interface, "hw", "ether", new_mac])
    subprocess.call(["ifconfig", interface, "up"])

parser = optparse.OptionParser()

parser.add_option("-i", "--interface", dest="interface", help="Interface to change its MAC address")
parser.add_option("-m", "--mac", dest="new_mac", help="New MAC address")

(options, arguments) = parser.parse_args()

change_mac(options.interface, options.new_mac)

Execute the following commands successfully to change the MAC.

python mac_changer.py -i eth0 -m :::::

Rewrite the Python script.

#!/usr/bin/env python

import subprocess
import optparse

def get_arguments():
    parser = optparse.OptionParser()
    parser.add_option("-i", "--interface", dest="interface", help="Interface to change its MAC address")
    parser.add_option("-m", "--mac", dest="new_mac", help="New MAC address")
    return parser.parse_args()

def change_mac(interface, new_mac):
    print("[+] Changing MAC address for " + interface + " to " + new_mac)
    subprocess.call(["ifconfig", interface, "down"])
    subprocess.call(["ifconfig", interface, "hw", "ether", new_mac])
    subprocess.call(["ifconfig", interface, "up"])

(options, arguments) = get_arguments()
change_mac(options.interface, options.new_mac)

Execute the following commands successfully to change the MAC.

python mac_changer.py -i eth0 -m :::::33

Decision Making

• Execute code ONLY if a condition is true.

Rewrite the Python code using conditional statements.

#!/usr/bin/env python

import subprocess
import optparse

def get_arguments():
    parser = optparse.OptionParser()
    parser.add_option("-i", "--interface", dest="interface", help="Interface to change its MAC address")
    parser.add_option("-m", "--mac", dest="new_mac", help="New MAC address")
    (options, arguments) = parser.parse_args()
    if not options.interface:
        parser.error("[-] Please specify an interface, use --help for more info.")
    elif not options.new_mac:
        parser.error("[-] Please specify a new mac, use --help for more info.")
    return options

def change_mac(interface, new_mac):
    print("[+] Changing MAC address for " + interface + " to " + new_mac)
    subprocess.call(["ifconfig", interface, "down"])
    subprocess.call(["ifconfig", interface, "hw", "ether", new_mac])
    subprocess.call(["ifconfig", interface, "up"])

options = get_arguments()
change_mac(options.interface, options.new_mac)

Test the script using the following commands.