Mac Wifi MAC spoofing

markpercival (Mark Percival) — Mon, 21 Apr 2008 18:03:44 GMT

A certain unnamed national provider of bagels has seen fit to limit free wifi during lunch hours. They do this based on MAC address. I never liked my MAC address anyways.

Update -- My previous code had two considerable bugs when I posted it. Caius Durling (http://caius.name/) made a considerable improvement with his own script. I've deleted my old code and just placed his here.



#!/usr/bin/env ruby

# 

# USAGE: Turn off wireless, run this, then turn it back on.

# ./random_mac.rb  # =>  random mac address

# ./random_mac.rb --reset # =>  original mac address



# Set this to your Original MAC Address

original_mac = ""



# Just a little warning

puts "Warning: You haven't set your original Mac Address in the script yet." if original_mac.empty?



# Generates a 2 digit code

def generate_pair

  a = rand(255).to_s(16)

  return (a.length < 2 ? generate_pair : a)

end



# Sets the mac address to the passed value

def set_mac_address( mac_addr )

  raise "MacAddressFormatError" if mac_addr.scan(/^(?:[\w\d]{2}\:){5}[\w\d]{2}$/).empty?

  puts "Old MAC address: #{`ifconfig en1 | grep ether`.match(/ether\s(.+)/)[1]}"

  `sudo ifconfig en1 ether #{mac_addr}`

  puts "New MAC address: #{`ifconfig en1 | grep ether`.match(/ether\s(.+)/)[1]}"

end







case ARGV.first

when "--reset"

  # Try to reset to old mac address

  if original_mac.empty?

    puts "ERROR - You need to set the old mac address in the script"

    exit(1)

  end

  puts "Resetting to old mac address"

  set_mac_address( original_mac )

  

when nil

  # Generate & set a random mac address

  random_mac = (0..5).map { |x| generate_pair }.join(":")

  set_mac_address( random_mac )

  

when "--help"

  # Show some help I guess

  puts [

    "USAGE: Turn off wireless, run this, then turn it back on.",

    "./random_mac.rb  # =>  random mac address",

    "./random_mac.rb --reset # =>  original mac address"

    ].join("\n")

  

else

  # Who knows?

  puts "Unknown Flag, try --help"

  exit(2)

end

DZone Snippets: spoofing code

Mac Wifi MAC spoofing