off-by-one.py

import argparse
from subprocess import call

# Useful for Bluetooth device discovery when Bluetooth device addresses may be one off from wireless MAC addresses
# See, for example, "Hacking Exposed: Wireless", 3rd edition, by Joshua Wright and Johnny Cache, pages 211-214.

# To generate the list of addresses and test using hcitool (or another command line tool):
# python3 off-by-one.py -l macs.lst | while read -r line; do hcitool name "$line"; done

def off_by_one(mac_list, flag):
	with open(mac_list) as f:
		lines = f.readlines()
		for line in lines: 
			mac = line.rstrip()
			first_octets = mac[:15] # Assumes a single character delimeter between octets (e.g. 00:11:22:33:44:55 or 00-11-22-33-44-55)
			last_octet = mac[-2:]

			if flag == 0: # Do both operations
				if last_octet.upper() == "FF": pass
				else:
					print("{}{:02x}".format(first_octets, int(last_octet, 16) + 1))
				if last_octet == "00": pass
				else:
					print("{}{:02x}".format(first_octets, int(last_octet, 16) -1))
			elif flag == 1: # Only do plus one
				if last_octet.upper() == "FF": pass
				else:
					print("{}{:02x}".format(first_octets, int(last_octet, 16) + 1))
			elif flag == 2: # Only do minus one
				if last_octet == "00": pass
				else:
					print("{}{:02x}".format(first_octets, int(last_octet, 16) - 1))

def main():
	parser = argparse.ArgumentParser(description='Given a list of MAC addresses, produce a list of addresses one higher and one lower.')
	parser.add_argument('-l', '--list', dest='mac_list', required=True, help='File containing list of MAC addresses, separated by line.')
	parser.add_argument('-p', '--plus-only', dest='plus_only', action='store_true', help='Only list MAC addresses one higher.')
	parser.add_argument('-m', '--minus-only', dest='minus_only', action='store_true', help='Only list MAC addresses one lower.')
	args = parser.parse_args()
	mac_list = args.mac_list
	plus_only = args.plus_only
	minus_only = args.minus_only
	if plus_only == False and minus_only == False:
		flag = 0
	elif plus_only == True and minus_only == False:
		flag = 1
	elif plus_only == False and minus_only == True:
		flag = 2
	elif plus_only == True and minus_only == True:
		print("The options '--plus-only' and '--minus-only' are mutually exclusie. Select only one.")
		exit()
	off_by_one(mac_list, flag)

if __name__ == '__main__':
	main()