dictionary-grepper.py

#!/usr/bin/python
import argparse, subprocess
import sys
import os.path

# Create a series of grep pipes to cut down a large dictionary of passwords to just ones relevant to a password policy

pipes = []

parser = argparse.ArgumentParser(description="Grep out a dictionary file")
parser.add_argument("-l", "--len", help="Minimum length of passwords")
parser.add_argument("-m", "--maxlen", help="Maximum length of passwords")
parser.add_argument("-e", "--excludelist", help="Exclude items from the specified word list")
parser.add_argument("-u", "--upper", action="store_true", help="Must contain an uppercase character")
parser.add_argument("-L", "--lower", action="store_true", help="Must contain a lowercase character")
parser.add_argument("-a", "--letter", action="store_true", help="Must contain an upper or lower case letter")
parser.add_argument("-n", "--numbers", action="store_true", help="Must contain a number")
parser.add_argument("-s", "--special", action="store_true", help="Must contain at least one special (non-alphanumeric) character")
parser.add_argument("-N", "--specnum", action="store_true", help="Must contain at least one special character or number")
parser.add_argument("-S", "--specupnum", action="store_true", help="Must contain at least one special character, uppercase character or number")
parser.add_argument("-f", "--firstupper", action="store_true", help="First character is uppercase")
parser.add_argument("-r", "--norepeat", action="store_true", help="No repeating characters")
parser.add_argument("-w", "--windows", action="store_true", help="Same as '-l 8 -u -L -N' to approximately match Windows minimum password complexity requirements: 8 chars, at least 3 of upper, lower, number, special, unicode")
parser.add_argument("dictionary", help="Input dictionary file")
args = parser.parse_args()

if not args.dictionary:
  parser.print_usage()
  sys.exit(2)

if not os.path.isfile( args.dictionary ):
  print(( "Not found: " + args.dictionary ))
  sys.exit(2)


# Work out grep pipes
pipes.append( ('cat', args.dictionary) )

if args.windows:
  if not args.len:
    args.len = 8
  args.upper = True
  args.lower = True
  args.specnum = True

if args.len:
  pipes.append( ['grep', r"^.\{{{0},\}}$".format(int(args.len))] )

if args.maxlen:
  pipes.append( ['grep', r'^.{,'+str(int(args.maxlen))+'}$' ] )

if args.excludelist:
  pipes.append( [ 'grep', '-x', '-v', '-F', '-f', args.excludelist ] )

if args.upper:
  pipes.append( ['grep', '[A-Z]'] )

if args.lower:
  pipes.append( ['grep', '[a-z]' ] )

if args.letter:
  pipes.append( ['grep', '[A-Za-z]' ] )

if args.numbers:
  pipes.append( ['grep', '[0-9]' ] )

if args.special:
  pipes.append( ['grep', '[^a-zA-Z0-9]' ] )

if args.specnum:
  pipes.append( ['grep', r'\([^a-zA-Z0-9]\|[0-9]\)' ])

if args.specupnum:
  pipes.append( ['grep', r'\([^a-zA-Z0-9]\|[0-9]\|[A-Z]\)' ])

if args.firstupper:
  pipes.append( ['grep', '^[A-Z]' ])

if args.norepeat:
  pipes.append( ['grep', '-v', r'\(.\)\1' ])

procs = []
for p in pipes:
  
  # Any stdout available?
  if len( procs ) > 0:
    out = procs[-1].stdout
  else:
    out = None

  procs.append( subprocess.Popen(p, stdout=subprocess.PIPE, stdin=out, universal_newlines=False) )

out,err = procs[-1].communicate()

print(out.decode('utf8'))