voussoirkit/voussoirkit/passwordy.py

172 lines
4.4 KiB
Python

'''
passwordy
=========
This module provides functions for generating random strings. All functions use
cryptographically strong randomness if the operating system supports it, and
non-cs randomness if it does not.
If os.urandom(1) gives you a byte, your system has cs randomness.
Command line usage:
> passwordy length <flags>
length:
Integer number of characters in normal mode.
Integer number of words in sentence mode.
# Sentence mode:
--sentence:
If this argument is passed, `length` random words are chosen.
--separator X:
When using sentence mode, the words will be joined with this string.
# Normal mode:
--letters:
Include ASCII letters in the password.
If none of the other following options are chosen, letters is the default.
--digits:
Include digits 0-9 in the password.
--hex
Include 0-9, a-f in the password.
--binary
Include 0, 1 in the password.
--punctuation
Include punctuation symbols in the password.
# Both modes:
--upper
Convert the entire password to uppercase.
--lower
Convert the entire password to lowercase.
--prefix X:
Add a static prefix to the password.
--suffix X:
Add a static suffix to the password.
'''
import argparse
import math
import os
import random
import string
import sys
from voussoirkit import betterhelp
from voussoirkit import pipeable
try:
os.urandom(1)
RNG = random.SystemRandom()
except NotImplementedError:
RNG = random
def make_password(
length,
*,
binary=False,
digits=False,
hex=False,
letters=False,
punctuation=False,
):
alphabet = set()
if letters:
alphabet.update(string.ascii_letters)
if digits:
alphabet.update(string.digits)
if hex:
alphabet.update('0123456789abcdef')
if binary:
alphabet.update('01')
if punctuation:
alphabet.update(string.punctuation)
if not alphabet:
raise ValueError('No alphabet options chosen.')
return ''.join(RNG.choices(tuple(alphabet), k=length))
def make_sentence(length, separator=' '):
'''
Returns a string containing `length` words, which come from
dictionary.common.
'''
import dictionary.common as common
words = RNG.choices(common.words, k=length)
words = [w.replace(' ', separator) for w in words]
result = separator.join(words)
return result
def random_digits(length):
'''
Shortcut function for when you don't want to type the make_password call.
'''
return ''.join(RNG.choices(string.digits, k=length))
def random_hex(length):
'''
Shortcut function for when you don't want to type the make_password call.
'''
randbytes = os.urandom(math.ceil(length / 2))
token = ''.join('{:02x}'.format(x) for x in randbytes)
token = token[:length]
return token
def passwordy_argparse(args):
if args.sentence:
password = make_sentence(args.length, args.separator)
else:
if not any([args.letters, args.digits, args.hex, args.binary, args.punctuation]):
letters = True
else:
letters = args.letters
password = make_password(
args.length,
binary=args.binary,
digits=args.digits,
hex=args.hex,
letters=letters,
punctuation=args.punctuation,
)
if args.lower:
password = password.lower()
elif args.upper:
password = password.upper()
prefix = args.prefix or ''
suffix = args.suffix or ''
password = f'{prefix}{password}{suffix}'
pipeable.stdout(password)
return 0
def main(argv):
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('length', type=int)
parser.add_argument('--sentence', action='store_true')
parser.add_argument('--separator', default=' ')
parser.add_argument('--letters', action='store_true')
parser.add_argument('--digits', action='store_true')
parser.add_argument('--hex', action='store_true')
parser.add_argument('--binary', action='store_true')
parser.add_argument('--punctuation', action='store_true')
parser.add_argument('--lower', action='store_true')
parser.add_argument('--upper', action='store_true')
parser.add_argument('--prefix', default=None)
parser.add_argument('--suffix', default=None)
parser.set_defaults(func=passwordy_argparse)
return betterhelp.single_main(argv, parser, __doc__)
if __name__ == '__main__':
raise SystemExit(main(sys.argv[1:]))