zkpwgen.py

# -*- coding: utf-8; -*-
from __future__ import print_function
import shutil
import random
from argparse import ArgumentParser

hiragana = range(0x3041, 0x308f)
katakana = range(0x30a1, 0x30f3)
numbers = range(0xff10, 0xff19)
letters_upper = range(0xff21, 0xff31)
letters_lower = range(0xff41, 0xff5a)

blacklist = u'ゐゑヰヱ'


def choose(char_type):
    while True:
        i = random.choice(char_type)
        try:
            c = unichr(i)
        except NameError:
            c = chr(i)
        if c not in blacklist:
            return c


def maybe():
    return random.randint(0, 9) < 3


def generate_simple(length, letters=True, numerals=True, secure=False):
    hira = secure or bool(random.getrandbits(1))
    upper = secure or (letters and bool(random.getrandbits(1)))
    lower = secure or (letters and not upper)
    return generate(length,
                    hira=hira,
                    kata=secure or not hira,
                    num=secure or numerals,
                    upper=upper,
                    lower=lower)


def generate(length, hira=True, kata=True, num=True, upper=True, lower=True):
    if length < [hira, kata, num, upper, lower].count(True):
        raise ValueError(
            'Password of length %d cannot meet requirements' % length)
    accum = []
    did_hira = False
    did_kata = False
    did_num = False
    did_upper = False
    did_lower = False
    while True:
        if hira:
            accum.append(choose(hiragana))
            did_hira = True
        if len(accum) >= length:
            break
        if kata:
            accum.append(choose(katakana))
            did_kata = True
        if len(accum) >= length:
            break
        if num and maybe():
            accum.append(choose(numbers))
            did_num = True
        if len(accum) >= length:
            break
        if upper and maybe():
            accum.append(choose(letters_upper))
            did_upper = True
        if len(accum) >= length:
            break
        if lower and maybe():
            accum.append(choose(letters_lower))
            did_lower = True
        if len(accum) >= length:
            break
    if all([did_hira == hira,
            did_kata == kata,
            did_num == num,
            did_upper == upper,
            did_lower == lower]):
        return ''.join(accum)
    else:
        return generate(length, hira=hira, kata=kata, num=num, upper=upper, lower=lower)


def main():
    parser = ArgumentParser(
        description='Generate random passwords of full-width Japanese characters')
    parser.add_argument('--secure', '-s', action='store_true',
                        help='generate completely random passwords')
    parser.add_argument('--one-column', '-1', action='store_true',
                        help="don't print the generated passwords in columns")
    parser.add_argument('--no-numerals', '-0', action='store_true',
                        help="don't include numbers in the password")
    parser.add_argument('--no-letters', '-L', action='store_true',
                        help="don't include Roman alphabet characters in the password")
    parser.add_argument('length', nargs='?', type=int,
                        default=8, help='the length of the password')
    parser.add_argument('count', nargs='?', type=int,
                        default=-1, help='the number of passwords to output')
    args = parser.parse_args()

    try:
        term_cols, _ = shutil.get_terminal_size((80, 20))
    except AttributeError:
        term_cols = 80
    num_cols = (1 if args.one_column else
                max(1, int(term_cols / (args.length * 2 + 1))))
    num_pw = (args.count if args.count != -1 else
              1 if args.one_column else num_cols * 20)
    for n in range(num_pw):
        pw = generate_simple(args.length,
                             letters=not args.no_letters,
                             numerals=not args.no_numerals,
                             secure=args.secure)
        if n % num_cols == num_cols - 1 or n == num_pw - 1:
            print(pw, end='\n')
        else:
            print(pw, end=' ')


if __name__ == '__main__':
    main()