code.kerkeslager.com Git - sandbox/blob - passgener.py

   1 import math, os, sys
   2
   3 PASSWORD_MIN_BITS_ENTROPY = 256
   4
   5 def open_dict():
   6     try:
   7         return open('/usr/share/dict/words')
   8     except FileNotFoundError:
   9         return open(' /usr/dict/words')
  10
  11 with open_dict() as dict_file:
  12     dict_words = dict_file.readlines()
  13
  14 dict_word_count = len(dict_words)
  15
  16 passphrase_word_count = math.ceil(math.log(2**PASSWORD_MIN_BITS_ENTROPY, dict_word_count))
  17
  18 bytes_entropy_per_word = math.ceil(math.log(dict_word_count, 2**8))
  19
  20 print(bytes_entropy_per_word)
  21
  22 def rand_word():
  23     try:
  24         return dict_words[int.from_bytes(os.urandom(bytes_entropy_per_word), byteorder='little')].strip()
  25     except IndexError:
  26         return rand_word()
  27
  28 passphrase = ' '.join(rand_word() for i in range(passphrase_word_count))
  29
  30 print(passphrase)