How To Safely Store A Password

Re:How To Safely Store A Password by iki23 on Friday July 01, 2011 @04:24AM (#2717508)

You can also initialize the words in more pythonic way:

  with open('/usr/share/dict/words') as wordlist:
      words = set(line[:-1] for line in wordlist)

Or, for one time check you can stop reading on match:

  import sys
  lookup = '%s\n' % sys.argv[1]
  with open('/usr/share/dict/words') as wordlist:
      [ sys.stdout.write('Dictionary password: %s' % lookup) or sys.exit(1) for line in wordlist if line == lookup ]

As for the objective, this checks only exact dictionary matches. In real world, you'd use cracklib to check any dictionary based or weak passwords rather than reinvent the wheel. See http://gdub.wordpress.com/2006/08/26/using-cracklib-to-requi...

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Re:How To Safely Store A Password by vog on Friday July 01, 2011 @04:38AM (#2717535)

While I agree that the first code is pythonic and nice, the second code is quite the opposite of that. Why forcing imperative code into a list comprehension? It is a lot easier to read as nested loop, as it doesn't build a dummy list with some strange "or" operation:

  import sys
  lookup = '%s\n' % sys.argv[1]
  with open('/usr/share/dict/words') as wordlist:
      for line in wordlist:
          if line == lookup:
              sys.stdout.write('Dictionary password: %s' % lookup)
              sys.exit(1)

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Re:How To Safely Store A Password by nerfhammer on Friday July 01, 2011 @11:09AM (#2718611)

better to pickle a frozenset and use that.

  import pickle

  # initialize:
  wordset = frozenset(line.lower().rstrip() for line in open('/usr/share/dict/words'))
  pickle.dump(wordset, open('/tmp/wordset.pkl', 'wb', -1))

  # when you want to use it:
  wordset = pickle.load(open('/tmp/wordset.pkl', 'rb'))

  'bear' in wordset # == True

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Re:How To Safely Store A Password by iki23 on Saturday July 02, 2011 @12:17AM (#2720986)

Thanks for the frozenset. Yet pickle makes the file 2 times bigger and 20 times slower to parse on my machine:

  >python wordlist.py -w wordlist -p wordlist.pkl
  >python wordlist.py -T wordlist wordlist.pkl 10 3
  2.6.6 (r266:84297, Aug 24 2010, 18:46:32) [MSC v.1500 32 bit (Intel)]
  words(wordfile): 142.50 best msec/loop
  words_slower(wordfile): 161.00 best msec/loop
  words_normalized(wordfile): 295.84 best msec/loop
  words_pickled(pickled): 2943.66 best msec/loop

The winner is:

  with open(wordfile) as wordlist:
      return frozenset(wordlist.read().split('\n'))

Source: https://gist.github.com/1059725

Wordlist: http://www.freebsd.org/cgi/cvsweb.cgi/src/share/dict/web2?re...

Do you have different results?

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Re:How To Safely Store A Password by iki23 on Friday July 01, 2011 @05:38PM (#2720256)

right, the space saving harmed readability indeed, thanks

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