passGen.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
Copyright (c) 2015 James Booth

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Random password generator.
usage: passGen.py -s <chars> -l <length> -c <count> -e <entropy> -o <outputFile>
"""

import sys, getopt, random, time, re
from math import log,pow

CHARS = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.:,;<>?"#$%&/()!@{}~=+'
ENTROPY = [
    (10, re.compile('\d')),
    (26, re.compile('[a-z]')),
    (26, re.compile('[A-Z]')),
    (24, re.compile('[-_.:,;<>?"#$%&/()!@{}~=+]')),
]

def main(argv):
    length = 8
    count = 1
    entropy = 42
    outputFile = ''
    try:
        opts, args = getopt.getopt(argv,'hs:l:x:e:o:')
    except getopt.GetoptError:
        printHelp()
    for opt, arg in opts:
        if opt == '-h':
            printHelp()
        elif opt in ('-s'):
            CHARS = arg
        elif opt in ('-l'):
            length = validate_int('-l', arg)
        elif opt in ('-x'):
            count = validate_int('-c',arg)
        elif opt in ('-e'):
            entropy = validate_int('-e',arg)
        elif opt in ('-o'):
            outputFile = arg
    generate(count,length,entropy,outputFile)

def validate_int(flag, arg):
    try:
        return int(arg)
    except ValueError:
        print '%s %r not an integer' % (flag, arg)
        sys.exit()

def calc_entropy(password):
    total = 0
    for weight, reg in ENTROPY:
        if reg.search(password):
            total += weight
    return log(pow(total,len(password)),2)
        
def generate(count,length,entropy,outputFile):
    try:
        f = open(outputFile, 'w')
    except IOError:
        f = sys.stdout
    timeout = time.time() + (count/10)
    catch = False
    while (count > 0):
        password = ''.join([random.choice(CHARS) for n in xrange(length)])
        if calc_entropy(password) >= entropy:
            count -= 1
            f.write(password+'\n')
        if time.time() > timeout:
            catch = True
            count -=1
    if catch:
        print 'One or more timeouts occured.'
        print 'Try adjusting the chars, length and/or entropy values'

def printHelp():
    print '\nusage: passGen.py -s <chars> -l <length> -c <count> -e <entropy> -o <outputFile>\n'
    print 'defaults: (if no argument specified)'
    print '[-s] abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.:,;<>?"#$%&/()!@{}~'
    print '[-l] 8'
    print '[-c] 1'
    print '[-e] 42'
    print '[-o] {output to console}\n'
    sys.exit()

if __name__ =='__main__':main(sys.argv[1:])