phopass.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# phopass.py - Generate phonemic passwords.
#
##### LICENSE ################################################################
# Copyright (c) 2008 Zachary Voase
# 
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
##############################################################################
# This program was inspired/copied/stolen from the PhonemicPassword plugin for
# Ruby on Rails. The original (Ruby) version was written by Obie Fernandez,
# and is available here:
#
#     http://obiefernandez.com/svn/plugins/phonemic_passwords
#
##############################################################################

"""
phopass.py - Generate phonemic passwords.

To generate a phonemic password, call ``generate_password()`` with an optional
integer keyword argument ``length``. It will return a string containing the
generated password. The length of the returned password will default to 8
characters.

This file may also be run as a script from the command line. In this case, the
default password length is 8, but an additional integer argument may be given
which will yield a different length.

This program was inspired/copied/stolen from the PhonemicPassword plugin for
Ruby on Rails. The original (Ruby) version was written by Obie Fernandez, and
is available at his website_.

.. _website: http://obiefernandez.com/svn/plugins/phonemic_passwords
"""

import os
import random
import sys

#################
# Phoneme flags #
#################

CONSONANT = 1
VOWEL = 1 << 1
DIPHTHONG = 1 << 2
NOT_FIRST = 1 << 3
NOT_LAST = 1 << 4
RARE = 1 << 5

################
# Phoneme data #
################

PHONEMES = {
    'a': '010000',
    'ae': '011111',
    'ah': '011000',
    'ai': '011000',
    'ao': '011000',
    'au': '011000',
    'aw': '011000',
    'ay': '011100',
    'b': '100000',
    'bl': '101010',
    'br': '101010',
    'c': '100010',
    'ch': '101000',
    'ck': '101100',
    'cl': '101010',
    'cr': '101010',
    'd': '100000',
    'dr': '101010',
    'e': '010000',
    'ea': '011000',
    'ee': '011100',
    'ei': '011110',
    'eo': '011110',
    'eu': '011000',
    'ew': '011100',
    'f': '100010',
    'ff': '100100',
    'fl': '100010',
    'fr': '100010',
    'g': '100000',
    'gg': '101101',
    'gh': '101100',
    'gl': '101010',
    'h': '100010',
    'i': '010000',
    'ia': '011000',
    'ie': '011110',
    'j': '100011',
    'k': '100011',
    'kl': '100011',
    'kr': '100011',
    'l': '100000',
    'ld': '101100',
    'll': '101101',
    'lt': '101100',
    'ly': '101100',
    'm': '100000',
    'mp': '101100',
    'n': '100000',
    'ng': '101100',
    'nt': '101100',
    'o': '010000',
    'oh': '011000',
    'oo': '011001',
    'ough': '011101',
    'ow': '011000',
    'p': '100000',
    'ph': '101011',
    'pl': '101011',
    'pr': '101010',
    'qu': '101011',
    'r': '100000',
    'rt': '101000',
    's': '100000',
    'sch': '101000',
    'sh': '101000',
    'sk': '101000',
    'st': '101000',
    't': '100000',
    'th': '101000',
    'tr': '101010',
    'ts': '101100',
    'tt': '100111',
    'tw': '101010',
    'u': '010000',
    'ui': '010111',
    'v': '100010',
    'w': '100010',
    'wh': '100010',
    'x': '100001',
    'y': '100000',
    'z': '100001',
}

for key, value in PHONEMES.items():
    PHONEMES[key] = int(value, 2)

############################
# Password-generation code #
############################

def generate_password(length=8):
    password, first, last, previous = '', True, False, (None, None)
    desired = CONSONANT if random.randint(0, 4) else VOWEL
    while len(password) < length:
        phoneme = random.choice(list(PHONEMES.keys()))
        phoneme_signature = PHONEMES[phoneme]
        phoneme_flags = [
            phoneme_signature & CONSONANT,
            phoneme_signature & VOWEL,
            phoneme_signature & DIPHTHONG,
            phoneme_signature & NOT_FIRST,
            phoneme_signature & NOT_LAST,
            phoneme_signature & RARE]
        if ((desired not in phoneme_flags) or
            (first and (NOT_FIRST in phoneme_flags)) or
            (last and (NOT_LAST in phoneme_flags)) or
            (len(phoneme) > (length - len(password))) or
            (
                (CONSONANT in phoneme_flags) and
                (DIPHTHONG in phoneme_flags) and
                (phoneme in password)) or
            (previous[0] and (
                (phoneme in previous[0]) or
                (previous[0] in phoneme))) or
            ((DIPHTHONG in phoneme_flags) and (not random.randint(0, 3))) or
            ((RARE in phoneme_flags) and random.randint(0, 7))):
            continue
        password += phoneme
        last = (length - len(password)) <= 2
        if len(password) >= length:
            return password
        desired = VOWEL if (desired == CONSONANT) else CONSONANT
        previous = (phoneme, phoneme_flags)
        if first:
            first = False

####################################
# This can be run as a script, too #
####################################

if __name__ == '__main__':
    if sys.argv[1:]:
        length = int(sys.argv[1])
    else:
        length = 8
    sys.stdout.write(generate_password(length) + os.linesep)