#!/usr/bin/python
#
#
#
# PassGen.py
# Password generator
#
# Copyright 2004
#


from random import choice
import sys
import os
import string


def mashWords():
	'''Get words and mash them together with other words'''

	wDivider = (' ', '_', '-','.')
	noOfWords = choice((1,2,3))
	if noOfWords == 1:
		resultPasswd = chooseMethod(getWord())
	elif noOfWords == 2:
		randWord = chooseMethod(getWord())
		randWord2 = chooseMethod(getWord())
		resultPasswd = '%s%s%s' % (randWord, choice(wDivider), randWord2)
	else:
		randWord = chooseMethod(getWord())
		randWord2 = chooseMethod(getWord())
		randWord3 = chooseMethod(getWord())
		resultPasswd = '%s%s%s%s%s' % (randWord, choice(wDivider), randWord2, choice(wDivider), randWord3)

	return(resultPasswd)




def chooseMethod(sheepWord):
	'''Use different ways to modify random characters of the word'''

	countDigits = range(21)
	#countDigits = (0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)
	#tortureMethods = ('changeCase','insertDigits','replaceChars')
	#Inserting digits makes the passwords hard to memorize. Must fix.

	tortureMethods = ('changeCase','replaceChars')

	finalWord = sheepWord
	a = choice(countDigits)
	while a >= 0:
		currentMethod = choice(tortureMethods)
		if currentMethod == 'changeCase':
			finalWord = changeCase(finalWord)
		elif currentMethod == 'insertDigits':
			finalWord = insertDigits(finalWord)
		else:
			finalWord = replaceChars(finalWord)
		a = a-1

	return(finalWord)



def replaceChars(rawWord):
	'''Substitutes various characters with similar characters'''

	# List of possible replacements for characters
	someChanges = (
('a','@'), ('A','@'), ('a','6'), ('A','6'),
('@','a'), ('@','A'), ('6','a'), ('6','A'),
('B','8'), ('8','B'),
('c','('), ('C','('), ('(','c'), ('(','C'),
('e','3'), ('E','3'), ('3','e'), ('3','E'),
('h','#'), ('H','#'), ('#','h'), ('#','H'),
('i','1'), ('I','1'), ('i','!'), ('I','!'),
('1','i'), ('1','I'), ('!','i'), ('!','I'),
('l','1'), ('L','1'), ('l','!'), ('L','!'), ('L','7'),
('1','l'), ('1','L'), ('!','l'), ('!','L'), ('7','L'),
('o','0'), ('O','0'), ('0','o'), ('0','O'),
('s','$'), ('S','$'), ('s','5'), ('S','5'),
('$','s'), ('$','S'), ('$','5'), ('$','5'),
('t','+'), ('T','+'), ('+','t'), ('+','T'),
('x','%'), ('X','%'), ('%','x'), ('%','X'),
('z','2'), ('Z','2'), ('2','z'), ('2','Z')
)

	randChange = choice(someChanges)
	cookedWord = string.replace(rawWord,randChange[0],randChange[1],1)

	return(cookedWord)



def changeCase(sheepWord):
	'''Swap the case for a random letter in a word'''

	charList = []
	a = 0
	for c in sheepWord:
		charList.append(a)
		a = a+1
	itemNo = choice(charList)

	changedWord = '%s%s%s' % (sheepWord[:itemNo], string.swapcase(sheepWord[itemNo]), sheepWord[itemNo+1:])
	return(changedWord)




def insertDigits(sheepWord):
	'''Insert random digits before or after the password'''

	digitsToInsert = ('0','1','2','3','4','5','6','7','8','9')
	noOfDigits = (0,1,2,0)
	digitPosition = ('b','a')

	chosenDigits = ''
	a = choice(noOfDigits)
	while a > 0:
		chosenDigits = '%s%s' %(chosenDigits, choice(digitsToInsert))
		a = a-1

	pos = choice(digitPosition)
	if pos == 'a':
		changedWord = '%s%s' % (sheepWord, chosenDigits)
	else:
		changedWord = '%s%s' % (chosenDigits, sheepWord)

	return(changedWord)




def checkPasswd(freshPasswd):
	'''Check to see if the password has at least one lowercase, one uppercase
	one digit and one meta character'''

	# Using regex like this was the best way I could come up with though
	# I'm sure it could be done in a better way
	import re

	mPat = re.compile(r'[!@#$%^&*()+=]')
	nPat = re.compile(r'[0-9]')
	lPat = re.compile(r'[a-z]')
	uPat = re.compile(r'[A-Z]')

	mMatch = mPat.search(freshPasswd)
	if mMatch:
		nMatch = nPat.search(freshPasswd)
		if nMatch:
			lMatch = lPat.search(freshPasswd)
			if lMatch:
				uMatch = uPat.search(freshPasswd)
				if uMatch:
					result = 'good'
				else:
					result = 'bad'
			else:
				result = 'bad'
		else:
			result = 'bad'
	else:
		result = 'bad'

	return(result)




def getWord():
	'''Choose a random word from the dictionary that is at least 6 characters
	and no more than 10'''

	global DICTWORDS

	goodWord = choice(DICTWORDS)

	# A check to keep the word from containing problematic characters, being
	# too short or too long.
	searchResult = string.find(goodWord,'\'') + string.find(goodWord,'\"')
	if (searchResult != -2) | (len(goodWord) < 6) | (len(goodWord) > 10):
		goodWord = getWord()

	goodWord = string.strip(goodWord)

	return(goodWord)




def cgiPage():
	'''Gets input from a html form and outputs the results'''

	import cgi

	cgiLocation = '/python/passgen.py'

	print 'Content-type: text/html\n\n'
	print '<html><head></head><body>'

	form = cgi.FieldStorage()
	if form.has_key('generate'):
		pCount = int(form['count'].value)
		noOfPasswds = pCount

		if noOfPasswds < 21:
			passList = '<p>'
			while noOfPasswds > 0:
				newPasswd = mashWords()
				# Generate new passwords until a good one is found
				while (checkPasswd(newPasswd) == 'bad'):
					newPasswd = mashWords()
				passList = '%s\n%s<br />' % (passList, newPasswd)
				noOfPasswds = noOfPasswds - 1
			passList = '%s</p>' % passList

		else:
			passList = '<p>Nice try sonny</p>'

		print '''
		<form action="%s" method="post">
			<p><b>Number of passwords to generate (upto 20):</b>
				<input name="count" size="10" value="%s" /></p>
			<p><input value="Generate" name="generate" type="submit" /></p>
		</form>\n<hr />\n(Please note that unless run on the same system or
		over SSL, these passwords are being transmitted in plain text and
		could be intercepted)\n<hr />\n''' % (cgiLocation, pCount)
		print passList
	else:
		print '''
		<form action="%s" method="post">
			<p><b>Number of passwords to generate (upto 20):</b>
				<input name="count" size="10" /></p>
			<p><input value="Generate" name="generate" type="submit" /></p>
		</form>''' % cgiLocation

	print '</body></html>'
	sys.exit(0)

	return()




###########################################
##                 Start                 ##
###########################################


# Dictionary file
dictFile = '/usr/share/dict/words'

d = open(dictFile)
DICTWORDS = d.readlines()
d.close()

# Testing
#DICTWORDS = ['Sa\'jjad','Test','Sufyan','Zaidi','Za\"idi','abc','1234','1234567890']



# Decide on the method
if os.environ.has_key("GATEWAY_INTERFACE"):
	cgiPage()
elif len(sys.argv) > 1:
	noOfPasswords = int(sys.argv[1])
else:
	noOfPasswords = 1


while noOfPasswords > 0:
	newPasswd = mashWords()
	# Generate new passwords until a good one is found
	while (checkPasswd(newPasswd) == 'bad'):
		newPasswd = mashWords()
	print newPasswd
	noOfPasswords = noOfPasswords - 1

sys.exit(0)