Added support for back conversion.

StringMasks.py

#!/usr/bin/python
def stringToInt(name):
	name=name[::-1]
	val=0
	offset=0
	for char in name:
		val = val + ((ord(char) & 0xff) << offset)
		offset = offset + 8
	return val

def intToString(val):
	name=""
	offset=0
	while 1==1:
		ascii=(val >> offset) & 0xff
		if ascii == 0:
			break
		name = name + chr(ascii)
		offset = offset + 8
	return name[::-1]

def findMask(f,t):
	fVal=stringToInt(f)
	tVal=stringToInt(t)
	return (fVal ^ tVal)


ostring=raw_input("From? ")
mask=findMask(ostring,raw_input("To? "))
print mask
print intToString(stringToInt(ostring) ^ mask)

print "Convert Back!"
ostring=raw_input("Input? ")
mask=raw_input("Mask? ")
print intToString(stringToInt(ostring) ^ long(mask))