Xor little tool to play with XOR encryption

myxor.py

#!/usr/bin/env python3
import base64
import argparse
import string

class XorBreak:
	def __init__(self, clear, ciphertext, key, cribs):
		self.clear = clear
		self.ciphertext = ciphertext
		self.key = key
		self.cribs = cribs
		self.key_padd = ""

	def pad_key(self, text):
		return self.key * (len(text)//len(self.key)+1)

	def cipher(self):
		self.ciphertext = ""
		self.key_padd = self.pad_key(self.clear)
		for i in range(len(self.clear)):
			self.ciphertext += chr(ord(self.clear[i]) ^ ord(self.key_padd[i]))
		return self.ciphertext


	def uncipher(self):
		self.key_padd = self.pad_key(self.ciphertext)
		self.uncipher = ""
		for i in range(len(self.ciphertext)):
			self.uncipher += chr(self.ciphertext[i] ^ ord(self.key_padd[i]))
		return self.uncipher


	def get_key(self):
		self.possibles_keys = []
		for i in range(len(self.ciphertext)-len(self.cribs)+1):
			self.possible_key = ""
			for j in range(len(self.cribs)):
				self.possible_key += chr(self.ciphertext[i+j] ^ ord(self.cribs[j]))
			self.possibles_keys.append(self.possible_key)
		return self.possibles_keys

def main():

	parser = argparse.ArgumentParser(description='Simple tool for use and break xor encryption ')
	parser.add_argument('-p', '--plaintext', help='Plaintext input file', type=argparse.FileType('r'))
	parser.add_argument('-c', '--ciphertext', help='Ciphertext input file', type=argparse.FileType('rb'))
	parser.add_argument('-k', '--key', help='Input Key : Required for encryption or decryption')
	parser.add_argument('--cribs', help='Known part of plaintext : should be longer than the key length')
	args = parser.parse_args()

	if args.plaintext != None and args.key != None and args.ciphertext == None and args.cribs == None:
		crypt = XorBreak(args.plaintext.read(), "", args.key, "")
		print(crypt.cipher())

	elif args.plaintext == None and args.key != None and args.ciphertext != None and args.cribs == None:
		decrypt = XorBreak("", args.ciphertext.read(),args.key,"")
		print(decrypt.uncipher())

	elif args.plaintext == None and args.key == None and args.ciphertext != None and args.cribs != None:
		crack = XorBreak("", args.ciphertext.read(), "", args.cribs)
		for keys in crack.get_key():
			printable = True
			for c in keys:
				if c not in string.ascii_letters + string.digits + string.punctuation + ' ':
					printable = False
			if printable:
				print(keys)
	else:
		parser.print_help()

if __name__ == '__main__':
	main()