#!/usr/bin/env python3

from PIL import Image
import secrets
from sys import argv

img1 = Image.open(argv[2])
bs1 = img1.tobytes()

if argv[1] == 'encrypt':
  bs2 = secrets.token_bytes(len(bs1))
  Image.frombuffer(img1.mode, img1.size, bs2).save(argv[3])
else:
  bs2 = Image.open(argv[3]).tobytes()

bs3 = bytes(b1 ^ b2 for b1, b2 in zip(bs1, bs2))
Image.frombuffer(img1.mode, img1.size, bs3).save(argv[4])