ecb_encrypt_image.py

#!/usr/bin/env python

from PIL import Image
from Crypto.Cipher import AES

KEY = "YELLOW SUBMARINE"
INPUT = "logo.png"
OUTPUT = "encrypted.png"


def pad(plaintext: bytearray, block_size=AES.block_size):
    """PKCS#7 Padding"""
    num_pad = block_size - (len(plaintext) % block_size)
    return plaintext + bytearray([num_pad for x in range(num_pad)])

plaintext_img = Image.open(INPUT)

cipher = AES.new(KEY, AES.MODE_ECB)
encrypted_image = cipher.encrypt(bytes(pad(plaintext_img.tobytes())))

Image.frombytes(plaintext_img.mode, plaintext_img.size, encrypted_image).save(OUTPUT)