from Crypto.Cipher import AES
import os
from binascii import hexlify

BLOCK_SIZE = 16
def pad(raw):
    if len(raw) % 16>0:
        return raw + bytes(16-(len(raw)%16))
    return raw

def aes_enc(key, msg):
    cipher = AES.new(key, AES.MODE_ECB)
    return cipher.encrypt(msg)

secret_key = os.urandom(32) # 32 bytes secret (AES-256)
print('Secret KEY='+str(hexlify(secret_key).upper()))

f = open('BLK.BMP','rb')
plain_text = f.read()
f.close()
print('plain_text bytes='+str(len(plain_text)))
plain_text_padded = pad(plain_text) # Padding plain text to 16 block size
print('plain_text_padded bytes='+str(len(plain_text_padded)))

cypher_text = aes_enc(secret_key, plain_text_padded)
print(hexlify(cypher_text))