如何附加到AES加密文件

import os
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.backends import default_backend

def encrypt_file(file_path, key):
    backend = default_backend()
    iv = os.urandom(16)  # 生成一个随机的16字节的初始向量
    cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=backend)
    encryptor = cipher.encryptor()
    with open(file_path, "rb") as f:
        data = f.read()
    encrypted_data = encryptor.update(data)
    encrypted_data += encryptor.finalize()
    with open(file_path + ".enc", "wb") as f:
        f.write(encrypted_data)

def decrypt_file(file_path, key):
    backend = default_backend()
    iv = os.urandom(16)  # 生成一个随机的16字节的初始向量
    cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=backend)
    decryptor = cipher.decryptor()
    with open(file_path + ".enc", "rb") as f:
        encrypted_data = f.read()
    decrypted_data = decryptor.update(encrypted_data)
    decrypted_data += decryptor.finalize()
    with open(file_path, "wb") as f:
        f.write(decrypted_data)

key = "0123456789abcdef"  # 16字节的密钥
encrypt_file("input.txt", key)
decrypt_file("input.txt.enc", key)