python实现AES算法的文件加密代码准确

在Python中，我们可以使用`cryptography`库来实现AES（高级加密标准）算法的文件加密。以下是一个简单的示例，展示了如何使用AES对文件进行加密和解密：

from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
from cryptography.hazmat.backends import default_backend
import os

def generate_key(password, salt, iterations):
    kdf = PBKDF2HMAC(
        algorithm=hashes.SHA256(),
        length=32,
        salt=salt,
        iterations=iterations,
        backend=default_backend()
    )
    key = kdf.derive(password.encode())
    return key

def encrypt_file(file_path, output_path, password):
    with open(file_path, 'rb') as in_file:
        data = in_file.read()

    salt = os.urandom(16)
    key = generate_key(password, salt, 100000)  # 强度较高的迭代次数
    cipher = Cipher(algorithms.AES(key), modes.CBC(os.urandom(16)), backend=default_backend())

    encryptor = cipher.encryptor()
    ct_bytes = encryptor.update(data) + encryptor.finalize()
    
    iv = cipher.iv
    encrypted_data = iv + ct_bytes

    with open(output_path, 'wb') as out_file:
        out_file.write(encrypted_data)

def decrypt_file(input_path, output_path, password):
    with open(input_path, 'rb') as in_file:
        encrypted_data = in_file.read()

    iv = encrypted_data[:16]
    ct_bytes = encrypted_data[16:]

    key = generate_key(password, iv, 100000)  # 使用相同的盐和迭代次数
    cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
    decryptor = cipher.decryptor()
    pt_bytes = decryptor.update(ct_bytes) + decryptor.finalize()

    with open(output_path, 'wb') as out_file:
        out_file.write(pt_bytes)

# 示例用法
password = "your_password"
encrypt_file("input.txt", "output.enc", password)
decrypt_file("output.enc", "output_decrypted.txt", password)