# ccav_app/ccav_utils.py

from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.primitives import padding as sym_padding
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.backends import default_backend
import base64
import os

def pad(data):
    padder = padding.PKCS7(128).padder()
    padded_data = padder.update(data) + padder.finalize()
    return padded_data

def unpad(data):
    unpadder = padding.PKCS7(128).unpadder()
    unpadded_data = unpadder.update(data) + unpadder.finalize()
    return unpadded_data

def derive_key(secret_key):
    salt = os.urandom(16)  # Generate a random salt (16 bytes)
    kdf = PBKDF2HMAC(
        algorithm=hashes.SHA256(),
        iterations=100000,
        salt=salt,
        length=32,  # Use 32 bytes for a 256-bit key
        backend=default_backend()
    )
    key = base64.urlsafe_b64encode(kdf.derive(secret_key.encode()))
    return key

def encrypt(plain_text, secret_key):
    key = derive_key(secret_key)
    iv = os.urandom(16)
    cipher = Cipher(algorithms.AES(key), modes.CFB(iv), backend=default_backend())
    encryptor = cipher.encryptor()
    encrypted_text = encryptor.update(plain_text.encode()) + encryptor.finalize()
    return base64.b64encode(iv + encrypted_text).decode()

def decrypt(cipher_text, secret_key):
    key = derive_key(secret_key)
    data = base64.b64decode(cipher_text.encode())
    iv = data[:16]
    cipher = Cipher(algorithms.AES(key), modes.CFB(iv), backend=default_backend())
    decryptor = cipher.decryptor()
    decrypted_text = decryptor.update(data[16:]) + decryptor.finalize()
    return unpad(decrypted_text).decode()

这是我的ccavutil.py文件，我通过加密和解密获取数据和密钥
但出错
ValueError at /cc/

Invalid key size (352) for AES.

请求方法：POSTRequest URL：http://127.0.0.1:8000/cc/Django版本：4.2.1异常类型：ValueErrorException值：AES的密钥大小无效（352）。
我想在我的网站集成ccavenue支付网关，但得到错误