在解密時將 C# 代碼轉換為 python

Question

using System.Security.Cryptography;

public Task<byte[]> Decrypt(byte[] encryptedBytes, string encryptionKey)
{
    if (encryptedBytes == null)
        throw new ArgumentNullException("encryptedBytes can't be null");

    if (string.IsNullOrEmpty(encryptionKey))
        throw new ArgumentNullException("encryptionKey can't be null");

    byte[] encryptedTextBytes = encryptedBytes;
    this._encryptionKey = encryptionKey;

    var encryptionKeyBytes = Encoding.UTF32.GetBytes(this._encryptionKey);
    Rfc2898DeriveBytes generatedKey = new Rfc2898DeriveBytes(this._encryptionKey, new byte[] { 0x65, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x65 });
    var sessionKey = generatedKey.GetBytes(32);
    var iV = generatedKey.GetBytes(16);

    return Task.Run(() =>
    {
        return (Decrypt(encryptedTextBytes, sessionKey, iV));

    });
}

public byte[] Decrypt(byte[] dataToDecrypt, byte[] key, byte[] iv)
{
    using (var aes = new AesCryptoServiceProvider())
    {
        aes.Mode = CipherMode.CBC;
        aes.Padding = PaddingMode.PKCS7;

        aes.Key = key;
        aes.IV = iv;

        using (var memoryStream = new MemoryStream())
        {
            var cryptoStream = new CryptoStream(memoryStream, aes.CreateDecryptor(), CryptoStreamMode.Write);

            cryptoStream.Write(dataToDecrypt, 0, dataToDecrypt.Length);
            cryptoStream.FlushFinalBlock();

            var decryptBytes = memoryStream.ToArray();

            return decryptBytes;
        }
    }
}

您好，我需要幫助將上述 c# 代碼轉換為等效的 python 代碼。 由於我是 python 的新手，因此不確定此處要使用哪些相關庫。 如果有人可以在這里幫助我，那就太好了。

到目前為止，我已經嘗試了下面的代碼，但看起來它不起作用：

from Crypto.Cipher import AES
from Crypto.Protocol.KDF import PBKDF2
from PIL import Image
_encryptionKey='secret'.encode("utf-32")
salt = '\0x65\0x76\0x61\0x6e\0x20\0x4d\0x65\0x64\0x76\0x65\0x64\0x65\0x65'.encode("utf-32")
key_bytes = PBKDF2(_encryptionKey, salt, dkLen=64)
session_key=key_bytes[:32]
iv= key_bytes[:16]
cipher = AES.new(session_key, AES.MODE_CBC, iv)
val = cipher.decrypt(ency_img)
Image.open(BytesIO(val))

這里ency_img是來自 MySQL 數據庫的加密圖像字節 object，列類型為longblob

來自 PIL Image 的錯誤

PIL.UnidentifiedImageError：無法識別圖像文件 <_io.BytesIO object at 0x7fb10d79a270>

Answer 1

我在@Topaco 的評論的幫助下找到了這個問題的解決方案。 謝謝你，伙計。

正如@Topaco 的評論中提到的，我必須進行以下更改：

1. 將\0x替換為\x
2. 將_encryptionKey和salt的編碼更改為utf-8而不是utf-32
3. iv的值為key_bytes[32:32+16]而不是key_bytes[:16]

以下是我的工作代碼：

from Crypto.Cipher import AES
from Crypto.Protocol.KDF import PBKDF2
from PIL import Image

_encryptionKey='secret'.encode("utf-8")
salt = '\x65\x76\x61\x6e\x20\x4d\x65\x64\x76\x65\x64\x65\x65'.encode("utf-8")
key_bytes = PBKDF2(_encryptionKey, salt, dkLen=64)
session_key=key_bytes[:32]
iv= key_bytes[32:32+16]
cipher = AES.new(session_key, AES.MODE_CBC, iv)
img = Image.open(BytesIO(val))
print(img.size)
Image.open(BytesIO(val))

希望這會幫助別人