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我有一个服务器/客户端系统，它加密服务器（python）上的图像并在客户端（c#）上解密它们。加密部分工作得很好，除了尝试解密几个块长的信息（例如，图像，而不是“Hello World”字符串）。

因此，当我尝试通过 CryptoStream 解密加密图像时 - 有时它可以工作，但由于某种原因 - 有时它不会。

这是图像的解密过程：

public static byte[] DecryptBytesFromBytes(byte[] encryptedImage, byte[] key)
        {
            byte[] decryptedImage;

            // Create an Aes object with the specified key and IV.
            using (Aes aesAlg = Aes.Create())
            {
                aesAlg.Key = key;
                aesAlg.Padding = PaddingMode.Zeros;
                aesAlg.Mode = CipherMode.CBC;

                byte[] IV = new byte[16];
                byte[] cipherBytes = new byte[encryptedImage.Length - IV.Length];

                Array.Copy(encryptedImage, IV, IV.Length);
                Array.Copy(encryptedImage, IV.Length, cipherBytes , 0, cipherBytes.Length);

                aesAlg.IV = IV;

                // Create a decryptor to perform the stream transform.
                ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

                using (var input = new MemoryStream(cipherBytes))
                using (var output = new MemoryStream())
                {
                    using (var cryptStream = new CryptoStream(input, decryptor, CryptoStreamMode.Read))
                    {
                        var buffer = new byte[1024];
                        var read = cryptStream.Read(buffer, 0, buffer.Length);
                        while (read > 0)
                        {
                            output.Write(buffer, 0, read);
                            read = cryptStream.Read(buffer, 0, buffer.Length); // Error here
                        }
                        decryptedImage= output.ToArray();
                    }
                }
                return decryptedImage;
            }

如果它有帮助，即使在执行以下操作时我也会遇到相同的错误：

cryptStream.CopyTo(output);

这是用于加密的python代码：

@staticmethod
def pad(s):
    return s + b"\0" * (AES.block_size - len(s) % AES.block_size)

def encrypt(self, message):
    message = self.pad(message)
    iv = Random.new().read(AES.block_size)
    cipher = AES.new(str.encode(self.key), AES.MODE_CBC, iv)
    return iv + cipher.encrypt(message)

例外

有时我会收到此错误：System.ArgumentException: Offset and length were out of bounds for the array or count is greater than the number of elements from index to the end of the source collection.

完整的堆栈跟踪：

at System.Buffer.BlockCopy (System.Array src, System.Int32 srcOffset, System.Array dst, System.Int32 dstOffset, System.Int32 count) [0x00097] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at Mono.Security.Cryptography.SymmetricTransform.InternalTransformBlock (System.Byte[] inputBuffer, System.Int32 inputOffset, System.Int32 inputCount, System.Byte[] outputBuffer, System.Int32 outputOffset) [0x000b0] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at Mono.Security.Cryptography.SymmetricTransform.FinalDecrypt (System.Byte[] inputBuffer, System.Int32 inputOffset, System.Int32 inputCount) [0x00020] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at Mono.Security.Cryptography.SymmetricTransform.TransformFinalBlock (System.Byte[] inputBuffer, System.Int32 inputOffset, System.Int32 inputCount) [0x0002e] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at System.Security.Cryptography.CryptoStream.Read (System.Byte[] buffer, System.Int32 offset, System.Int32 count) [0x002e3] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at Project.Crypto.DecryptBytesFromBytes (System.Byte[] encryptedImage, System.Byte[] key) [0x000b9] in C:\Users\user\Desktop\Project\Crypto.cs:129

注意Project.Crypto.DecryptBytesFromBytes是解密函数。

有谁知道它为什么会发生，我该如何解决？如果需要更多信息，请告诉我。

这是我在函数文档中找到的Read()：

// Exceptions:
//   T:System.ArgumentException:
//     Thesum of the count and offset parameters is longer than the length of the buffer.

顺便说一句，我使用 CBC 模式和零填充。

我想澄清最后一件事——我做这整个过程只是为了我可以获取加密的字节，然后把它们变成解密的字节。如果有另一种方法可以在 c# 中将字节解密为字节，请告诉我。

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