CryptoStream 实例关闭时抛出异常

Question

我有一个使用 RijndaelManaged Cipher 的 DecryptString 函数。它在 99.999% 的情况下都能工作，但偶尔会抛出“IndexOutOfRangeException”异常，并显示“索引超出数组范围”的消息。当它尝试关闭finally块中的cryptoStream时。

当它停止工作时，它将停止工作 20 分钟左右，然后再启动 再次工作，没有明显的解释。我确实有一个线索，那就是它只能

public string DecryptString(string InputText, string Password)
        {
            //checkParamSupplied("InputText", InputText);
            checkParamSupplied("Password", Password);

            MemoryStream memoryStream = null;
            CryptoStream cryptoStream = null;

            try
            {
                RijndaelManaged RijndaelCipher = new RijndaelManaged();

                byte[] EncryptedData = Convert.FromBase64String(InputText);

                byte[] Salt = Encoding.ASCII.GetBytes(Password.Length.ToString());

                PasswordDeriveBytes SecretKey = new PasswordDeriveBytes(Password, Salt);

                // Create a decryptor from the existing SecretKey bytes.
                ICryptoTransform Decryptor = RijndaelCipher.CreateDecryptor(SecretKey.GetBytes(32), SecretKey.GetBytes(16));

                memoryStream = new MemoryStream(EncryptedData);

                // Create a CryptoStream. (always use Read mode for decryption).
                cryptoStream = new CryptoStream(memoryStream, Decryptor, CryptoStreamMode.Read);

                // Since at this point we don't know what the size of decrypted data
                // will be, allocate the buffer long enough to hold EncryptedData;
                // DecryptedData is never longer than EncryptedData.
                byte[] PlainText = new byte[EncryptedData.Length];

                // Start decrypting.
                int DecryptedCount = cryptoStream.Read(PlainText, 0, PlainText.Length);

                // Convert decrypted data into a string. 
                string DecryptedData = Encoding.Unicode.GetString(PlainText, 0, DecryptedCount);

                // Return decrypted string.   
                return DecryptedData;
            }
            catch (Exception ex)
            {
                throw;
            }
            finally
            {
                //Close both streams.
                memoryStream.Close();
                cryptoStream.Close();
            }
        }

Answer 1

我注意到的一件事是，在您的 finally 块中关闭 cryptoStream 本身之前，您要关闭 cryptoStream 的基础流 - 也许您应该颠倒这两个语句？