C# 使用加密资源尝试/捕获/最终

我的网站上有以下代码。它将URL查询作为名为commandencrypted的字符串。我有一个try/catch/finally块，它将加密的命令复制到memorystream，然后将其解密回字符串。如果try块中出现任何错误，将在catch块中处理这些错误。但是，我希望确保在finally块中关闭所有使用的资源。当提供无效的URL查询命令时，我在尝试关闭csencryptedcommand CryptoStream时收到异常。异常详细信息遵循代码

    // Resources used for storing and decrypting the encrypted client command
    MemoryStream msencryptedcommand = null;
    RijndaelManaged rmencryptedcommand = null;
    CryptoStream csencryptedcommand = null;
    StreamReader srdecryptedcommand = null;
    MemoryStream msdecryptedcommand = null;

    try
    {
        // Copy the encrypted client command (where two characters represent a byte) to a memorystream
        msencryptedcommand = new MemoryStream();
        for (int i = 0; i < encryptedcommand.Length; )
        {
            msencryptedcommand.WriteByte(Byte.Parse(encryptedcommand.Substring(i, 2), NumberStyles.HexNumber));
            i = i + 2;
        }
        msencryptedcommand.Flush();
        msencryptedcommand.Position = 0;

        // Define parameters used for decryption
        byte[] key = new byte[] { //bytes hidden// };
        byte[] iv = new byte[] { //bytes hidden// };
        rmencryptedcommand = new RijndaelManaged();
        csencryptedcommand = new CryptoStream(msencryptedcommand, rmencryptedcommand.CreateDecryptor(key, iv), CryptoStreamMode.Read);
        msdecryptedcommand = new MemoryStream();

        // Decrypt the client command
        int decrytptedbyte;
        while ((decrytptedbyte = csencryptedcommand.ReadByte()) != -1)
        {
            msdecryptedcommand.WriteByte((byte)decrytptedbyte);
        }

        // Store the decrypted client command as a string
        srdecryptedcommand = new StreamReader(msdecryptedcommand);
        srdecryptedcommand.BaseStream.Position = 0;
        string decryptedcommand = srdecryptedcommand.ReadToEnd();
    }
    catch (Exception ex)
    {
        ErrorResponse("Invalid URL Query", context, ex.ToString());
        return;
    }
    finally
    {
        // If any resources were used, close or clear them
        if (srdecryptedcommand != null)
        {
            srdecryptedcommand.Close();
        }

        if (msdecryptedcommand != null)
        {
            msdecryptedcommand.Close();
        }

        if (csencryptedcommand != null)
        {
            csencryptedcommand.Close();
        }

        if (rmencryptedcommand != null)
        {
            rmencryptedcommand.Clear();
        }

        if (msencryptedcommand != null)
        {
            msencryptedcommand.Close();
        }
    }

//用于存储和解密加密客户端命令的资源
MemoryStream msencryptedcommand=null；
RijndaelManaged rmencryptedcommand=null；
CryptoStream csencryptedcommand=null；
StreamReader srdecryptedcommand=null；
MemoryStream msdecryptedcommand=null；
尝试
{
//将加密的客户端命令（其中两个字符表示一个字节）复制到memorystream
msencryptedcommand=new MemoryStream（）；
对于（int i=0；i

发生以下未处理的异常：System.Security.Cryptography.CryptographyException:要解密的数据长度无效。位于System.Security.Cryptography.Cryptography.RijndaelManagedTransform.TransformFinalBlock（字节[]inputBuffer，Int32 inputOffset，Int32 inputCount）的System.Security.Cryptography.CryptoStream.FlushFinalBlock（）位于System.Security.Cryptography.CryptoStream.Dispose（布尔处置）位于System.IO.Stream.Close（）的dongleupdate.ProcessRequest（HttpContext上下文）在update.ashx:System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute（）的System.Web.HttpApplication.ExecuteTep（IExecutionStep step，布尔值和同步完成）的第92行中，URL引用者：用户代理：Mozilla/5.0（Windows NT 6.1；WOW64）AppleWebKit/537.36（KHTML，类似Gecko）Chrome/30.0.1599.69 Safari/537.36请求URL:update.ashx？aa

编辑：

我将代码更改为使用语句。这也是确保关闭所有资源的有效方法吗

    try
    {
        // Copy the encrypted client command (where two characters represent a byte) to a memorystream
        using (MemoryStream msencryptedcommand = new MemoryStream())
        {
            for (int i = 0; i < encryptedcommand.Length; )
            {
                msencryptedcommand.WriteByte(Byte.Parse(encryptedcommand.Substring(i, 2), NumberStyles.HexNumber));
                i = i + 2;
            }
            msencryptedcommand.Flush();
            msencryptedcommand.Position = 0;

            // Define parameters used for decryption
            byte[] key = new byte[] { //bytes hidden// };
            byte[] iv = new byte[] { //bytes hidden// };
            using (RijndaelManaged rmencryptedcommand = new RijndaelManaged())
            {
                using (CryptoStream csencryptedcommand = new CryptoStream(msencryptedcommand, rmencryptedcommand.CreateDecryptor(key, iv), CryptoStreamMode.Read))
                {
                    using (MemoryStream msdecryptedcommand = new MemoryStream())
                    {

                        // Decrypt the client command
                        int decrytptedbyte;
                        while ((decrytptedbyte = csencryptedcommand.ReadByte()) != -1)
                        {
                            msdecryptedcommand.WriteByte((byte)decrytptedbyte);
                        }

                        // Store the decrypted client command as a string
                        using (StreamReader srdecryptedcommand = new StreamReader(msdecryptedcommand))
                        {
                            srdecryptedcommand.BaseStream.Position = 0;
                            string decryptedcommand = srdecryptedcommand.ReadToEnd();
                        }
                    }
                }
            }
        }
    }
    catch (Exception ex)
    {
        ErrorResponse("Invalid URL Query", context, ex.ToString());
        return;
    }

试试看
{
//将加密的客户端命令（其中两个字符表示一个字节）复制到memorystream
使用（MemoryStream msencryptedcommand=new MemoryStream（））
{
对于（int i=0；i

使用块和

using(csencryptedcommand = new CryptoStream(msencryptedcommand, 
    rmencryptedcommand.CreateDecryptor(key, iv), CryptoStreamMode.Read))
{
    // Do things with crypto stream here
}

protected override void Dispose(bool disposing)
{
    try
    {
        if (disposing)
        {
            if (!this._finalBlockTransformed)
            {
                this.FlushFinalBlock();
            }
            this._stream.Close();
        }
    }
    finally
    {
        try
        {
            this._finalBlockTransformed = true;
            if (this._InputBuffer != null)
            {
                Array.Clear(this._InputBuffer, 0, this._InputBuffer.Length);
            }
            if (this._OutputBuffer != null)
            {
                Array.Clear(this._OutputBuffer, 0, this._OutputBuffer.Length);
            }
            this._InputBuffer = null;
            this._OutputBuffer = null;
            this._canRead = false;
            this._canWrite = false;
        }
        finally
        {
            base.Dispose(disposing);
        }
    }
}

this._stream.Close();

using(msencryptedcommand = new MemoryStream())
{
    ....
}