解密txt文件时，数据长度无效

Question

我制作了一个控制台应用程序来解密文件。请参阅屏幕截图以获取详细错误消息。

如果您复制粘贴代码在控制台应用程序中。你应该能够调试。

1）需要创建文件夹SourceFolder \ Newfolder \和一个新的txt文件destination.txt

2）需要为C：\ DestinationFolder \ source.txt创建文件夹（加密文件不能在这里附加文件，希望你能做到一个

using System;
using System.IO;
using System.Security.Cryptography;

namespace ConsoleApp5
{
    class Program
    {
    //SALT is a random data that is used as addition to a password to encrypt data
    // The primary function is to protect against lists of often used password
    private static readonly byte[] SALT = new byte[] {0x26,0xdc,0xff,0x76,0x76,
                                                            0xad,0xed,0x7a,0x64,0xc5,0xfe
                                                            ,0x20,0xaf,0x4d,0x08,0x3c};

    static void Main(string[] args)
    {

        //Need to make a SourceFolder and but the file in there abc.txt
        string path = @"C:\SourceFolder\New folder\";
        string[] txtFile = Directory.GetFiles(path, "*.txt");
        string fileinnn = txtFile[0];



        //Get the filepath of the decrypted file. Need to make this folder and add a new file that is what i am donig for now for this cosole app 
        string filepathDecrypted = @"C:\DestinationFolder\destination.txt";  //this is a new file need to create

        //Get the password 
        string encrytionKey = "password.";
        Decrypt(fileinnn, filepathDecrypted, encrytionKey);
    }

    public static void Decrypt(string fileIn, string fileOut, string Password)
    {
        //open filestreat for encrypted source file
        using (System.IO.FileStream fsIn = new FileStream(fileIn, FileMode.Open, FileAccess.Read))
        {

            using (System.IO.FileStream fsOut = new FileStream(fileOut, FileMode.OpenOrCreate, FileAccess.Write))
            {
                try
                {
                    //Create Key and IV from the password with the SALT 
                    Rfc2898DeriveBytes pdf = new Rfc2898DeriveBytes(Password, SALT);

                    //Create a symmetric algorithm with Rijndael
                    Rijndael alg = Rijndael.Create();

                    alg.Padding = PaddingMode.PKCS7;
                    //alg.BlockSize = 128;


                    //SET key and IV 
                    alg.Key = pdf.GetBytes(32);
                    alg.IV = pdf.GetBytes(16);
                    //Create a cryptoStream 

                    using (CryptoStream cs = new CryptoStream(fsOut, alg.CreateDecryptor(), CryptoStreamMode.Write))
                    {
                        //Intialize the buffer and process the input in chunks 
                        // this is done to avoid reading the whole file which is huge and memory consumption. 

                        int bufferLen = 4096;
                        byte[] buffer = new byte[bufferLen];
                        int bytesRead;
                        do
                        { //read a chunck of data from the input file 
                            bytesRead = fsIn.Read(buffer, 0, bufferLen);

                            //Decrypt it 
                            cs.Write(buffer, 0, bytesRead);
                        }
                        while (bytesRead != 0);

                        //close everything 
                        cs.Close();   //this is where it throws exception
                        fsOut.Close();
                        fsIn.Close();
                    }
                }
                catch (Exception ex)
                {
                    var error = ex.Message;

                    throw;
                }
            }
        }
    }
}

}

我收到的错误消息