ویرایش کلاس به صورت دلخواه

سلام دوستان:
یک کلاس رمزنگاری فایلها رو می خوام طوری ویرایش کنم که متن رو از تکستباکس بگیره و به صورت فایل رمزنگاری شده ذخیره کنه.
کار اصلی کلاس اینه که فایل رو ازمون میگیره و به صورت رمزنگاری شده ذخیره می کنه.
با سپاس فراوان.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Security.Cryptography;

using System.IO;





namespace AES_CryptoService

{

    public class AES_Crypto_Algorithm

    {





        public static byte[] GenerateRandomSalt()

        {

            byte[] data = new byte[32];





            using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider())

            {

                for (int i = 0; i < 10; i++)

                {

                    // Fille the buffer with the generated data

                    rng.GetBytes(data);

                }

            }





            return data;

        }





        public void FileEncrypt(string inputFile, string password)

        {





            //generate random salt

            byte[] salt = GenerateRandomSalt();





            //create output file name

            FileStream fsCrypt = new FileStream(inputFile + ".aes", FileMode.Create);





            //convert password string to byte arrray

            byte[] passwordBytes = System.Text.Encoding.UTF8.GetBytes(password);





            //Set Rijndael symmetric encryption algorithm

            RijndaelManaged AES = new RijndaelManaged();

            AES.KeySize = 256;

            AES.BlockSize = 128;

            AES.Padding = PaddingMode.PKCS7;





            var key = new Rfc2898DeriveBytes(passwordBytes, salt, 50000);

            AES.Key = key.GetBytes(AES.KeySize / 8);

            AES.IV = key.GetBytes(AES.BlockSize / 8);





            //Cipher modes: http://security.stackexchange.com/qu...aes-encryption

            AES.Mode = CipherMode.CFB;





            // write salt to the begining of the output file, so in this case can be random every time

            fsCrypt.Write(salt, 0, salt.Length);





            CryptoStream cs = new CryptoStream(fsCrypt, AES.CreateEncryptor(), CryptoStreamMode.Write);





            FileStream fsIn = new FileStream(inputFile, FileMode.Open);





            //create a buffer (1mb) so only this amount will allocate in the memory and not the whole file

            byte[] buffer = new byte[1048576];

            int read;





            try

            {

                while ((read = fsIn.Read(buffer, 0, buffer.Length)) > 0)

                {

                    //Application.DoEvents(); // -> for responsive GUI, using Task will be better!

                    cs.Write(buffer, 0, read);

                }





                // Close up

                fsIn.Close();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Error: " + ex.Message);

            }

            finally

            {

                cs.Close();

                fsCrypt.Close();

            }

        }





        public void FileDecrypt(string inputFile, string outputFile, string password)

        {

            byte[] passwordBytes = System.Text.Encoding.UTF8.GetBytes(password);

            byte[] salt = new byte[32];





            FileStream fsCrypt = new FileStream(inputFile, FileMode.Open);

            fsCrypt.Read(salt, 0, salt.Length);





            RijndaelManaged AES = new RijndaelManaged();

            AES.KeySize = 256;

            AES.BlockSize = 128;

            var key = new Rfc2898DeriveBytes(passwordBytes, salt, 50000);

            AES.Key = key.GetBytes(AES.KeySize / 8);

            AES.IV = key.GetBytes(AES.BlockSize / 8);

            AES.Padding = PaddingMode.PKCS7;

            AES.Mode = CipherMode.CFB;





            CryptoStream cs = new CryptoStream(fsCrypt, AES.CreateDecryptor(), CryptoStreamMode.Read);





            FileStream fsOut = new FileStream(outputFile, FileMode.Create);





            int read;

            byte[] buffer = new byte[1048576];





            try

            {

                while ((read = cs.Read(buffer, 0, buffer.Length)) > 0)

                {

                    //Application.DoEvents();

                    fsOut.Write(buffer, 0, read);

                }

            }

            catch (CryptographicException ex_CryptographicException)

            {

                Console.WriteLine("CryptographicException error: " + ex_CryptographicException.Message);

            }

            catch (Exception ex)

            {

                Console.WriteLine("Error: " + ex.Message);

            }





            try

            {

                cs.Close();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Error by closing CryptoStream: " + ex.Message);

            }

            finally

            {

                fsOut.Close();

                fsCrypt.Close();

            }

        }





    }

    //end of class.





}