C# encryption and decryption

In c#.net, when im trying to decrypt the file it shows me this error but it works for encryption.

ERROR: The process cannot access the file SecureDownloadManager.log because it is being used by another process

Code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Security;
using System.Security.Cryptography;
using System.IO;
using System.Text.RegularExpressions;
using System.Runtime.InteropServices;

namespace Encryption

public partial class Form1 : Form

string inputFile;
string outputFile;
public Form1()

InitializeComponent();



private void button1_Click(object sender, EventArgs e)


//EncryptFile();
try

OpenFileDialog dialog = new OpenFileDialog();
dialog.Filter = "All Files (*.*)
catch (Exception ex)

MessageBox.Show(ex.Message);




private void button2_Click(object sender, EventArgs e)
//Decrypt File
try
";
dialog.InitialDirectory = @"Desktop";
dialog.Title = "Please select a file to decrypt.";

dialog.ShowDialog();

inputFile = dialog.FileName;
outputFile = inputFile;

string password = @"myKey123"; // Your Key Here

UnicodeEncoding UE = new UnicodeEncoding();
byte key = UE.GetBytes(password);

string cryptFile = outputFile;
FileStream fsCrypt = new FileStream(inputFile, FileMode.Create);

RijndaelManaged RMCrypto = new RijndaelManaged();

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

FileStream fsOut = new FileStream(outputFile, FileMode.Open, FileAccess.Write, FileShare.ReadWrite);

int data;
while ((data = cs.ReadByte()) != -1)
fsOut.WriteByte((byte)data);

fsOut.Close();
cs.Close();
fsCrypt.Close();

catch (Exception ex)

MessageBox.Show(ex.Message);







2 Answers
2

Try the following code and let me know if it resolves the problem.

//EncryptFile();
try

OpenFileDialog dialog = new OpenFileDialog();
dialog.Filter = "All Files (*.*)
catch (Exception ex)

MessageBox.Show(ex.Message);



The error is due to the objects not being completely disposed. You need to use a 'using' clause to release objects after use.

You can use the following code that uses FileStream instead:

FileStream

System.IO.File.WriteAllBytes(outputFile);


which replaces:

FileStream fsOut = new FileStream(outputFile, FileMode.Open, FileAccess.Write, FileShare.ReadWrite);

int data;
while ((data = cs.ReadByte()) != -1)
fsOut.WriteByte((byte)data);

fsOut.Close();
cs.Close();
fsCrypt.Close();


I hope it resolves your issue.

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