FolderLocker.cs

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Management;
using System.Security.AccessControl;
using System.Security.Cryptography;
using System.Text;
using System.Windows.Forms;

namespace AntiVirus_Project
{
    class FolderLocker
    {
        public bool no_valut = true;
        private string salted_pass = string.Empty;
        private string password = string.Empty;
        private string vault_loc = string.Empty;
        private string hashKey = "Netsky_key_2015@#$%138";
        private List<string> users = new List<string>();
        private ConsoleSetups con = new ConsoleSetups();

        public FolderLocker()
        {
            GetUsers();
            RegistryKey key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Netsky Antivirus");
            if (key != null)
            {
                //using faked sub keys like update and uniqueID to mislead users who are exploring registry
                //so they will not be able to recognize the original password and vault location
                //for more security both password and vault locations are encrypted
                salted_pass = key.GetValue("Update").ToString();
                vault_loc = key.GetValue("UniqueID").ToString();

                //now decrypt the salted_pass and vault_loc to get original one
                no_valut = false;
                salted_pass = Decrypt(salted_pass, hashKey);
                vault_loc = Decrypt(vault_loc, hashKey);
            }
            else
                no_valut = true;

        }

        public void CreateOrUnlockFolder(Form1 main)
        {
            if(no_valut)
            {
                //there's no vault, show user first time info and take vault location and password
                MetroFramework.MetroMessageBox.Show(main, "Please create a folder anywhere in your computer and select the location of that folder. It will be used as vault and put your important files inside that folder to protect and lock it", "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);
                FolderBrowserDialog fbd = new FolderBrowserDialog();
                fbd.ShowNewFolderButton = true;
                fbd.Description = "Select the folder to make a new vault";
                if(fbd.ShowDialog() == DialogResult.OK)
                {
                    using(var form = new VaultPassword())
                    {
                        form.Text = "Create Password";
                        form.metroTile1.Text = "Create";
                        var result = form.ShowDialog();
                        if(result == DialogResult.OK)
                        {
                            password = form.password;
                            con.RunExternalExe("attrib.exe", "+s +h +r +a " + '"' + fbd.SelectedPath + '"');
                            SetPermission(fbd.SelectedPath, AccessControlType.Deny);
                            RegistryKey key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Netsky Antivirus");
                            if(key!=null)
                            {
                                key.SetValue("Update", Encrypt(password, hashKey));
                                key.SetValue("UniqueID", Encrypt(fbd.SelectedPath, hashKey));
                            }
                            else
                            {
                                key = Registry.LocalMachine.CreateSubKey(@"SOFTWARE\Netsky Antivirus");
                                key.SetValue("Update", Encrypt(password, hashKey));
                                key.SetValue("UniqueID", Encrypt(fbd.SelectedPath, hashKey));
                            }
                            no_valut = false;
                            salted_pass = password;
                            vault_loc = fbd.SelectedPath;
                            MetroFramework.MetroMessageBox.Show(main,"Vault created successfully","Done",MessageBoxButtons.OK,MessageBoxIcon.Information);
                        }//end if
                    }//end using
                }//end if
            }
            else
            {
                //vault is there, get key and open it
                using (var form = new VaultPassword())
                {
                    form.Text = "Enter password";
                    form.metroTile1.Text = "Open";
                    var result = form.ShowDialog();
                    if(result == DialogResult.OK)
                    {
                        password = form.password;
                        if (password == salted_pass)
                        {
                            SetPermission(vault_loc, AccessControlType.Allow);
                            con.RunExternalExe("attrib.exe", "-s -h -r -a " + '"' + vault_loc + '"');
                            Process.Start(vault_loc);
                        }
                        else
                            MetroFramework.MetroMessageBox.Show(main, "Invalid password", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                }
            }
        }

        public void LockFolder(Form1 main)
        {
            if(!no_valut)
            {
                con.RunExternalExe("attrib.exe", "+s +h +r +a " + '"' + vault_loc + '"');
                SetPermission(vault_loc, AccessControlType.Deny);
                MetroFramework.MetroMessageBox.Show(main, "Vault locked successfully","Done",MessageBoxButtons.OK,MessageBoxIcon.Information);
            }
        }

        public bool DestroyFolder(Form1 main)
        {
            if (no_valut)
                return false;
            else
            {
                //destroy the vault and reg settings
                using (var form = new VaultPassword())
                {
                    form.Text = "Enter password";
                    form.metroTile1.Text = "Open";
                    var result = form.ShowDialog();
                    if (result == DialogResult.OK)
                    {
                        password = form.password;
                        if (password == salted_pass)
                        {
                            SetPermission(vault_loc, AccessControlType.Allow);
                            con.RunExternalExe("attrib.exe", "-s -h -r -a " + '"' + vault_loc+ '"');
                            EmptyFolder(new DirectoryInfo(vault_loc));
                            Directory.Delete(vault_loc);
                            Registry.LocalMachine.DeleteSubKey(@"SOFTWARE\Netsky Antivirus");
                            
                            MetroFramework.MetroMessageBox.Show(main, "Vault successfully deleted", "Done", MessageBoxButtons.OK, MessageBoxIcon.Information);
                            no_valut = true;
                        }
                        else
                            MetroFramework.MetroMessageBox.Show(main, "Invalid password", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                }
                return true;
            }

        }

        private void GetUsers()
        {
	        SelectQuery sQuery = new SelectQuery("Win32_UserAccount","Domain='"+ System.Environment.UserDomainName.ToString() + "'");
	        try
	        {
		        ManagementObjectSearcher mSearcher = new ManagementObjectSearcher(sQuery);
		        foreach(ManagementObject mObject in mSearcher.Get())
		        {
                    users.Add(mObject["Name"].ToString());
		        }
	        }
	        catch{}
        }

        private void SetPermission(string folder,AccessControlType type)
        {
            if (type == AccessControlType.Deny)
            {
                DirectoryInfo info = new DirectoryInfo(folder);
                DirectorySecurity security = info.GetAccessControl();

                foreach (string user in users)
                {
                    security.AddAccessRule(new FileSystemAccessRule(user, FileSystemRights.ReadAndExecute, type));
                    security.AddAccessRule(new FileSystemAccessRule(user, FileSystemRights.Traverse, type));
                    security.AddAccessRule(new FileSystemAccessRule(user, FileSystemRights.Write, type));
                    security.AddAccessRule(new FileSystemAccessRule(user, FileSystemRights.Delete, type));
                    security.AddAccessRule(new FileSystemAccessRule(user, FileSystemRights.DeleteSubdirectoriesAndFiles, type));
                    security.AddAccessRule(new FileSystemAccessRule(user, FileSystemRights.ExecuteFile, type));
                    security.AddAccessRule(new FileSystemAccessRule(user, FileSystemRights.Modify, type));
                    security.AddAccessRule(new FileSystemAccessRule(user, FileSystemRights.Read, type));
                }
                info.SetAccessControl(security);
            }
            else
            {
                string arg = "cmd.exe /c takeown /f " + '"' +folder +'"' + " /r /d y && icacls " + '"' + folder + '"' + " /grant administrators:F /t /c /l /q";
                con.RunExternalExe("cmd.exe", arg);
            }
        }

        private string Encrypt(string strToEncrypt, string strKey)
        {
            try
            {
                TripleDESCryptoServiceProvider objDESCrypto = new TripleDESCryptoServiceProvider();
                MD5CryptoServiceProvider objHashMD5 = new MD5CryptoServiceProvider();
                byte[] byteHash, byteBuff;
                string strTempKey = strKey;
                byteHash = objHashMD5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(strTempKey));
                objHashMD5 = null;
                objDESCrypto.Key = byteHash;
                objDESCrypto.Mode = CipherMode.ECB; //CBC, CFB
                byteBuff = ASCIIEncoding.ASCII.GetBytes(strToEncrypt);
                return Convert.ToBase64String(objDESCrypto.CreateEncryptor().TransformFinalBlock(byteBuff, 0, byteBuff.Length));
            }
            catch (Exception ex)
            {
                return "Wrong Input. " + ex.Message;
            }
        }

        private string Decrypt(string strEncrypted, string strKey)
        {
            try
            {
                TripleDESCryptoServiceProvider objDESCrypto = new TripleDESCryptoServiceProvider();
                MD5CryptoServiceProvider objHashMD5 = new MD5CryptoServiceProvider();
                byte[] byteHash, byteBuff;
                string strTempKey = strKey;
                byteHash = objHashMD5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(strTempKey));
                objHashMD5 = null;
                objDESCrypto.Key = byteHash;
                objDESCrypto.Mode = CipherMode.ECB; //CBC, CFB
                byteBuff = Convert.FromBase64String(strEncrypted);
                string strDecrypted = ASCIIEncoding.ASCII.GetString(objDESCrypto.CreateDecryptor().TransformFinalBlock(byteBuff, 0, byteBuff.Length));
                objDESCrypto = null;
                return strDecrypted;
            }
            catch (Exception ex)
            {
                return "Wrong Input. " + ex.Message;
            }
        }

        private void EmptyFolder(DirectoryInfo directoryInfo)
        {
            foreach (FileInfo file in directoryInfo.GetFiles())
            {
                file.Delete();
            }

            foreach (DirectoryInfo subfolder in directoryInfo.GetDirectories())
            {
                EmptyFolder(subfolder);
            }
        }

    } //end of class
} //end of namespace