using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace CS_AES_Files

{

    class Program

    {

        static void Pause()

        {

            Console.Write(“Press any key to continue . . . “);

            Console.ReadKey(true);

        }

        static void Main(string[] args)

        {

            String inputFile;

            String outputFile;

            String outputFile1;

            String password;

            inputFile = “test.png”;// “Program.cs”;

            outputFile = “test_e.png”;//”Program_e.cs”;

            outputFile1 = “test_d.png”;//”Program_d.cs”;

            password = “P@$$WORD”;

            SecureAES aes = new SecureAES();

            aes.AES_Encrypt(inputFile, password, outputFile);

            aes.AES_Decrypt(outputFile, password, outputFile1);

            Pause();

        }

    }

}

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Security.Cryptography;

using System.Text;

using System.Threading;

namespace CS_AES_Files

{

    public class SecureAES

    {

        //https://github.com/mullak99/SecureAES

        public SecureAES()

        {

            return;

        }

        public string CreateRandomPassword(int length)

        {

            const string valid = “abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890-=_+[]{}:;@’~#,<.>/?`¬!$%^&*()”;

            StringBuilder res = new StringBuilder();

            Random rnd = new Random();

            while (0 < length–)

            {

                res.Append(valid[rnd.Next(valid.Length)]);

            }

            return res.ToString();

        }

        public static byte[] GenerateRandomSalt()

        {

            byte[] data = new byte[32];

            using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider())

            {

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

                {

                    rng.GetBytes(data);

                }

            }

            return data;

        }

        public void AES_Encrypt(string inputFile, string password, string outputName = null)

        {

            byte[] salt = GenerateRandomSalt();

            if (outputName == null)

            {

                outputName = inputFile + “.encrypted”;

            }

            FileStream fsCrypt = new FileStream(outputName, FileMode.Create);

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

            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);

            AES.Mode = CipherMode.CFB;

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

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

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

            byte[] buffer = new byte[1048576];

            int read;

            try

            {

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

                {

                    //Application.DoEvents();

                    cs.Write(buffer, 0, read);

                }

                fsIn.Close();

            }

            catch (Exception ex)

            {

            }

            finally

            {

                cs.Close();

                fsCrypt.Close();

            }

        }

        public bool AES_Decrypt(string inputFile, string password, string outputName = null)

        {

            if (Path.GetExtension(inputFile) == “.encrypted” || !String.IsNullOrEmpty(outputName))

            {

                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);

                if (outputName == null)

                {

                    outputName = inputFile.Replace(“.encrypted”, “”);

                }

                FileStream fsOut = new FileStream(outputName, 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 (System.Security.Cryptography.CryptographicException ex_CryptographicException)

                {

                }

                catch (Exception ex)

                {

                }

                try

                {

                    cs.Close();

                }

                catch (Exception ex)

                {

                }

                finally

                {

                    fsOut.Close();

                    fsCrypt.Close();

                }

                return true;

            }

            else

            {

                return false;

            }

        }

    }

}