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

namespace ConsoleApp1
{
    class Program
    {
        private static string GeneratePassword(DateTime dt) => ((int)dt.Subtract(new DateTime(1970, 1, 1)).TotalSeconds).ToString();

        private static byte[] CreateKey(string password, int keyBytes = 32) => new Rfc2898DeriveBytes(password, Salt, 300).GetBytes(keyBytes);

        private static readonly byte[] Salt = new byte[] {10,20,30,40,50,60,70,80};

        static void Main(string[] args)
        {
            string filename = "dbname.db.enc";
            if (!File.Exists(filename))
            {
                Console.WriteLine("No such file!");
                Environment.Exit(-111);
            }
            string d = File.ReadAllText(filename);
            byte[] array = Convert.FromBase64String(d);
            DateTime dt = new DateTime(2018, 05, 14, 0, 0, 0);

            DateTime maxDate = new DateTime(2018, 05, 16, 20, 0, 0);
            do
            {
                try
                {
                    if (dt > maxDate)
                    {
                        Console.WriteLine("Reached the min date");
                        break;
                    }
                    string text = "GeronimoAlpha" + GeneratePassword(dt);
                    RijndaelManaged rijndaelManaged = new RijndaelManaged();
                    rijndaelManaged.Key = CreateKey(text, 32);
                    rijndaelManaged.IV = new byte[] { 0x18, 0x15, 0x4F, 0x9A, 0x4C, 0xBD, 0x15, 0x40, 0xE2, 0xB5, 0x43, 0x1E, 0x66, 0x68, 0x14, 0x04 };

                    using (MemoryStream msDecrypt = new MemoryStream(array))
                    {
                        ICryptoTransform transform = rijndaelManaged.CreateDecryptor();
                        using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, transform, CryptoStreamMode.Read))
                        {
                            using (MemoryStream srDecrypt = new MemoryStream())
                            {

                                csDecrypt.CopyTo(srDecrypt);
                                File.WriteAllBytes("dbname." + text + ".db", srDecrypt.ToArray());
                            }
                        }
                    }
                }
                catch (CryptographicException)
                {
                    //continue

                }
                finally
                {
                    dt = dt.AddSeconds(1);
                }


            }
            while (true);
        }
    }
}