MARKUS

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Runtime.InteropServices;

using System.Security.Cryptography;

using System.Text;

using System.Threading.Tasks;

namespace CommonLib

{

    public class Common

    {

        [DllImport("kernel32")]

        private static extern int GetPrivateProfileString(string section, string key, string def, StringBuilder retVal, int size, string filePath);

        public static string AppDataFolder

        {

            get

            {

                return Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData), "MARKUS");

            }

        }

        public static string GetConfigString(string section, string key, string def)

        {

            System.Text.StringBuilder strbuilder = new System.Text.StringBuilder(512);

            GetPrivateProfileString(section, key, def, strbuilder, 512, Path.Combine(AppDataFolder, "FinalService.ini"));

            return strbuilder.ToString();

        }

        public static string GetConnectionString()

        {

            System.Text.StringBuilder strbuilder = new System.Text.StringBuilder(512);

            GetPrivateProfileString("ConnectionString", "STRING", "", strbuilder, 512, Path.Combine(AppDataFolder, "FinalService.ini"));

            return Decrypt(strbuilder.ToString(), "Doftech1073#");

        }

        private static string Decrypt(string textToDecrypt, string key)

        {

            RijndaelManaged rijndaelCipher = new RijndaelManaged();

            rijndaelCipher.Mode = CipherMode.CBC;

            rijndaelCipher.Padding = PaddingMode.PKCS7;

            rijndaelCipher.KeySize = 128;

            rijndaelCipher.BlockSize = 128;

            byte[] encryptedData = Convert.FromBase64String(textToDecrypt);

            byte[] pwdBytes = Encoding.UTF8.GetBytes(key);

            byte[] keyBytes = new byte[16];

            int len = pwdBytes.Length;

            if (len > keyBytes.Length)

            {

                len = keyBytes.Length;

            }

            Array.Copy(pwdBytes, keyBytes, len);

            rijndaelCipher.Key = keyBytes;

            rijndaelCipher.IV = keyBytes;

            byte[] plainText = rijndaelCipher.CreateDecryptor().TransformFinalBlock(encryptedData, 0, encryptedData.Length);

            return Encoding.UTF8.GetString(plainText);

        }

    }

}