using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Security.Cryptography;

using System.IO;

public class Program

{

    public static void Main()

    {

        string encrypt_result = Encrypt("test");

        Console.WriteLine("Resultado de encriptacion::  " + encrypt_result);

        string decrypt_result = Decrypt(encrypt_result);

        Console.WriteLine("Resultado de desencriptacion::  " + decrypt_result);

    }

            static readonly string password = "P455W0rd_Disa";

        public static string Encrypt(string plainText)

        {

            if (plainText == null)

            {

                return null;

            }

            // Get the bytes of the string

            var bytesToBeEncrypted = Encoding.UTF8.GetBytes(plainText);

            var passwordBytes = Encoding.UTF8.GetBytes(password);

​

            // Hash the password with SHA256

            passwordBytes = SHA512.Create().ComputeHash(passwordBytes);

​

            var bytesEncrypted = Encrypt(bytesToBeEncrypted, passwordBytes);

​

            return Convert.ToBase64String(bytesEncrypted);

        }

​

        /// <summary>

        /// Decrypt a string.

        /// </summary>

        /// <param name="encryptedText">String to be decrypted</param>

        /// <exception cref="FormatException"></exception>

        public static string Decrypt(string encryptedText)

        {

            if (encryptedText == null)

            {

                return null;

            }

            // Get the bytes of the string

            var bytesToBeDecrypted = Convert.FromBase64String(encryptedText);

            var passwordBytes = Encoding.UTF8.GetBytes(password);

​

            passwordBytes = SHA512.Create().ComputeHash(passwordBytes);

​

            var bytesDecrypted = Decrypt(bytesToBeDecrypted, passwordBytes);

​

            return Encoding.UTF8.GetString(bytesDecrypted);

        }

​

        private static byte[] Encrypt(byte[] bytesToBeEncrypted, byte[] passwordBytes)

        {

            byte[] encryptedBytes = null;

            var saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };

​

            using (MemoryStream ms = new MemoryStream())

            {

                using (RijndaelManaged AES = new RijndaelManaged())

                {

                    var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000);

​

                    AES.KeySize = 256;

                    AES.BlockSize = 128;

                    AES.Key = key.GetBytes(AES.KeySize / 8);

                    AES.IV = key.GetBytes(AES.BlockSize / 8);

​

                    AES.Mode = CipherMode.CBC;

​

                    using (var cs = new CryptoStream(ms, AES.CreateEncryptor(), CryptoStreamMode.Write))

                    {

                        cs.Write(bytesToBeEncrypted, 0, bytesToBeEncrypted.Length);

                        cs.Close();

                    }

​

                    encryptedBytes = ms.ToArray();

                }

            }

​

            return encryptedBytes;

        }

​

        private static byte[] Decrypt(byte[] bytesToBeDecrypted, byte[] passwordBytes)

        {

            byte[] decryptedBytes = null;

            var saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };

​

            using (MemoryStream ms = new MemoryStream())

            {

                using (RijndaelManaged AES = new RijndaelManaged())

                {

                    var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000);

​

                    AES.KeySize = 256;

                    AES.BlockSize = 128;

                    AES.Key = key.GetBytes(AES.KeySize / 8);

                    AES.IV = key.GetBytes(AES.BlockSize / 8);

                    AES.Mode = CipherMode.CBC;

​

                    using (var cs = new CryptoStream(ms, AES.CreateDecryptor(), CryptoStreamMode.Write))

                    {

                        cs.Write(bytesToBeDecrypted, 0, bytesToBeDecrypted.Length);

                        cs.Close();

                    }

​

                    decryptedBytes = ms.ToArray();

                }

            }

​

            return decryptedBytes;

        }

}