using System;

using System.IO;

using System.Security.Cryptography;

using System.Text;

using System.Text.Json;

​

public class SampleData

{

    public DateTimeOffset Date { get; set; }

​

    public string FirstName { get; set; }

​

    public string LastName { get; set; }

}

​

public class Program

{

    public static void Main()

    {

        byte[] Key = Encoding.ASCII.GetBytes("MZNLsW6exLFbVzpWn3glqlYPuXAXy8VG");

        byte[] IV = Encoding.ASCII.GetBytes("o2toHFUPwW7UCMjq");

        var sampleData = new SampleData{Date = DateTime.Parse("2019-08-01"), FirstName = "Delmwin", LastName = "Baeka"};

        // Serialize json to string

        string jsonString = JsonSerializer.Serialize(sampleData);

        Console.WriteLine(jsonString);

        EncryptAesManaged(jsonString, Key, IV);

    }

​

    static void EncryptAesManaged(string raw, byte[] Key, byte[] IV)

    {

        try

        {

            string encrypted = Encrypt(raw, Key, IV);

            // Print encrypted string    

            Console.WriteLine(encrypted);

        }

        catch (Exception exp)

        {

            Console.WriteLine(exp.Message);

        }

    }

​

    static string Encrypt(string plainText, byte[] Key, byte[] IV)

    {

        byte[] encrypted;

        // Create a new AesManaged.    

        using (AesManaged aes = new AesManaged())

        {

            aes.Mode = CipherMode.CBC;

            // Create encryptor    

            ICryptoTransform encryptor = aes.CreateEncryptor(Key, IV);

            // Create MemoryStream    

            using (MemoryStream ms = new MemoryStream())

            {

                // Create crypto stream using the CryptoStream class

                using (CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))

                {

                    // Create StreamWriter and write data to a stream    

                    using (StreamWriter sw = new StreamWriter(cs))

                        sw.Write(plainText);

                    encrypted = ms.ToArray();

                }

            }

        }

​

        // Return encrypted data as base 64

        return Convert.ToBase64String(encrypted);

    }

}