using System;

using System.Linq;

using System.IO;

using System.Security.Cryptography;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        var apiKey = "";

        var encKey = "";

        var token = Encrypt("dt=20220511190000|api-key="+apiKey, encKey);

        Console.WriteLine("api-key=" + apiKey + ";token=" +  System.Net.WebUtility.UrlEncode(token));

    }

    public static string Encrypt(string plainText, string encryptionKey, int vectorBytesLength = 16)

    {

        RijndaelManaged rj = new RijndaelManaged();

        rj.Mode = CipherMode.CBC;

​

        byte[] key = new byte[32];

        key = Enumerable.Range(0, encryptionKey.Length)

                            .Where(x => x % 2 == 0)

                            .Select(x => Convert.ToByte(encryptionKey.Substring(x, 2), 16))

                            .ToArray();

​

        rj.Key = key;

        byte[] iv;

        using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider())

        {

            byte[] nonce = new byte[vectorBytesLength];

            rng.GetBytes(nonce);

            iv = nonce;

        }

        rj.IV = iv;

​

        MemoryStream ms = new MemoryStream();

        using (CryptoStream cs = new CryptoStream(ms, rj.CreateEncryptor(key, iv), CryptoStreamMode.Write))

        {

            using (StreamWriter sw = new StreamWriter(cs))

            {

                sw.Write(plainText);

                sw.Close();

            }

            cs.Close();

        }

​

        byte[] encoded = ms.ToArray();

        byte[] cyphertext = new byte[iv.Length + encoded.Length];

        iv.CopyTo(cyphertext, 0);

        encoded.CopyTo(cyphertext, iv.Length);

​

        return Convert.ToBase64String(cyphertext);

    }

}