EnvelopeGenerator/EnvelopeGenerator.Extensions/EncodingExtensions.cs

using Microsoft.Extensions.Logging;
using System.Text;

namespace EnvelopeGenerator.Extensions
{
    /// <summary>
    /// Provides extension methods for decoding and extracting information from an envelope receiver ID.
    /// </summary>
    public static class EncodingExtensions
    {
        public static string EncodeEnvelopeReceiverId(this long readOnlyId)
        {
            //The random number is used as a salt to increase security but it is not saved in the database.
            string combinedString = $"{Random.Shared.Next()}::{readOnlyId}::{Random.Shared.Next()}";
            byte[] bytes = Encoding.UTF8.GetBytes(combinedString);
            string base64String = Convert.ToBase64String(bytes);

            return base64String;
        }

        public static string EncodeEnvelopeReceiverId(this (string envelopeUuid, string receiverSignature) input)
        {
            string combinedString = $"{input.envelopeUuid}::{input.receiverSignature}";
            byte[] bytes = Encoding.UTF8.GetBytes(combinedString);
            string base64String = Convert.ToBase64String(bytes);

            return base64String;
        }
    }
}