FarmMapsApiClient/FarmmapsApi/HttpMessageHandlers/FarmmapsAuthenticationHandler.cs

using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using IdentityModel;

namespace FarmmapsApi.HttpMessageHandlers
{
    public class FarmmapsAuthenticationHandler : DelegatingHandler
    {
        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            if (!request.Headers.Authorization.Scheme.Equals(OidcConstants.AuthenticationSchemes.AuthorizationHeaderBearer) ||
                string.IsNullOrEmpty(request.Headers.Authorization.Parameter))
            {
                return new HttpResponseMessage(HttpStatusCode.Unauthorized)
                {
                    Content = new StringContent("You must authenticate before using the API")
                };
            }
            return await base.SendAsync(request, cancellationToken);
        }
    }
}