Hangfire dashboard authorization filter using basic authentication and relying on browser support to allow user to input username and password.

HFDashboardAuthFilter.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Hangfire.Annotations;
using Hangfire.Dashboard;
using Microsoft.AspNetCore.Http;

namespace MyApp.ScheduledTask
{
    public class HFDashboardAuthFilter : Hangfire.Dashboard.IDashboardAuthorizationFilter
    {
        public bool Authorize([NotNull] DashboardContext context)
        {
            var httpContext = context.GetHttpContext();

            var header = httpContext.Request.Headers["Authorization"];

            if (string.IsNullOrWhiteSpace(header))
            {
                SetChallengeResponse(httpContext);
                return false;
            }

            var authValues = System.Net.Http.Headers.AuthenticationHeaderValue.Parse(header);

            if (!"Basic".Equals(authValues.Scheme, StringComparison.InvariantCultureIgnoreCase))
            {
                SetChallengeResponse(httpContext);
                return false;
            }

            var parameter = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(authValues.Parameter));
            var parts = parameter.Split(':');

            if (parts.Length < 2)
            {
                SetChallengeResponse(httpContext);
                return false;
            }

            var username = parts[0];
            var password = parts[1];

            if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
            {
                SetChallengeResponse(httpContext);
                return false;
            }

            if (username == "johndoe" && password == "123")
            {
                return true;
            }

            SetChallengeResponse(httpContext);
            return false;
        }

        private void SetChallengeResponse(HttpContext httpContext)
        {
            httpContext.Response.StatusCode = 401;
            httpContext.Response.Headers.Append("WWW-Authenticate", "Basic realm=\"Hangfire Dashboard\"");
            httpContext.Response.WriteAsync("Authentication is required.");
        }

    }
}