xCommons/Attributes/RequireXPoweredAttribute.cs

using System.Linq;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using xCommons.Constants;
using xCommons.Extensions;

namespace xCommons.Attributes {
    public partial class RequireXPoweredAttribute : AuthorizeAttribute, IAuthorizationFilter {

        private readonly bool ignoreAnonymous;

        public RequireXPoweredAttribute (bool IgnoreAnonymous = true) {
            ignoreAnonymous = IgnoreAnonymous;
        }

        public void OnAuthorization (AuthorizationFilterContext context) {
            //
            var config = context.GetXAppConfiguration ();

            //
            var isExistsXPowered = context.HttpContext.Request.Headers
                .Any (h => h.Key
                    .ToNormalString () == XAuthorization.XPoweredBy.ToNormalString () &&
                    h.Value == config.XPoweredValue);

            //
            var isAnonymous = context.IsAnonymousAllowed ();
            var handler = ignoreAnonymous ? isAnonymous ? false : true : true;

            //
            if (handler &&
                !isExistsXPowered) {
                context.Result = new UnauthorizedResult ();
            }
        }
    }
}