Authorization attribute for MVC application operating outside of Umbraco environment.

UmbracoAuthorize.cs

public class UmbracoAuthorize : AuthorizeAttribute
    {
        private readonly IUmbracoService _umbracoService;

        public UmbracoAuthorize()
        {
            _umbracoService = new UmbracoService();
        }

        public UmbracoAuthorize(IUmbracoService umbracoService)
        {
            _umbracoService = umbracoService;
        }

        protected override bool AuthorizeCore(HttpContextBase httpContext)
        {
            if (HttpContext.Current == null) { return false; }

            // Do not check cookie every time, if it's logged in with correct permissions, return true.
            var cookie = httpContext.Request.Cookies.Get("UMB_UCONTEXT");
            if (cookie == null || string.IsNullOrEmpty(cookie.Value)) { return false; }

            try
            {
                var cookieValue = new Guid(cookie.Value);
                
                // Will check cookie agaisnt dbo.umbracoUserLogins and dbo.umbracoUserType
                var umbracoUser = _umbracoService.GetCurrentUser(cookieValue);

                if (string.IsNullOrEmpty(umbracoUser.UserName) || string.IsNullOrEmpty(umbracoUser.TypeAlias) || umbracoUser.IsDisabled)
                {
                    return false;
                }

                if (CheckForUserAdminTypeAlias(umbracoUser.TypeAlias.ToLowerInvariant()))
                {
                    return false;
                }

                if (cookieValue != umbracoUser.ContextId)
                {
                    return false;
                }

                httpContext.User = new GenericPrincipal(new GenericIdentity(umbracoUser.UserName), new[] { umbracoUser.TypeAlias });
                FormsAuthentication.SetAuthCookie(umbracoUser.UserName, false);
            }
            catch (Exception exception)
            {
                // _loggerService.Error(@"ERROR - ", exception);
                return false;
            }

            return true;
        }

        private static bool CheckForAdminUserTypeAlias(string userTypeAlias)
        {
            return userTypeAlias != "admin";
        }
    }