I have an ASP.NET MVC web application that is authenticating users server-side against ArcGIS Portal successfully using Owin.Security.Providers.ArcGISPortal.
I would like to use the granted authorization client-side in the browser without requiring the user to login a second time via ArcGIS's JavaScript API v3.21. Does anyone have any pointers regarding how to obtain a relevant token and pass this through client-side to access portal secured web maps, etc.?
There is a context.AccessToken that I can obtain via ArcGISPortalAuthenticationHandler and make available as a claim, but when I try to use this manually via a url like so