How to persist policy authorization results for users in ASP.NET Core, MVC 6? - caching

Question

Currently I have a simple custom policy handler that looks like so:
protected override void Handle(AuthorizationContext context, UserPolicyRequirement requirement)
{
// authorize user against policy requirements
if (_authorizationTask.AuthorizeUserAgainstPolicy(context.User, requirement))
{
// User passed policy req's
context.Succeed(requirement);
}
}
Problem is, this authorization step takes a long time to execute, but this is required in many different areas of the website. Is there any readily available mechanisms to save/cache the results of this policy authorization so that I only need to do this once per session?
I am currently using Windows Authentication, if that helps.

Answer 1

If per session way does not cause any problem, you can use Session to store user data. Simple implementation is something like below:
First you need a service to get user data from any store
public interface IGetUserDataService
{
<type> GetUserData();
}
I assume that there is Session configuration(see) and IGetUserDataService implementation.
Then you need to create a middleware to handle Session
public class SessionMiddleware
{
private readonly RequestDelegate _next;
private readonly IGetUserDataService _getUserDataService;
public SessionMiddleware(RequestDelegate next, IGetUserDataService getUserDataService)
{
_next = next;
_getUserDataService = getUserDataService;
}
public async Task Invoke(HttpContext context)
{
//user data is obtained only once then is stored in Session
if (context.Session.Get("UserData") == null)
{
context.Session.Set("UserData", getUserDataService.GetData());
}
await _next.Invoke(context);
}
}
//In Startup.cs
app.UseMiddleware<SessionMiddleware>();
Finally get and use session data in handler
public class YourHandler : AuthorizationHandler<YourRequirement>
{
private readonly IHttpContextAccessor _accessor;
public YourHandler(IHttpContextAccessor accessor)
{
_accessor = accessor;
}
protected override void Handle(AuthorizationContext context, PermissionRequirement requirement)
{
var userData =(<type>)_accessor.HttpContext.Session.Get("UserData");
// check
}
}