Providing Role Claims

RoleProfileService.cs

/*
This needs to be registered with the IdentityServer in the Startup.cs
by calling AddProfileService<RoleProfileService>() on the builder returned
by AddIdentityServer.

ex...

var builder = services.AddIdentityServer(options =>
            {
                options.Events.RaiseErrorEvents = true;
                options.Events.RaiseInformationEvents = true;
                options.Events.RaiseFailureEvents = true;
                options.Events.RaiseSuccessEvents = true;
            })
            .AddInMemoryIdentityResources(Config.GetIdentityResources())
            .AddInMemoryApiResources(Config.GetApis())
            .AddInMemoryClients(Config.GetClients())
            .AddAspNetIdentity<ApplicationUser>()
            .AddProfileService<RoleProfileService>();
*/

using System;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;
using IdentityModel;
using IdentityServer4.Extensions;
using IdentityServer4.Models;
using IdentityServer4.Services;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;

namespace IdentityServerAspNetIdentity.Extensions
{
    public class RoleProfileService : IProfileService
    {
        readonly UserManager<ApplicationUser> _userManager;
        readonly IHttpContextAccessor _httpContextAccessor;

        public RoleProfileService(UserManager<ApplicationUser> userManager,
            IHttpContextAccessor httpContextAccessor)
        {
            _userManager = userManager;
            _httpContextAccessor = httpContextAccessor;
        }

        public async Task GetProfileDataAsync(ProfileDataRequestContext context)
        {
            var sub = context.Subject.GetSubjectId();
            var user = await _userManager.FindByIdAsync(sub);
            var roleClaims = (await _userManager.GetRolesAsync(user))
                .Select(role => new Claim(JwtClaimTypes.Role, role));
            context.IssuedClaims.AddRange(roleClaims);
        }

        public Task IsActiveAsync(IsActiveContext context)
        {
            //TODO: You might want to implement this differently.
            return Task.CompletedTask;
        }
    }
}