RptRequirementHandler.cs

using System;
using System.Linq;
using System.Security.Claims;
using System.Text.Json;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authorization;

namespace API.Authorization.RPT
{
    public class RptRequirementHandler : AuthorizationHandler<RptRequirement>
    {
        protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, RptRequirement requirement)
        {
            var authorizationClaim = context.User.FindFirstValue("authorization");
            if (String.IsNullOrWhiteSpace(authorizationClaim))
            {
                return Task.CompletedTask;
            }
            
            /* Sample value for authorizationClaim
            {
                "permissions":[
                    {
                        "scopes":["read"],
                        "rsid":"deb61104-5008-4001-8792-ac5734b1235b",
                        "rsname":"customers"
                    },
                    {
                        "scopes":["read","create","update","archive"],
                        "rsid":"cca3a1af-b8c5-478f-acee-01044961db50",
                        "rsname":"projects"
                    }
                ]
            }
            */
            var json = JsonDocument.Parse(authorizationClaim);
            var permissions = json.RootElement.GetProperty("permissions");
            foreach (var permission in permissions.EnumerateArray())
            {
                if (permission.GetProperty("rsname").GetString() != requirement.Resource)
                {
                    continue;
                }

                if (permission.GetProperty("scopes")
                    .EnumerateArray()
                    .Any(scope => scope.GetString() == requirement.Scope))
                {
                    context.Succeed(requirement);
                    return Task.CompletedTask;
                }
            }
            return Task.CompletedTask;
        }
    }
}