icarus/Authorization/Handlers/HasScopeHandler.cs

using System;
using System.Linq;
using System.Threading.Tasks;

using Microsoft.AspNetCore.Authorization;

using Icarus.Authorization;

namespace Icarus.Authorization.Handlers;

public class HasScopeHandler : AuthorizationHandler<HasScopeRequirement>
{
    protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, HasScopeRequirement requirement)
    {
        if (!context.User.HasClaim(c => c.Type == "scope" && c.Issuer == requirement.Issuer))
        {
            return Task.CompletedTask;
        }

        var scopes = context.User.FindFirst(c =>
            c.Type == "scope" && c.Issuer == requirement.Issuer).Value.Split(' ');

        if (scopes.Any(s => s == requirement.Scope))
        {
            context.Succeed(requirement);
        }

        return Task.CompletedTask;
    }
}