You don't need to override Authorize or IsInRole. Just add the roles as claim to the User.Identity. You can use middleware to do the claims transformation.
As an example I suggest you take a look at the PolicyServer. It has the same approach. The free OSS version adds claims in the middleware.
/// Add the policy server claims transformation middleware to the pipeline.
/// This middleware will turn application roles and permissions into claims
/// and add them to the current user
public static IApplicationBuilder UsePolicyServerClaims(this IApplicationBuilder app)
{
return app.UseMiddleware<PolicyServerClaimsMiddleware>();
}
Where PolicyServerClaimsMiddleware is:
public class PolicyServerClaimsMiddleware
{
private readonly RequestDelegate _next;
/// <summary>
/// Initializes a new instance of the <see cref="PolicyServerClaimsMiddleware"/> class.
/// </summary>
/// <param name="next">The next.</param>
public PolicyServerClaimsMiddleware(RequestDelegate next)
{
_next = next;
}
/// <summary>
/// Invoke
/// </summary>
/// <param name="context">The context.</param>
/// <param name="client">The client.</param>
/// <returns></returns>
public async Task Invoke(HttpContext context, IPolicyServerRuntimeClient client)
{
if (context.User.Identity.IsAuthenticated)
{
var policy = await client.EvaluateAsync(context.User);
var roleClaims = policy.Roles.Select(x => new Claim("role", x));
var permissionClaims = policy.Permissions.Select(x => new Claim("permission", x));
var id = new ClaimsIdentity("PolicyServerMiddleware", "name", "role");
id.AddClaims(roleClaims);
id.AddClaims(permissionClaims);
context.User.AddIdentity(id);
}
await _next(context);
}
}
And from startup:
public void ConfigureServices(IServiceCollection services)
{
services.AddMvcCore(options =>
{
// workaround: https://github.com/aspnet/Mvc/issues/7809
options.AllowCombiningAuthorizeFilters = false;
})
.SetCompatibilityVersion(CompatibilityVersion.Version_2_1)
.AddAuthorization();
// This is not relevant for you, but just to show how policyserver is implemented.
// The bottom line is that you can implement this anyway you like.
// this sets up the PolicyServer client library and policy
// provider - configuration is loaded from appsettings.json
services.AddPolicyServerClient(Configuration.GetSection("Policy"))
.AddAuthorizationPermissionPolicies();
}
public void Configure(IApplicationBuilder app)
{
app.UseAuthentication();
// add this middleware to make roles and permissions available as claims
// this is mainly useful for using the classic [Authorize(Roles="foo")] and IsInRole functionality
// this is not needed if you use the client library directly or the new policy-based authorization framework in ASP.NET Core
app.UsePolicyServerClaims();
app.UseMvc();
}
The example reads the configuration from file, which may be an option for you as well. But you can also implement a store and add some caching.
If you want to add some authorization logic then I suggest you create some policies and authorization handlers. Just make sure that you use the middleware at the right place.
An alternative is to use your own filter / attribute:
//using Microsoft.AspNetCore.Authorization;
//using Microsoft.AspNetCore.Mvc;
//using Microsoft.AspNetCore.Mvc.Filters;
public class CustomPolicyAttribute : AuthorizeAttribute, IAsyncAuthorizationFilter
{
private int _number;
public CustomPolicyAttribute(int number)
{
_number = number;
}
public async Task OnAuthorizationAsync(AuthorizationFilterContext context)
{
var service = (IAuthorizationService)context.HttpContext.RequestServices.GetService(typeof(IAuthorizationService));
var requirement = new CustomRequirement
{
Number = _number
};
var result = await service.AuthorizeAsync(context.HttpContext.User, null, requirement);
if (!result.Succeeded)
context.Result = new ForbidResult();
}
}
You can use this in a couple of ways. Use as attribute (the Authorize equivalent):
[CustomPolicy(1)]
public async Task<IActionResult> DoSomething()
{
}
Or validate manually (the IsInRole equivalent):
public class MyController : Controller
{
private readonly IAuthorizationService _authorizationService;
public MyController(IAuthorizationService authorizationService)
{
_authorizationService = authorizationService;
}
public async Task<IActionResult> DoSomething(int number)
{
var requirement = new CustomRequirement
{
Number = number
};
var result = await _authorizationService.AuthorizeAsync(User, null, requirement);
if (!result.Succeeded) return Forbid();
return View("success");
}
}
You will need an AuthorizationHandler to evaluate the requirement:
public class CustomRequirementHandler : AuthorizationHandler<CustomRequirement>
{
// Use dependency injection to include services you need.
public CustomRequirementHandler ()
{
}
protected override async Task HandleRequirementAsync(AuthorizationHandlerContext context, CustomRequirement requirement)
{
// Add your advanced check here.
if (requirement.Number > 0)
{
context.Succeed(requirement);
}
}
}
And register that in the startup:
services.AddTransient<IAuthorizationHandler, CustomRequirementHandler>();
In the handler you can add your own logic. In that case you won't have to add policies and you don't have to add authorization as claims.
