I have an existing ASP.NET core application where I need to block a set group of users from actions on some of my controllers. I can do this on a per task basic but am looking for a way to function the entire block to avoid as much duplication as possible.
An example of how I did this for a Task is:
public async Task<IActionResult> Index()
{
if(RestrictedUserCheckConditions) return RedirectToAction(nameof("RestrictionView"), "UserErrors");
//continue with action for unrestricted users.
...
}
Is there a way I can function this to achive something like below to avoid too much duplication? Otherwise I have a lot of code to add to a lot of Tasks!
public async Task<IActionResult> Index()
{
RestrictedUserCheck();
//continue with action for unrestricted users.
...
}
Thanks in advance
You can create a Custom Authorize attribute to prevent user access the action method:
For example: create a CustomAuthorizeAttribute with the following code:
public class CustomAuthorizeAttribute : TypeFilterAttribute
{
//this method will access the block users, and transfer the data to the ClaimRequirementFilter
public CustomAuthorizeAttribute(string blockUser) : base(typeof(ClaimRequirementFilter))
{
Arguments = new object[] { new Claim(ClaimTypes.Name, blockUser) };
}
}
public class ClaimRequirementFilter : IAuthorizationFilter
{
readonly Claim _claim; //we can get the block users from this property.
public ClaimRequirementFilter(Claim claim)
{
_claim = claim;
}
public void OnAuthorization(AuthorizationFilterContext context)
{
//query current user's claims and check whether current user is in the block user list
var hasClaim = context.HttpContext.User.Claims.Any(c => c.Type == _claim.Type && _claim.Value.ToLower().Split(',').Contains(c.Value.ToLower()));
//if current user is the block user, prevent user access the action method, and return a forbidresult.
if (hasClaim)
{
context.Result = new ForbidResult();
}
}
}
Then apply the above attribute on the action method:
[CustomAuthorize("bb#hotmail.com,cc#hotmail.com")]
public IActionResult Privacy()
{
return View();
}
the result as below:
[Note] In the above sample, we are using the Asp.net core Identity, after login, it already adds the current user claims. If you don't use Asp.net core Identity, you have to add the claims to the HttpContext by yourself.
Besides, you can also use Policy based and Role based authorization to do it, refer the following links:
Policy-based authorization in ASP.NET Core
Policy-Based And Role-Based Authorization In ASP.NET Core 3.0 Using Custom Handler
Right now, my user table has a bool called Admin. As the code shows, if user.admin = true, the user is able to see the admin area button and access it.
#if (Common.UsuarioLogueado.Admin) {
<li>Admin control panel</li>
}
This is working as intended. However, non admin users can still go to the control panel by accessing it´s url http://localhost/appName/admin/ClientesAdmin/list
How do I prevent such thing? I was thinking about showing an error msg
Going along with the other answers about using Roles, and the AuthorizeAttribute.. which in my opinion is the better way to achieve what you're trying to do, there is another way.
You could just simply redirect the user to another page.. preferable an error page saying you don't have access to the requested page, or just a 401 page which the AuthorizeAttribute would do if you weren't authorized.
Alternate Solution
public class ClientesAdmin : Controller {
// [Authorize(Roles="Admin")] could do it this way
public ActionResult List() {
// or..
if(!Common.UsuarioLogueado.Admin)
{
return new HttpStatusCodeResult(401);
// or
// return View("Error") // usually there is an 'Error' view the Shared folder
}
return View();
}
}
This is not the best solution but I don't know how far along your project is, but simply an alternate solution.
This is how I do it. However your membership system needs to be using ASP.Net Roles for this to work properly.
In your controller you just add the data annotation Authorize. for the function to be accessed by the client, they must be logged in and have the roll specified in the function.
This solution may not be direct cut and paste, but you can see the basic usage then perhaps do a little more research on the Authorize functionality.
public class MyController : Controller {
[Authorize(Roles="Admin")]
public ActionResult AdminIndex() {
return View();
}
[Authorize(Roles = "basic")]
public ActionResult BasicUsersIndex() {
return View();
}
}
Ideally you should be using role based access control. By limiting access by the role, rather than a boolean value in a table you could decorate your CientesAdmin controller with an Authorize Attribute like below.
[Authorize(Roles = "Admin")]
public class CientesAdminController : Controller
{
}
You could also use razor helpers to check if a user IsInRole("Admin").
There is a lot of help on the net to guide you down this path, but if your app is already developed you probably want to stage your changes. Then the recommendation would be to create your own AuthoriseAttribue. Something like.
public class RestrictAccessToAdmins : AuthorizeAttribute
{
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
//Do the default Authorise Logic (Check if user is loggedin)
base.AuthorizeCore(httpContext);
if (httpContext.User.IsInRole("Admin")) return true;
var id = httpContext.User.Identity.GetUserId();
using (ApplicationDbContext context = new ApplicationDbContext())
{
//Implement you own DB logic here returning a true or false.
return context.Common.First(u => u.userid == id).UsuarioLogueado.Admin;
}
}
}
To use the attribute you'd do the following.
[RestrictAccessToAdmins]
public class CientesAdminController : Controller
{
}
Then over time, with better understanding of the default authorise attribute and a bit of refactoring you could easily change the attribute to below :)
[RestrictAccessToAdmins(Roles = "Admin")]
public class CientesAdminController : Controller
{
}
I'm creating a workflow tool that will be used on our company intranet. Users are authenticated using Windows Authentication and I've set up a custom RoleProvider that maps each user to a pair of roles.
One role indicates their seniority (Guest, User, Senior User, Manager etc.) and the other indicates their role/department (Analytics, Development, Testing etc.). Users in Analytics are able to create a request that then flows up the chain to Development and so on:
Models
public class Request
{
public int ID { get; set; }
...
public virtual ICollection<History> History { get; set; }
...
}
public class History
{
public int ID { get; set; }
...
public virtual Request Request { get; set; }
public Status Status { get; set; }
...
}
In the controller I have a Create() method that will create the Request header record and the first History item:
Request Controller
public class RequestController : BaseController
{
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create (RequestViewModel rvm)
{
Request request = rvm.Request
if(ModelState.IsValid)
{
...
History history = new History { Request = request, Status = Status.RequestCreated, ... };
db.RequestHistories.Add(history);
db.Requests.Add(request);
...
}
}
}
Each further stage of the request will need to be handled by different users in the chain. A small subset of the process is:
User creates Request [Analytics, User]
Manager authorises Request [Analytics, Manager]
Developer processes Request [Development, User]
Currently I have a single CreateHistory() method that handles each stage of the process. The status of the new History item is pulled up from the View:
// GET: Requests/CreateHistory
public ActionResult CreateHistory(Status status)
{
History history = new History();
history.Status = status;
return View(history);
}
// POST: Requests/CreateHistory
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult CreateHistory(int id, History history)
{
if(ModelState.IsValid)
{
history.Request = db.Requests.Find(id);
...
db.RequestHistories.Add(history);
}
}
The CreateHistory View itself will render a different partial form depending on the Status. My intention was that I could use a single generic CreateHistory method for each of the stages in the process, using the Status as a reference to determine which partial View to render.
Now, the problem comes in rendering and restricting available actions in the View. My CreateHistory View is becoming bloated with If statements to determine the availability of actions depending on the Request's current Status:
#* Available user actions *#
<ul class="dropdown-menu" role="menu">
#* Analyst has option to withdraw a request *#
<li>#Html.ActionLink("Withdraw", "CreateHistory", new { id = Model.Change.ID, status = Status.Withdrawn }, null)</li>
#* Request manager approval if not already received *#
<li>...</li>
#* If user is in Development and the Request is authorised by Analytics Manager *#
<li>...</li>
...
</ul>
Making the right actions appear at the right time is the easy part, but it feels like a clumsy approach and I'm not sure how I would manage permissions in this way. So my question is:
Should I create a separate method for every stage of the process in the RequestController, even if this results in a lot of very similar methods?
An example would be:
public ActionResult RequestApproval(int id)
{
...
}
[MyAuthoriseAttribute(Roles = "Analytics, User")]
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult RequestApproval(int id, History history)
{
...
}
public ActionResult Approve (int id)
{
...
}
[MyAuthoriseAttribute(Roles = "Analytics, Manager")]
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Approve (int id, History history)
{
...
}
If so, how do I handle rendering the appropriate buttons in the View? I only want a set of valid actions appear as controls.
Sorry for the long post, any help would be greatly appreciated.
First of all if you have a lot of logic encapsulated in boolean based operations I highly recommend using the Specifications Pattern this and this should start you off well. It is highly reusable and allows great maintainability when existing logic changes or you need to add new logic. Look into making composite specifications that specify exactly what can be satisfied e.g. If the user is a manager and the request is unapproved.
Now with regards to your problem in your view - although when I faced the same issue in the past I had followed a similar approach to ChrisDixon. It was simple and easy to work with but looking back at the app now I find it tedious since it is burried in if statements. The approach I would take now is to create custom action links or custom controls that take the authorization into context when possible. I started writing some code to do this but in the end realized that this must be a common issue and hence found something a lot better than I myself intended to write for this answer. Although aimed at MVC3 the logic and purpose should still hold up.
Below are the snippets in case the article ever gets removed. :)
The is the extension method that checks the controller for the Authorized Attribute. In the foreach loop you can check for the existence of your own custom attribute and authorize against it.
public static class ActionExtensions
{
public static bool ActionAuthorized(this HtmlHelper htmlHelper, string actionName, string controllerName)
{
ControllerBase controllerBase = string.IsNullOrEmpty(controllerName) ? htmlHelper.ViewContext.Controller : htmlHelper.GetControllerByName(controllerName);
ControllerContext controllerContext = new ControllerContext(htmlHelper.ViewContext.RequestContext, controllerBase);
ControllerDescriptor controllerDescriptor = new ReflectedControllerDescriptor(controllerContext.Controller.GetType());
ActionDescriptor actionDescriptor = controllerDescriptor.FindAction(controllerContext, actionName);
if (actionDescriptor == null)
return false;
FilterInfo filters = new FilterInfo(FilterProviders.Providers.GetFilters(controllerContext, actionDescriptor));
AuthorizationContext authorizationContext = new AuthorizationContext(controllerContext, actionDescriptor);
foreach (IAuthorizationFilter authorizationFilter in filters.AuthorizationFilters)
{
authorizationFilter.OnAuthorization(authorizationContext);
if (authorizationContext.Result != null)
return false;
}
return true;
}
}
This is a helper method to get the ControllerBase object which is used in the above snippet to interrogate the action filters.
internal static class Helpers
{
public static ControllerBase GetControllerByName(this HtmlHelper htmlHelper, string controllerName)
{
IControllerFactory factory = ControllerBuilder.Current.GetControllerFactory();
IController controller = factory.CreateController(htmlHelper.ViewContext.RequestContext, controllerName);
if (controller == null)
{
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, "The IControllerFactory '{0}' did not return a controller for the name '{1}'.", factory.GetType(), controllerName));
}
return (ControllerBase)controller;
}
}
This is the custom Html Helper that generates the action link if authorization passes. I have tweaked it from the original article to remove the link if not authorized.
public static MvcHtmlString ActionLinkAuthorized(this HtmlHelper htmlHelper, string linkText, string actionName, string controllerName, RouteValueDictionary routeValues, IDictionary<string, object> htmlAttributes)
{
if (htmlHelper.ActionAuthorized(actionName, controllerName))
{
return htmlHelper.ActionLink(linkText, actionName, controllerName, routeValues, htmlAttributes);
}
else
{
return MvcHtmlString.Empty;
}
}
Call it as you would normally call an ActionLink
#Html.ActionLinkAuthorized("Withdraw", "CreateHistory", new { id = Model.Change.ID, status = Status.Withdrawn }, null)
When coding in MVC (or, well, any language) I try and keep all, or most of, my logical statements away from my Views.
I'd keep your logic processing in your ViewModels, so:
public bool IsAccessibleToManager { get; set; }
Then, in your view, it's simple to use this variable like #if(Model.IsAccessibleToManager) {}.
This is then populated in your Controller, and can be set however you see fit, potentially in a role logic class that keeps all this in one place.
As for the methods in your Controller, keep these the same method and do the logical processing inside the method itself. It's all entirely dependant on your structure and data repositories, but I'd keep as much of the logical processing itself at the Repository level so it's the same in every place you get/set that data.
Normally you'd have attribute tags to not allow these methods for certain Roles, but with your scenario you could do it this way...
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Approve (int id, History history)
{
try {
// The logic processing will be done inside ApproveRecord and match up against Analytics or Manager roles.
_historyRepository.ApproveRecord(history, Roles.GetRolesForUser(yourUser));
}
catch(Exception ex) {
// Could make your own Exceptions here for the user not being authorised for the action.
}
}
What about creating different views for each type of role, and then returning the appropriate view, from a single action?
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Approve (int id, History history)
{
// Some pseudo-logic here:
switch(roles)
{
case Manager:
case User:
{
return View("ManagerUser");
}
case Manager:
case Analyst:
{
return View("ManagerAnalyst");
}
}
}
Of course, this approach would require you to create a view for the different combinations of roles, but at least you'd be able to render the appropriate view code without the UI logic cluttering the views.
I would suggest you to use a provider to generate a list of available actions for user.
First I would define AwailableAction enum than describe what action your users might potentially have. Maybe you already have one.
Then you can define IAvailableActionFactory interface and implement it with your logic:
public interface IAvailableActionProvider
{
ReadOnlyCollection<AwailableAction> GetAvailableActions(User, Request, History/*, etc*/) // Provide parameters that need to define actions.
}
public class AvailableActionProvider : IAvailableActionProvider
{
ReadOnlyCollection<AwailableAction> GetAvailableActions(User, Request, History)
{
// You logic goes here.
}
}
Internally this provider would use similar logic you currently inplemented in the view. This approach will keep the view clean and ensure testability of the logic. Optionaly inside provivder you can use different strategies for different users and make the implementation even more decoupled.
Then in controller you define the dependency on this provider and either resolve it through container of instantioate directly if you don't use container yet.
public class RequestController : BaseController
{
private readonly IAvailableActionProvider _actionProvider;
public RequestController(IAvailableActionProvider actionProvider)
{
_actionProvider = actionProvider;
}
public RequestController() : this(new AvailableActionProvider())
{
}
...
}
Then in your action use provider to obtain available actions you can either create new view model than will contain actions or simply put it to ViewBag:
// GET: Requests/CreateHistory
public ActionResult CreateHistory(Status status)
{
History history = new History();
history.Status = status;
ViewBag.AvailableActions = _actionProvider.GetAvailableActions(User, Request, history);
return View(history);
}
And finally in view you can generate list of action based in items in ViewBag.
I hope it helps. Let me know if you have questions about it.
I would advise using claims concurrently with roles. If a role needs access to a resource I will give them a claim to the resource, meaning actionResult. If their role matches the controller, for simplicity reasons, I currently check if they have a claim to the resource. I use the Roles at the controller level so if a Guest or some other account needs anonymous access I can simple add the attribute, but more often than not I should have put it in the correct controller.
Here is some code to show.
<Authorize(Roles:="Administrator, Guest")>
Public Class GuestController
Inherits Controller
<ClaimsAuthorize("GuestClaim")>
Public Function GetCustomers() As ActionResult
Dim guestClaim As Integer = UserManager.GetClaims(User.Identity.GetUserId()).Where(Function(f) f.Type = "GuestClaim").Select(Function(t) t.Value).FirstOrDefault()
Dim list = _customerService.GetCustomers(guestClaim)
Return Json(list, JsonRequestBehavior.AllowGet)
End Function
End Class
On a project I am currently working on I have three roles: Admin, Super-user and User.
Admins can delete users, delete comments etc, but Super-users must be able to delete comments too. So I built an AdminController and Authorized it with Admin. One method must be accessable with the Super-user, so I authorized it for the Super-user but that won't work.
[Authorize(Roles = "Admin")]
public class AdminController : Controller
{
(... here be only admin methods ...)
[HttpGet]
[Authorize(Roles = "Super-user")]
public ActionResult Delete()
{
//deletes a comment
return View();
}
(... here be only admin methods ...)
}
I looked into overriding the Authorize attribute but I'm trying to find a solution where that is not needed, any idea's on how to authorize just one method for the Super-user?
The Admin as the Super-user must have access to the method Delete().
Thanks!
I think as #Felix Cen pointed specifying this should work at controller
[Authorize(Roles = "Admin, Super-user")]
and then specify this at the method level
[Authorize(Roles = "Super-user")]
Alternatively you can use a deny attribute as pointed out in this question
public class DenyAttribute : AuthorizeAttribute
{
protected override bool AuthorizeCore(HttpContextBase httpContext) {
if (httpContext == null) {
throw new ArgumentNullException("httpContext");
}
IPrincipal user = httpContext.User;
if (!user.Identity.IsAuthenticated) {
return false;
}
if (Users.Length > 0 && Users.Split(',').Any( u => string.Compare( u.Trim(), user.Identity.Name, StringComparer.OrdinalIgnoreCase))) {
return false;
}
if (Roles.Length > 0 && Roles.Split(',').Any( u => user.IsInRole(u.Trim()))) {
return false;
}
return true;
}
Another question here(i think that i sort of like this specific answer here)
My personal take on this would be to split the controller. Just create
another controller For the actions you don't need authentication.
Or you could have :
BaseController
doesn't require authentication - here you have all your "base stuff" :).
BaseAuthController : BaseController
all actions here require authentication.
That way you can have authentication when you want , just by deriving
from a specific class.
I am attempting to build a system that allows users to perform certain actions, but their account must have a specific 'Ticket' per time they do it. For instance, suppose they wish to create a Product, they would need a CreateProductTicket.
I could simply do this with some 'if' statements, sure, but I want to try a bit more of a robust solution. My structure looks something like this...
interface ITicket<T> where T : ITicketable
{
}
My basic goal is to build an Attribute, perhaps like the following..
public class TicketRequiredAttribute : Attribute
{
public TicketRequiredAttribute(ITicket<T> ticket)
{
if(ticket == null)
return;
}
}
And to be able to decorate Controller or Repository Actions with this. So like ...
ProductsControlller
[TicketRequired(CreateProductTicket)]
public ActionResult CreateProduct(Product product)
{
// ... **I am unsure how to tell if TicketRequired was true or not**
}
Problem 1
I'm not familiar enough with attributes to know how to tell if TicketRequired was 'met' or not. Can anyone enlighten me on this?
Problem 2
The problem I am running into is with database querying. I want to be able to check the user (IMembershipRepository has a GetUser method), but I'm not entirely certain how to do that through an attribute.
Using Castle.Windsor, I have my Dependency Injection set up to inject repositories into controllers. I suppose I could pass the IMembershipRepository through the TicketRequired constructor, but I have a feeling that will become very messy - and extremely unstable. Is there a more logical way to approach this?
You're almost there. You can find more details at http://www.asp.net/mvc/tutorials/understanding-action-filters-cs
I would only use the attribute on the action since the website is where I do all my authorization.
Here is a possible solution. I have not tested this, but it should work. You'll need to verify the way I'm redirecting, not sure if that's the proper way.
public class TicketRequiredActionFilter : ActionFilterAttribute
{
private Type _ticketType;
public TicketRequiredAttribute(Type ticketType)
{
_ticketRequired = ticketType;
}
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
UserServices userServices = GetUserServicesViaDIContainer(); // you'll need to figure out how to implement this
string userId = filterContext.HttpContext.User.Identity.Name
bool hasTicket = userServices.HasTicket(_ticketType, (int)userId); // again, you'll need to figure out the exact implementation
if(!hasTicket)
{
filterContext.Result = new RedirectToRouteResult(new RouteValueDictionary { { "controller", "Home" }, {"action", "NoPermission" } })
}
else
{
base.OnActionExecuting(filterContext);
}
}
}
In your controller:
[TicketRequiredActionFilter(typeof(CreateProductTicket))]
public ActionResult MyMethod()
{
// do stuff as if the person is authorized and has the ticket
}
If the user doesn't have the ticket, a redirect is issues;, otherwise, continue as normal.
This sounds very much like user roles.
How are you handling the user membership? If your using the built-in asp.net membership you can use roles. So each user will have a certain number of roles in your case one of the will be "CreateProductTicket" then you can decorate your action or controller with the Authorize attribute. Something like:
[Authorize(Roles="CreateProductTicket")]
public ActionResult CreateProduct(Product product)
If a user doesn't have the role or is not authorized then they can access the action.