dynamically mapping roles to controllers in ASP.Net MVC - asp.net-mvc

I am currently hard coding the authorized roles in the filter in my MVC applications like so:
[Authorize(Roles = "Administrator,Manager")]
I'd like to eventually have a way to map the roles to each controller, so that the site admin can handle assigning what roles can perform each set of actions.
string roles = DoSomethingToGetAllowableRoles(controllerName);
[Authorize(Roles = roles)]
I'm imagining that I need to have a database table that somehow keeps a listing of each controller, and then another table mapping the controllers to the roles. What I'd like is a page where I can list out each controller and then have a set of check boxes that lists each role that applies to that controller.
Anyone have an example or can lead me in a direction that will accomplish this?

You're going to need to write your own authorization filter (probably by extending the built in one).
The reason for this is that you can't assign attribute parameters dynamically like that.
You won't need to mess with the MVC source code - you just need to create a class which inherits from System.Web.Mvc.AuthrorizeAttribute, override AuthorizeCore, and then use your attribute in place of the default:
public class CustomAuthorizeAttribute : System.Web.Mvc.AuthorizeAttribute
{
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
// Put your custom logic here, returning true for success and false for failure,
// or return base.AuthorizeCore(httpContext) to defer to the base implementation
}
}

Related

What is Webform's "UrlAuthorizationModule.CheckUrlAccessForPrincipal" equivalent for MVC?

I got a problem as i am writing a custom SSO solution for my company. To mkae it simple, i've made a custom authentication httpmodule that intercepts all requests so as to check user authentication state. If not authenticated, user is redirected to my custom sso login page.
The thing is, when user is not authenticated, i'd like to check if he can access the requested page/resource... With Webforms, no problem, i add an authorization block in web.config, and i use UrlAuthorizationModule.CheckUrlAccessForPrincipal with an anonymous user. Everything works fine...
But when i apply my module to an MVC (3) web site, this does not work anymore (for obvious reasons, like the possibility to access the same controller and/or action from differents urls when using routing, and because authorizations are made through controller attributes).
How can I achieve this ?? I've been searching all day long, didn't find anything about that :/
ASP.NET MVC 3 Internet Application template includes a basic AccountController which implements the following actions (along with the associated models and views):
LogOn
Register
ChangePassword / ChangePasswordSuccess
You simply need the [Authorize] attribute on the Actions or classes you wish to secure. But if you need something really custom you can do something like I've done.
I created a custom class to override security in my application.
public class AuthorizeActivityAttribute : AuthorizeAttribute
{
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
HttpContext currentContext = HttpContext.Current;
//Do your custom authentication stuff here and return true or false depending on results
Return true;
}
}
And now in my Controller I have the following:
[AuthorizeActivity]
public ActionResult Index()
{
ViewBag.Message = "Welcome";
return View();
}
I had the same problem.
See solution here: MVC equivalent of Webforms "UrlAuthorizationModule.CheckUrlAccessForPrincipal"
You would have to read the information from the other controller. This
can be done by instantiating its context and the Descriptor, then
instantiating the AuthorizationContext for that controller and read
the filter info.

Good approach for globally accessing the Logged-in User

I want to be able to globally access the logged-in user in (Controllers, HtmlHelpers and other helper classes) throughout the whole application without getting exceptions that User is null and with the ability to handle guests (not-logged-in users).
Should this be handled within my UsersRepository? If so, how to? or is there a better approach?
You can create custom identity and principal classes. Your custom identity class can extend whatever you are currently using and can then simply add the extra information you need.
Then in a global action filter, simply overwrite the current principal with your customized one. Then you can access it from anywhere like a normal identity, but if you need your additional information, you simply cast it to your custom identity class. Which will grant you access to your additional information.
You can write a custom action filter that is executed on every request (you register it as a global filter). This filter would load the user (from the user´s repository for example) and put it the http context for example or in the ViewData.
EDIT:
Ok, the code for the filter could look like this (in this case, it loads the user to the ViewData collection). I didn´t consider anonymous users here.
public class LoadUserToViewDataAttribute : ActionFilterAttribute
{
private IUserRepository _userRepository;
public LoadUserToViewDataAttribute(IUserRepository userRepository)
{
_userRepository = userRepository;
}
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
var controller = filterContext.Controller;
var userName = filterContext.HttpContext.User.Identity.Name;
var user = _repository.GetUser(userName);
controller.ViewData.Add("CurrentUser", user);
}
}

Enforce security check in ASP.NET MVC?

I am implementing a collaborative web gallery, and I have a few roles for each user:
Admin
DeleteImage
DeleteOwnImage
etc..
For any controller-action, we can apply [Authorize] tag to them plus which roles we want to allow, right? It is fine for Admin/DeleteImage since these two are global; but my question is, like DeleteOwnImage is kind of contextual, in order to determine whether it is valid, we need:
To know what image it is trying to delete (from request)
Retrieve the owner of that image (from service or repository)
Compare current user = that owner
Obviously [Authorize] is not enough to do so, but is it possible to do that on custom ActionFilters? Any hint?
Yes, this is possible with a custom action filter. You can extend from AuthorizeAttribute, the most basic implementation being something like:
public class OwnImageAuthorizeAttribute : AuthorizeAttribute {
public string ImageIdKey { get; set; }
protected override bool AuthorizeCore(HttpContextBase httpContext) {
bool authorized = false;
// Get the current user
var currentUser = ...;
// Get the image ID, whether it is in the route or querystring
int imageId
if(int.TryParse(httpContext.RouteData.Values(ImageIdKey), out imageId)) {
// From querystring: httpContext.Request.Querystring[ImageIdKey]
// Authorize the user
authorized = YourMethodToCheckIfUserIsOwner(currentUser, imageId);
}
return authorized;
}
Then, decorate your method:
[OwnImageAuthorize(ImageIdKey = "imageId")]
public ActionResult MyAction() { }
You can find some more details here.
You can easily add something like this in an ActionFilter, Just add an action filter with OnActionExecuting implemented.
Although, depending on your DB schema this could be achieved on the DB level with your query. You could just delete when owner equals recieved recieved id. (I mean, inside the action method and not in the filter)
EDIT:
If you're using some kind of IOC container for the repositories, you should look around for the new IOC features in MVC3 (if you're using MVC3) to inject dependencies into your action filters.
http://bradwilson.typepad.com/blog/2010/07/service-location-pt4-filters.html
EDIT2:
BTW, I myself don't really like doing too much business logic in ActionFilters, especially involving calls to the DB. Even more when it's something very specific that'll be used for one action.

How can I Implement a Custom RoleProvider?

I'm trying to implement a custom RoleProvider in my ASP.NET MVC application.
I've created a custom MembershipProvider and it works, in that I'm able to successfully validate the user. The next step is to implement the RoleProvider to restrict access to certian Controllers to Admin users only.
Can anyone provide me with a quick outline of the steps I need to take?
The point that I'm at now is I have my controller with the Authorize filter, like so:
[Authorize(Roles="Admin")]
public class AdminOnlyController : Controller
{
// stuff
}
and I have my CustomRoleProvider class, with the following method along with a load of not-implemented Methods:
public override string[] GetRolesForUser(string username)
{
if (username == "dave")
{
return new string[] { "Admin" };
}
}
I think I need to add the user to the Role somehow but I don't know how to do that. Ideally the end result would be a scenario where unauthorized users can't access certain controllers, and I in my Views I could determine whether to show links with something like:
if (User.IsInRole("Admin"))
{
// show links to Admin Controllers
}
Can anyone point me in the right direction?
I used this as as base line for a custom role manager: http://davidhayden.com/blog/dave/archive/2007/10/17/CreateCustomRoleProviderASPNETRolePermissionsSecurity.aspx
Should work in MVC or Web Forms.
UPDATE: Since that web page no longer exists, you could try this one instead. The basic requirements are that you need to implement the RoleProvider interface, namely:
void AddUsersToRoles(string[] usernames, string[] roleNames)
string[] GetRolesForUser(string id)
bool RoleExists(string roleName)
For the not-implemented methods, be sure to throw a NotImplementedException. This should help you figure out which methods are needed in your custom provider to get the job done.
I suspect you'll have to implement IsUserInRole.

ASP.NET MVC 1.0 Authentication

I realise that I can prevent unauthenticated users from accessing views at controller level by applying the [Authorize] attribute and can also filter views down to individual users or roles using this. However, my question is regarding doing the opposite... Is there a way to deny authenticated users from certain views without having to manually add in checks to see if they're authenticated in the opening lines of the controller code? Ideally an [Unauthorized] attribute or an equivalent if such a thing exists?
The reason for this is that I don't want authenticated users to be able to visit the account creation pages of the site I'm working on, as well as other resources. I realise I could check them in the controller explicitly but I'd prefer to decorate the controller methods if at all possible.
Thanks :)
This is along the lines of what LukLed was referring to:
public class UnAuthorizedAttribute : AuthorizeAttribute
{
public override void OnAuthorization(AuthorizationContext filterContext)
{
bool excludeCondition = false;
if (excludeCondition)
filterContext.Result = new HttpUnauthorizedResult();
else
base.OnAuthorization(filterContext);
}
}
Simply put in the logic for your excludeCondition. You can also to choose to do things like redirect to other views. Just mark your code with [UnAuthorized]
You can write your own authorization filter. Inherit from FilterAttribute and implement IAuthorizationFilter. Call it UnauthorizedAttibute and you will be able to use it like [Authorize].
Hear You can read about filters:
http://www.asp.net/LEARN/mvc/tutorial-14-cs.aspx
A simple way to accomplish this? Just leave the action untagged, and start with:
If(Request.IsAuthenticated)
// redirect somewhere, or return another view...
this could also be accomplished fairly simply if you are already using a roleprovider. then your actions would just need to be filtered by the appropriate role:
[Authorize(Roles = "Admin, Editor")]

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