asp.net mvc user authentication/permission - asp.net-mvc

i'm new to asp.net mvc and starting the following project. The company wants an intra-net website for various groups of people to upload files to a database, run reports off the it and amend data in several master tables in the database. The company use Active Directory and do not want the users to log in again to use the web site. The website will have different sections for various groups and the user's access to a particular page should be controlled from a database.
So far this is what i've come up with
changed the membership provider to link to the active directory server (based on Mike's blog post)
removed AccountController and the Views/Account folder
created a custom authentication class based on this link
I need to pull from a table in the database, based on user's AD id, his "role" (int), then cast it into the relevant SiteRoles. Would implementing this query in CustomAuthorizeAttribute be adviseable? is there a better place to pull the data from the table and store it somewhere so it can be reused rather than having to run a database query every time AuthorizeCore is called (which will happen whenever a user invokes a controller/action)?

A custom AuthorizeAttribute is definately the way to go as it will be applied before all other action filters.
Kindness,
Dan

I would use the out-of-the box ActiveDirectoryMembershipProvider rather than a custom attribute (because reinventing the wheel is generally bad, and reinventing the wheel in the area of security is bad to the point of incompetence in most cases), and the AzMan Role Provider to map AD groups and accounts to app roles.
This pairing gives you far more features out of the box (e.g., standardized GUI interface for permissions) than custom code, and is probably more secure, too.

You could do everything you want using the MVC provided FormAuthentication. Just create your custom ValidateLogOn method in the AccountController. Example:
public ActionResult LogOn(string userName, string password, bool rememberMe, string returnUrl)
{
if (!ValidateLogOn(userName, password))
{
return View();
}
FormsAuth.SignIn(userName, rememberMe);
Session["userlogin"] = userName;
if (!String.IsNullOrEmpty(returnUrl))
{
return Redirect(returnUrl);
}
else
{
return RedirectToAction("Index", "Home");
}
}
Where your ValidateLogOn will be something like:
private bool ValidateLogOn(string userName, string password)
{
if (String.IsNullOrEmpty(userName))
{
ModelState.AddModelError("username", "You must specify a username.");
}
if (String.IsNullOrEmpty(password))
{
ModelState.AddModelError("password", "You must specify a password.");
}
/*
* Do your LDAP Validation stuff (DB queries, etc) here.
*/
}

Related

asp.net identity with domain controller

I need to achieve to authenticate users with their domain user/password, if they're are in the domain controller, but the application should be available for other users as well, who should be authenticated with their own username/password; this should be stored in the application database, and their username/password to be checked against the DB.
So far i started with new asp.net template in vs2015, choosing Individual User Accounts.
I'm able to authenticate users agains domain controller, but if that is succeeded I'm unable to store the user to HttpContext.User property.
In SignInManager i call PasswordSignIn and return Success or Failure depending on AD check.
public SignInStatus PasswordSignIn(string userName, string password, bool isPersistent, bool shouldLockout) {
if(AuthenticateAD(userName, password)) {
//
// to create identity/principal and assign to HttpContext.User
//
return SignInStatus.Success;
}
else {
return SignInStatus.Failure;
}
}
public bool AuthenticateAD(string username, string password) {
using(var context = new PrincipalContext(ContextType.Domain, "domainname")) {
return context.ValidateCredentials(username, password);
}
}
thanks for any hint!
The only way this really works is if you create proxy users in your application for users in AD. Essentially, you just set up a script that populates new users/updates existing users based on the data in AD on a schedule (nightly, etc. based on your needs). Then, you're dealing with just one type of user whether they're part of the domain or external. The only change you need to make is to selectively authenticate via AD or via the standard password authentication. Either way, the same user principal is in play.
You can use ADFS and allow users to choose where to authenticate. It is quite trivial to implement using default template. Just like usual login mechanics with Sign-in via google and local account.
I think this is most correct way of doing things, because domain users may end up with Kerberos/Ntlm, if they want, and it lowers complexity of your system.
Here is a WS-Fed example: Using Claims in your Web App is Easier with the new OWIN Security Components
For other stuff you can create app with default template. This app will have external authentication stuff as example.

Security check an User to a access controller action

Hello guys I have a MVC actions that have Authorize attribute set on them. For each one of these actions there is a password/ security pin which is only valid for that Action.
public ActionResult Action_1()// generic pin 1
{
Return RedirectToAction("PinCheck", new { returnUrl = "Action_1" });
...
}
[Authorize]
public ActionResult Action_2()// generic pin 2
{
...
}
[Authorize]
public ActionResult PinCheck(string returnUrl)// generic pin 1
{
// request three characters of the pin in random.
...
}
[Authorize]
[HttpPost]
public ActionResult PinCheck(string a, string b, string c, string returnUrl)// generic pin 1
{
// check the three chars.
...
// How do I store pin check for the controller was a success and don't ask the user unless he closes browser or logout
}
My plan of action is checking pins stored by the Admin for the particular User for that particular Action in the Database. So far I have achieved checking PinCheck() routine but the problem I face is that the User has to enter the pin every time he requests that particular action. I made a way around this by saving an encrypted cookie on PinCheck success. But is there a way to modify the Authorize attribute and the Authentication cookie itself to achieve What I am doing?
You can also represent each Pin verified as a claim stored as part of the ClaimsIdentity in the cookie so that you can just query against the user's claims looking for the appropriate PinClaim in each Action. If you are using the ASP.NET Identity, you can do something like so when you verify the pin:
await manager.AddClaimAsync(User.Identity.GetUserId(), new Claim("<mypinclaim>", "<value>"))
await SignInAsync() // And then resign the user in to regenerate the cookie with the claim
One ways of doing this is by creating a custom role provider. You could create one by inheriting from RoleProvider. Then override IsUserInRole and optionally FindUsersInRole, GetAllRoles, GetUsersInRole to reflect your pin management logic.
Once done, register the custom role provide via the web.config.
A good article on custom role providers (http://bojanskr.blogspot.com.au/2011/12/custom-role-provider.html)

MVC4 Trying to get the security model to work with my Environment

I hope someone will be able to put me on the right track, been trying to resolve this now for hours.
I am currently in the process of redeveloping a web application and I would like to use the MVC4 attributes for managing access to the various parts of the application.
The issue I am having is that the Authentication & Permissions are all handled by middle-ware applications that the web app has to interface with.
I was wondering if even with this restriction would I be able to use the security attributes & letting the web app know that the user is Authenticated.
Yes, you will be able to use existing Authorize attribute. All you have to do is write a custom Membership and Role providers that will use your existing services instead of relying on the default SQL database.
If you don't want to go through all this hassle you could also write a custom authorization attribute (deriving from AuthorizeAttribute) and inside the AuthorizeCore method call your service to check whether the current user has the desired roles.
Definitely. Not only is it possible, but also it's pretty easy. And if you can think of ASP.NET Roles as "activities", then you don't need to derive anything; everything you need is built in.
These examples assume securityService is the service that communicates with your middle-ware applications, and has two methods, GetUser and GetUserRoles:
Your Login action method
[HttpPost]
public ActionResult Login(LoginModel model, string returnUrl)
{
if (!ModelState.IsValid) return View();
var user = securityService.GetUser(model.Username, model.Password);
if (user == null)
{
ModelState.AddModelError("", "Username or password are incorrect.");
return View();
}
FormsAuthentication.SetAuthCookie(user.Username, model.Remember);
return Redirect(returnUrl);
}
In your Global.asax.cs
protected void Application_AuthenticateRequest()
{
if (Request.IsAuthenticated)
{
string username = User.Identity.Name;
string[] roles = securityService.GetUserRoles(username);
IIdentity identity = new GenericIdentity(username);
Context.User = new GenericPrincipal(identity, roles);
}
}
That's it. Login handles the authentication (when the user logs in), while Application_AuthenticateRequest handles the authorization (on every request). You then proceed to decorate your action methods with Authorize(Roles = "XYZ") making sure "XYZ" matches what comes back from your GetUserRoles method.

Obtaining the current Principal outside of the Web tier

I have the following ntier app: MVC > Services > Repository > Domain. I am using Forms authentication. Is it safe to use Thread.CurrentPrincipal outside of my MVC layer to get the currently logged in user of my application or should I be using HttpContext.Current.User?
The reason I ask is there seems to be some issues around Thread.CurrentPrincipal, but I am cautious to add a reference to System.Web outside of my MVC layer in case I need to provide a non web font end in the future.
Update
I have been following the advice recieved so far to pass the username into the Service as part of the params to the method being called and this has lead to a refinement of my original question. I need to be able to check if the user is in a particular role in a number of my Service and Domain methods. There seems to be a couple of solutions to this, just wondering which is the best way to proceed:
Pass the whole HttpContext.Current.User as a param instead of just the username.
Call Thread.CurrentPrincipal outside of my web tier and use that. But how do I ensure it is equal to HttpContext.Current.User?
Stick to passing in the username as suggested so far and then use Roles.IsUserInRole. The problem with this approach is that it requires a ref to System.Web which I feel is not correct outside of my MVC layer.
How would you suggest I proceed?
I wouldn't do either, HttpContext.Current.User is specific to your web layer.
Why not inject the username into your service layer?
Map the relevant User details to a new Class to represent the LoggedInUser and pass that as an argument to your Business layer method
public class LoggedInUser
{
public string UserName { set;get;}
//other relevant proerties
}
Now set the values of this and pass to your BL method
var usr=new LoggedInUser();
usr.UserName="test value "; //Read from the FormsAuthentication stuff and Set
var result=YourBusinessLayerClass.SomeOperation(usr);
You should abstract your user information so that it doesn't depend on Thread.CurrentPrincipal or HttpContext.Current.User.
You could add a constructor or method parameter that accepts a user name, for example.
Here's an overly simplified example of a constructor parameter:
class YourBusinessClass
{
string _userName;
public YourBusinessClass(string userName)
{
_userName = userName;
}
public void SomeBusinessMethodThatNeedsUserName()
{
if (_userName == "sally")
{
// do something for sally
}
}
}
I prefer option number 2( use Thread.CurrentPrincipal outside of web tier ). since this will not polute your service tier & data tier methods. with bonuses: you can store your roles + additional info in the custom principal;
To make sure Thread.CurrentPrincipal in your service and data tier is the same as your web tier; you can set your HttpContext.Current.User (Context.User) in Global.asax(Application_AuthenticateRequest). Other alternative location where you can set this are added at the bottom.
sample code:
//sample synchronizing HttpContext.Current.User with Thread.CurrentPrincipal
protected void Application_AuthenticateRequest(Object sender, EventArgs e)
{
HttpCookie authCookie = Request.Cookies[FormsAuthentication.FormsCookieName];
//make sure principal is not set for anonymous user/unauthenticated request
if (authCookie != null && Request.IsAuthenticated)
{
FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);
//your additional info stored in cookies: multiple roles, privileges, etc
string userData = authTicket.UserData;
CustomPrincipal userPrincipal = PrincipalHelper.CreatePrincipal(authTicket.Name, authTicket.UserData, Request.IsAuthenticated);
Context.User = userPrincipal;
}
}
of course first you must implement your login form to create authorization cookies containing your custom principal.
Application_AuthenticateRequest will be executed for any request to server(css files, javascript files, images files etc). To limit this functionality only to controller action, you can try setting the custom principal in ActionFilter(I haven't tried this). What I have tried is setting this functionality inside an Interceptor for Controllers(I use Castle Windsor for my Dependency Injection and Aspect Oriented Programming).
I believe you are running into this problem because you need to limit your domains responsibility further. It should not be the responsibility of your service or your document to handle authorization. That responsibility should be handled by your MVC layer, as the current user is logged in to your web app, not your domain.
If, instead of trying to look up the current user from your service, or document, you perform the check in your MVC app, you get something like this:
if(Roles.IsUserInRole("DocumentEditorRole")){
//UpdateDocument does NOT authorize the user. It does only 1 thing, update the document.
myDocumentService.UpdateDocument(currentUsername, documentToEdit);
} else {
lblPermissionDenied.InnerText = #"You do not have permission
to edit this document.";
}
which is clean, easy to read, and allows you to keep your services and domain classes free from authorization concerns. You can still map Roles.IsUserInRole("DocumentEditorRole")to your viewmodel, so the only this you are losing, is the CurrentUserCanEdit method on your Document class. But if you think of your domain model as representing real world objects, that method doesn't belong on Document anyway. You might think of it as a method on a domain User object (user.CanEditDocument(doc)), but all in all, I think you will be happier if you keep your authorization out of your domain layer.

How does the Authorize tag work? - ASP.NET MVC

How does the Authorize Tag determine if the user is authorized or not?
Like say, if a user logs in and they try to go to a view that has an Authorize tag. How does it determine if a user is authorized or not? Does it do a query to database and check?
How about if they go to a view with a role authorization? Does it query the membership role table?
I am just wondering since I have what the ASP.NET membership tables considers duplicate userNames. I use a serious of fields to determine which user is what, allowing users to have the same duplicate userName, but still be unique in my database.
This caused me to have to write custom methods for lots of .NET membership stuff since it all used "userName" to do searching instead of using the UserId.
So I am now wondering if this could be the case with the Authorize tag. Since I have no clue how it works and like if I was not using .NET membership I would not have a clue how it would determine it.
The Authorize tag uses all the built in membership checks from ASP.NET. It's VERY easy to roll your own tag. For example:
public class MyAuthorize : AuthorizeAttribute
{
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
if (httpContext == null) throw new ArgumentNullException("httpContext");
// Make sure the user is authenticated.
if (httpContext.User.Identity.IsAuthenticated == false) return false;
// Do you own custom stuff here
bool allow = CheckIfAllowedToAccessStuff();
return allow;
}
}
You then can use the [MyAuthorize] tag which will use your custom checks.
ControllerActionInvoker parses the attribute and calls OnAuthorization() on it when it's time to check the credentials.
The AuthorizationAttribute.OnAuthorization() method basically checks to see if User.Identity.IsAuthenticated is true or not. This just draws on the functionality of FormsAuthentication or whatever other authentication scheme you may be using.

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