ASP.Net MVC - forms authentication using an external URL - asp.net-mvc

Our organization has a central solution for forms authentication. I am trying to implement an ASP.Net MVC app that uses this external URL - and it worked till RC! was released...
Here's what's happening
In an ActionAttribute Extension
I check for s session var
if not found
check for a request data chuck
if found, set the session var
if not found - redirect to external URL
if found
continue.
The trouble is that till I updated to RC1, this worked. Since then, so many requests are being sent to the external URL that it detects a DoS attack and shuts me out!
I removed the redirection code and replaced it with the web.config changes for Forms Auth - and the same thing happened...

Why not use Microsoft Geneva instead of attempting to roll your own authentication provider?

CODE:
public class MyAuthenticate : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
if (filterContext.HttpContext.Session["user"] == null)
{
using (Authenticator dp = new Authenticator())
{
MyUser mu;
string data = string.Empty;
try
{
data = filterContext.HttpContext.Request["Data"];
}
catch { };
if (!string.IsNullOrEmpty(data))
{
mu = dp.Redeem(data);
if (mu.authenticated)
{
filterContext.HttpContext.Session.Clear();
AuthenticatedUser user = new AuthenticatedUser(mu);
filterContext.HttpContext.Session.Add("user", user);
FormsAuthentication.SetAuthCookie(user.UserId, false);
}
else
{
filterContext.HttpContext.Response.Redirect("MY EXTERNAL URL GOES HERE!!");
}
}
else
{
filterContext.HttpContext.Response.Redirect("MY EXTERNAL URL GOES HERE!!");
}
}
}
base.OnActionExecuting(filterContext);
}
}
}

I resolved this issue by creating a static dictionary of requesting IPs, and dropping duplicate requests from the same IP. Not a very nice solution - so if anyone figures out a better solution - let me know.

Related

ASP NET MVC5 randomly redirects to my login page

I have an ASP.NET MVC application with ActionFilters for Authentication and no Forms Authentication. "SegurancaAction" is the attribute responsible for validating authentication and exists in every controller endpoint except in the login ones (as expected).
I'm facing a problem in which sometimes I try to access one of my controllers and the GET request goes to my login endpoint. In the method Application_BeginRequest at Global.asax, I can see the very first attempt is at 'security/login' (the route to my login endpoint) instead of the one I want. I can also see this endpoint being called in debugging apps such as Fiddler, or ASP.NET Trace or Glimpse MVC5.
Besides calling the wrong action, once I login again this issue keeps happening for the same endpoint I was trying to access, redirecting my site to the login page over and over.
SegurancaAction:
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
Autenticacoes autenticacao = _authApp.IsAutenticado(filterContext.HttpContext.Session.SessionID);
if (autenticacao == null)
{
if (filterContext.HttpContext.Request.IsAjaxRequest())
filterContext.Result = new HttpStatusCodeResult(System.Net.HttpStatusCode.Unauthorized);
else
{
filterContext.HttpContext.Response.RedirectPermanent("/security/login");
return;
}
}
else
{
// other stuff
}
}
SecurityController:
[HttpPost]
[ConfigAction]
public ActionResult Login(vm_Login login)
{
if (ModelState.IsValid)
{
if (!String.IsNullOrEmpty(login.Login) && !String.IsNullOrEmpty(login.Senha))
{
Entidades entidade = _entidadeApp.GetByUsuarioSenha(login.Login, login.Senha);
if (entidade == null)
{
ViewBag.FalhaAutenticacao = "As credenciais informadas não conferem!";
return View("Login");
}
else
{
string encryptionKey = System.Configuration.ConfigurationManager.AppSettings["EncryptionKey"];
var a = _autenticacaoApp.Autenticar(entidade.Id, encryptionKey, login.Senha, HttpContext.Session.SessionID);
}
Response.RedirectPermanent("~/principal/index");
}
}
else
{
ViewBag.FalhaAutenticacao = "É necessário informar o usuario e a senha!";
}
return View();
}
All _autenticacaoApp.Autenticar(...) method does is to create an authentication entry on the database, it's a completely custom code.
Does anyone know why this issue happens? Sometimes I can reproduce it by deleting the cookies that contain ASP.NET_Session ID and RequestVerificationToken. So far I know those cookies are automatically generated and I notice that sometimes when I login again they are not re-generated.
I figured out the issue. It was this "RedirectPermanent" method being used here:
filterContext.HttpContext.Response.RedirectPermanent("/security/login");
It tells the browser that the resource I'm trying to access is no longer available and is now located at this new Url. The browser records this information and always redirects to the new resource.
I just changed it to use "Redirect" instead.

SignalR with sliding expiration with Forms Authentication

I got a problem when using SignalR with sliding expiration with Forms Authentication.
Because of the SignalR keep polling from server, user auth never expired...
I've researched a lot... and found an interesting article from http://www.asp.net/signalr/overview/security/introduction-to-security#reconcile
They said:
the user's authentication status may change if your site uses sliding expiration with Forms Authentication, and there is no activity to keep the authentication cookie valid. In that case, the user will be logged out and the user name will no longer match the user name in the connection token.
I need to have user's auth expired if he idle for 20 minutes, but I can't..
any ideas?
Thanks a lot!
I ran into this same issue. I found one method posted on GitHub issues that utilizes an HttpModule to remove the auth cookie at the end of the pipeline. This worked great in my scenario.
https://github.com/SignalR/SignalR/issues/2907
public class SignalRFormsAuthenticationCleanerModule : IHttpModule
{
public void Init(HttpApplication application)
{
application.PreSendRequestHeaders += OnPreSendRequestHeaders;
}
private bool ShouldCleanResponse(string path)
{
path = path.ToLower();
var urlsToClean = new string[] { "/signalr/", "<and any others you require>" };
// Check for a Url match
foreach (var url in urlsToClean)
{
var result = path.IndexOf(url, StringComparison.OrdinalIgnoreCase) > -1;
if (result)
return true;
}
return false;
}
protected void OnPreSendRequestHeaders(object sender, EventArgs e)
{
var httpContext = ((HttpApplication)sender).Context;
if (ShouldCleanResponse(httpContext.Request.Path))
{
// Remove Auth Cookie from response
httpContext.Response.Cookies.Remove(FormsAuthentication.FormsCookieName);
return;
}
}
}

Serving an iCalendar file in ASPNET MVC with authentication

I'm trying to serve an iCalendar file (.ics) in my MVC application.
So far it's working fine. I have an iPhone subscribing to the URL for the calendar but now I need to serve a personalised calendar to each user.
When subscribing to the calendar on the iPhone I can enter a username and password, but I don't know how to access these in my MVC app.
Where can I find details of how the authentication works, and how to implement it?
It turns out that Basic Authentication is what is required. I half had it working but my IIS configuration got in the way. So, simply returning a 401 response when there is no Authorization header causes the client (e.g. iPhone) to require a username/password to subscribe to the calendar.
On the authorization of the request where there is an Authorization request header, the basic authentication can be processed, retrieving the username and password from the base 64 encoded string.
Here's some useful code for MVC:
public class BasicAuthorizeAttribute : AuthorizeAttribute
{
public override void OnAuthorization(AuthorizationContext filterContext)
{
if (filterContext == null)
{
throw new ArgumentNullException("filterContext");
}
var auth = filterContext.HttpContext.Request.Headers["Authorization"];
if (!String.IsNullOrEmpty(auth))
{
var encodedDataAsBytes = Convert.FromBase64String(auth.Replace("Basic ", ""));
var value = Encoding.ASCII.GetString(encodedDataAsBytes);
var username = value.Substring(0, value.IndexOf(':'));
var password = value.Substring(value.IndexOf(':') + 1);
if (MembershipService.ValidateUser(username, password))
{
filterContext.HttpContext.User = new GenericPrincipal(new GenericIdentity(username), null);
}
else
{
filterContext.Result = new HttpStatusCodeResult(401);
}
}
else
{
if (AuthorizeCore(filterContext.HttpContext))
{
var cachePolicy = filterContext.HttpContext.Response.Cache;
cachePolicy.SetProxyMaxAge(new TimeSpan(0));
cachePolicy.AddValidationCallback(CacheValidateHandler, null);
}
else
{
filterContext.HttpContext.Response.Clear();
filterContext.HttpContext.Response.StatusDescription = "Unauthorized";
filterContext.HttpContext.Response.AddHeader("WWW-Authenticate", "Basic realm=\"Secure Calendar\"");
filterContext.HttpContext.Response.Write("401, please authenticate");
filterContext.HttpContext.Response.StatusCode = 401;
filterContext.Result = new EmptyResult();
filterContext.HttpContext.Response.End();
}
}
}
private void CacheValidateHandler(HttpContext context, object data, ref HttpValidationStatus validationStatus)
{
validationStatus = OnCacheAuthorization(new HttpContextWrapper(context));
}
}
Then, my controller action looks like this:
[BasicAuthorize]
public ActionResult Calendar()
{
var userName = HttpContext.User.Identity.Name;
var appointments = GetAppointments(userName);
return new CalendarResult(appointments, "Appointments.ics");
}
I found this really helpful, but i hit a few problems during the development and i thought i would share some of them to help save other people some time.
I was looking to get data from my web application into the calendar for an android device and i was using discountasp as a hosting service.
The first problem i hit was that the validation did not work when uploaded to the server, stangely enough it was accepting my control panel login for discountasp but not my forms login.
The answer to this was to turn off Basic Authentication in IIS manager. This resolved the issue.
Secondly, the app i used to sync the calendar to the android device was called iCalSync2 - its a nice app and works well. But i found that it only worked properly when the file was delivered as a .ics (duh for some reason i put it as a .ical.. it must have been late) and i also had to choose the webcal option
Lastly i found i had to add webcal:// to the start of my url instead of http://
Also be careful as the code posted above ignores the roles input variable and always passes nothing so you might need to do some role based checks inside your calendar routine or modify the code above to process the roles variable.

ELMAH - Using custom error pages to collecting user feedback

I'm looking at using ELMAH for the first time but have a requirement that needs to be met that I'm not sure how to go about achieving...
Basically, I am going to configure ELMAH to work under asp.net MVC and get it to log errors to the database when they occur. On top of this I be using customErrors to direct the user to a friendly message page when an error occurs. Fairly standard stuff...
The requirement is that on this custom error page I have a form which enables to user to provide extra information if they wish. Now the problem arises due to the fact that at this point the error is already logged and I need to associate the loged error with the users feedback.
Normally, if I was using my own custom implementation, after I log the error I would pass through the ID of the error to the custom error page so that an association can be made. But because of the way that ELMAH works, I don't think the same is quite possible.
Hence I was wondering how people thought that one might go about doing this....
Cheers
UPDATE:
My solution to the problem is as follows:
public class UserCurrentConextUsingWebContext : IUserCurrentConext
{
private const string _StoredExceptionName = "System.StoredException.";
private const string _StoredExceptionIdName = "System.StoredExceptionId.";
public virtual string UniqueAddress
{
get { return HttpContext.Current.Request.UserHostAddress; }
}
public Exception StoredException
{
get { return HttpContext.Current.Application[_StoredExceptionName + this.UniqueAddress] as Exception; }
set { HttpContext.Current.Application[_StoredExceptionName + this.UniqueAddress] = value; }
}
public string StoredExceptionId
{
get { return HttpContext.Current.Application[_StoredExceptionIdName + this.UniqueAddress] as string; }
set { HttpContext.Current.Application[_StoredExceptionIdName + this.UniqueAddress] = value; }
}
}
Then when the error occurs, I have something like this in my Global.asax:
public void ErrorLog_Logged(object sender, ErrorLoggedEventArgs args)
{
var item = new UserCurrentConextUsingWebContext();
item.StoredException = args.Entry.Error.Exception;
item.StoredExceptionId = args.Entry.Id;
}
Then where ever you are later you can pull out the details by
var item = new UserCurrentConextUsingWebContext();
var error = item.StoredException;
var errorId = item.StoredExceptionId;
item.StoredException = null;
item.StoredExceptionId = null;
Note this isn't 100% perfect as its possible for the same IP to have multiple requests to have errors at the same time. But the likely hood of that happening is remote. And this solution is independent of the session, which in our case is important, also some errors can cause sessions to be terminated, etc. Hence why this approach has worked nicely for us.
The ErrorLogModule in ELMAH (version 1.1 as of this writing) provides a Logged event that you can handle in Global.asax and which you can use to communicate details, say via HttpContext.Items collection, to your custom error page. If you registered the ErrorLogModule under the name ErrorLog in web.config then your event handler in Global.asax will look like this:
void ErrorLog_Logged(object sender, ErrorLoggedEventArgs args)
{
var id = args.Entry.Id
// ...
}

ASP.NET MVC - HTTP Authentication Prompt

Is it possible to make my application ask for username and password prompting for it before render a view?
Just like on twitter API to get information about your account:
http://twitter.com/account/verify_credentials.xml
So before render the view || file it asks you to insert you username and password, I think this is made directly on the server since the curl request is based on username:password as well like this:
curl -u user:password http://twitter.com/account/verify_credentials.xml
As I'm trying to build an API following the same structure I would like to know how I can do this on ASP.NET MVC C#. I've already used this on ruby rails and its pretty simple like:
before_filter :authenticate
def authenticate
authenticate_or_request_with_http_basic do |username, password|
username == "foo" && password == "bar"
end
I don't think that [Authorize] filter is the same since I believe it's just a redirection,
and it redirects you to the Accounts Internal Controller that is based on the accounts database, in this case I will use another database, specifically from a webservice and do the validation after the information is submitted.
But I need the action to require the user and pass credentials on its request.
Thanks in advance
UPDATE:
Actually to request a page that requires this authentication (i.e. Twitter)
I would have to declare this on its request
request.Credentials = new NetworkCredential("username", "password");
And this would reflect that prompted username and password.
So, it's exactly the same thing but from the other side, if it's possible to provide information to the authentication prompt on request, how could I require this authentication on the request instead?
So everytime somebody tries to make a request to my application on example:
http://myapplication/clients/verify_credentials
it should ask for a username and password with that server prompt
so to retrive information on curl for example it would be like this
curl -u user:password http://myapplication/clients/verify_credentials
Well, to require basic authentication you need to return 401 status code. But doing that will cause the current authentication module to execute its default unauthorized handler (for forms authentication, this means redirecting to login page).
I wrote an ActionFilterAttribte to see if I can get the behaviour you want when there's no authentication module installed in web.config.
public class RequireBasicAuthentication : ActionFilterAttribute {
public override void OnActionExecuting(ActionExecutingContext filterContext) {
var req = filterContext.HttpContext.Request;
if (String.IsNullOrEmpty(req.Headers["Authorization"])) {
var res = filterContext.HttpContext.Response;
res.StatusCode = 401;
res.AddHeader("WWW-Authenticate", "Basic realm=\"Twitter\"");
res.End();
}
}
}
And the controller action :
[RequireBasicAuthentication]
public ActionResult Index() {
var cred = System.Text.ASCIIEncoding.ASCII
.GetString(Convert.FromBase64String(
Request.Headers["Authorization"].Substring(6)))
.Split(':');
var user = new { Name = cred[0], Pass = cred[1] };
return Content(String.Format("user:{0}, password:{1}",
user.Name, user.Pass));
}
That action successfully prints the username and password I enter. But I really doubt that's the best way to do this. Do you have no choice except asking for username and password this way?
You really want to create a service and not a web application, based on what I have read. I am guessing here, but I think you picked ASP.NET MVC to take advantage of the routing and building the URL's the way you want? Correct me if I am wrong.
In my opinion the best way to solve the problem you are having is to build RESTful web services with WCF if you are returning data. This article should help you get started if you want to go this route.
Otherwise, you will need to go further up the stack for handling the request and authenticating it. If this is the case, I can help with providing more info and code.
I modified the çağdaş answer to put the whole logic inside my custom ActionFilter attribute.
public class BasicAuthenticationAttribute : ActionFilterAttribute
{
public string BasicRealm { get; set; }
protected string Username { get; set; }
protected string Password { get; set; }
public BasicAuthenticationAttribute(string username, string password)
{
this.Username = username;
this.Password = password;
}
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
var req = filterContext.HttpContext.Request;
var auth = req.Headers["Authorization"];
if (!String.IsNullOrEmpty(auth))
{
var cred = System.Text.ASCIIEncoding.ASCII.GetString(Convert.FromBase64String(auth.Substring(6))).Split(':');
var user = new { Name = cred[0], Pass = cred[1] };
if (user.Name == Username && user.Pass == Password) return;
}
var res = filterContext.HttpContext.Response;
res.StatusCode = 401;
res.AddHeader("WWW-Authenticate", String.Format("Basic realm=\"{0}\"", BasicRealm ?? "Ryadel"));
res.End();
}
}
It can be used to put under Basic Authentication a whole controller:
[BasicAuthenticationAttribute("your-username", "your-password",
BasicRealm = "your-realm")]
public class HomeController : BaseController
{
...
}
or a specific ActionResult:
public class HomeController : BaseController
{
[BasicAuthenticationAttribute("your-username", "your-password",
BasicRealm = "your-realm")]
public ActionResult Index()
{
...
}
}
NOTE: The above implementation requires the developer to manually insert the username and password as ActionFilter required parameters but can be easily extended to make it support any authorization mechanism (MembershipProvider, ASP.NET Identity, custom userbase on an external DBMS or file, etc.) by removing the custom constructor and modifying the OnActionExecuting method IF block accordingly.
For additional info, you can also read this post I wrote on my blog.
Here's the way that has worked for me. It's a little foot work but it will make IIS and MVC3 behave a lot more like all the other Basic Http authentication systems, like Apache...
Step 1.
Make sure "Basic Authentication" is installed for IIS.
( Example: Control Panel -> Programs and Features -> Turn Windows features on or off )
*I'm using Windows 7 at the moment and am not sure the exact path. [GOOGLE: installing basic authentication in IIS] should get you close.
Step 2.
Make sure Basic Authentication is enabled under your site. If you had to install this in the previous step you need to make sure you reset the IIS service and that all the app pools actually went down.
Step 3.
(Note: I am using MVC3, and feel this should work in most models, including ASP.Net, without a lot of fuss.)
In your project you will need to add the following classes:
public class ServicePrincipal : IPrincipal { // This answers the "What am I allowed to do" question
// In real life, this guy will contain all your user info
// and you can put what ever you like and retrieve it
// later via the HttpContext, on your application side.
// Some fun with casting will be required.
public static IPrincipal Default {
get {
return new ServicePrincipal {
Identity = new ServiceIdentity {
AuthenticationType = "Test",
IsAuthenticated = true,
Name = "Basic"
}
};
}
}
public IIdentity Identity { get; set; }
public bool IsInRole(string role) {
// If you want to use role based authorization
// e.g. [Authorize(Roles = "CoolPeople")]
// This is the place to do it and you can do
// anything from load info from a db or flat file
// or simple case statement...though that would
// be silly.
return true;
}
}
public class ServiceIdentity : IIdentity { // This answers the "Who Am I" Question
public string AuthenticationType { get; set; }
public bool IsAuthenticated { get; set; }
public string Name { get; set; }
}
public class ServiceModule : IHttpModule { // This is the module for IIS
public void Init(HttpApplication context) {
context.AuthenticateRequest += this.BasicAuthenticationRequest;
}
public void BasicAuthenticationRequest(object sender, EventArgs e) {
HttpApplication app = sender as HttpApplication;
if( !ServiceProvider.Authenticate(app.Context) ) {
// Total FAIL!
}
}
public void Dispose() {
// Clean up the mess, if needed.
}
}
public class ServiceProvider {
public static bool Authenticate( HttpContext context ) {
// For the example we are going to create a nothing user
// say he is awesome, pass him along through and be done.
// The heavy lifting of the auth process will go here
// in the real world.
HttpContext.Current.User = ServicePrincipal.Default;
return true;
}
}
Step 3a. [edit]
Here's the different libs you'll be "using"
using System.Security.Principal;
using System.Web;
Just wanted to throw those in. I hate it when folks leave them out. :)
Step 4.
Add the following to your web config. Please note I am including the surrounding structure, for example the "configuration" tag... It's just a road map, if you already have a "configuration" tag don't add the other or IIS gets upset with you.
<configuration>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true">
<add name="ServiceCredentialModule" type="{Namespace}.ServiceModule"/>
</modules>
</system.webServer>
<configuration>
Please note that the Namespace in {Namespace}.ServiceModule is the Namespace you put the classes from Step 3 into.
...and that's pretty much it.

Resources