Spring security - same page to deliver different content based on user role - spring

i tried to search for any previous post related to my issue but couldnt find any. I have a scenario where in page handles 3 different scenarios and one of them not working. This page returns different content depending on if the user is authenticated or anonymous.
localhost:8080/myApp/muUrl?test=authenticatedContent - > used for Scenario 1 & 2
localhost:8080/myApp/muUrl?test=anonymousContent -> used for Scenario 3
Scenario:
1) Authenticated user accesing the page url - the user gets displayed correct information. Works fine
2) Anonymous user accesing page URL with parameters that requires authentication - If anonymous, there is second level of check on the content they are accessing. for example, based on the GET parameters, there is custom logic to determine if the user has to be authenticated. In which case the page gets redirected to login page (WORKS fine).
3) Anonymous user accessing page URL with parameters that doesnt need authentication - in this case i get the SAvedRequest and redirect to the URL which is taking me to an infinite loop.
Am i missing something very obvious or is there a way in AuthenticationProcessFilterEntryPoint to say "DON'T redirect to LOGIN page but process it" ?
thanks.

I found a solution at last (someone suggested it to me on the Spring forums).
The idea is to use the #PreAuthorize annotation in the controllers as described here: see here
See code sample below:
#RequestMapping("/")
#PreAuthorize("isAuthenticated()")
public String authenticatedHomePage() {
return "authenticatedHomePage";
}
#RequestMapping("/")
public String homePage() {
return "homePage";
}

Related

What might cause a session ID to sometimes change after redirect (Java/Kotlin Spring web app)?

I have a web application built with Kotlin+Spring which identifies users by session ID. On a static front page I have a form which, on submit, sends a POST request to "/start". This is handled by Spring by executing some code and redirecting user to another page "/page" – here's the minimal code:
#Controller
class SomeController() {
// No GetMapping("/"), because '/' is 100% static
#PostMapping("/start")
fun start(#ModelAttribute someModelAttr: SomeModelAttr, model: Model,
response: HttpServletResponse,
session: HttpSession) {
log.info { "POST /start visited by ${session.id}" }
val id = getSomeStuffSynchronously(someModelAttr, session.id);
response.sendRedirect("page/${id}")
}
#GetMapping("/page/{id}")
fun page(#PathVariable id: String,
model: Model,
session: HttpSession) {
log.info { "GET /page/${id} visited by ${session.id}" }
doOtherStuff(id, session.id);
return "page" // i.e. render a Thymeleaf template
}
The code above assumes that the session ID in start and page is the same. However, sometimes (but not always) this is false which breaks stuff for the users. In this situation, the log lines are basically:
POST /start visited by abcd
Log from getSomeStuffSynchronously(someModelAttr, "abcd")
GET /page/123 visited by vxyz
Unfortunately I could not capture headers sent and received by the browser when this happens, because when I tried, I could not reproduce this issue.
I've checked:
This issue might happen regardless of whether the user uses incognito mode in their browser, or not
I have not yet observed this happening on other requests than front-page->/start->/page/id
I do not have caching enabled neither at my hosting provider nor in Spring
I do not have a huge load on my website
I do not use spring-security
Sessions are Cookie sessions and are managed by spring-session-redis, with timeout in Redis set to 15 minutes. However I did not see any obvious correlation between the time between visits to the site and this issue happening.
My question is: what might cause the session ID to change during the redirect?
The reason for getting a different sessions, might be because the cookie/url param containing a reference to the session might not have been set/is used (so a new session is generated every time).
It might be an obvious question but are you sure the filter responsible for handling the session is registered? E.g. did you add the #EnableRedisHttpSession annotation to a configuration class (see redig http session docs)?
Relying on session.id is unreliable between redirects, but as a work-around one can use RedirectAttributes and store relevant data that will be needed in the second request handler as flash attributes – see e.g. How to pass the model as a redirect attribute in spring

How to return to intended page in this case

I have the typical scenario of an online newspaper where you have the article and below a form to comment, but where you need to login to comment. So on clicking it takes you to the log page and it should return you to that page once you have authenticated.
So, because the form is part of a page that the user can see without being logged in, I cannot write the middleware for that page created by a PostController, (get route).
The CommentController only has one method, which is the store one for the Form. so, of course, if I placed a middleware for that controller, it would fail because although it would indeed take you to the login page on clicking the submit button, the Intended URL saved would be that Post for the form, so on returning after authenticating, it would take you to a non existent URL page under the name of the Post route for that Form.
I have read about Auth::guards and the like but could not come clear with it,
This
Laravel 5 - After login redirect back to previous page
asks exactly the same question that I do, it is the same scenario, but I dont see how his answer works, because defining a protected variable (and I have that already) like protected $redirectTo in the Auth controller only tells where to go after authenticating, and it is only a fixed route, in my case it takes you to the dashboard. But I dont want to be taken to the dashboard, it has to return to the page where the article and the comment form are.
I found the solution at Laracasts. I must say I really dont understand it, but it works. It adds two functions to the AuthController.
https://laracasts.com/discuss/channels/laravel/redirect-to-page-where-login-button-was-clicked
public function showLoginForm()
{
if(!session()->has('from')){
session()->put('from', url()->previous());
}
return view('auth.login');
}
public function authenticated($request,$user)
{
return redirect(session()->pull('from',$this->redirectTo));
}
It's been a while since i've done this, but this should work normally.
You could add a GET param in your link from the comment section to login page.
http://....com/login?intended=http://yourredirectlink.com/#form
Put the intended url in in the session variable url.intended and after login you redirect like so
Redirect::intended('/');
This will redirect back to the the url '/' if the session variable is not available.

ASP.Net MVC 3 Querystring Parameter

I am developing an ASP.Net MVC 3 Web Application. Within some of my Views I display tabular data to the user, and beside each record in the table there is an Edit link. When the user clicks this link it takes them to an edit page where they can edit and update the record.
My issue is that once the user clicks the edit link, the URL becomes something like this
http://www.mytestsite.com/myData/edit/3
The '3' is the ID of the record to be updated, however, there is nothing stopping the user from changing the '3' to another digit, and this then means they can edit potentially a record which does not belong to them.
Does anyone have a solution on how I can prevent this from happening?
Thanks for you help.
You need to introduce Authentication and Authorisation into your application. Here is one article of many out there on how to get started with this. You will additionally need to work out how to store logged on user identity and then how to attach this to the record when it was created in the first place. You must then validate, on the server, that the subsequent edit request is being made by the user who created the record in the first place (or by a user who has a role on your system which allows them to do this, such as an Administrator).
Even if the ID wasn't being displayed on the URL a malicious user could still manipulate the HTTP Request to pass an ID of their choice. In any secure system you should always, always, always validate that the currently logged on user genuinely has permission to carry out the requested action. You should never rely on what comes back from the browser to determine this (aside from the authentication context which is managed securely by the MVC framework. Usually).
I believe you should have the information about who have the edit permission on this purticular resource, in your tables. Ex : in your table you might have the "CreatedById" column where you store the ID of the user who created this record. Now in your edit action method, you check the "CreatedById" of the current Item is same as of the "UserId" of the Current user (you maye get this from the session, if you stored it there). Something like this.
public ActionResult Edit(int id)
{
int currentUserID=1; // TO DO : get this value from session or somewhere
ProductVieWModel product=myRepo.GetProduct(id);
if(product!=null)
{
if(product.CreatedById==currentUserID)
{
return View(product);
}
else
{
return View("NotAutherized");
}
}
return View("ProdcutNotFound");
}
You should try using the GUID data type as it helps in these kind of situations, and the user cannot easily guess the next value

Azure ACS + Form value storage

I'm using Azure ACS in my ASP.net MVC 3 website (hosted in Azure too), the scenario is this:
A user first enters my website and fills a one field form, then they need to chose a provider and login, but first I want to store the field value so when they come back from login I'm able to create a profile with this value for the loged in user.
So I believe when they first enter the site and then leaves to login and enters the site again those are two different sessions am I right? and that's the reason the stored data using session state (through SQL Server) is not present when they come back after login am I right? if this is true what would be the best approach then? if not then I'm doing something wrong storing temp data right?
Thanks
UPDATE:
I have discovered that HttpContext.Application state works keeping the data, still I'm not sure if it's a good idea to use it in a controller considering it's in Azure, will it work on production properly??
You can pass state around in the WS-Federation redirect sequence using the wctx URL parameter. In the action that handles the initial POST request, you should get hold of the form parameter you want to keep, then redirect to you identity provider selection page (this will have to be a custom page) with the form parameter appended to the URL. When the user selects an IP on your page, you can pass the parameter on again using the wctx parameter. The WS-Federation passive requestor profile says that this should be returned to you eventually when the IP redirects the user back to your site.
This has some details
http://msdn.microsoft.com/en-us/library/bb608217.aspx
Edit: To get the wctx parameter out of the request when the user finally comes back to your app. Put something like this in the action code:
var fam = FederatedAuthentication.WSFederationAuthenticationModule;
if (fam.CanReadSignInResponse(System.Web.HttpContext.Current.Request, true))
{
string wctxValue = this.HttpContext.Request.Form["wctx"];
}
My preference is to have the wcxt parameter represent a redirect URL (URL encoded) with your parameter as a query parameter in that so it be a URL encoded version of this:
wctx=https://yourserver/yourapp/yourpage?yourparameter=foo
Then the action that was receiving the redirect from the ACS would simply pull out the value of wctx and do a redirect to it without any more processing. This keeps things simple.
Another approach would be to save whatever data you need to pass around in the Database, and just pass around some ID that refers back to the database record. You'll pass this ID to IP and back through wctx (as Mike mentioned above).
This will solve the issue of limited length of URLs (in case your data is very large). Of course you would need to manage deletion of this data, but this shouldn't be hard.

MVC 3 Page navigation security rules

I have a MVC3 application which follows PRG pattern, I am looking for a best way to define navigation rules to my application. For example I have application with pages A, B, C and D. Lets say A is a logon page. After user logon successfully, user will be redirected to page B. Now I do not want let the user to type url of page C in the address bar and get access to page C (Page C should be accessible only after POST ing page B or from Page D back button) I have to setup similar rules for all other pages as well (lets say when user is in page D, should not allow them to get into Page B)
currently I have one option where I can check the #Request.UrlRefferer property to get the source of the every request and decide which page to redirect to. I am not sure this is a best solution.
Appreciate your feedbacks!!
Do not base your security on this. Use the [Authorize] attribute to define security. The UrlReferrer can easily be forged as well.
Why are you trying to limit this? If you have a business reason the user most go through a particular flow, then consider either a cookie, session, or database entry to note their current 'completion' status - IE some somewhat persistent method to determine this. You could also form a token based on say - a session id - that gets passed into each page. If the token exists and matches the user's current session , then load the page for them. Of course this could be forged if the user understands this - but if you are simply trying to ensure the proper flow then this is a way as well. The user would not get a link with the current session id in it until they hit the prior step.
If you don't want a particular page to be accessible via the URL, one option available is to make sure there's no way to access the page via a URL. To access the page, make a POST action that will return a view rather than a redirect. This would mean the view your POST action returns will be shown on a page with the URL of the previous page. For exameple:
Page A URL is /login and after logging in, the user is redirected to Page B. The URL is now /home. Page B sends a POST request and the contents of the page becomes Page C but the URL still remains as /home. The only way to view the contents of Page C would be to visit Page B and send a POST request.
This breaks the PRG pattern but that's one option.
There is one more alternative, store the current permissions of the user indicating which page they're allowed to enter and check if the user is authorized to view a page before executing the action. You could place the code in an ActionAttribute which you can apply to your action methods or entire controllers. If you'd like a more detailed explanation of this technique, leave me a comment and I'll write up another answer describing this technique in more detail.
Here's a quick proof-of-concept of the technique described above:
public class PermissionsNeeded : ActionFilterAttribute
{
string expectedPermission;
public PermissionsNeeded(string permission)
{
expectedPermission = permission;
}
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
var currentPermissions = filterContext.HttpContext.Session["CurrentPermissions"] as IEnumerable<string> ?? new List<string>();
// If user does NOT have permission to access the action method
if(!currentPermissions.Contains(expectedPermission)
{
throw new HttpException(403, "User is not authorized to view this page");
}
}
}
class YourController : Controller
{
[HttpPost]
public ActionResult PageB()
{
var currentPermissions = Session["CurrentPermissions"] ?? new List<string>();
currentPermissions.Add("PostedFromPageB");
Session["CurrentPermissions"] = currentPermissions;
return RedirectToAction("PageC");
}
[PermissionsNeeded("PostedFromPageB")
public ActionResult PageC()
{
return View();
}
}
Currently, the custom attribute will only accept one permission at a time which is a simply limitation to rectify. You'd be responsible for removing the permissions stored in the Session when you feel the user shouldn't have certain permissions anymore. I threw an HttpException that return a 403 status code (unauthorized access) but if you'd instead like to return an ActionResult such as a RedirectToRoute or a View, you could set a value to the filterContext.Result property.
I end up doing this task as below:
On successful completion of every page, save the page Name in database
When user request for a new page, simply check the page they have completed last from database and decide what to do.
I chooses this approach simply because it will definitely help during Problem Solving/Troubleshooting once application is in Production, which is huge for me.
Thanks everyone for your responses!

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