I want to write a servlet with which I can create a new session.
The servlet requires the user to authenticate with BASIC authentication and returns the standard session cookie (using HttpServletRequest#getSession(true)). However, if the client uses the received session cookie in his next request instead of BASIC authentication it is not authenticated. The server recognizes the session but it doesn't contain the user information.
I'm using Tomcat and after a bit of debugging the reason is also obvious: the user information (Principal) is added to session upon authentication. However when the first BASIC authentication is taking place no session exists yet as this will be created by the servlet. Does anyone have idea how to solve this problem?
After one night of sleep [1] I believe I have come up with a working solution myself. The following snippet (using JAX-RS, but it shouldn't be too difficult to translate it to plain servlet code) does the trick if the calling client will follow redirects:
public Response getSessionCookie() {
boolean sessionExists = m_servletRequest.getSession(false) != null;
if (sessionExists) {
return Response.noContent().build();
} else {
HttpSession session = m_servletRequest.getSession();
return Response.status(Status.TEMPORARY_REDIRECT)
.header("Location",
m_uriInfo.getAbsolutePathBuilder().matrixParam("jsessionid", session.getId()).build())
.build();
}
}
The first request will create a session and redirect the client to the same address but with the session ID in the URL (which is important). The client will follow the request and send the same BASIC authentication data again but now it will be registered in the existing session. The second invocation of the method above will simply return an empty response with the session cookie that can now be used for subsequent requests.
Note that the session cookie is different for me in the second response but looking at Tomcat code this seems to be deliberate (successful authentication will always create a new session).
[1] Sleep is highly underestimated!
Related
In ASP.NET MVC from one controller in one area I am using:
TempData["Model"] = model;
then RedirectToAction to pass the model to another controller in another area. In the controller action method I immediately pull the data back out of the model.
I am concerned that if I deploy to a web farm then TempData's use of session state will cause issues but am not sure if I can get away with it in this case because I immediately pull the model out of TempData again in the action method I pass to?
You are right to be concerned, a RedirectToAction sends the client a 302 message containing a url of the redirected resource. This is then the clients responsibilty to create a new request to the redirected resource. There is no guarantee this resource will be served by the original server. The fact that the request is pulled immediately from TempData makes no difference to this approach, at some point it is going to error.
You need to have some means of managing sessions. You could configure HTTP session affinity so that requests served from a server will always return to the originating server.
You could use cookies for session state or implement a session state provider.
This blog post is also a good start on the overview of the options.
If you are using InProc session state you might run into problems because in the redirect you could be sent to another server where the same session will not be available.
Two possible options are to either implement a cookie based TempData provider or switch to another session-state mode. Note that cookie based TempData is completely visible to users, though there are implementations where you encrypt the data.
Try with cooke based instead of session tempdata
See below link
http://volaresystems.com/Blog/post/2011/06/30/Sessionless-MVC-without-losing-TempData
Avoid the use of TempData all together. If you are sending your model in the redirection then use something like
RedirectToAction("MyAction", new {model = myModel});
public actionresult MyAction(model model)
{
/// Mode Code
return View(MyView, model);
}
Assuming that you controller action will take the model as parameter.
I am using Spring to create my webapp. I have a scenario like:
An ExternalService sends a GET request to my Controller that has a mapping /DoOperation with some user info as param. I get the param check the user if he is logged into my system or not if NOT i send him to OpenId verification with returnUrl, which is in same webapp say /Authenticated.
The ExternalService does not provide a returnUrl (Not related to OpenId returnUrl) and forces to respond the same request it made at /DoOperation.
Now, How could I keep the very HttpServletResponse (if there is a way, apparently there is not) so that I can write a response once I have gone somewhere else e.g. at OpenID page to verify user and then /Authenticate in this case... so that ExternalService could read it.
Could Servlet Filter help here?
I am creating a RESTful web service using ASP.NET WebApi. I am requiring that all incoming requests go over SSL because I will be using Basic HTTP Authentication. The client is responsible for including the credentials in the request header and the web service will authenticate the client on each request.
The actual authentication requires making a database call. Is there a way to cache the database results (the username and password) so that I don't have to make a database call for every incoming request that occurs in a short period of time?
So when a request comes in the web service will look for the username/password combo in the cache. If it is found it will process the request. If it isn't found, it will make the database call to authenticate and then add the username/password to the cache.
The easiest cache that I can think of to use would be using System.Web.Caching. Below is an extremely simplified version of adding a value to the current cache and then retrieving it for processing. I would not recommend using this code as is.
// GET api/values/5
[HttpGet]
public string GetValue(int id)
{
HttpContext.Current.Cache.Insert("2", "test1");
var value = Convert.ToString(HttpContext.Current.Cache.Get(id.ToString()));
return !string.IsNullOrEmpty(value) ? value : "nothing found";
}
I'd like to use ASP.NET MVC's views as mail template engine. For that, I am calling one controller action from another controller action using a System.ComponentModel.Component.WebClient, parse the returned web page and send it via e-mail.
In this scenario, is it possible to forward the current user's login credentials (I am using FormsAuthentication) to the controller action requested by the WebClient? User passwords are encrypted, so I can't just create a new NetworkCredentials instance with his user name and password.
Yes, you can just copy the .ASPXAUTH cookie from your current Request object to the WebClient
EDIT: I haven't actually tried this myself, so maybe the .ASPXAUTH cookie is removed from the Request object for security reasons.
But since you have access to the machine key, you can create your own cookies on the fly. Here's the code that should do it (I can't find the project where I actually did that)
var ticket = new FormsAuthenticationTicket(User.Identity.Name, true, 5);
string aspxAuthCookieValue = FormsAuthentication.Encrypt(ticket);
This code creates a forms authentication cookie for your current user name and with an expiration time of 5 minutes.
Instead of performing a http request, aren't you looking for something like "rendering a view to a string"
We have an application that does single sign-on using a centralized authentication server (CAS). We'd like to do single sign-out, such that if the user logs out of one application (say a front-end portal), the user is automatically signed out of all applications using the same single sign-on ticket.
The expectation would be that each application would register a sign-out hook (URL) with the CAS at the time of logon to that application. When the CAS receives the sign out request from one of the applications, it invokes the sign-out hook for all the application sharing the SSO ticket.
My question is this: is there a way to abandon an InProc session from a different session? I presume, since the HTTP request will be coming from the CAS server, that it will get its own session, but it is the session of the user that I want to terminate. I have pretty good idea of how to do this using a separate session state server, but I'd like to know if it is possible using InProc session state.
Haha, well... It looks like you can. I was wondering myself if there was any way to do this, turns out, there is.
When you use InProc, the InProcSessionStateStore (internal class) persist the session state in an internal (non public) cache. You can access this cache through reflection and remove the session state manually.
using System;
using System.Reflection;
using System.Web;
object obj = typeof(HttpRuntime).GetProperty("CacheInternal",
BindingFlags.NonPublic | BindingFlags.Static)
.GetValue(null, null);
if (obj != null)
{
MethodInfo remove = obj.GetType()
.GetMethod("Remove", BindingFlags.NonPublic | BindingFlags.Instance,
Type.DefaultBinder, new Type[] { typeof(string) }, null);
object proc = remove.Invoke(obj, new object[] { "j" + state.SessionID });
}
The end result is, that the next request will take on the same SessionID, but the HttpSessionState will be empty. You'll still get the Session_Start and Session_End events.
After doing a bit of digging around and considering the answers provided so far I've come up with an alternative that lets me continue to use InProc session. Basically, it consists of extending the HttpModule that already handles single sign-on to detected CAS sign outs and redirect the browser to the application sign out page.
Outline:
Sign-On:
For each new single sign-on request, create a new SSO cookie and encode a unique value in it to identify the session (not the session id, so it isn't leaked).
Construct the the sign-out callback url, encoded with the identifier, and register it with the CAS server.
Sign-Out:
When a sign-out request is received from the CAS server, decode the identifier and store it in an application-wide cache. This needs to be pinned in the cache at least long enough for the session to expire naturally.
For each request, look for the SSO cookie and check its value against the cached, signed-out session identifiers. If there is a hit, remove the SSO cookie and redirect the browser to the application's sign-out url.
For each sign-out, check to see if there is an SSO cookie, if so, forward the sign-out request to the CAS. In any event, abandon the user's session, and sign them out of the application.
Page_Load:
Check for the presence of the SSO cookie. If there isn't one, redirect to the sign out page.
No can do.
http://forums.asp.net/p/416094/416094.aspx#416094
With InProc SessionState, you won't be able to access the data... With StateServer, you still will have a sticky scenario trying to access the correct API to remove the session.
You will most likely want to use a database backed state solution like the pre-packaged SqlServer state provider or a third party solution like DOTSS: http://codeplex.com/dotss
With the database backed solution, you will be able to lookup the state record in a table by session id and mark it as completed. These techniques will vary based on the provider you choose.