I am doing an asp.net project.
In this i blocked user log in, meant's if a user logged in one system or browser he can't log in in other browser or system.
Now the problem is i want to free resources if the user directly closing the browser of shutdown the system.
Your description is somewhat vague on 'how you block the user'. Nevertheless:
Http is a stateless protocoll and you are not able to tell if a browser window is open or not.
You can manipulate this behaviour be setting the session timeout lower. You can set a session cookie, which expires at the end of the session.
Alternativly there is a javascript snippet here, that imitates this behaviour. Scroll down a little bit to get the snippet.
Related
In my web application, there's a link sending a redirect (302 to another GET request) together with some cookies. It works fine, except when used from MS Access by a guy I remotely work with. I know close to nothing about what and how he does, I only know that he uses Application.FollowHyperlink.
The link from Access should be opened in a browser, but after the redirect, there seem to be no cookies there. When used normally, there's no problem. Can it be like that Access handles the link itself and sends the redirected URL to the browser?
Maybe a stupid question, but I have no idea about Access (never ever seen it) and I'm sitting only on the server side. There's nothing interesting in the server logs...
The problem was MS doing some complicated things like here instead of simply opening an URL in a browser. Access accesses the page, sees the new URL, and gets and eats all cookies. While digesting the cookies, it points the browser to the new URL. The browser has no cookies and no access to anything.
This summarizes it nicely:
This problem occurs because of missing session cookies for the Web server. This problem is specific to certain Web-server designs that depend on cookie information instead of authentication information or that depend on cookie information plus authentication information.
To me it sounds like "works with MS only", though I'm not exactly sure what "authentication" they mean.
When using WIF, the client is able to set the persistentCookiesOnPassiveRedirects which by default is false. Here is the provided definition:
persistentCookiesOnPassiveRedirects: Specifies whether persistent
cookies are issued when the module is enabled to initiate
WS-Federation passive protocol redirects. A persistent cookie will
outlast user sessions.
OK that sounds clear, but I still do not get it and changing the value between true/fasle does not seem to make any difference. Does it have anything to do about pulling up another site in a separate browser that trusts the same STS provider and making it so the user does not have to log in again?
I suppose an example of a site and STS working together would be really helpful to explain exactly what this setting does. Thanks!
It means that the FedAuth cookies issued by WIF will be persistent (as opposed to tied to a user session). If you close the browser and open it again, the cookies will still be sent to your site and token negotiation will not happen (you will not be redirected to the STS).
If it is false, each time you close the browser and open it again the negotiation will be triggered, because there's no token anymore. (Cookies is where WIF stores the information of the security token).
Notice that the STS itself will also issue cookies (different from your app) and those might be persistent, so the actual authentication might not happen the second time even if you set the flag to false.
Notice also that WIF can optionally store the information it needs somewhere else (server side).
Last but not least, the token might expire, in that case the negotiation will be triggered regardless of the flag.
The question that I have is very basic: Is there a way to inform the web browser that the content of the cookie has changed?
I don't want to keep looking at the file and check if it has been updated because it'll cause performance degree on my app.
Thanks in advance!
It's always the job of the server to "push" the new cookie to the browser (in ASP.NET, by setting Response.Cookies("cookie_name")).
I'm not sure to understand your concern, only your application can know that the user's cookie needs to be changed, but it's usually not stored as a file on the server.
You would probably have to check for the Cookie or Set-Cookie http headers that come with the ASP page whenever it reloads in your application, though this would not account for changes made by javascript.
If the ASP page is refreshing each time a cookie changes, that is likely to be a much larger overhead than the WPF reading the cookie from the disk.
Well, since the ASP page needs to be active in order to SET the cookies, why couldn't you just use a HttpClient to request the cookies in your WPF app and on the server, set the cookies. Then send HTTP Response depending on whether or not you set the cookies. If you receive a 200 OK response, you can know your cookies are set. If there's an error, send a 500 Server Error back.
I have an asp .net webforms app that uses forms authentication. For a small number of users we have a problem where they log in, they navigate to a couple of pages and then they are asked to log in again. Once logged in for a second time they seem to be able to stay logged in as expected. They shouldn't be asked to login the second time.
This is a single server, no web farms, nothing tricky.
This only happens to a few users, but it does seem to be all users from the same building. I am unable to replicate this and at this point might even start to deny that t was happening if one of our trainers hadn't watched it happen to a couple of customers.
Has anyone else seen anything like this?
I am also seeing a lot of "Membership credential verification failed." errors in the event log. This may be related, but all the googling I've done seems to point to web farms and the like, not a single server.
UPDATE
There is no proxy server, the IIS server and the browser (IE8) are both on the same machine.
The AV software installed is Symantec Endpoint, on one machine, on the other the user didn't have any AV at all (AV Fail!).
The browser is IE 8 with no frills, not a single addin that didn't come with the default installation.
Both session and user login time-outs are set to 30 mins and the problem happens within 1 min of the user logging on.
Logging shows the user to only have one IP address.
I have tried the sessionMode in all it's variations, this doesn't seem to make any difference.
Something has to be causing ASP.NET to think these users have new sessions or their authentication cookie is getting invalidated. Here a a few things I can think to check:
Are the users accessing the site through a proxy server? One of our customers has a proxy that will sometimes close all open connections causing ASP.NET to see the session as new.
Could an overly agressive anti-virus, anti-spyware product be "eating" the session authentication cookie?
Do they have a cookie manager browser add-in that is causing the authentication cookie to disappear or change?
Sounds basic but I've seen this happen because of site timeouts being set too short. If the user sits on the page for longer than the timeout, they will be forced to logon again. And this could be specific to a page when that page presents a large amount of data that takes a while for them to go through.
One other thing I just thought of, have you allowed multiple worker processes for the ASP.NET process (aka web gardens)? If so, the same constraints as with a web farm would apply for authentication.
Crack open Fiddler from the problem user's PC and see what's getting passed in the headers. My bet is on a proxy server and or networking issue.
Are the users possibly coming from a dynamic ip address? I've seen problems where the users sessions get messed up because the IP address that they're accessing the site from changes for some reason.
Are the people this is happening using a browser that's somehow different (different browser, different version, different extensions)? That could be a clue.
In general, when the problem is somewhat reproducible or at least predictable, I use Http Fiddler. Install it on a client machine, turn it on, and start browsing (this works via a system proxy - so it'll work for firefox, IE and any other proxy-supporting browsers alike). Fiddler will record all http traffic between client and server, and you can then peruse such a session later on to find any oddities.
It's a long shot, but one thing I've seen happen occasionally that can lead to these sorts of unpredictable errors is scripting parallelization issues: sometimes buttons + links have onclick handlers which cause a post-back. If you have several such handlers that fire on the same event - in particular when the default event still fires additionally to your custom onclick or whatnot - you may be causing several postbacks when it appears to be just a single postback. That can cause all kinds of unpredictable weirdness as it's not entirely clear which request ends up "winning" - and some odd errors may cause a session to terminate. Since this behaviour is very browser + network latency sensitive, it seems quite unpredictable when it occurs.
Delete the cookie on the client PC's that are playing up
ASP.NET Forms Authentication can redirect users to the login page if they do not have the credentials to access a specific page. It does this so that users who may have more than one login are given the opportunity to login with another account which may have the appropriate access. Basic question I know, but are the users using the same credentials the second time they log in?
Its possible that you have don't have specifically specified asp.net to use cookie based session but are allowing either cookie or cookieless sessions.
In the later case the session id is embedded in the Url. The type of issues you are experiences might be explained by that. Basically depending on how you define your links, some of them would not get the session id, so the user would get a new session when using those links - or maybe during a redirect. That could explain why at specific parts of your site the users loose their session.
If you have the mixed mode enabled, try setting it to only cookieless and go through your site.
Update: Based on the extra info posted there is surely more info needed for it. Some extra things to check:
Are you using subdomains, if that's the case the cookie might not be configured to allow that and that doesn't fail in all environments.
If you are using in-process session, make sure there isn't a bug in the application causing it to restart the process
Maybe what's causing it to ask for login again is an authorization check, and you have an issue on some roles related code
Is it possible that the user is just opening a separate window? ;)
To rule out the possibility of the browser or a browser addon messing things up, have you checked their User Agent strings? If they are randomly distributed it might not cause the problem, but if they're all the same, this might be a hint too.
I have a Drupal site with user logins. Embedded within this site is a Flash application that shows some data to everybody but allows extra functionality if the user is logged on. From within Flash, I'm using XMLRPC to access the system.check method (to determine whether the user is logged in) and the user.login method (to log in a user from within Flash).
Within Flash, everything works fine. However the Flash login state does not seem to correspond to the rest of the site. For example, if I invoke user.login via XMLRPC, subsequent calls to system.check show that I am logged in, but the Drupal user page still says I'm logged out. Or if I am logged in both places and then I log out via the Drupal user page, the next call to system.check still indicates that I am logged in.
How can I make the login state consistent between the Drupal GUI and my embedded Flash app?
(Note: I am not using any XMLRPC library, I am just constructing the requisite XML manually and sending POST methods using a URLRequest object.)
EDIT: I have confirmed via this question and also via testing with a Web Proxy that the SESS cookie returned by the user login page is being picked up and sent back by the flash application.
EDIT: And now I have shown experimentally that even though Flash (via Safari) is sending the same cookie, it gets back a DIFFERENT cookie when it connects to the XMLRPC service than when it requests and HTML page. In other words, Drupal just doesn't support this kind of synchronization and I'm stuck. I'm accepting the answer below that put me on the right track.
EDIT: AMHPHP is not fully released for Drupal6 as of this writing, but it turned out to be installed on the site anyway. Using the DrupalSite library, I was very easily able to log into and out of the site from flash, and the login remained consistent between flash and HTML.
I'm not terribly familar with Flash, but do the URLRequest objects "inherit" state from the browser session, including the user login cookies? If not, you'll need to explicitly send the login cookie with your hand-built request or Drupal will think that it's just coming from another web browser at the same IP address.
If you're not quite sure, using the Firebug plugin might be useful. It lets you inspect any requests that are being piped through the browser, examine their headers, and look at the raw HTTP response object that comes back.
Update: Even more important than the flash widget getting a session cookie is the flash widget getting the SAME session cookie as the web browser itself. Drupal allows users to log in from multiple machines simultaneously, so if the browser is creating one session and the flash widget is creating another, you'd see the behavior you're describing...
It can't be done.
(For details, please see my final edit to the original question and the equivalent information in my comment to #Eaton.)