I have a web application where I want users to only be able to use it from one location (meaning a user can't actively be using the application at two locations). Currently I got this working in a very common way by only allowing 1 cookie session to be valid and removing any existing ones when a user logs in. Unfortunately I've been told that my method of only allowing 1 cookie is unacceptable because my users move around a lot to different sites and are tired of having to login every time. An easy solution would just be to allow more than 1 cookie, but I can't do this because I need to make sure a user account is not being used at two locations at the same time.
I'm wondering what is the best way to implement a system like this where a user can't be active at more than 1 location, but shouldn't necessarily have to login at every location they visit.
One possible idea I had was to allow multiple cookies to be recorded, but once a cookie becomes active (meaning I notice that session navigating the application) all of the other cookies are locked out for a certain timelimit like 15 mins. If no cookie session has been active for 15 mins then allow any cookie to login and gain dominance over the others untill it exceeds the timelimit.
Edit: It's ok for them to remain logged in after they leave a location
One way to do this is to log their last ip address and at what time that access was. On each access, you can check their last access.
If the last access is from the same ip, let them through.
If the last access is from a different ip, check how long ago that was. You can then define a cut-off point for how long they need to be idle before they can access it from another location. 15 minutes seems reasonable.
All of this can be done on the backend and this would possibly provide a higher level of security.
The browser allows users to store their credentials. Let them use this feature to log back in without hassle.
No need for a timeout. Allow multiple cookies, but only one active one.
Instruct your users to close the application when they leave their workstations. Make this something that's easy to do. Put a close button on each page or perhaps catch onBeforeUnload and notify the server that the page is no longer being displayed. Do keep the session when the user closes the application, but mark it as currently inactive.
When you get a request with a cookie that belongs to an inactive session, activate that session without complaints if the user has no other session active.
If the user still has another session active, something fishy is going on. So remove all sessions and send the user to the login screen.
(That'll teach them :) )
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I am creating a web application which will be used by App's Administrators and for security reasons we don't want to allow multiple active logins from a single user at any point of time.
I am storing session data in the web browser's cookie and want backend to have active user's information who are currently logged in to the application so that on successful login request I can find out if this particular user already has an active session. If that is possible then I can block the login for that user.
One way to do that is storing IsLoggedIn in the Database with LastLoginTime and on each login, I can use this two flags to identify if an active session exists.
Open to other better solutions if any
I think a more robust solution than checking last login times would be to generate and store an id for each new login and then include a middleware to make sure the session's id for each user matches what you expect. That way every time the user logs in on another device the previous one will be invalidated and only one session will be valid at a time. You may even just be able to use express-session's req.session.id.
.. Or is it enough to just check for a session variable that indicates a successful login has in fact been performed?
What are different ways to go about this? The ideal and not so ideal?
Thanks!
Third alternative: HMAC-ed cookie. No need to hit database/session-store at all.
Details.
Even if a user has an active session that is restores via cookie for example, you need to verify his account data.
If you don't check the current database entries for a user, he could possibly login although his profile has been banned or something like that.
The reverse situation can happen if your user opens a session in one browser (at home for example), upgrades his account to some "premium" (or whatever) account with another session (maybe from his office). When he returns home, he would get his old session that has no "premium" privileges.
So, always check the data for your user profiles. I would recommend to check them on EVERY request to your website. Your session data should only say WHO the user is and not WHAT he is allowed to do.
how do I prevent my users for more than one simultaneous login per account. I am using Vb.Net SQL.
Just coming from a 'web programmers' point of view, there is one really simple way:
You have to use some sort of central session system, where a Cookie on the user's browser has a hash, or some unique key that is also stored in the database. One each page request, or at set intervals, you check if that hash exists in the database.
Then, whenever you have a user log in, you delete any hashes that are tied to that user in the database, and then you create a new one for the user logging in.
What happens is if a user logs in, and you delete existing hashes from the database, then the other user will be logged out when you go to check for their hash in the database.
Not VB-specific, but: when the user logs in, keep track of the fact they are logged in. You can keep this in a cookie (watching out for the fact that a cookie can be tampered with.) You can keep track of it in a session variable. Or you could keep a boolean field in the database, "is_logged_in".
Then, when the user attempts to log in, you can check to see if they've already done so. If they're already logged in, the script might just return them to the home page (provided they used valid credentials. Otherwise a rogue user could type a username but leave the password blank, and depending on the behavior of your program, could see if a user was logged on at that specific time.)
Also, it is common that when someone is logged in, the webpage itself replaces the "Login" link with some text that says "Welcome, rascher!" and maybe links to their profile or preferences page.
Edit: Also remember to set is_logged_in (no matter how you track it) to "false" if they log out. It might also help to time this out - say, when the user closes the browser, or after "n hours" of inactivity (though that can be really annoying.) It will depend on how long people are generally logged into the system. Also note that someone might log in on their home computer, stay logged in, and then try to log in to the same place from work or their iphone. You might could look at ways of dealing with this (if the IP address is different than the current login, then log the other person out? Or something.)
In our system one client may have multiple operators. However there is a "wish" from client.
One company has an account, however there can be mulitple operators assigned to this company. Client wants us to prepare a solution that only one operator from company can log in to the system at same time. How can I achieve this?
Just by making sure they system has the ability to validate the login on each request. Either
Actively (by querying state -- possibly a database to compare some secrets) or
Passively -- using some form of cryptography and tokens (possibly in the cookie).
Option one is easiest, option 2 is fastest. If you validate on each request you can make sure that only one user remains logged in -- if another user signs in you can invalidate the existing active login -- perhaps with a cooldown period of n amount minutes.
You have to develop some form of login scheme -- kerberos is the defacto scheme -- read this easy to follow tutorial on kerberos Designing an Authentication System: a Dialogue in Four Scenes It should show you what you really need to do.
You could use a database field to flag that they are logged in. Update the field to 'logged in' when they do so, and then update it to 'logged out' when they log out.
You'd also need to monitor login sessions for expiry to update the field if a user never bothered to explicitly logout.
The best approach I've used:
Create a table used to track whether an operator is logged in (e.g. userid and last_accessed_dt)
On each page request by the operator update the last requested date/time
When an operator attempts to login they can only do so if the last requested data/time > timeout period of sessions on your website (E.g. 30 minutes) or if they are the Last Operator User ID ... this way they can quickly recover from a logoff etc.
When an operator logs off have the Last Accessed cleared
When the session times out have the Last Accessed cleared
"I am using WPF application and the server is written in WCF, however this can be achieved. But what in situation when user has an application opened and was inactive for 30min?"
This system is going to be single-user, so I suggest you start a counter thread when a user logs in. When counter reaches 30 minutes, write a value to the db indicating that user has timed out and other users are free to login. Obviously, you should do the same thing when user explicitly logs out.
I'm wondering when login timeouts are being used, specifically when using same session (same browser session). On a number of sites I have completed recently I have added 60 minute timeouts and they seem to be causing problems, such as users are not able to fill out larger forms (like a resume submission--people don't think of copying their resume from another program or saving part way through). On one site, I have implemented a div/popup forcing the user to enter their password to continue in the current session, without having to login again.
But on other sites, such as Facebook, it seems you are never logged out as long as you are using the same browser window, even without "remembering" your password.
The main reason I usually use timeouts is to ensure the data is secure, such that another party can't sit down at the computer a few hours later and use the system as the original user.
I'm wondering how you decide when a site should time out users because of inactivity?
I'm thinking the answer would be language agnostic.
IMO, they're valid when:
security is critical (ie. banking)
the likelihood of seat-swapping is
high (ie. public terminals)
Regardless, there may be instances like your resume system, where you want people on public terminals to be able to carry out an act that may leave them inactive for longer than your desired or necessary timeout.
I suppose you just have to handle that in a smart fashion - either figure out a way they can get the data in quicker (which would be ace, spending an hour filling out a form is not fun - can they just upload a file?), or ensuring they can continue without any data loss after being prompted to log in again.
Even though 60 minutes seems like a long time to fill out a single form (perhaps the forms should be divided into multiple pages?), you can probably use SlidingExpiration to solve the problem where your users get logged out even though the browser session is alive.
I think the timeout for an auth cookie is a Security level decision. If your site is SSL secured, you would probably have minimal timeout values (user session would expire within a matter of minutes). On the other hand, for sites with non-critical security, you could set a medium timeout value.
When I sign on to online banking, for example, it asks me whether or not I am using a "public terminal": and if I say yes then it enforces stricter security, or if no then laxer.