one userid can login once at a time

chayanvinayak

Can any one suggest me the login script so that using one userid only one person can login at a time.

constarints :

Script should be like this that a abnormal disconnection will not permanently bolck the user.

------------------------this is challenging task --- question asked for highest level PHP builder

laserlight

What have you tried so far?

chayanvinayak

hi laserlight

i have tried using session but session is for internet explorer only .
i have tried that when even a user login it makes login field=1 and when ever it logsout
it make it =0 .so that if login field is=1 no one can login further
but here there is a problem if user gets disconnected abnormaly it gets permanently blocked.

laserlight

i have tried using session but session is for internet explorer only .

This is not true. Are you sure that you implemented sessions correctly?

That said, it is possible for two users to be logged in simultaneously with sessions. This is exploited by session hijacking and session fixation attacks.

The way that I would use is this:
From the point of successful login onwards, issue a new hash identifier on each page load.
This can be in the form of a cookie, or a session variable.
The current hash identifier for the user would be stored in the database, and the user might also be tracked with his/her database table user id (to ensure that hash collision is harmless).

chayanvinayak

hi LL

thanks for your support , but i dont have good knowledge of php so if you can provide me the code for that , i will greatly appreciate your support..

thanks