cookie expiring problems

[Stefan]

I am using the following code to set a cookie for 30 seconds:
$value = $_GET[submit_enter];
if (! isset($_COOKIE['testit'])){
setcookie('test it',$value,time ()+30,'/');
}
What happens:
1. On the windows apache server the cookie disappears after 30 seconds
2. On the linux apache server the cookie disappears after hours????

Fact is: Servertime is localtime

Questions:
1. Does anyone know about this problem on a linux machine?
2. Do we really need the time() to set a cookie?
3. Is there a special configuration to be done (php.ini or somewhere else)?

Thank you for your help
Stefan

[B. Johannessen]

Re: cookie expiring problems

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Stefan wrote:[color=blue]
> I am using the following code to set a cookie for 30 seconds:[/color]
[clip]

Setting cookies with a short[1] lifetime is not reliable. The
reason for this is simple: The cookie expiry time is an absolute
value, not a delta, and this time is set by the server but
evaluated by the client. As a result if the clients clock is 29 seconds
ahead of the servers clock, and the server sends a cookie with a
30 second lifetime, the cookie only lives for 1 second.
[color=blue]
> What happens:
> 1. On the windows apache server the cookie disappears after 30 seconds
> 2. On the linux apache server the cookie disappears after hours????[/color]

This could (and probably is) caused by the server and client clocks
beeing out of sync and/or timezone related issues.

If you need short lived cookies, you'll have to include the
expiry time in the cookies *value*, and check it server side.


Bob

[1] The shorter the time, the lower the reliability. I'd say
anything less then a week is likely to get you into trouble
on a regular basis.

- --
| B. Johannessen <bob@db.org> +47 97 15 20 09 - http://db.org/
| Mail & Spam - News, Drafts & Standards - http://db.org/blog/
| On The Origin Of Spam; Spam Statistics - http://db.org/spam/
- --
-----BEGIN PGP SIGNATURE-----

iD8DBQFANErtooi sUyMOFlgRAllbAJ 0VZQoYBkUbSzoy7 3fuwH2I0eMq0QCe Pcb1
a06yMkT4fjGOtSG goxqAIwQ=
=WAhe
-----END PGP SIGNATURE-----