PHP session_id changes between pages or when refreshing the page - php

The problem is that every time I refresh the page or when I change the page to another one, the session_id changes and new session file is created in session_save_path.
Here is the initial part of my code:
<?php
session_start();
echo session_id();
...
?>
Obviously the session variables (which is the thing that I need) don't work.
A curious thing is that the page works fine on localhost but doesn't work when I try it on the server.
Thanks in advance.

Check this setting in your server: session.auto_start
This will cause session to be autostarted in each page whether you call session_start() or not.
Make sure that there are no phantom CRLFs or such stuff before session starts. In production the error_reporting can be off so it might not get caught, but the session might find difficulty getting written. This can sometimes cause this.

On your server, in php.ini check TTL for your cookies. session.cookie_lifetime defines how long the cookie will last in seconds (default is 0, which means until the browser is closed) and session.gc_maxlifetime defines how long before the data is deleted, also in seconds.
And make sure the session file isn't stored in a /tmp folder.

Looks like your directory with sessions is not writable.
That's why php generates a new session file each time.
Check your chmod for sessions folder.

Related

Share session on subdomains in php

I have a problem sharing the session between two subdomains, and I've read a lot of threads here and other places.
I have www.xx.com and sub.xx.com and I've set
session_name("PHPSESSXX");
session_set_cookie_params(0, '/', '.xx.com');
and the session.save_path is the same on both domains.
I get a cookie called PHPSESSXX on both domains, and it has the same value.
When I log on to www.xx.com I get a session with some details in it, and it stays that way until I go to sub.xx.com. Then the session on sub.xx.com is empty, and if I refresh www.xx.com, the session there is gone as well. So it does something, but it seems to be overwriting the session data each time I visit a different subdomain.
Any ideas anyone? - Can i debug this somehow?
Btw: I'm using ssl on both domains.
cheers
PHP session ids are saved in Cookies. To make a cookie available in all the sub-domains you need to assign it to the root domain. Then all the sub-domains will get the session id from cookie and PHP can find the session using passed session id.
As it turns out, You just need to set the session.cookie_domain to the root domain in php.ini file
session.cookie_domain = ".example.com"
Also check manual for different approaches used to set an ini entry.
Your question is answered here
Sharing SESSION Variables Between Multiple Subdomains
My solution was to set a flag in .htaccess like this:
php_flag "suhosin.session.cryptdocroot" 0
And it now works perfectly ;o)
The problem was that Suhosin was installed on the system, and the ini variable
suhosin.session.cryptdocroot = On
encrypted the session files in such a way, that when a different subdomain tried to change the session, it deleted everything for security reasons.
It didn't work for me to set the variable to Off or [nothing] in the ini-file, though maybe I didn't find the right file.
I also tried setting it in PHP without any luck. Like this:
ini_set('suhosin.session.cryptdocroot', 0)
cheers

cookie gets deleted from another page?

I have a strange case with my cookies.
On my overview.php i set
setcookie('threads_more','1',time()+3600,"/");
If the user gets back to index I delete the cookie with
setcookie('threads_more','1',time()-3600,"/");
But the cookie gets also deleted if I browse to other pages in this directory although there is no setcookie. Its like the setcookie command from index.php gets executed on every page in this directory. On pages in another directory the cookie stays alive. If I remove the deletecookie command on index.php it works fine.
Anyone an Idea?
Thanks a lot!
Kornel
Try
A. Remove. "/" the domain setting when setting cookies.
B. Check ode if you are setting cookies with blank node.
Idea is use default domain.
Another thing you should check, if you are using port 80.

session variable value changed

I am using session to store some data in my php website, but in some page when I fetched the data in the session is changed some times and some time its same.
I searched lots of and find some answer at
session id value changes
" if you have register globals on, you may be seeing behavior like that if you use the variable $id in your code. As a test, try:
<?php
session_start();
$_SESSION['testing'] = 'Foo';
$testing = 'bar';
die($_SESSION['testing']);
?>
"
help me i searched in my php file but i dont find similar variables like session variables so what is the problem ??
give me some details about php session and if possible suggest good books.
edited :
i have set the php.ini as all of you saying its problem of register_global off and than ckeck by using phpinfo(); function and check the register_global is off.
but after some time i logged in with my id and than at mypage menu.php accessed by me after that its changed session logged id and i logged in another account automatically.
please help me
Disabling Register_Globals by adding the following line in your php.ini file may fix this problem.
register_globals = Off
If you are using a Shared Web Hosting service, follow:
If you have access to /cgi-bin folder then create your custom php.ini file inside it.
And if you dont have access, then create your custom php.ini file in root folder.
And then add above mentioned line in php.ini file.
Adding the following line of code in your .htaccess file also fix your problem.
php_flag register_globals off
You shouldn't be using register globals so it shouldn't be an issue.
Add this line to .htaccess to disable if you have register globals running:
php_flag register_globals off
it can't be done with ini_set() at runtime so you will need to use htaccess or php.ini as in previous answer.
It's unlikely these days that register_globals is your problem. More likely it's to do with a) where the actual session data is being stored; and b) how the "session ID" is being transmitted from one request to the next.
The first thing to look at is session_save_path(), which tells PHP where on disk to store the data that you put into the session variables.
The other part is a little more complicated, but is about how the cookie is set which lets PHP know to load the same session rather than creating a new one. You might need to look at things like the lifetime of this cookie, or the scope (domain / sub-domain / URL path) it applies to. Have a look at session_set_cookie_params(), and in general have a read through that section of the PHP manual to understand how sessions work.

Could session_start() in php be messing up my users sessions lengths?

My php.ini file is set to expire sessions within 24 hours. But my users complain after being logged out after just 20 minutes or so.
I use session_start at the beginning of every page. Could that be messing things up for me?
Or could there be anything else causing this?
Just realized I might be on a shared hosting. And it might have some group settings for garbage collection with sessions. Anyone know how to look into this or set mine to be more specific?
Thanks!
Check phpinfo() to see what the settings really are. PHP has multiple .ini files, and its settings can be overridden in multiple places, so your session session may not be the ones actually in effect. phpinfo's output will show what the "Local" this-is-now-whats-in-effect settings are.
Beyond that, session_start() won't delete a session itself, but it MAY trigger a session garbage collector run based on a few gc_* .ini settings. It's a probabilistic thing, though, and won't happen every time you start a session.
Another possibility is that your session files are going into a system temp directory somewhere, and something external to PHP is cleaning up that directory at 20 minute intervals. So check what the session.save_path setting is and see if anything's cleaning up that location.
ini_set('session.gc_maxlifetime',28800); #28800 - just an example time - set your own
ini_set('session.gc_probability',1);
ini_set('session.gc_divisor',1);
session_save_path('/path to your sessions folder');
ob_start();
session_start();
You do need to create a session folder first.
This works for sure on GoDaddy shared hosting.
On VPS you can use this or just update your php.ini file.

PHP Session Id changes between pages

I have a problem where i am losing the PHP session between 2 pages.
The session_start() is included in a file called session-inc.php into every page requiring a session to be set. This works for all pages on the site except one particular page, member-profile.php. When this page is visited a new session with a different id (same session name) is set and used instead.
A few more details:
Session name is set manually
All pages are on the same server under the same domain name
If i put an additional session_start() above the include('session-inc.php') in the member-profile.php file, the session is carried over correctly
I have tried setting the session_cookie_domain and session.session_name in the .htaccess, this worked for this domain but it stopped the session being passed over to out payment domain
We are running apache 2.2.6 with php 5.2.5
Putting the session_start() above the include('session-inc.php') in the member-profile.php file is the quick and dirty fix for this problem, but i am wondering if anybody know why this would be happening.
Cheers
Will
According to PHP documentation, session_start must be called before any output is sent back to the browser-- could this page have a rogue CR/LF, Unicode byte-order mark or similar that is causing output before you include('session-inc.php')?
While migrating a legacy site from PHP4 to PHP5 I noticed a php.ini configuration setting that causes php to auto-start the session upon every request. It's an alternative to placing session_start() onto every page...
There are multiple ways to enable this setting:
Put the following line into php.ini:
session.auto_start = on
or put this into your apache virtual-site config or .htaccess file:
<IfModule mod_php5.c>
php_flag session.auto_start on
</IfModule>
and it should make $_SESSION changes available across all pages
I have just encountered this problem. Interestingly, browsing via http://127.0.0.1 instead of http://localhost helped me.
I just spent all day diagnosing this issue in my Ionic3 - to - PHP project. TL; DR - make sure your client is actually sending session credentials.
In the interest of helping anyone who makes this mistake, I will share how I found the problem.
I used these tools to diagnose the session on both the client and server:
1) Add a test file with phpinfo() to the server to review PHP session options.
2) Review the PHP code to make sure that no output, intentional or un-intentional occurs before the session_start() line. Check the status bar of Visual Studio Code to make sure the Byte Order Mark (BOM) is absent from the PHP files.
3) Review server PHP logs (in /var/log/nginx/error.log for me). Add error_log() lines to the php file to dump the session_id() or $_SESSION array.
4) Use tcpdump -An 'port 80 or port 443' to view the actual HTTP requests and replies. (That's where I discovered the missing cookies).
For an Ionic3 data provider the correct syntax for the client is:
var obsHttp = this.http.post(url, body,
{ headers: new HttpHeaders({
'Content-Type':'application/x-www-form-urlencoded'
}),withCredentials: true }).timeout(this.timeoutTime);
Notice the withCrentials:true
One needs to call subscribe on the obsHttp() observable to send the request.
Found the issue
There was a byte order mark at the beginning of the main includes file of the second domain. as stated by ken, cant have any output before a session start, it was not setting the session correctly.
SOLUTION:
session.auto_start = on
in file: php.ini
It solved the issue of re-generating session id on page reload (page refresh / change pages).
The issue appeared after the update of CPanel (and included Multi PHP), even the php version remained the same.
The PHP.ini file didn't had that variable at all.
Went in Cpanel -> MultiPHP INI Editor -> Editor Mode (not Basic, in basic you do not have this setting) and added the line. Press Save.
TIPS / WHEN TO USE THIS SOLUTION:
To determine if that is the problem, put a line at the very beginning and at the very end of your index.php file to check the session id. Use function:
session_id();
Navigate through pages / reload the page. If the session_id value changes the problem is not in your code and this solution should solve your problem (the session is lost outside of your code).
I also tried to verify the availability of saving session on the web server (session.save_path) but, even if it was a lead, it was not the case.
I imagine this is a "feature" of Cpanel with MULTIPHP UPDATE that will happen quite often.
I had this problem, and the cause was that PHP was ignoring all cookies after the first 100. (I asked this question to try to find out why, but so far nobody has figured it out). The browser was sending the PHPSESSID*, but since it was the 110th cookie, PHP was ignoring it.
To figure out if this problem is what's affecting you, use your browser's dev tools to look at the cookies that the browser is sending with the request, and compare that list to the $_COOKIE array in PHP. They should be the same. But if the browser is sending a PHPSESSID*, and there's no PHPSESSID* in $_COOKIE, then that would explain why sessions aren't working.
I solved the problem by not having my site use so many cookies, which is good practice anyway.
*PHPSESSID is the default session name. Your site may use a different name.
To solve the session_id change after each request, you change the parameter session.auto_start and session.cookie_httponly into the php configuration file.
to find the used php configuration file
php -i | grep "php.ini"
then you open it, and try to find the parameter session.auto_start . you set
session.auto_start = 1
session.cookie_httponly = 0
finally you restart your httpd/apache service.
Found the issue
In my case it was due to Varnish Settings please check your varnish settings. PHPSESSID you can exclude the cookie from the Varnish Settings.
I'm not an expert, but found a solution after careful investigation of domain name in the cookies info of two webpages opened on Firefox. (Right click on the page, select inspection and the storage). checked domain names and found that one with www.example.com and the other without www (example.com). changed all the page links to same format and the problem solved for my case.
Found the problem was a byte order mark (BOM) being ouputted at the start of the file. Got rid of it and it sorted out the session problem.

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