What is php session timeout

How to Set Session Timeout in PHP: A Guide for Newbies

As a web developer, you might need to create websites with user logins, comment sections, and other features that require users to keep their accounts active. As such, it’s important to implement a way of limiting the time that users can spend on your website. This is called setting session timeout in PHP. Without this restriction, users can stay logged in on your website indefinitely.

This blog post will explain what session timeout in PHP is and why you would need it. Then we’ll provide step-by-step instructions for implementing session timeout in your own website projects. So keep reading to learn more!

What is session timeout in PHP?

A session is a temporary online exchange between two parties. A user can start a session with your website by logging into it, for example. The session is a two-way exchange: it allows users to interact with your website, and it also allows your website to interact with users. One example of how this exchange can be beneficial is that it lets you create user accounts on your website — and then log those users out when they’re done. This is called session timeout in PHP. Session timeout is the length of time that your website will keep a user logged in if they’ve already logged in.

Set the Session Timeout in PHP

Before you start, you’ll need to know your PHP version and whether your computer is set up for PHP development. Then you can follow these steps to set a session timeout. – Enable session timeout: The first thing you need to do is set your website to use session timeout in PHP. You can do this in your server’s configuration file.

It’s also worth noting that you can set the session timeout in the PHP configuration file (php.ini) by setting the session.gc_maxlifetime option. This option specifies the maximum lifetime of a session in seconds. For example, to set the session timeout to 30 minutes, you can set session.gc_maxlifetime to 1800 (30 minutes * 60 seconds):

To set the session timeout in PHP, you can use the `session_set_cookie_params` function. This function allows you to specify the lifetime of the session cookie in seconds. For example, to set the session timeout to 30 minutes, you can use the following code:

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How to change PHP session timeout

A session is a way to store information (in variables) to be used across multiple HTTP Requests, to simulate a “state” across pages navigation.

Unlike a cookie, the information is not stored on the end users computer but in the application server.

For security reasons, sessions has a time limit to exist than they expire. PHP has a default timeout session limit and sometimes it is not the timeout your application needs. In this post we gonna learn how to change the PHP Session Timeout.

How long is a PHP session timeout

The PHP session timeout depends on the server configuration or the relevant directives session.gc_maxlifetime in php.ini file.

Typically the default PHP session timeout is 24 minutes (1440 seconds), but your webhost may have altered the default to something else.

What is reasonable session timeout?

OWASP, one of the most authoritative web application security standards organizations, says about session timeouts:

“Insufficient session expiration by the web application increases the exposure of other session-based attacks, as for the attacker to be able to reuse a valid session ID and hijack the associated session, it must still be active. The shorter the session interval is, the lesser the time an attacker has to use the valid session ID. The session expiration timeout values must be set accordingly with the purpose and nature of the web application, and balance security and usability, so that the user can comfortably complete the operations within the web application without his session frequently expiring…Common idle timeouts ranges are 2-5 minutes for high-value applications and 15- 30 minutes for low risk applications.”

From the federal guideline perspective, the draft NIST 800-63B – Digital Identity Guidelines proposes the following recommendation for providing high confidence for authentication: “Reauthentication of the subscriber SHALL be repeated following no more than 30 minutes of user inactivity.”

So your sessions should not last longer than 30 minutes. Read the Session timeout considerations in this article.

Setting PHP Session Timeout

The timeout limit of the session in PHP is configured using two directives in the php.ini file:

• session.gc_maxlifetime: It is used to set the time limit in seconds to store the session information in the server for a long time.
• session.cookie_lifetime: It is used to set the expiration time limit for the PHPSESSID cookie.

Another way to set PHP session timeout is by using the ini_set() function in a PHP script.

Using php.ini settings for session timeout

Find the directive session.gc_maxlifetime and choose smallest possible. The session.gc_maxlifetime is a setting for deleting obsolete session ID. Reliance on this setting is not recommended. Developers should manage the lifetime of sessions with a timestamp by themselves.

It specifies the number of seconds after which data will be seen as ‘garbage’ and potentially cleaned up. Garbage collection may occur during session start (depending on session.gc_probability and session.gc_divisor ). Defaults to 1440 (24 minutes).

Find the directive session.cookie_lifetime and set it to 0 (zero). This value has a particular meaning. It informs browsers not to store the cookie to permanent storage. Therefore, when the browser is terminated, the session ID cookie is deleted immediately. If developers set this other than 0, it may allow other users to use the session ID. Most applications should use “0” for this.

If an auto-login feature is required, developers must implement their own secure auto-login feature. Do not use long life session IDs for this.

Using ini_set directives for setting session timeout

You can set session.gc_maxlifetime and session.cookie_lifetime using the ini_set(, ) function.

For this, at the begining of your script, call the function passing the directive and the desired value to set it.

See the following example:

php  //Set the session timeout for 2 seconds  $timeout = 2;  //Set the maxlifetime of the session  ini_set( "session.gc_maxlifetime", $timeout );  //Set the cookie lifetime of the session  ini_set( "session.cookie_lifetime", $timeout );  //Start a new session  session_start();  //Set the default session name  $s_name = session_name();  //Check the session exists or not  if(isset( $_COOKIE[ $s_name ] ))   setcookie( $s_name, $_COOKIE[ $s_name ], time() + $timeout, '/' );   echo "Session is created for $s_name.
"; > else   echo "Session is expired.
"; > ?> 

The following output will appear after executing the above script for the first time:

Session is created for PHPSESSID. 

And executing it again after 2 seconds the output will be:

Conclusion

The right session timeout for PHP applications can be configured using the global php.ini file or by scripts, what gives to developers more control on how much sessions should last.

References

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How to Change PHP Session Timeout

As a web developer, understanding PHP session timeout is essential to building secure and reliable web applications. A PHP session is a way to store user information across multiple pages, and session timeout refers to the duration for which a session remains active before expiring.

In this step-by-step guide, we will walk you through the process of changing PHP session timeout.

What is PHP Session Timeout?

When a user visits a website, a session is created on the server, which stores user data such as login credentials, shopping cart contents, or other information that needs to persist across multiple pages. The session remains active until the user logs out or the session times out.

Session timeout refers to the duration for which a session remains active before it is automatically terminated by the server. This is typically done to prevent unauthorized access to sensitive user data if the user is inactive for a certain period.

How to Change PHP Session Timeout

Step 1: Determine the Current Session Timeout Value

Before changing the PHP session timeout value, you need to determine the current value. The default PHP session timeout value is 24 minutes, but it can be changed by modifying the “session.gc_maxlifetime” directive in your php.ini file.

To determine the current value, you can use the following PHP code:

This code will output the current session timeout value in seconds.

Step 2: Change the Session Timeout Value

To change the PHP session timeout value, you need to modify the “session.gc_maxlifetime” directive in your php.ini file. The “php.ini” file is typically located in the root directory of your PHP installation.

Open the php.ini file in a text editor and search for the following line:

The value “1440” represents the default session timeout value in seconds, which is equivalent to 24 minutes.

To change the session timeout value, replace the default value with your desired value in seconds. For example, to set the session timeout to 30 minutes, you would set the value to 1800 seconds:

Save the changes to the “php.ini” file and restart your web server to apply the new session timeout value.

Step 3: Verify the New Session Timeout Value

After changing the session timeout value, you can verify that the new value has been applied by using the same PHP code as in step 1:

This code should output the new session timeout value in seconds.

Changing the PHP session timeout value is a straightforward process that can be done by modifying the session.gc_maxlifetime directive in your php.ini file. By following this step-by-step guide, you can set the session timeout value to better suit the needs of your web application.

How Does PHP Session Timeout Work?

PHP session timeout works by using a session ID to identify the user’s session. When a user visits a website, the server generates a unique session ID and stores it in a cookie on the user’s computer.

Every time the user navigates to a new page on the website, the session ID is sent back to the server, which uses it to retrieve the user’s session data. The server then updates the session timeout, which is typically set to a default value of 24 minutes.

If the user remains inactive for the duration of the session timeout, the session is automatically terminated, and the user is logged out of the website. This helps to prevent unauthorized access to sensitive user data if the user forgets to log out.

Why is PHP Session Timeout Important?

PHP session timeout is essential for security purposes. If a user forgets to log out of a website and their session remains active, anyone with access to the user’s computer can potentially access their sensitive data.

For example, if a user leaves their computer unattended while still logged into their online banking account, anyone who gains access to the computer can potentially make unauthorized transactions.

Setting a session timeout ensures that the user’s session is automatically terminated after a certain period of inactivity, reducing the risk of unauthorized access.

Conclusion

Understanding PHP session timeout is essential to building secure and reliable web applications. By setting a session timeout, you can ensure that user data remains secure even if the user forgets to log out or leaves their computer unattended.

It’s important to note that session timeout should be balanced between security and user experience. Setting a session timeout that is too short can be frustrating for users, while a session timeout that is too long can increase the risk of unauthorized access.

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