menadwork/session2db

Session2DB

A drop-in replacement for PHP's default session handler which stores session data in a database, providing both better performance and better security and protection against session fixation and session hijacking.

Session2DB implements session locking - a way to ensure that data is correctly handled in a scenario with multiple concurrent AJAX requests.

It is also a solution for applications that are scaled across multiple web servers (using a load balancer or a round-robin DNS) and where the user's session data needs to be available. Storing sessions in a database makes them available to all of the servers!

The library supports "flashdata" - session variable which will only be available for the next server request, and which will be automatically deleted afterwards. Typically used for informational or status messages (for example: "data has been successfully updated").

Session2DB is was inspired by John Herren's code from the Trick out your session handler article and Chris Shiflett's articles about PHP sessions.

The code is heavily commented and generates no warnings/errors/notices when PHP's error reporting level is set to E_ALL.

Features

acts as a wrapper for PHP’s default session handling functions, but instead of storing session data in flat files it stores them in a database, providing better security and better performance
it is a drop-in and seamingless replacement for PHP’s default session handler: PHP sessions will be used in the same way as prior to using the library; you don’t need to change any existing code!
implements row locks, ensuring that data is correctly handled in scenarios with multiple concurrent AJAX requests
because session data is stored in a database, the library represents a solution for applications that are scaled across multiple web servers (using a load balancer or a round-robin DNS)
has comprehensive documentation
the code is heavily commented and generates no warnings/errors/notices when PHP’s error reporting level is set to E_ALL

Requirements

PHP 5+ with the mysqli extension activated, MySQL 4.1.22+

How to install

composer require voku/session2db

How to use

After installing, you will need to initialise the database table from the install directory from this repo, it will containing a file named session_data.sql. This file contains the SQL code that will create a table that is used by the class to store session data. Import or execute the SQL code using your preferred MySQL manager (like phpMyAdmin or the fantastic Adminer) into a database of your choice.

*Note that this class assumes that there is an active connection to a MySQL database and it does not attempt to create one!

<?php
    use voku\db\DB;
    use voku\helper\Session2DB;

    // include autoloader
    require_once 'composer/autoload.php';

    $db = DB::getInstance('yourDbHost', 'yourDbUser', 'yourDbPassword', 'yourDbName');

    // example
    // $db = DB::getInstance('localhost', 'root', '', 'test');
    
    $session = new Session2DB();

    // from now on, use sessions as you would normally
    // this is why it is called a "drop-in replacement" :)
    $_SESSION['foo'] = 'bar';

    // data is in the database!

menadwork / session2db