Session managment using db and secure sessions

by jamied_uk 1st December 2013, 19:15

Code:: Found at http://www.wikihow.com/Create-a-Secure-Session-Managment-System-in-PHP-and-MySQL CREATE DATABASE `secure_sessions` ; User: "sec_user" Password: "eKcGZr59zAa2BEWU" CREATE USER 'sec_user'@'localhost' IDENTIFIED BY 'eKcGZr59zAa2BEWU'; GRANT SELECT, INSERT, UPDATE, DELETE ON `secure_sessions`.* TO 'sec_user'@'localhost'; CREATE TABLE `sessions` ( `id` char(128) NOT NULL, `set_time` char(10) NOT NULL, `data` text NOT NULL, `session_key` char(128) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ now the function session.class.php ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ class session { function __construct() { // set our custom session functions. session_set_save_handler(array($this, 'open'), array($this, 'close'), array($this, 'read'), array($this, 'write'), array($this, 'destroy'), array($this, 'gc')); // This line prevents unexpected effects when using objects as save handlers. register_shutdown_function('session_write_close'); } function start_session($session_name, $secure) { // Make sure the session cookie is not accessable via javascript. $httponly = true; // Hash algorithm to use for the sessionid. (use hash_algos() to get a list of available hashes.) $session_hash = 'sha512'; // Check if hash is available if (in_array($session_hash, hash_algos())) { // Set the has function. ini_set('session.hash_function', $session_hash); } // How many bits per character of the hash. // The possible values are '4' (0-9, a-f), '5' (0-9, a-v), and '6' (0-9, a-z, A-Z, "-", ","). ini_set('session.hash_bits_per_character', 5); // Force the session to only use cookies, not URL variables. ini_set('session.use_only_cookies', 1); // Get session cookie parameters $cookieParams = session_get_cookie_params(); // Set the parameters session_set_cookie_params($cookieParams["lifetime"], $cookieParams["path"], $cookieParams["domain"], $secure, $httponly); // Change the session name session_name($session_name); // Now we cat start the session session_start(); // This line regenerates the session and delete the old one. // It also generates a new encryption key in the database. session_regenerate_id(true); } function open() { $host = 'localhost'; $user = 'sec_user'; $pass = 'eKcGZr59zAa2BEWU'; $name = 'secure_sessions'; $mysqli = new mysqli($host, $user, $pass, $name); $this->db = $mysqli; return true; } function close() { $this->db->close(); return true; } function read($id) { if(!isset($this->read_stmt)) { $this->read_stmt = $this->db->prepare("SELECT data FROM sessions WHERE id = ? LIMIT 1"); } $this->read_stmt->bind_param('s', $id); $this->read_stmt->execute(); $this->read_stmt->store_result(); $this->read_stmt->bind_result($data); $this->read_stmt->fetch(); $key = $this->getkey($id); $data = $this->decrypt($data, $key); return $data; } function write($id, $data) { // Get unique key $key = $this->getkey($id); // Encrypt the data $data = $this->encrypt($data, $key); $time = time(); if(!isset($this->w_stmt)) { $this->w_stmt = $this->db->prepare("REPLACE INTO sessions (id, set_time, data, session_key) VALUES (?, ?, ?, ?)"); } $this->w_stmt->bind_param('siss', $id, $time, $data, $key); $this->w_stmt->execute(); return true; } function destroy($id) { if(!isset($this->delete_stmt)) { $this->delete_stmt = $this->db->prepare("DELETE FROM sessions WHERE id = ?"); } $this->delete_stmt->bind_param('s', $id); $this->delete_stmt->execute(); return true; } function gc($max) { if(!isset($this->gc_stmt)) { $this->gc_stmt = $this->db->prepare("DELETE FROM sessions WHERE set_time < ?"); } $old = time() - $max; $this->gc_stmt->bind_param('s', $old); $this->gc_stmt->execute(); return true; } private function getkey($id) { if(!isset($this->key_stmt)) { $this->key_stmt = $this->db->prepare("SELECT session_key FROM sessions WHERE id = ? LIMIT 1"); } $this->key_stmt->bind_param('s', $id); $this->key_stmt->execute(); $this->key_stmt->store_result(); if($this->key_stmt->num_rows == 1) { $this->key_stmt->bind_result($key); $this->key_stmt->fetch(); return $key; } else { $random_key = hash('sha512', uniqid(mt_rand(1, mt_getrandmax()), true)); return $random_key; } } private function encrypt($data, $key) { $salt = 'cH!swe!retReGu7W6bEDRup7usuDUh9THeD2CHeGE*ewr4n39=E@rAsp7c-Ph@pH'; $key = substr(hash('sha256', $salt.$key.$salt), 0, 32); $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB); $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); $encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $data, MCRYPT_MODE_ECB, $iv)); return $encrypted; } private function decrypt($data, $key) { $salt = 'cH!swe!retReGu7W6bEDRup7usuDUh9THeD2CHeGE*ewr4n39=E@rAsp7c-Ph@pH'; $key = substr(hash('sha256', $salt.$key.$salt), 0, 32); $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB); $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); $decrypted = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, base64_decode($data), MCRYPT_MODE_ECB, $iv); return $decrypted; } } Using sessions with the custom session manager. Below is how you would start a new session; you would need to include this on every page you want to access the sessions, use it instead of session_start(); Starting a session: require('session.class.php'); $session = new session(); // Set to true if using https $session->start_session('_s', false); $_SESSION['something'] = 'A value.'; echo $_SESSION['something'];