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Thijs Kinkhorst authoredaf333cbb
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<?php
/**
* This file is part of SimpleSAMLphp. See the file COPYING in the root of the distribution for licence information.
*
* This file defines a session handler which uses the default php session handler for storage.
*
* @author Olav Morken, UNINETT AS. <andreas.solberg@uninett.no>
* @package SimpleSAMLphp
*/
namespace SimpleSAML;
use SimpleSAML\Error\CannotSetCookie;
use SimpleSAML\Utils\HTTP;
class SessionHandlerPHP extends SessionHandler
{
/**
* This variable contains the session cookie name.
*
* @var string
*/
protected $cookie_name;
/**
* An associative array containing the details of a session existing previously to creating or loading one with this
* session handler. The keys of the array will be:
*
* - id: the ID of the session, as returned by session_id().
* - name: the name of the session, as returned by session_name().
* - cookie_params: the parameters of the session cookie, as returned by session_get_cookie_params().
*
* @var array
*/
private $previous_session = [];
/**
* Initialize the PHP session handling. This constructor is protected because it should only be called from
* \SimpleSAML\SessionHandler::createSessionHandler(...).
*/
protected function __construct()
{
// call the parent constructor in case it should become necessary in the future
parent::__construct();
$config = Configuration::getInstance();
$this->cookie_name = $config->getString('session.phpsession.cookiename', null);
if (session_status() === PHP_SESSION_ACTIVE) {
if (session_name() === $this->cookie_name || $this->cookie_name === null) {
Logger::warning(
'There is already a PHP session with the same name as SimpleSAMLphp\'s session, or the '.
"'session.phpsession.cookiename' configuration option is not set. Make sure to set ".
"SimpleSAMLphp's cookie name with a value not used by any other applications."
);
}
/*
* We shouldn't have a session at this point, so it might be an application session. Save the details to
* retrieve it later and commit.
*/
$this->previous_session['cookie_params'] = session_get_cookie_params();
$this->previous_session['id'] = session_id();
$this->previous_session['name'] = session_name();
session_write_close();
}
if (!empty($this->cookie_name)) {
session_name($this->cookie_name);
} else {
$this->cookie_name = session_name();
}
$params = $this->getCookieParams();
if (!headers_sent()) {
session_set_cookie_params(
$params['lifetime'],
$params['path'],
$params['domain'],
$params['secure'],
$params['httponly']
);
}
$savepath = $config->getString('session.phpsession.savepath', null);
if (!empty($savepath)) {
session_save_path($savepath);
}
}
/**
* Restore a previously-existing session.
*
* Use this method to restore a previous PHP session existing before SimpleSAMLphp initialized its own session.
*
* WARNING: do not use this method directly, unless you know what you are doing. Calling this method directly,
* outside of \SimpleSAML\Session, could cause SimpleSAMLphp's session to be lost or mess the application's one. The
* session must always be saved properly before calling this method. If you don't understand what this is about,
* don't use this method.
*/
public function restorePrevious()
{
if (empty($this->previous_session)) {
return; // nothing to do here
}
// close our own session
session_write_close();
session_name($this->previous_session['name']);
session_set_cookie_params(
$this->previous_session['cookie_params']['lifetime'],
$this->previous_session['cookie_params']['path'],
$this->previous_session['cookie_params']['domain'],
$this->previous_session['cookie_params']['secure'],
$this->previous_session['cookie_params']['httponly']
);
session_id($this->previous_session['id']);
$this->previous_session = [];
@session_start();
/*
* At this point, we have restored a previously-existing session, so we can't continue to use our session here.
* Therefore, we need to load our session again in case we need it. We remove this handler from the parent
* class so that the handler is initialized again if we ever need to do something with the session.
*/
parent::$sessionHandler = null;
}
/**
* Create a new session id.
*
* @return string The new session id.
*/ public function newSessionId()
{
// generate new (secure) session id
if (function_exists('session_create_id')) {
$sid_length = (int) ini_get('session.sid_length');
$sid_bits_per_char = (int) ini_get('session.sid_bits_per_character');
if (($sid_length * $sid_bits_per_char) < 128) {
\SimpleSAML\Logger::warning("Unsafe defaults used for sessionId generation!");
}
$sessionId = session_create_id();
} else {
$sessionId = bin2hex(openssl_random_pseudo_bytes(16));
}
\SimpleSAML\Session::createSession($sessionId);
return $sessionId;
}
/**
* Retrieve the session ID saved in the session cookie, if there's one.
*
* @return string|null The session id saved in the cookie or null if no session cookie was set.
*
* @throws \SimpleSAML\Error\Exception If the cookie is marked as secure but we are not using HTTPS.
*/
public function getCookieSessionId()
{
if (!$this->hasSessionCookie()) {
return null; // there's no session cookie, can't return ID
}
// do not rely on session_id() as it can return the ID of a previous session. Get it from the cookie instead.
session_id($_COOKIE[$this->cookie_name]);
$session_cookie_params = session_get_cookie_params();
if ($session_cookie_params['secure'] && !HTTP::isHTTPS()) {
throw new \SimpleSAML\Error\Exception('Session start with secure cookie not allowed on http.');
}
@session_start();
return session_id();
}
/**
* Retrieve the session cookie name.
*
* @return string The session cookie name.
*/
public function getSessionCookieName()
{
return $this->cookie_name;
}
/**
* Save the current session to the PHP session array.
*
* @param \SimpleSAML\Session $session The session object we should save.
*/
public function saveSession(\SimpleSAML\Session $session)
{
$_SESSION['SimpleSAMLphp_SESSION'] = serialize($session);
}
/**
* Load the session from the PHP session array.
* * @param string|null $sessionId The ID of the session we should load, or null to use the default.
*
* @return \SimpleSAML\Session|null The session object, or null if it doesn't exist.
*
* @throws \SimpleSAML\Error\Exception If it wasn't possible to disable session cookies or we are trying to load a
* PHP session with a specific identifier and it doesn't match with the current session identifier.
*/
public function loadSession($sessionId = null)
{
assert(is_string($sessionId) || $sessionId === null);
if ($sessionId !== null) {
if (session_id() === '') {
// session not initiated with getCookieSessionId(), start session without setting cookie
$ret = ini_set('session.use_cookies', '0');
if ($ret === false) {
throw new \SimpleSAML\Error\Exception('Disabling PHP option session.use_cookies failed.');
}
session_id($sessionId);
@session_start();
} elseif ($sessionId !== session_id()) {
throw new \SimpleSAML\Error\Exception('Cannot load PHP session with a specific ID.');
}
} elseif (session_id() === '') {
$this->getCookieSessionId();
}
if (!isset($_SESSION['SimpleSAMLphp_SESSION'])) {
return null;
}
$session = $_SESSION['SimpleSAMLphp_SESSION'];
assert(is_string($session));
$session = unserialize($session);
return ($session !== false) ? $session : null;
}
/**
* Check whether the session cookie is set.
*
* This function will only return false if is is certain that the cookie isn't set.
*
* @return boolean True if it was set, false otherwise.
*/
public function hasSessionCookie()
{
return array_key_exists($this->cookie_name, $_COOKIE);
}
/**
* Get the cookie parameters that should be used for session cookies.
*
* This function contains some adjustments from the default to provide backwards-compatibility.
*
* @return array The cookie parameters for our sessions.
* @link http://www.php.net/manual/en/function.session-get-cookie-params.php
*
* @throws \SimpleSAML\Error\Exception If both 'session.phpsession.limitedpath' and 'session.cookie.path' options
* are set at the same time in the configuration.
*/
public function getCookieParams()
{
$config = Configuration::getInstance();
$ret = parent::getCookieParams();
if ($config->hasValue('session.phpsession.limitedpath') && $config->hasValue('session.cookie.path')) {
throw new \SimpleSAML\Error\Exception(
'You cannot set both the session.phpsession.limitedpath and session.cookie.path options.'
);
} elseif ($config->hasValue('session.phpsession.limitedpath')) {
$ret['path'] = $config->getBoolean(
'session.phpsession.limitedpath',
false
) ? $config->getBasePath() : '/';
}
$ret['httponly'] = $config->getBoolean('session.phpsession.httponly', true);
return $ret;
}
/**
* Set a session cookie.
*
* @param string $sessionName The name of the session.
* @param string|null $sessionID The session ID to use. Set to null to delete the cookie.
* @param array|null $cookieParams Additional parameters to use for the session cookie.
*
* @throws \SimpleSAML\Error\CannotSetCookie If we can't set the cookie.
*/
public function setCookie($sessionName, $sessionID, array $cookieParams = null)
{
if ($cookieParams === null) {
$cookieParams = session_get_cookie_params();
}
if ($cookieParams['secure'] && !HTTP::isHTTPS()) {
throw new CannotSetCookie(
'Setting secure cookie on plain HTTP is not allowed.',
CannotSetCookie::SECURE_COOKIE
);
}
if (headers_sent()) {
throw new CannotSetCookie(
'Headers already sent.',
CannotSetCookie::HEADERS_SENT
);
}
if (session_id() !== '') {
// session already started, close it
session_write_close();
}
session_set_cookie_params(
$cookieParams['lifetime'],
$cookieParams['path'],
$cookieParams['domain'],
$cookieParams['secure'],
$cookieParams['httponly']
);
session_id($sessionID);
@session_start();
}
}