Files
runff/lib/SimpleSAML/Auth/State.php
2019-04-29 16:09:00 +02:00

421 lines
13 KiB
PHP
Executable File

<?php
/**
* This is a helper class for saving and loading state information.
*
* The state must be an associative array. This class will add additional keys to this
* array. These keys will always start with 'SimpleSAML_Auth_State.'.
*
* It is also possible to add a restart URL to the state. If state information is lost, for
* example because it timed out, or the user loaded a bookmarked page, the loadState function
* will redirect to this URL. To use this, set $state[SimpleSAML_Auth_State::RESTART] to this
* URL.
*
* Both the saveState and the loadState function takes in a $stage parameter. This parameter is
* a security feature, and is used to prevent the user from taking a state saved one place and
* using it as input a different place.
*
* The $stage parameter must be a unique string. To maintain uniqueness, it must be on the form
* "<classname>.<identifier>" or "<module>:<identifier>".
*
* There is also support for passing exceptions through the state.
* By defining an exception handler when creating the state array, users of the state
* array can call throwException with the state and the exception. This exception will
* be passed to the handler defined by the EXCEPTION_HANDLER_URL or EXCEPTION_HANDLER_FUNC
* elements of the state array.
*
* @author Olav Morken, UNINETT AS.
* @package SimpleSAMLphp
*/
class SimpleSAML_Auth_State
{
/**
* The index in the state array which contains the identifier.
*/
const ID = 'SimpleSAML_Auth_State.id';
/**
* The index in the cloned state array which contains the identifier of the
* original state.
*/
const CLONE_ORIGINAL_ID = 'SimpleSAML_Auth_State.cloneOriginalId';
/**
* The index in the state array which contains the current stage.
*/
const STAGE = 'SimpleSAML_Auth_State.stage';
/**
* The index in the state array which contains the restart URL.
*/
const RESTART = 'SimpleSAML_Auth_State.restartURL';
/**
* The index in the state array which contains the exception handler URL.
*/
const EXCEPTION_HANDLER_URL = 'SimpleSAML_Auth_State.exceptionURL';
/**
* The index in the state array which contains the exception handler function.
*/
const EXCEPTION_HANDLER_FUNC = 'SimpleSAML_Auth_State.exceptionFunc';
/**
* The index in the state array which contains the exception data.
*/
const EXCEPTION_DATA = 'SimpleSAML_Auth_State.exceptionData';
/**
* The stage of a state with an exception.
*/
const EXCEPTION_STAGE = 'SimpleSAML_Auth_State.exceptionStage';
/**
* The URL parameter which contains the exception state id.
*/
const EXCEPTION_PARAM = 'SimpleSAML_Auth_State_exceptionId';
/**
* State timeout.
*/
private static $stateTimeout = null;
/**
* Get the persistent authentication state from the state array.
*
* @param array $state The state array to analyze.
*
* @return array The persistent authentication state.
*/
public static function getPersistentAuthData(array $state)
{
// save persistent authentication data
$persistent = array();
if (array_key_exists('PersistentAuthData', $state)) {
foreach ($state['PersistentAuthData'] as $key) {
if (isset($state[$key])) {
$persistent[$key] = $state[$key];
}
}
}
// add those that should always be included
$mandatory = array(
'Attributes',
'Expire',
'LogoutState',
'AuthInstant',
'RememberMe',
'saml:sp:NameID'
);
foreach ($mandatory as $key) {
if (isset($state[$key])) {
$persistent[$key] = $state[$key];
}
}
return $persistent;
}
/**
* Retrieve the ID of a state array.
*
* Note that this function will not save the state.
*
* @param array &$state The state array.
* @param bool $rawId Return a raw ID, without a restart URL. Defaults to FALSE.
*
* @return string Identifier which can be used to retrieve the state later.
*/
public static function getStateId(&$state, $rawId = false)
{
assert(is_array($state));
assert(is_bool($rawId));
if (!array_key_exists(self::ID, $state)) {
$state[self::ID] = SimpleSAML\Utils\Random::generateID();
}
$id = $state[self::ID];
if ($rawId || !array_key_exists(self::RESTART, $state)) {
// Either raw ID or no restart URL. In any case, return the raw ID.
return $id;
}
// We have a restart URL. Return the ID with that URL.
return $id.':'.$state[self::RESTART];
}
/**
* Retrieve state timeout.
*
* @return integer State timeout.
*/
private static function getStateTimeout()
{
if (self::$stateTimeout === null) {
$globalConfig = SimpleSAML_Configuration::getInstance();
self::$stateTimeout = $globalConfig->getInteger('session.state.timeout', 60 * 60);
}
return self::$stateTimeout;
}
/**
* Save the state.
*
* This function saves the state, and returns an id which can be used to
* retrieve it later. It will also update the $state array with the identifier.
*
* @param array &$state The login request state.
* @param string $stage The current stage in the login process.
* @param bool $rawId Return a raw ID, without a restart URL.
*
* @return string Identifier which can be used to retrieve the state later.
*/
public static function saveState(&$state, $stage, $rawId = false)
{
assert(is_array($state));
assert(is_string($stage));
assert(is_bool($rawId));
$return = self::getStateId($state, $rawId);
$id = $state[self::ID];
// Save stage
$state[self::STAGE] = $stage;
// Save state
$serializedState = serialize($state);
$session = SimpleSAML_Session::getSessionFromRequest();
$session->setData('SimpleSAML_Auth_State', $id, $serializedState, self::getStateTimeout());
SimpleSAML\Logger::debug('Saved state: '.var_export($return, true));
return $return;
}
/**
* Clone the state.
*
* This function clones and returns the new cloned state.
*
* @param array $state The original request state.
*
* @return array Cloned state data.
*/
public static function cloneState(array $state)
{
$clonedState = $state;
if (array_key_exists(self::ID, $state)) {
$clonedState[self::CLONE_ORIGINAL_ID] = $state[self::ID];
unset($clonedState[self::ID]);
SimpleSAML\Logger::debug('Cloned state: '.var_export($state[self::ID], true));
} else {
SimpleSAML\Logger::debug('Cloned state with undefined id.');
}
return $clonedState;
}
/**
* Retrieve saved state.
*
* This function retrieves saved state information. If the state information has been lost,
* it will attempt to restart the request by calling the restart URL which is embedded in the
* state information. If there is no restart information available, an exception will be thrown.
*
* @param string $id State identifier (with embedded restart information).
* @param string $stage The stage the state should have been saved in.
* @param bool $allowMissing Whether to allow the state to be missing.
*
* @throws SimpleSAML_Error_NoState If we couldn't find the state and there's no URL defined to redirect to.
* @throws Exception If the stage of the state is invalid and there's no URL defined to redirect to.
*
* @return array|NULL State information, or null if the state is missing and $allowMissing is true.
*/
public static function loadState($id, $stage, $allowMissing = false)
{
assert(is_string($id));
assert(is_string($stage));
assert(is_bool($allowMissing));
SimpleSAML\Logger::debug('Loading state: '.var_export($id, true));
$sid = self::parseStateID($id);
$session = SimpleSAML_Session::getSessionFromRequest();
$state = $session->getData('SimpleSAML_Auth_State', $sid['id']);
if ($state === null) {
// Could not find saved data
if ($allowMissing) {
return null;
}
if ($sid['url'] === null) {
throw new SimpleSAML_Error_NoState();
}
\SimpleSAML\Utils\HTTP::redirectUntrustedURL($sid['url']);
}
$state = unserialize($state);
assert(is_array($state));
assert(array_key_exists(self::ID, $state));
assert(array_key_exists(self::STAGE, $state));
// Verify stage
if ($state[self::STAGE] !== $stage) {
/* This could be a user trying to bypass security, but most likely it is just
* someone using the back-button in the browser. We try to restart the
* request if that is possible. If not, show an error.
*/
$msg = 'Wrong stage in state. Was \''.$state[self::STAGE].
'\', should be \''.$stage.'\'.';
SimpleSAML\Logger::warning($msg);
if ($sid['url'] === null) {
throw new Exception($msg);
}
\SimpleSAML\Utils\HTTP::redirectUntrustedURL($sid['url']);
}
return $state;
}
/**
* Delete state.
*
* This function deletes the given state to prevent the user from reusing it later.
*
* @param array &$state The state which should be deleted.
*/
public static function deleteState(&$state)
{
assert(is_array($state));
if (!array_key_exists(self::ID, $state)) {
// This state hasn't been saved
return;
}
SimpleSAML\Logger::debug('Deleting state: '.var_export($state[self::ID], true));
$session = SimpleSAML_Session::getSessionFromRequest();
$session->deleteData('SimpleSAML_Auth_State', $state[self::ID]);
}
/**
* Throw exception to the state exception handler.
*
* @param array $state The state array.
* @param SimpleSAML_Error_Exception $exception The exception.
*
* @throws SimpleSAML_Error_Exception If there is no exception handler defined, it will just throw the $exception.
*/
public static function throwException($state, SimpleSAML_Error_Exception $exception)
{
assert(is_array($state));
if (array_key_exists(self::EXCEPTION_HANDLER_URL, $state)) {
// Save the exception
$state[self::EXCEPTION_DATA] = $exception;
$id = self::saveState($state, self::EXCEPTION_STAGE);
// Redirect to the exception handler
\SimpleSAML\Utils\HTTP::redirectTrustedURL(
$state[self::EXCEPTION_HANDLER_URL],
array(self::EXCEPTION_PARAM => $id)
);
} elseif (array_key_exists(self::EXCEPTION_HANDLER_FUNC, $state)) {
// Call the exception handler
$func = $state[self::EXCEPTION_HANDLER_FUNC];
assert(is_callable($func));
call_user_func($func, $exception, $state);
assert(false);
} else {
/*
* No exception handler is defined for the current state.
*/
throw $exception;
}
}
/**
* Retrieve an exception state.
*
* @param string|NULL $id The exception id. Can be NULL, in which case it will be retrieved from the request.
*
* @return array|NULL The state array with the exception, or NULL if no exception was thrown.
*/
public static function loadExceptionState($id = null)
{
assert(is_string($id) || $id === null);
if ($id === null) {
if (!array_key_exists(self::EXCEPTION_PARAM, $_REQUEST)) {
// No exception
return null;
}
$id = $_REQUEST[self::EXCEPTION_PARAM];
}
$state = self::loadState($id, self::EXCEPTION_STAGE);
assert(array_key_exists(self::EXCEPTION_DATA, $state));
return $state;
}
/**
* Get the ID and (optionally) a URL embedded in a StateID, in the form 'id:url'.
*
* @param string $stateId The state ID to use.
*
* @return array A hashed array with the ID and the URL (if any), in the 'id' and 'url' keys, respectively. If
* there's no URL in the input parameter, NULL will be returned as the value for the 'url' key.
*
* @author Andreas Solberg, UNINETT AS <andreas.solberg@uninett.no>
* @author Jaime Perez, UNINETT AS <jaime.perez@uninett.no>
*/
public static function parseStateID($stateId)
{
$tmp = explode(':', $stateId, 2);
$id = $tmp[0];
$url = null;
if (count($tmp) === 2) {
$url = $tmp[1];
}
return array('id' => $id, 'url' => $url);
}
}