<?php
namespace SimpleSAML\XHTML;
/**
* This class implements a generic IdP discovery service, for use in various IdP
* discovery service pages. This should reduce code duplication.
*
* Experimental support added for Extended IdP Metadata Discovery Protocol by Andreas 2008-08-28
* More information: https://docs.oasis-open.org/security/saml/Post2.0/sstc-saml-idp-discovery.pdf
*
* @author Jaime Pérez <jaime.perez@uninett.no>, UNINETT AS.
* @author Olav Morken, UNINETT AS.
* @author Andreas Åkre Solberg <andreas@uninett.no>, UNINETT AS.
* @package SimpleSAMLphp
*/
class IdPDisco
{
/**
* An instance of the configuration class.
*
* @var \SimpleSAML\Configuration
*/
protected $config;
/**
* The identifier of this discovery service.
*
* @var string
*/
protected $instance;
/**
* An instance of the metadata handler, which will allow us to fetch metadata about IdPs.
*
* @var \SimpleSAML\Metadata\MetaDataStorageHandler
*/
protected $metadata;
/**
* The users session.
*
* @var \SimpleSAML\Session
*/
protected $session;
/**
* The metadata sets we find allowed entities in, in prioritized order.
*
* @var array
*/
protected $metadataSets;
/**
* The entity id of the SP which accesses this IdP discovery service.
*
* @var string
*/
protected $spEntityId;
/**
* HTTP parameter from the request, indicating whether the discovery service
* can interact with the user or not.
*
* @var boolean
*/
protected $isPassive;
/**
* The SP request to set the IdPentityID...
*
* @var string|null
*/
protected $setIdPentityID = null;
/**
* The name of the query parameter which should contain the users choice of IdP.
* This option default to 'entityID' for Shibboleth compatibility.
*
* @var string
*/
protected $returnIdParam;
/**
* The list of scoped idp's. The intersection between the metadata idpList
* and scopedIDPList (given as a $_GET IDPList[] parameter) is presented to
* the user. If the intersection is empty the metadata idpList is used.
*
* @var array
*/
protected $scopedIDPList = array();
/**
* The URL the user should be redirected to after choosing an IdP.
*
* @var string
*/
protected $returnURL;
/**
* Initializes this discovery service.
*
* The constructor does the parsing of the request. If this is an invalid request, it will throw an exception.
*
* @param array $metadataSets Array with metadata sets we find remote entities in.
* @param string $instance The name of this instance of the discovery service.
*
* @throws Exception If the request is invalid.
*/
public function __construct(array $metadataSets, $instance)
{
assert(is_string($instance));
// initialize standard classes
$this->config = \SimpleSAML\Configuration::getInstance();
$this->metadata = \SimpleSAML\Metadata\MetaDataStorageHandler::getMetadataHandler();
$this->session = \SimpleSAML\Session::getSessionFromRequest();
$this->instance = $instance;
$this->metadataSets = $metadataSets;
$this->log('Accessing discovery service.');
// standard discovery service parameters
if (!array_key_exists('entityID', $_GET)) {
throw new \Exception('Missing parameter: entityID');
} else {
$this->spEntityId = $_GET['entityID'];
}
if (!array_key_exists('returnIDParam', $_GET)) {
$this->returnIdParam = 'entityID';
} else {
$this->returnIdParam = $_GET['returnIDParam'];
}
$this->log('returnIdParam initially set to ['.$this->returnIdParam.']');
if (!array_key_exists('return', $_GET)) {
throw new \Exception('Missing parameter: return');
} else {
$this->returnURL = \SimpleSAML\Utils\HTTP::checkURLAllowed($_GET['return']);
}
$this->isPassive = false;
if (array_key_exists('isPassive', $_GET)) {
if ($_GET['isPassive'] === 'true') {
$this->isPassive = true;
}
}
$this->log('isPassive initially set to ['.($this->isPassive ? 'TRUE' : 'FALSE').']');
if (array_key_exists('IdPentityID', $_GET)) {
$this->setIdPentityID = $_GET['IdPentityID'];
}
if (array_key_exists('IDPList', $_REQUEST)) {
$this->scopedIDPList = $_REQUEST['IDPList'];
}
}
/**
* Log a message.
*
* This is an helper function for logging messages. It will prefix the messages with our
* discovery service type.
*
* @param string $message The message which should be logged.
*/
protected function log($message)
{
\SimpleSAML\Logger::info('idpDisco.'.$this->instance.': '.$message);
}
/**
* Retrieve cookie with the given name.
*
* This function will retrieve a cookie with the given name for the current discovery
* service type.
*
* @param string $name The name of the cookie.
*
* @return string The value of the cookie with the given name, or null if no cookie with that name exists.
*/
protected function getCookie($name)
{
$prefixedName = 'idpdisco_'.$this->instance.'_'.$name;
if (array_key_exists($prefixedName, $_COOKIE)) {
return $_COOKIE[$prefixedName];
} else {
return null;
}
}
/**
* Save cookie with the given name and value.
*
* This function will save a cookie with the given name and value for the current discovery
* service type.
*
* @param string $name The name of the cookie.
* @param string $value The value of the cookie.
*/
protected function setCookie($name, $value)
{
$prefixedName = 'idpdisco_'.$this->instance.'_'.$name;
$params = array(
// we save the cookies for 90 days
'lifetime' => (60 * 60 * 24 * 90),
// the base path for cookies. This should be the installation directory for SimpleSAMLphp
'path' => $this->config->getBasePath(),
'httponly' => false,
);
\SimpleSAML\Utils\HTTP::setCookie($prefixedName, $value, $params, false);
}
/**
* Validates the given IdP entity id.
*
* Takes a string with the IdP entity id, and returns the entity id if it is valid, or
* null if not.
*
* @param string|null $idp The entity id we want to validate. This can be null, in which case we will return null.
*
* @return string|null The entity id if it is valid, null if not.
*/
protected function validateIdP($idp)
{
if ($idp === null) {
return null;
}
if (!$this->config->getBoolean('idpdisco.validate', true)) {
return $idp;
}
foreach ($this->metadataSets as $metadataSet) {
try {
$this->metadata->getMetaData($idp, $metadataSet);
return $idp;
} catch (\Exception $e) {
// continue
}
}
$this->log('Unable to validate IdP entity id ['.$idp.'].');
// the entity id wasn't valid
return null;
}
/**
* Retrieve the users choice of IdP.
*
* This function finds out which IdP the user has manually chosen, if any.
*
* @return string The entity id of the IdP the user has chosen, or null if the user has made no choice.
*/
protected function getSelectedIdP()
{
/* Parameter set from the Extended IdP Metadata Discovery Service Protocol, indicating that the user prefers
* this IdP.
*/
if (!empty($this->setIdPentityID)) {
return $this->validateIdP($this->setIdPentityID);
}
// user has clicked on a link, or selected the IdP from a drop-down list
if (array_key_exists('idpentityid', $_GET)) {
return $this->validateIdP($_GET['idpentityid']);
}
/* Search for the IdP selection from the form used by the links view. This form uses a name which equals
* idp_<entityid>, so we search for that.
*
* Unfortunately, php replaces periods in the name with underscores, and there is no reliable way to get them
* back. Therefore we do some quick and dirty parsing of the query string.
*/
$qstr = $_SERVER['QUERY_STRING'];
$matches = array();
if (preg_match('/(?:^|&)idp_([^=]+)=/', $qstr, $matches)) {
return $this->validateIdP(urldecode($matches[1]));
}
// no IdP chosen
return null;
}
/**
* Retrieve the users saved choice of IdP.
*
* @return string The entity id of the IdP the user has saved, or null if the user hasn't saved any choice.
*/
protected function getSavedIdP()
{
if (!$this->config->getBoolean('idpdisco.enableremember', false)) {
// saving of IdP choices is disabled
return null;
}
if ($this->getCookie('remember') === '1') {
$this->log('Return previously saved IdP because of remember cookie set to 1');
return $this->getPreviousIdP();
}
if ($this->isPassive) {
$this->log('Return previously saved IdP because of isPassive');
return $this->getPreviousIdP();
}
return null;
}
/**
* Retrieve the previous IdP the user used.
*
* @return string The entity id of the previous IdP the user used, or null if this is the first time.
*/
protected function getPreviousIdP()
{
return $this->validateIdP($this->getCookie('lastidp'));
}
/**
* Retrieve a recommended IdP based on the IP address of the client.
*
* @return string|null The entity ID of the IdP if one is found, or null if not.
*/
protected function getFromCIDRhint()
{
foreach ($this->metadataSets as $metadataSet) {
$idp = $this->metadata->getPreferredEntityIdFromCIDRhint($metadataSet, $_SERVER['REMOTE_ADDR']);
if (!empty($idp)) {
return $idp;
}
}
return null;
}
/**
* Try to determine which IdP the user should most likely use.
*
* This function will first look at the previous IdP the user has chosen. If the user
* hasn't chosen an IdP before, it will look at the IP address.
*
* @return string The entity id of the IdP the user should most likely use.
*/
protected function getRecommendedIdP()
{
$idp = $this->getPreviousIdP();
if ($idp !== null) {
$this->log('Preferred IdP from previous use ['.$idp.'].');
return $idp;
}
$idp = $this->getFromCIDRhint();
if (!empty($idp)) {
$this->log('Preferred IdP from CIDR hint ['.$idp.'].');
return $idp;
}
return null;
}
/**
* Save the current IdP choice to a cookie.
*
* @param string $idp The entityID of the IdP.
*/
protected function setPreviousIdP($idp)
{
assert(is_string($idp));
$this->log('Choice made ['.$idp.'] Setting cookie.');
$this->setCookie('lastidp', $idp);
}
/**
* Determine whether the choice of IdP should be saved.
*
* @return boolean True if the choice should be saved, false otherwise.
*/
protected function saveIdP()
{
if (!$this->config->getBoolean('idpdisco.enableremember', false)) {
// saving of IdP choices is disabled
return false;
}
if (array_key_exists('remember', $_GET)) {
return true;
}
return false;
}
/**
* Determine which IdP the user should go to, if any.
*
* @return string The entity id of the IdP the user should be sent to, or null if the user should choose.
*/
protected function getTargetIdP()
{
// first, check if the user has chosen an IdP
$idp = $this->getSelectedIdP();
if ($idp !== null) {
// the user selected this IdP. Save the choice in a cookie
$this->setPreviousIdP($idp);
if ($this->saveIdP()) {
$this->setCookie('remember', '1');
} else {
$this->setCookie('remember', '0');
}
return $idp;
}
$this->log('getSelectedIdP() returned null');
// check if the user has saved an choice earlier
$idp = $this->getSavedIdP();
if ($idp !== null) {
$this->log('Using saved choice ['.$idp.'].');
return $idp;
}
// the user has made no choice
return null;
}
/**
* Retrieve the list of IdPs which are stored in the metadata.
*
* @return array An array with entityid => metadata mappings.
*/
protected function getIdPList()
{
$idpList = array();
foreach ($this->metadataSets as $metadataSet) {
$newList = $this->metadata->getList($metadataSet);
/*
* Note that we merge the entities in reverse order. This ensures that it is the entity in the first
* metadata set that "wins" if two metadata sets have the same entity.
*/
$idpList = array_merge($newList, $idpList);
}
return $idpList;
}
/**
* Return the list of scoped idp
*
* @return array An array of IdP entities
*/
protected function getScopedIDPList()
{
return $this->scopedIDPList;
}
/**
* Filter the list of IdPs.
*
* This method returns the IdPs that comply with the following conditions:
* - The IdP does not have the 'hide.from.discovery' configuration option.
*
* @param array $list An associative array containing metadata for the IdPs to apply the filtering to.
*
* @return array An associative array containing metadata for the IdPs that were not filtered out.
*/
protected function filterList($list)
{
foreach ($list as $entity => $metadata) {
if (array_key_exists('hide.from.discovery', $metadata) && $metadata['hide.from.discovery'] === true) {
unset($list[$entity]);
}
}
return $list;
}
/**
* Check if an IdP is set or if the request is passive, and redirect accordingly.
*
* @return void If there is no IdP targeted and this is not a passive request.
*/
protected function start()
{
$idp = $this->getTargetIdp();
if ($idp !== null) {
$extDiscoveryStorage = $this->config->getString('idpdisco.extDiscoveryStorage', null);
if ($extDiscoveryStorage !== null) {
$this->log('Choice made ['.$idp.'] (Forwarding to external discovery storage)');
\SimpleSAML\Utils\HTTP::redirectTrustedURL($extDiscoveryStorage, array(
'entityID' => $this->spEntityId,
'IdPentityID' => $idp,
'returnIDParam' => $this->returnIdParam,
'isPassive' => 'true',
'return' => $this->returnURL
));
} else {
$this->log(
'Choice made ['.$idp.'] (Redirecting the user back. returnIDParam='.$this->returnIdParam.')'
);
\SimpleSAML\Utils\HTTP::redirectTrustedURL($this->returnURL, array($this->returnIdParam => $idp));
}
}
if ($this->isPassive) {
$this->log('Choice not made. (Redirecting the user back without answer)');
\SimpleSAML\Utils\HTTP::redirectTrustedURL($this->returnURL);
}
}
/**
* Handles a request to this discovery service.
*
* The IdP disco parameters should be set before calling this function.
*/
public function handleRequest()
{
$this->start();
// no choice made. Show discovery service page
$idpList = $this->getIdPList();
$idpList = $this->filterList($idpList);
$preferredIdP = $this->getRecommendedIdP();
$idpintersection = array_intersect(array_keys($idpList), $this->getScopedIDPList());
if (sizeof($idpintersection) > 0) {
$idpList = array_intersect_key($idpList, array_fill_keys($idpintersection, null));
}
$idpintersection = array_values($idpintersection);
if (sizeof($idpintersection) == 1) {
$this->log(
'Choice made ['.$idpintersection[0].'] (Redirecting the user back. returnIDParam='.
$this->returnIdParam.')'
);
\SimpleSAML\Utils\HTTP::redirectTrustedURL(
$this->returnURL,
array($this->returnIdParam => $idpintersection[0])
);
}
/*
* Make use of an XHTML template to present the select IdP choice to the user. Currently the supported options
* is either a drop down menu or a list view.
*/
switch ($this->config->getString('idpdisco.layout', 'links')) {
case 'dropdown':
$templateFile = 'selectidp-dropdown.php';
break;
case 'links':
$templateFile = 'selectidp-links.php';
break;
default:
throw new \Exception('Invalid value for the \'idpdisco.layout\' option.');
}
$t = new Template($this->config, $templateFile, 'disco');
$fallbackLanguage = 'en';
$defaultLanguage = $this->config->getString('language.default', $fallbackLanguage);
$translator = $t->getTranslator();
$language = $translator->getLanguage()->getLanguage();
$tryLanguages = [0 => $language, 1 => $defaultLanguage, 2 => $fallbackLanguage];
$newlist = [];
foreach($idpList as $entityid => $data) {
$newlist[$entityid]['entityid'] = $entityid;
foreach ( $tryLanguages as $lang ) {
if ( $name = $this->getEntityDisplayName($data, $lang) ) {
$newlist[$entityid]['name'] = $name;
continue;
}
}
if ( empty($newlist[$entityid]['name']) ) {
$newlist[$entityid]['name'] = $entityid;
}
foreach ( $tryLanguages as $lang ) {
if ( !empty($data['description'][$lang]) ) {
$newlist[$entityid]['description'] = $data['description'][$lang];
continue;
}
}
if ( !empty($data['icon']) ) {
$newlist[$entityid]['icon'] = $data['icon'];
$newlist[$entityid]['iconurl'] = \SimpleSAML\Utils\HTTP::resolveURL($data['icon']);
}
}
usort($newlist, function($idpentry1, $idpentry2) {
return strcasecmp($idpentry1['name'],$idpentry2['name']);
});
$t->data['idplist'] = $newlist;
$t->data['preferredidp'] = $preferredIdP;
$t->data['return'] = $this->returnURL;
$t->data['returnIDParam'] = $this->returnIdParam;
$t->data['entityID'] = $this->spEntityId;
$t->data['urlpattern'] = htmlspecialchars(\SimpleSAML\Utils\HTTP::getSelfURLNoQuery());
$t->data['rememberenabled'] = $this->config->getBoolean('idpdisco.enableremember', false);
$t->show();
}
private function getEntityDisplayName(array $idpData, $language)
{
if(isset($idpData['UIInfo']['DisplayName'][$language]) ) {
return $idpData['UIInfo']['DisplayName'][$language];
} elseif ( isset($idpData['name'][$language]) ) {
return $idpData['name'][$language];
} elseif ( isset($idpData['OrganizationDisplayName'][$language]) ) {
return $idpData['OrganizationDisplayName'][$language];
}
return null;
}
}