Files
2019-04-29 16:09:00 +02:00

338 lines
11 KiB
PHP
Executable File

<?php
namespace SimpleSAML\Metadata\Sources;
use SimpleSAML\Logger;
use SimpleSAML\Utils\HTTP;
/**
* This class implements SAML Metadata Query Protocol
*
* @author Andreas Åkre Solberg, UNINETT AS.
* @author Olav Morken, UNINETT AS.
* @author Tamas Frank, NIIFI
* @package SimpleSAMLphp
*/
class MDQ extends \SimpleSAML_Metadata_MetaDataStorageSource
{
/**
* The URL of MDQ server (url:port)
*
* @var string
*/
private $server;
/**
* The fingerprint of the certificate used to sign the metadata. You don't need this option if you don't want to
* validate the signature on the metadata.
*
* @var string|null
*/
private $validateFingerprint;
/**
* The cache directory, or null if no cache directory is configured.
*
* @var string|null
*/
private $cacheDir;
/**
* The maximum cache length, in seconds.
*
* @var integer
*/
private $cacheLength;
/**
* This function initializes the dynamic XML metadata source.
*
* Options:
* - 'server': URL of the MDQ server (url:port). Mandatory.
* - 'validateFingerprint': The fingerprint of the certificate used to sign the metadata.
* You don't need this option if you don't want to validate the signature on the metadata.
* Optional.
* - 'cachedir': Directory where metadata can be cached. Optional.
* - 'cachelength': Maximum time metadata cah be cached, in seconds. Default to 24
* hours (86400 seconds).
*
* @param array $config The configuration for this instance of the XML metadata source.
*
* @throws \Exception If no server option can be found in the configuration.
*/
protected function __construct($config)
{
assert(is_array($config));
if (!array_key_exists('server', $config)) {
throw new \Exception(__CLASS__.": the 'server' configuration option is not set.");
} else {
$this->server = $config['server'];
}
if (array_key_exists('validateFingerprint', $config)) {
$this->validateFingerprint = $config['validateFingerprint'];
} else {
$this->validateFingerprint = null;
}
if (array_key_exists('cachedir', $config)) {
$globalConfig = \SimpleSAML_Configuration::getInstance();
$this->cacheDir = $globalConfig->resolvePath($config['cachedir']);
} else {
$this->cacheDir = null;
}
if (array_key_exists('cachelength', $config)) {
$this->cacheLength = $config['cachelength'];
} else {
$this->cacheLength = 86400;
}
}
/**
* This function is not implemented.
*
* @param string $set The set we want to list metadata for.
*
* @return array An empty array.
*/
public function getMetadataSet($set)
{
// we don't have this metadata set
return array();
}
/**
* Find the cache file name for an entity,
*
* @param string $set The metadata set this entity belongs to.
* @param string $entityId The entity id of this entity.
*
* @return string The full path to the cache file.
*/
private function getCacheFilename($set, $entityId)
{
assert(is_string($set));
assert(is_string($entityId));
$cachekey = sha1($entityId);
return $this->cacheDir.'/'.$set.'-'.$cachekey.'.cached.xml';
}
/**
* Load a entity from the cache.
*
* @param string $set The metadata set this entity belongs to.
* @param string $entityId The entity id of this entity.
*
* @return array|NULL The associative array with the metadata for this entity, or NULL
* if the entity could not be found.
* @throws \Exception If an error occurs while loading metadata from cache.
*/
private function getFromCache($set, $entityId)
{
assert(is_string($set));
assert(is_string($entityId));
if (empty($this->cacheDir)) {
return null;
}
$cachefilename = $this->getCacheFilename($set, $entityId);
if (!file_exists($cachefilename)) {
return null;
}
if (!is_readable($cachefilename)) {
throw new \Exception(__CLASS__.': could not read cache file for entity ['.$cachefilename.']');
}
Logger::debug(__CLASS__.': reading cache ['.$entityId.'] => ['.$cachefilename.']');
/* Ensure that this metadata isn't older that the cachelength option allows. This
* must be verified based on the file, since this option may be changed after the
* file is written.
*/
$stat = stat($cachefilename);
if ($stat['mtime'] + $this->cacheLength <= time()) {
Logger::debug(__CLASS__.': cache file older that the cachelength option allows.');
return null;
}
$rawData = file_get_contents($cachefilename);
if (empty($rawData)) {
$error = error_get_last();
throw new \Exception(
__CLASS__.': error reading metadata from cache file "'.$cachefilename.'": '.$error['message']
);
}
$data = unserialize($rawData);
if ($data === false) {
throw new \Exception(__CLASS__.': error unserializing cached data from file "'.$cachefilename.'".');
}
if (!is_array($data)) {
throw new \Exception(__CLASS__.': Cached metadata from "'.$cachefilename.'" wasn\'t an array.');
}
return $data;
}
/**
* Save a entity to the cache.
*
* @param string $set The metadata set this entity belongs to.
* @param string $entityId The entity id of this entity.
* @param array $data The associative array with the metadata for this entity.
*
* @throws \Exception If metadata cannot be written to cache.
*/
private function writeToCache($set, $entityId, $data)
{
assert(is_string($set));
assert(is_string($entityId));
assert(is_array($data));
if (empty($this->cacheDir)) {
return;
}
$cachefilename = $this->getCacheFilename($set, $entityId);
if (!is_writable(dirname($cachefilename))) {
throw new \Exception(__CLASS__.': could not write cache file for entity ['.$cachefilename.']');
}
Logger::debug(__CLASS__.': Writing cache ['.$entityId.'] => ['.$cachefilename.']');
file_put_contents($cachefilename, serialize($data));
}
/**
* Retrieve metadata for the correct set from a SAML2Parser.
*
* @param \SimpleSAML_Metadata_SAMLParser $entity A SAML2Parser representing an entity.
* @param string $set The metadata set we are looking for.
*
* @return array|NULL The associative array with the metadata, or NULL if no metadata for
* the given set was found.
*/
private static function getParsedSet(\SimpleSAML_Metadata_SAMLParser $entity, $set)
{
assert(is_string($set));
switch ($set) {
case 'saml20-idp-remote':
return $entity->getMetadata20IdP();
case 'saml20-sp-remote':
return $entity->getMetadata20SP();
case 'shib13-idp-remote':
return $entity->getMetadata1xIdP();
case 'shib13-sp-remote':
return $entity->getMetadata1xSP();
case 'attributeauthority-remote':
$ret = $entity->getAttributeAuthorities();
return $ret[0];
default:
Logger::warning(__CLASS__.': unknown metadata set: \''.$set.'\'.');
}
return null;
}
/**
* Overriding this function from the superclass SimpleSAML_Metadata_MetaDataStorageSource.
*
* This function retrieves metadata for the given entity id in the given set of metadata.
* It will return NULL if it is unable to locate the metadata.
*
* This class implements this function using the getMetadataSet-function. A subclass should
* override this function if it doesn't implement the getMetadataSet function, or if the
* implementation of getMetadataSet is slow.
*
* @param string $index The entityId or metaindex we are looking up.
* @param string $set The set we are looking for metadata in.
*
* @return array An associative array with metadata for the given entity, or NULL if we are unable to
* locate the entity.
* @throws \Exception If an error occurs while validating the signature or the metadata is in an
* incorrect set.
*/
public function getMetaData($index, $set)
{
assert(is_string($index));
assert(is_string($set));
Logger::info(__CLASS__.': loading metadata entity ['.$index.'] from ['.$set.']');
// read from cache if possible
try {
$data = $this->getFromCache($set, $index);
} catch (\Exception $e) {
Logger::error($e->getMessage());
// proceed with fetching metadata even if the cache is broken
$data = null;
}
if ($data !== null && array_key_exists('expires', $data) && $data['expires'] < time()) {
// metadata has expired
$data = null;
}
if (isset($data)) {
// metadata found in cache and not expired
Logger::debug(__CLASS__.': using cached metadata for: '.$index.'.');
return $data;
}
// look at Metadata Query Protocol: https://github.com/iay/md-query/blob/master/draft-young-md-query.txt
$mdq_url = $this->server.'/entities/'.urlencode($index);
Logger::debug(__CLASS__.': downloading metadata for "'.$index.'" from ['.$mdq_url.']');
try {
$xmldata = HTTP::fetch($mdq_url);
} catch (\Exception $e) {
// Avoid propagating the exception, make sure we can handle the error later
$xmldata = false;
}
if (empty($xmldata)) {
$error = error_get_last();
Logger::info('Unable to fetch metadata for "'.$index.'" from '.$mdq_url.': '.
(is_array($error) ? $error['message'] : 'no error available'));
return null;
}
/** @var string $xmldata */
$entity = \SimpleSAML_Metadata_SAMLParser::parseString($xmldata);
Logger::debug(__CLASS__.': completed parsing of ['.$mdq_url.']');
if ($this->validateFingerprint !== null) {
if (!$entity->validateFingerprint($this->validateFingerprint)) {
throw new \Exception(__CLASS__.': error, could not verify signature for entity: '.$index.'".');
}
}
$data = self::getParsedSet($entity, $set);
if ($data === null) {
throw new \Exception(__CLASS__.': no metadata for set "'.$set.'" available from "'.$index.'".');
}
try {
$this->writeToCache($set, $index, $data);
} catch (\Exception $e) {
// Proceed without writing to cache
Logger::error('Error writing MDQ result to cache: '.$e->getMessage());
}
return $data;
}
}