<?php
/**
* This class implements the dynamic SAML profile, where the entityID equals a URL where
* metadata is located. The XML files should be in the SAML 2.0 metadata format.
*
* @author Andreas Åkre Solberg, UNINETT AS.
* @author Olav Morken, UNINETT AS.
* @package simpleSAMLphp
*/
class SimpleSAML_Metadata_MetaDataStorageHandlerDynamicXML extends SimpleSAML_Metadata_MetaDataStorageSource {
/**
* The cache directory, or NULL if no cache directory is configured.
*/
private $cacheDir;
/**
* The maximum cache length, in seconds.
*/
private $cacheLength;
/**
* This function initializes the dynamic XML metadata source.
*
* Options:
* - '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 $config The configuration for this instance of the XML metadata source.
*/
protected function __construct($config) {
assert('is_array($config)');
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 returns an associative array with metadata for all entities in the given set. The
* key of the array is the entity id.
*
* @param $set The set we want to list metadata for.
* @return An associative array with all entities in the given set.
*/
public function getMetadataSet($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);
$globalConfig = SimpleSAML_Configuration::getInstance();
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 $entityId The entity id of this entity.
* @return array|NULL The associative array with the metadata for this entity, or NULL
* if the entity could not be found.
*/
private function getFromCache($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('Could not read cache file for entity [' . $cachefilename. ']');
SimpleSAML_Logger::debug('MetaData - Handler.DynamicXML: 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()) {
SimpleSAML_Logger::debug('MetaData - Handler.DynamicXML: Cache file older that the cachelength option allows.');
return NULL;
}
$rawData = file_get_contents($cachefilename);
if (empty($rawData)) {
throw new Exception('Error reading metadata from cache file "' . $cachefilename . '": ' .
SimpleSAML_Utilities::getLastError());
}
$data = unserialize($rawData);
if ($data === FALSE) {
throw new Exception('Error deserializing cached data from file "' . $cachefilename .'".');
}
if (!is_array($data)) {
throw new Exception('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 $data The associative array with the metadata for this entity.
*/
private function writeToCache($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('Could not write cache file for entity [' . $cachefilename. ']');
SimpleSAML_Logger::debug('MetaData - Handler.DynamicXML: 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();
default:
SimpleSAML_Logger::warning('MetaData - Handler.DynamicXML: 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 $index The entityId or metaindex we are looking up.
* @param $set The set we are looking for metadata in.
* @return An associative array with metadata for the given entity, or NULL if we are unable to
* locate the entity.
*/
public function getMetaData($index, $set) {
assert('is_string($index)');
assert('is_string($set)');
if (!preg_match('@(https?://([-\w\.]+)+(:\d+)?(/([\w/_\.]*(\?\S+)?)?)?)@', $index)) {
SimpleSAML_Logger::info('MetaData - Handler.DynamicXML: EntityID/index [' . $index . '] does not look like a URL. Skipping.' );
return NULL;
}
SimpleSAML_Logger::info('MetaData - Handler.DynamicXML: Loading metadata entity [' . $index . '] from [' . $set . ']' );
/* Read from cache if possible. */
$data = $this->getFromCache($set, $index);
if ($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. */
SimpleSAML_Logger::debug('MetaData - Handler.DynamicXML: Using cached metadata.');
return $data;
}
SimpleSAML_Logger::debug('MetaData - Handler.DynamicXML: Downloading [' . $index . ']' );
$xmldata = file_get_contents($index);
if (empty($xmldata)) {
throw new Exception('Error downloading metadata from "' . $index . '": ' .
SimpleSAML_Utilities::getLastError());
}
$entities = SimpleSAML_Metadata_SAMLParser::parseDescriptorsString($xmldata);
SimpleSAML_Logger::debug('MetaData - Handler.DynamicXML: Completed parsing of [' .
$index . '] Found [' . count($entities). '] entries.' );
if (count($entities) === 0) {
throw new Exception('No entities found in "' . $index . '".');
}
if (!array_key_exists($index, $entities)) {
throw new Exception ('No entity with correct entity id found in "' . $index . '".');
}
$entity = $entities[$index];
$data = self::getParsedSet($entity, $set);
if ($data === NULL) {
throw new Exception('No metadata for set "' . $set .
'" available from "' . $index . '".');
}
$this->writeToCache($set, $index, $data);
return $data;
}
}
?>