Adding support for dynamically loading metadata from entity IDs and cache them

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@532 44740490-163a-0410-bde0-09ae8108e29a

lib/SimpleSAML/Metadata/MetaDataStorageHandlerDynamicXML.php

+<?php
+
+require_once((isset($SIMPLESAML_INCPREFIX)?$SIMPLESAML_INCPREFIX:'') . 'SimpleSAML/Configuration.php');
+require_once((isset($SIMPLESAML_INCPREFIX)?$SIMPLESAML_INCPREFIX:'') . 'SimpleSAML/Metadata/MetaDataStorageSource.php');
+require_once((isset($SIMPLESAML_INCPREFIX)?$SIMPLESAML_INCPREFIX:'') . 'SimpleSAML/Metadata/SAMLParser.php');
+require_once((isset($SIMPLESAML_INCPREFIX)?$SIMPLESAML_INCPREFIX:'') . 'SimpleSAML/Logger.php');
+
+/**
+ * This class implements the dynamic SAML profile, where the entityID equals an 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
+ * @version $Id$
+ */
+class SimpleSAML_Metadata_MetaDataStorageHandlerDynamicXML extends SimpleSAML_Metadata_MetaDataStorageSource {
+
+	/**
+	 * This variable contains an associative array with the parsed metadata.
+	 */
+	private $metadata;
+	private $config;
+
+	/**
+	 * This function initializes the XML metadata source. The configuration must contain one of
+	 * the following options:
+	 * - 'file': Path to a file with the metadata. This path is relative to the simpleSAMLphp
+	 *           base directory.
+	 * - 'url': URL we should download the metadata from. This is only meant for testing.
+	 *
+	 * @param $config  The configuration for this instance of the XML metadata source.
+	 */
+	protected function __construct($config) {
+
+		$this->config = $config;
+	
+		/* Get the configuration. 
+		$globalConfig = SimpleSAML_Configuration::getInstance();
+
+		if(array_key_exists('cache', $config)) {
+			$src = $globalConfig->resolvePath($config['file']);
+		} elseif(array_key_exists('url', $config)) {
+			$src = $config['url'];
+		} else {
+			throw new Exception('Missing either \'file\' or \'url\' in XML metadata source configuration.');
+		}
+
+
+		$SP1x = array();
+		$IdP1x = array();
+		$SP20 = array();
+		$IdP20 = array();
+
+		$entities = SimpleSAML_Metadata_SAMLParser::parseDescriptorsFile($src);
+		foreach($entities as $entityId => $entity) {
+
+			$md = $entity->getMetadata1xSP();
+			if($md !== NULL) {
+				$SP1x[$entityId] = $md;
+			}
+
+			$md = $entity->getMetadata1xIdP();
+			if($md !== NULL) {
+				$IdP1x[$entityId] = $md;
+			}
+
+			$md = $entity->getMetadata20SP();
+			if($md !== NULL) {
+				$SP20[$entityId] = $md;
+			}
+
+			$md = $entity->getMetadata20IdP();
+			if($md !== NULL) {
+				$IdP20[$entityId] = $md;
+			}
+
+		}
+
+		$this->metadata = array(
+			'shib13-sp-remote' => $SP1x,
+			'shib13-idp-remote' => $IdP1x,
+			'saml20-sp-remote' => $SP20,
+			'saml20-idp-remote' => $IdP20,
+			);
+		*/
+
+	}
+
+
+	/**
+	 * 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) {
+		/*
+		if(array_key_exists($set, $this->metadata)) {
+			return $this->metadata[$set];
+		}
+		*/
+
+		/* We don't have this metadata set. */
+		return array();
+	}
+	
+	
+	private function getCacheFilename($entityId) {
+		$cachekey = sha1($entityId);
+		$globalConfig = SimpleSAML_Configuration::getInstance();
+		return $globalConfig->resolvePath($this->config['cachedir']) . '/' . $cachekey . '.cached.xml';
+	}
+	
+	
+	private function getFromCache($entityId) {
+		$cachefilename = $this->getCacheFilename($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 . '] => [' . $cachefilename . ']' );
+		return file_get_contents($cachefilename);		
+	}
+	
+	private function writeToCache($entityId, $xmldata) {
+		$cachefilename = $this->getCacheFilename($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, $xmldata);
+	}
+	
+	
+	/**
+	 * 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) {
+		
+		
+		SimpleSAML_Logger::info('MetaData - Handler.DynamicXML: Loading metadata entity [' . $index . '] from [' . $set . ']' );
+
+		
+		/* Get the configuration. */
+		$globalConfig = SimpleSAML_Configuration::getInstance();
+
+		if (!preg_match('@(https?://([-\w\.]+)+(:\d+)?(/([\w/_\.]*(\?\S+)?)?)?)@', $index)) {
+			SimpleSAML_Logger::info('MetaData - Handler.DynamicXML: EntityID/index [' . $index . '] does not look like an URL. Skipping.' );
+			return NULL;
+		}
+
+		$xmldata = NULL;
+
+		/**
+		 * Read from cache if cache is defined.
+		 */
+		if (!empty($this->config['cachedir'])) {
+			$xmldata = $this->getFromCache($index);
+		}
+
+		if (empty($xmldata)) {
+			$xmldata = file_get_contents($index);
+		
+			if (!empty($this->config['cachedir'])) {
+				$this->writeToCache($index, $xmldata);
+			}
+		}
+
+		
+		$entities = SimpleSAML_Metadata_SAMLParser::parseDescriptorsString($xmldata);
+
+
+		SimpleSAML_Logger::debug('MetaData - Handler.DynamicXML: Completed parsing of [' . $index . '] Found [' . count($entities). '] entries.' );
+
+		foreach($entities as $entityId => $entity) {
+
+			SimpleSAML_Logger::debug('MetaData - Handler.DynamicXML: Looking for [' . $index . '] found [' . $entityId . '] entries.' );
+		
+			switch($set) {
+				case 'saml20-idp-remote' : 
+					$md = $entity->getMetadata20IdP();
+					if ($md !== NULL) return $md;
+					break;
+
+				case 'saml20-sp-remote' : 
+					$md = $entity->getMetadata20SP();
+					if ($md !== NULL) return $md;
+					break;
+
+				case 'shib13-idp-remote' : 
+					$md = $entity->getMetadata1xIdP();
+					if ($md !== NULL) return $md;
+					break;
+
+				case 'shib13-sp-remote' : 
+					$md = $entity->getMetadata1xSP();
+					if ($md !== NULL) return $md;
+					break;
+					
+			}
+
+
+		}
+		
+		return NULL;
+		
+	}
+	
+	
+}
+
+?>
\ No newline at end of file

lib/SimpleSAML/Metadata/MetaDataStorageSource.php

@@ -2,6 +2,7 @@
 
 require_once((isset($SIMPLESAML_INCPREFIX)?$SIMPLESAML_INCPREFIX:'') . 'SimpleSAML/Metadata/MetaDataStorageHandlerFlatfile.php');
 require_once((isset($SIMPLESAML_INCPREFIX)?$SIMPLESAML_INCPREFIX:'') . 'SimpleSAML/Metadata/MetaDataStorageHandlerXML.php');
+require_once((isset($SIMPLESAML_INCPREFIX)?$SIMPLESAML_INCPREFIX:'') . 'SimpleSAML/Metadata/MetaDataStorageHandlerDynamicXML.php');
 
 /**
  * This abstract class defines an interface for metadata storage sources.
@@ -41,6 +42,8 @@ abstract class SimpleSAML_Metadata_MetaDataStorageSource {
 			return new SimpleSAML_Metadata_MetaDataStorageHandlerFlatFile($sourceConfig);
 		case 'xml':
 			return new SimpleSAML_Metadata_MetaDataStorageHandlerXML($sourceConfig);
+		case 'dynamicxml':
+			return new SimpleSAML_Metadata_MetaDataStorageHandlerDynamicXML($sourceConfig);
 		default:
 			throw new Exception('Invalid metadata source type: "' . $type . '".');
 		}