MetaLoader.php

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<?php
class sspmod_metarefresh_MetaLoader
{
    private $expire;
    private $metadata;
    private $oldMetadataSrc;
    private $stateFile;
    private $changed;
    private $state;
    private $types = array(
        'saml20-idp-remote',
        'saml20-sp-remote',
        'shib13-idp-remote',
        'shib13-sp-remote',
        'attributeauthority-remote'
    );


    public function __construct($expire = null, $stateFile = null, $oldMetadataSrc = null)
    {
        $this->expire = $expire;
        $this->metadata = array();
        $this->oldMetadataSrc = $oldMetadataSrc;
        $this->stateFile = $stateFile;
        $this->changed = false;

        // Read file containing $state from disk
        if (is_readable($stateFile)) {
            include $stateFile;
        }

        $this->state = array();

    }


    public function getTypes()
    {
        return $this->types;
    }


    public function setTypes($types)
    {
        if (!is_array($types)) {
            $types = array($types);
        }
        $this->types = $types;
    }


    public function loadSource($source)
    {
        if (preg_match('@^https?://@i', $source['src'])) {
            // Build new HTTP context
            $context = $this->createContext($source);

            // GET!
            try {
                list($data, $responseHeaders) = \SimpleSAML\Utils\HTTP::fetch($source['src'], $context, true);
            } catch(Exception $e) {
                SimpleSAML\Logger::warning('metarefresh: ' . $e->getMessage());
            }

            // We have response headers, so the request succeeded
            if (!isset($responseHeaders)) {
                // No response headers, this means the request failed in some way, so re-use old data
                SimpleSAML\Logger::debug('No response from ' . $source['src'] . ' - attempting to re-use cached metadata');
                $this->addCachedMetadata($source);
                return;
            } elseif (preg_match('@^HTTP/1\.[01]\s304\s@', $responseHeaders[0])) {
                // 304 response
                SimpleSAML\Logger::debug('Received HTTP 304 (Not Modified) - attempting to re-use cached metadata');
                $this->addCachedMetadata($source);
                return;
            } elseif (!preg_match('@^HTTP/1\.[01]\s200\s@', $responseHeaders[0])) {
                // Other error
                SimpleSAML\Logger::debug('Error from ' . $source['src'] . ' - attempting to re-use cached metadata');
                $this->addCachedMetadata($source);
                return;
            }
        } else {
            // Local file.
            $data = file_get_contents($source['src']);
            $responseHeaders = null;
        }

        // Everything OK. Proceed.
        if (isset($source['conditionalGET']) && $source['conditionalGET']) {
            // Stale or no metadata, so a fresh copy
            SimpleSAML\Logger::debug('Downloaded fresh copy');
        }

        try {
            $entities = $this->loadXML($data, $source);
        } catch(Exception $e) {
            SimpleSAML\Logger::debug('XML parser error when parsing ' . $source['src'] . ' - attempting to re-use cached metadata');
            SimpleSAML\Logger::debug('XML parser returned: ' . $e->getMessage());
            $this->addCachedMetadata($source);
            return;
        }

        foreach ($entities as $entity) {

            if (isset($source['blacklist'])) {
                if (!empty($source['blacklist']) && in_array($entity->getEntityID(), $source['blacklist'], true)) {
                    SimpleSAML\Logger::info('Skipping "' .  $entity->getEntityID() . '" - blacklisted.' . "\n");
                    continue;
                }
            }

            if (isset($source['whitelist'])) {
                if (!empty($source['whitelist']) && !in_array($entity->getEntityID(), $source['whitelist'], true)) {
                    SimpleSAML\Logger::info('Skipping "' .  $entity->getEntityID() . '" - not in the whitelist.' . "\n");
                    continue;
                }
            }

            if (array_key_exists('certificates', $source) && $source['certificates'] !== null) {
                if (!$entity->validateSignature($source['certificates'])) {
                    SimpleSAML\Logger::info('Skipping "' . $entity->getEntityId() . '" - could not verify signature using certificate.' . "\n");
                    continue;
                }
            }

            if (array_key_exists('validateFingerprint', $source) && $source['validateFingerprint'] !== null) {
                if (!array_key_exists('certificates', $source) || $source['certificates'] == null) {
                    if (!$entity->validateFingerprint($source['validateFingerprint'])) {
                        SimpleSAML\Logger::info('Skipping "' . $entity->getEntityId() . '" - could not verify signature using fingerprint.' . "\n");
                        continue;
                    }
                } else {
                    SimpleSAML\Logger::info('Skipping validation with fingerprint since option certificate is set.' . "\n");
                }
            }

            $template = null;
            if (array_key_exists('template', $source)) {
                $template = $source['template'];
            }

            if (in_array('shib13-sp-remote', $this->types, true)) {
                $this->addMetadata($source['src'], $entity->getMetadata1xSP(), 'shib13-sp-remote', $template);
            }
            if (in_array('shib13-idp-remote', $this->types, true)) {
                $this->addMetadata($source['src'], $entity->getMetadata1xIdP(), 'shib13-idp-remote', $template);
            }
            if (in_array('saml20-sp-remote', $this->types, true)) {
                $this->addMetadata($source['src'], $entity->getMetadata20SP(), 'saml20-sp-remote', $template);
            }
            if (in_array('saml20-idp-remote', $this->types, true)) {
                $this->addMetadata($source['src'], $entity->getMetadata20IdP(), 'saml20-idp-remote', $template);
            }
            if (in_array('attributeauthority-remote', $this->types, true)) {
                $attributeAuthorities = $entity->getAttributeAuthorities();
                if (!empty($attributeAuthorities)) {
                     $this->addMetadata($source['src'], $attributeAuthorities[0], 'attributeauthority-remote', $template);
                }
            }
        }

        $this->saveState($source, $responseHeaders);
    }

    private function createContext($source)
    {
        $config = SimpleSAML_Configuration::getInstance();
        $name = $config->getString('technicalcontact_name', null);
        $mail = $config->getString('technicalcontact_email', null);

        $rawheader = "User-Agent: SimpleSAMLphp metarefresh, run by $name <$mail>\r\n";

        if (isset($source['conditionalGET']) && $source['conditionalGET']) {
            if (array_key_exists($source['src'], $this->state)) {
                $sourceState = $this->state[$source['src']];

                if (isset($sourceState['last-modified'])) {
                    $rawheader .= 'If-Modified-Since: ' . $sourceState['last-modified'] . "\r\n";
                }

                if (isset($sourceState['etag'])) {
                    $rawheader .= 'If-None-Match: ' . $sourceState['etag'] . "\r\n";
                }
            }
        }

        return array('http' => array('header' => $rawheader));
    }


    private function addCachedMetadata($source)
    {
        if (isset($this->oldMetadataSrc)) {
            foreach ($this->types as $type) {
                foreach ($this->oldMetadataSrc->getMetadataSet($type) as $entity) {
                    if (array_key_exists('metarefresh:src', $entity)) {
                        if ($entity['metarefresh:src'] == $source['src']) {
                            $this->addMetadata($source['src'], $entity, $type);
                        }
                    }
                }
            }
        }
    }


    private function saveState($source, $responseHeaders)
    {
        if (isset($source['conditionalGET']) && $source['conditionalGET']) {
            // Headers section
            if ($responseHeaders !== null) {
                $candidates = array('last-modified', 'etag');

                foreach ($candidates as $candidate) {
                    if (array_key_exists($candidate, $responseHeaders)) {
                        $this->state[$source['src']][$candidate] = $responseHeaders[$candidate];
                    }
                }
            }

            if (!empty($this->state[$source['src']])) {
                // Timestamp when this src was requested.
                $this->state[$source['src']]['requested_at'] = $this->getTime();
                $this->changed = true;
            }
        }
    }

    private function loadXML($data, $source)
    {
        try {
            $doc = \SAML2\DOMDocumentFactory::fromString($data);
        } catch (Exception $e) {
            throw new Exception('Failed to read XML from ' . $source['src']);
        }
        if ($doc->documentElement === null) {
            throw new Exception('Opened file is not an XML document: ' . $source['src']);
        }
        return SimpleSAML_Metadata_SAMLParser::parseDescriptorsElement($doc->documentElement);
    }


    public function writeState()
    {
        if ($this->changed) {
            SimpleSAML\Logger::debug('Writing: ' . $this->stateFile);
            SimpleSAML\Utils\System::writeFile(
                $this->stateFile,
                "<?php\n/* This file was generated by the metarefresh module at ".$this->getTime() . ".\n".
                " Do not update it manually as it will get overwritten. */\n".
                '$state = ' . var_export($this->state, true) . ";\n?>\n",
                0644
            );
        }
    }


    public function dumpMetadataStdOut()
    {
        foreach ($this->metadata as $category => $elements) {

            echo '/* The following data should be added to metadata/' . $category . '.php. */' . "\n";

            foreach ($elements as $m) {
                $filename = $m['filename'];
                $entityID = $m['metadata']['entityid'];

                echo "\n";
                echo '/* The following metadata was generated from ' . $filename . ' on ' . $this->getTime() . '. */' . "\n";
                echo '$metadata[\'' . addslashes($entityID) . '\'] = ' . var_export($m['metadata'], true) . ';' . "\n";
            }

            echo "\n";
            echo '/* End of data which should be added to metadata/' . $category . '.php. */' . "\n";
            echo "\n";
        }
    }


    private function addMetadata($filename, $metadata, $type, $template = null)
    {
        if ($metadata === null) {
            return;
        }

        if (isset($template)) {
            $metadata = array_merge($metadata, $template);
        }

        $metadata['metarefresh:src'] = $filename;
        if (!array_key_exists($type, $this->metadata)) {
            $this->metadata[$type] = array();
        }

        // If expire is defined in constructor...
        if (!empty($this->expire)) {
            // If expire is already in metadata
            if (array_key_exists('expire', $metadata)) {
                // Override metadata expire with more restrictive global config-
                if ($this->expire < $metadata['expire']) {
                    $metadata['expire'] = $this->expire;
                }

                // If expire is not already in metadata use global config
            } else {
                $metadata['expire'] = $this->expire;
            }
        }
        $this->metadata[$type][] = array('filename' => $filename, 'metadata' => $metadata);
    }


    public function writeARPfile($config)
    {
        assert($config instanceof SimpleSAML_Configuration);

        $arpfile = $config->getValue('arpfile');
        $types = array('saml20-sp-remote');

        $md = array();
        foreach ($this->metadata as $category => $elements) {
            if (!in_array($category, $types, true)) {
                continue;
            }
            $md = array_merge($md, $elements);
        }

        // $metadata, $attributemap, $prefix, $suffix
        $arp = new sspmod_metarefresh_ARP($md,
            $config->getValue('attributemap', ''),
            $config->getValue('prefix', ''),
            $config->getValue('suffix', '')
        );


        $arpxml = $arp->getXML();

        SimpleSAML\Logger::info('Writing ARP file: ' . $arpfile . "\n");
        file_put_contents($arpfile, $arpxml);
    }


    public function writeMetadataFiles($outputDir)
    {
        while (strlen($outputDir) > 0 && $outputDir[strlen($outputDir) - 1] === '/') {
            $outputDir = substr($outputDir, 0, strlen($outputDir) - 1);
        }

        if (!file_exists($outputDir)) {
            SimpleSAML\Logger::info('Creating directory: ' . $outputDir . "\n");
            $res = @mkdir($outputDir, 0777, true);
            if ($res === false) {
                throw new Exception('Error creating directory: ' . $outputDir);
            }
        }

        foreach ($this->types as $type) {
            $filename = $outputDir . '/' . $type . '.php';

            if (array_key_exists($type, $this->metadata)) {
                $elements = $this->metadata[$type];
                SimpleSAML\Logger::debug('Writing: ' . $filename);

                $content  = '<?php' . "\n" . '/* This file was generated by the metarefresh module at '. $this->getTime() . "\n";
                $content .= ' Do not update it manually as it will get overwritten' . "\n" . '*/' . "\n";

                foreach ($elements as $m) {
                    $entityID = $m['metadata']['entityid'];
                    $content .= "\n";
                    $content .= '$metadata[\'' . addslashes($entityID) . '\'] = ' . var_export($m['metadata'], true) . ';' . "\n";
                }

                $content .= "\n" . '?>';

                SimpleSAML\Utils\System::writeFile($filename, $content, 0644);
            } elseif (is_file($filename)) {
                if (unlink($filename)) {
                    SimpleSAML\Logger::debug('Deleting stale metadata file: ' . $filename);
                } else {
                    SimpleSAML\Logger::warning('Could not delete stale metadata file: ' . $filename);
                }
            }
        }
    }


    public function writeMetadataSerialize($outputDir)
    {
        assert(is_string($outputDir));

        $metaHandler = new SimpleSAML_Metadata_MetaDataStorageHandlerSerialize(array('directory' => $outputDir));

        /* First we add all the metadata entries to the metadata handler. */
        foreach ($this->metadata as $set => $elements) {
            foreach ($elements as $m) {
                $entityId = $m['metadata']['entityid'];

                SimpleSAML\Logger::debug(
                    'metarefresh: Add metadata entry ' .
                    var_export($entityId, true) . ' in set ' . var_export($set, true) . '.'
                );
                $metaHandler->saveMetadata($entityId, $set, $m['metadata']);
            }
        }

        /* Then we delete old entries which should no longer exist. */
        $ct = time();
        foreach ($metaHandler->getMetadataSets() as $set) {
            foreach ($metaHandler->getMetadataSet($set) as $entityId => $metadata) {
                if (!array_key_exists('expire', $metadata)) {
                    SimpleSAML\Logger::warning(
                        'metarefresh: Metadata entry without expire timestamp: ' . var_export($entityId, true) .
                        ' in set ' . var_export($set, true) . '.'
                    );
                    continue;
                }
                if ($metadata['expire'] > $ct) {
                    continue;
                }
                SimpleSAML\Logger::debug('metarefresh: ' . $entityId . ' expired ' . date('l jS \of F Y h:i:s A', $metadata['expire']));
                SimpleSAML\Logger::debug(
                    'metarefresh: Delete expired metadata entry ' .
                    var_export($entityId, true) . ' in set ' . var_export($set, true) . '. (' . ($ct - $metadata['expire']) . ' sec)'
                );
                $metaHandler->deleteMetadata($entityId, $set);
            }
        }
    }


    private function getTime()
    {
        /* The current date, as a string. */
        date_default_timezone_set('UTC');
        return date('Y-m-d\\TH:i:s\\Z');
    }
}