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authorJames Walker <walkah@walkah.net>2010-02-25 17:08:50 -0500
committerJames Walker <walkah@walkah.net>2010-02-25 17:09:54 -0500
commit3d0ba3efc84a78a24d4a3a60472e47aef92546dd (patch)
tree35c87fdfb5ea026cc7904452990e9a5924b799c6
parent5cb6e54bedd6aa7dda14bb43fd29d8c119fe6d4c (diff)
adding a new, more generic "discovery" class that does LRDD disco
(rather than webfinger specific)
-rw-r--r--plugins/OStatus/lib/discovery.php303
1 files changed, 303 insertions, 0 deletions
diff --git a/plugins/OStatus/lib/discovery.php b/plugins/OStatus/lib/discovery.php
new file mode 100644
index 000000000..1159f2151
--- /dev/null
+++ b/plugins/OStatus/lib/discovery.php
@@ -0,0 +1,303 @@
+<?php
+/**
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * A sample module to show best practices for StatusNet plugins
+ *
+ * PHP version 5
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @package StatusNet
+ * @author James Walker <james@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
+ * @link http://status.net/
+ */
+
+/**
+ * This class implements LRDD-based service discovery based on the "Hammer Draft"
+ * (including webfinger)
+ *
+ * @see http://groups.google.com/group/webfinger/browse_thread/thread/9f3d93a479e91bbf
+ */
+class Discovery
+{
+
+ const LRDD_REL = 'lrdd';
+ const PROFILEPAGE = 'http://webfinger.net/rel/profile-page';
+ const UPDATESFROM = 'http://schemas.google.com/g/2010#updates-from';
+
+ public $methods = array();
+
+ public function __construct()
+ {
+ $this->registerMethod('Discovery_LRDD_Host_Meta');
+ $this->registerMethod('Discovery_LRDD_Link_Header');
+ $this->registerMethod('Discovery_LRDD_Link_HTML');
+ }
+
+
+ public function registerMethod($class)
+ {
+ $this->methods[] = $class;
+ }
+
+ /**
+ * Given a "user id" make sure it's normalized to either a webfinger
+ * acct: uri or a profile HTTP URL.
+ */
+ public static function normalize($user_id)
+ {
+ if (substr($user_id, 0, 5) == 'http:' ||
+ substr($user_id, 0, 6) == 'https:' ||
+ substr($user_id, 0, 5) == 'acct:') {
+ return $user_id;
+ }
+
+ if (strpos($user_id, '@') !== FALSE) {
+ return 'acct:' . $user_id;
+ }
+
+ return 'http://' . $user_id;
+ }
+
+ public static function isWebfinger($user_id)
+ {
+ $uri = Discovery::normalize($user_id);
+
+ return (substr($uri, 0, 5) == 'acct:');
+ }
+
+ /**
+ * This implements the actual lookup procedure
+ */
+ public function lookup($id)
+ {
+ // Normalize the incoming $id to make sure we have a uri
+ $uri = $this->normalize($id);
+
+ foreach ($this->methods as $class) {
+ $links = call_user_func(array($class, 'discover'), $uri);
+
+ if ($link = Discovery::getService($links, Discovery::LRDD_REL)) {
+ // Load the LRDD XRD
+ if ($link['template']) {
+ $xrd_uri = Discovery::applyTemplate($link['template'], $uri);
+ } else {
+ $xrd_uri = $link['href'];
+ }
+
+ $xrd = $this->fetchXrd($xrd_uri);
+ if ($xrd) {
+ return $xrd;
+ }
+ }
+ }
+
+ throw new Exception('Unable to find services for '. $id);
+ }
+
+ public static function getService($links, $service) {
+ foreach ($links as $link) {
+ if ($link['rel'] == $service) {
+ return $link;
+ }
+ }
+ }
+
+
+ public static function applyTemplate($template, $id)
+ {
+ $template = str_replace('{uri}', urlencode($id), $template);
+
+ return $template;
+ }
+
+
+ public static function fetchXrd($url)
+ {
+ try {
+ $client = new HTTPClient();
+ $response = $client->get($url);
+ } catch (HTTP_Request2_Exception $e) {
+ return false;
+ }
+
+ if ($response->getStatus() != 200) {
+ return false;
+ }
+
+ return XRD::parse($response->getBody());
+ }
+}
+
+interface Discovery_LRDD
+{
+ public function discovery($uri);
+}
+
+class Discovery_LRDD_Host_Meta implements Discovery_LRDD
+{
+ function discover($uri)
+ {
+ if (Discovery::isWebfinger($uri)) {
+ // We have a webfinger acct: - start with host-meta
+ list($name, $domain) = explode('@', $id);
+ } else {
+ $domain = @parse_url($uri, PHP_URL_HOST);
+ }
+
+ $url = 'http://'. $domain .'/.well-known/host-meta';
+
+ $xrd = Discovery::fetchXrd($url);
+
+ if ($xrd) {
+ if ($xrd->host != $domain) {
+ return false;
+ }
+
+ return $xrd->links;
+ }
+ }
+}
+
+class Discovery_LRDD_Link_Header implements Discovery_LRDD
+{
+ public function discover($uri)
+ {
+ try {
+ $client = new HTTPClient();
+ $response = $client->get($url);
+ } catch (HTTP_Request2_Exception $e) {
+ return false;
+ }
+
+ if ($response->getStatus() != 200) {
+ return false;
+ }
+
+ $link_header = $response->getHeader('Link');
+ if (!$link_header) {
+ return false;
+ }
+
+ return Discovery_LRDD_Link_Header::parseHeader($header);
+ }
+
+ protected static function parseHeader($header)
+ {
+ preg_match('/^<[^>]+>/', $header, $uri_reference);
+ if (empty($uri_reference)) return;
+
+ $link_uri = trim($uri_reference[0], '<>');
+ $link_rel = array();
+ $link_type = null;
+
+ // remove uri-reference from header
+ $header = substr($header, strlen($uri_reference[0]));
+
+ // parse link-params
+ $params = explode($header, ';');
+
+ foreach ($params as $param) {
+ if (empty($param)) continue;
+ list($param_name, $param_value) = explode('=', $param, 2);
+ $param_name = trim($param_name);
+ $param_value = preg_replace('(^"|"$)', '', trim($param_value));
+
+ // for now we only care about 'rel' and 'type' link params
+ // TODO do something with the other links-params
+ switch ($param_name) {
+ case 'rel':
+ $link_rel = trim($param_value);
+ break;
+
+ case 'type':
+ $link_type = trim($param_value);
+ }
+ }
+
+ return array(
+ 'href' => $link_uri,
+ 'rel' => $link_rel,
+ 'type' => $link_type);
+ }
+}
+
+class Discovery_LRDD_Link_HTML implements Discovery_LRDD
+{
+ public function discover($uri)
+ {
+ try {
+ $client = new HTTPClient();
+ $response = $client->get($url);
+ } catch (HTTP_Request2_Exception $e) {
+ return false;
+ }
+
+ if ($response->getStatus() != 200) {
+ return false;
+ }
+
+ return Discovery_LRDD_Link_HTML::parse($response->getBody());
+ }
+
+
+ public function parse($html)
+ {
+ $links = array();
+
+ preg_match('/<head(\s[^>]*)?>(.*?)<\/head>/is', $html, $head_matches);
+ $head_html = $head_matches[2];
+
+ preg_match_all('/<link\s[^>]*>/i', $head_html, $link_matches);
+
+ foreach ($link_matches[0] as $link_html) {
+ $link_url = null;
+ $link_rel = null;
+ $link_type = null;
+
+ preg_match('/\srel=(("|\')([^\\2]*?)\\2|[^"\'\s]+)/i', $link_html, $rel_matches);
+ if ( isset($rel_matches[3]) ) {
+ $link_rel = $rel_matches[3];
+ } else if ( isset($rel_matches[1]) ) {
+ $link_rel = $rel_matches[1];
+ }
+
+ preg_match('/\shref=(("|\')([^\\2]*?)\\2|[^"\'\s]+)/i', $link_html, $href_matches);
+ if ( isset($href_matches[3]) ) {
+ $link_uri = $href_matches[3];
+ } else if ( isset($href_matches[1]) ) {
+ $link_uri = $href_matches[1];
+ }
+
+ preg_match('/\stype=(("|\')([^\\2]*?)\\2|[^"\'\s]+)/i', $link_html, $type_matches);
+ if ( isset($type_matches[3]) ) {
+ $link_type = $type_matches[3];
+ } else if ( isset($type_matches[1]) ) {
+ $link_type = $type_matches[1];
+ }
+
+ $links[] = array(
+ 'href' => $link_url,
+ 'rel' => $link_rel,
+ 'type' => $link_type,
+ );
+ }
+
+ return $links;
+ }
+}