discovery piece - hand merged :P

1 files changed, 139 insertions, 0 deletions

diff --git a/plugins/OStatus/lib/Webfinger.php b/plugins/OStatus/lib/Webfinger.php
new file mode 100644
index 000000000..7ab6b421b
--- /dev/null
+++ b/plugins/OStatus/lib/Webfinger.php
@@ -0,0 +1,139 @@
+<?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/
+ */
+
+define('WEBFINGER_SERVICE_REL_VALUE', 'lrdd');
+
+/**
+ * Implement the webfinger protocol.
+ */
+class Webfinger
+{
+    /**
+     * Perform a webfinger lookup given an account.
+     */ 
+    public function lookup($id)
+    {
+        $id = $this->normalize($id);
+        list($name, $domain) = explode('@', $id);
+
+        $links = $this->getServiceLinks($domain);
+        if (!$links) {
+            return false;
+        }
+        
+        $services = array();
+        foreach ($links as $link) {
+            if ($link['template']) {
+                return $this->getServiceDescription($link['template'], $id);
+            }
+            if ($link['href']) {
+                return $this->getServiceDescription($link['href'], $id);
+            }
+        }
+    }
+
+    /**
+     * Normalize an account ID
+     */
+    function normalize($id)
+    {
+        if (substr($id, 0, 7) == 'acct://') {
+            return substr($id, 7); 
+        } else if (substr($id, 0, 5) == 'acct:') {
+            return substr($id, 5);
+        }
+
+        return $id;
+    }
+
+    function getServiceLinks($domain)
+    {
+        $url = 'http://'. $domain .'/.well-known/host-meta';
+        $content = $this->fetchURL($url);
+        $result = XRD::parse($content);
+
+        // Ensure that the host == domain (spec may include signing later)
+        if ($result->host != $domain) {
+            return false;
+        }
+        
+        $links = array();
+        foreach ($result->links as $link) {
+            if ($link['rel'] == WEBFINGER_SERVICE_REL_VALUE) {
+                $links[] = $link;
+            }
+
+        }
+        return $links;
+    }
+
+    function getServiceDescription($template, $id)
+    {
+        $url = $this->applyTemplate($template, 'acct:' . $id);
+
+        $content = $this->fetchURL($url);
+
+        return XRD::parse($content);
+    }
+
+    function fetchURL($url)
+    {
+        try {
+            $client = new HTTPClient();
+            $response = $client->get($url);
+        } catch (HTTP_Request2_Exception $e) {
+            return false;
+        }
+
+        if ($response->getStatus() != 200) {
+            return false;
+        }
+
+        return $response->getBody();
+    }
+
+    function applyTemplate($template, $id)
+    {
+        $template = str_replace('{uri}', urlencode($id), $template);
+
+        return $template;
+    }
+
+    function getHostMeta($domain, $template) {
+        $xrd = new XRD();
+        $xrd->host = $domain;
+        $xrd->links[] = array('rel' => 'lrdd',
+                              'template' => $template,
+                              'title' => array('Resource Descriptor'));
+
+        return $xrd->toXML();
+    }
+}
+
+