First steps on converting FeedSub into the pub/sub basis for OStatus communications:

* renamed FeedSub plugin to OStatus
* now setting avatar on subscriptions
* general fixes for subscription
* integrated PuSH hub to handle only user timelines on canonical ID url; sends updates directly
* set $config['feedsub']['nohub'] = true to test w/ foreign feeds that don't have hubs (won't actually receive updates though)
* a few bits of code documentation
* HMAC support for verified distributions (safest if sub setup is on HTTPS)

And a couple core changes:
* minimizing HTML output for exceptions in API requests to aid in debugging
* fix for rel=self link in apitimelineuser when id given

This does not not yet include any of the individual subscription management (Salmon notifications for sub/unsub, etc) nor a nice UI for user subscriptions.
Needs some further cleanup to treat posts as status updates instead of link references.

1 files changed, 272 insertions, 0 deletions

diff --git a/plugins/OStatus/classes/HubSub.php b/plugins/OStatus/classes/HubSub.php
new file mode 100644
index 000000000..1769f6c94
--- /dev/null
+++ b/plugins/OStatus/classes/HubSub.php
@@ -0,0 +1,272 @@
+<?php
+/*
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * 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/>.
+ */
+
+/**
+ * PuSH feed subscription record
+ * @package Hub
+ * @author Brion Vibber <brion@status.net>
+ */
+class HubSub extends Memcached_DataObject
+{
+    public $__table = 'hubsub';
+
+    public $hashkey; // sha1(topic . '|' . $callback); (topic, callback) key is too long for myisam in utf8
+    public $topic;
+    public $callback;
+    public $secret;
+    public $verify_token;
+    public $challenge;
+    public $lease;
+    public $sub_start;
+    public $sub_end;
+    public $created;
+
+    public /*static*/ function staticGet($topic, $callback)
+    {
+        return parent::staticGet(__CLASS__, 'hashkey', self::hashkey($topic, $callback));
+    }
+
+    protected static function hashkey($topic, $callback)
+    {
+        return sha1($topic . '|' . $callback);
+    }
+
+    /**
+     * return table definition for DB_DataObject
+     *
+     * DB_DataObject needs to know something about the table to manipulate
+     * instances. This method provides all the DB_DataObject needs to know.
+     *
+     * @return array array of column definitions
+     */
+
+    function table()
+    {
+        return array('hashkey' => DB_DATAOBJECT_STR + DB_DATAOBJECT_NOTNULL,
+                     'topic' => DB_DATAOBJECT_STR + DB_DATAOBJECT_NOTNULL,
+                     'callback' => DB_DATAOBJECT_STR + DB_DATAOBJECT_NOTNULL,
+                     'secret' => DB_DATAOBJECT_STR,
+                     'verify_token' => DB_DATAOBJECT_STR,
+                     'challenge' => DB_DATAOBJECT_STR,
+                     'lease' =>  DB_DATAOBJECT_INT,
+                     'sub_start' => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME,
+                     'sub_end' => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME,
+                     'created' => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME + DB_DATAOBJECT_NOTNULL);
+    }
+
+    static function schemaDef()
+    {
+        return array(new ColumnDef('hashkey', 'char',
+                                   /*size*/40,
+                                   /*nullable*/false,
+                                   /*key*/'PRI'),
+                     new ColumnDef('topic', 'varchar',
+                                   /*size*/255,
+                                   /*nullable*/false,
+                                   /*key*/'KEY'),
+                     new ColumnDef('callback', 'varchar',
+                                   255, false),
+                     new ColumnDef('secret', 'text',
+                                   null, true),
+                     new ColumnDef('verify_token', 'text',
+                                   null, true),
+                     new ColumnDef('challenge', 'varchar',
+                                   32, true),
+                     new ColumnDef('lease', 'int',
+                                   null, true),
+                     new ColumnDef('sub_start', 'datetime',
+                                   null, true),
+                     new ColumnDef('sub_end', 'datetime',
+                                   null, true),
+                     new ColumnDef('created', 'datetime',
+                                   null, false));
+    }
+
+    function keys()
+    {
+        return array_keys($this->keyTypes());
+    }
+
+    function sequenceKeys()
+    {
+        return array(false, false, false);
+    }
+
+    /**
+     * return key definitions for DB_DataObject
+     *
+     * DB_DataObject needs to know about keys that the table has; this function
+     * defines them.
+     *
+     * @return array key definitions
+     */
+
+    function keyTypes()
+    {
+        return array('hashkey' => 'K');
+    }
+
+    /**
+     * Validates a requested lease length, sets length plus
+     * subscription start & end dates.
+     *
+     * Does not save to database -- use before insert() or update().
+     *
+     * @param int $length in seconds
+     */
+    function setLease($length)
+    {
+        assert(is_int($length));
+
+        $min = 86400;
+        $max = 86400 * 30;
+
+        if ($length == 0) {
+            // We want to garbage collect dead subscriptions!
+            $length = $max;
+        } elseif( $length < $min) {
+            $length = $min;
+        } else if ($length > $max) {
+            $length = $max;
+        }
+
+        $this->lease = $length;
+        $this->start_sub = common_sql_now();
+        $this->end_sub = common_sql_date(time() + $length);
+    }
+
+    /**
+     * Send a verification ping to subscriber
+     * @param string $mode 'subscribe' or 'unsubscribe'
+     */
+    function verify($mode)
+    {
+        assert($mode == 'subscribe' || $mode == 'unsubscribe');
+
+        // Is this needed? data object fun...
+        $clone = clone($this);
+        $clone->challenge = common_good_rand(16);
+        $clone->update($this);
+        $this->challenge = $clone->challenge;
+        unset($clone);
+
+        $params = array('hub.mode' => $mode,
+                        'hub.topic' => $this->topic,
+                        'hub.challenge' => $this->challenge);
+        if ($mode == 'subscribe') {
+            $params['hub.lease_seconds'] = $this->lease;
+        }
+        if ($this->verify_token) {
+            $params['hub.verify_token'] = $this->verify_token;
+        }
+        $url = $this->callback . '?' . http_build_query($params, '', '&'); // @fixme ugly urls
+
+        try {
+            $request = new HTTPClient();
+            $response = $request->get($url);
+            $status = $response->getStatus();
+
+            if ($status >= 200 && $status < 300) {
+                $fail = false;
+            } else {
+                // @fixme how can we schedule a second attempt?
+                // Or should we?
+                $fail = "Returned HTTP $status";
+            }
+        } catch (Exception $e) {
+            $fail = $e->getMessage();
+        }
+        if ($fail) {
+            // @fixme how can we schedule a second attempt?
+            // or save a fail count?
+            // Or should we?
+            common_log(LOG_ERR, "Failed to verify $mode for $this->topic at $this->callback: $fail");
+            return false;
+        } else {
+            if ($mode == 'subscribe') {
+                // Establish or renew the subscription!
+                // This seems unnecessary... dataobject fun!
+                $clone = clone($this);
+                $clone->challenge = null;
+                $clone->setLease($this->lease);
+                $clone->update($this);
+                unset($clone);
+
+                $this->challenge = null;
+                $this->setLease($this->lease);
+                common_log(LOG_ERR, "Verified $mode of $this->callback:$this->topic for $this->lease seconds");
+            } else if ($mode == 'unsubscribe') {
+                common_log(LOG_ERR, "Verified $mode of $this->callback:$this->topic");
+                $this->delete();
+            }
+            return true;
+        }
+    }
+
+    /**
+     * Insert wrapper; transparently set the hash key from topic and callback columns.
+     * @return boolean success
+     */
+    function insert()
+    {
+        $this->hashkey = self::hashkey($this->topic, $this->callback);
+        return parent::insert();
+    }
+
+    /**
+     * Send a 'fat ping' to the subscriber's callback endpoint
+     * containing the given Atom feed chunk.
+     *
+     * Determination of which items to send should be done at
+     * a higher level; don't just shove in a complete feed!
+     *
+     * @param string $atom well-formed Atom feed
+     */
+    function push($atom)
+    {
+        $headers = array('Content-Type: application/atom+xml');
+        if ($this->secret) {
+            $hmac = sha1($atom . $this->secret);
+            $headers[] = "X-Hub-Signature: sha1=$hmac";
+        } else {
+            $hmac = '(none)';
+        }
+        common_log(LOG_INFO, "About to push feed to $this->callback for $this->topic, HMAC $hmac");
+        try {
+            $request = new HTTPClient();
+            $request->setBody($atom);
+            $response = $request->post($this->callback, $headers);
+
+            if ($response->isOk()) {
+                return true;
+            }
+            common_log(LOG_ERR, "Error sending PuSH content " .
+                                "to $this->callback for $this->topic: " .
+                                $response->getStatus());
+            return false;
+
+        } catch (Exception $e) {
+            common_log(LOG_ERR, "Error sending PuSH content " .
+                                "to $this->callback for $this->topic: " .
+                                $e->getMessage());
+            return false;
+        }
+    }
+}
+