]> git.mxchange.org Git - friendica.git/blobdiff - src/Protocol/ActivityPub/Receiver.php
The quote functionality is simplified
[friendica.git] / src / Protocol / ActivityPub / Receiver.php
index 4a138729830d6c01fbad755482a8d89614ef95b1..30348c7adeb1142feba3bac60394634b8a7441f1 100644 (file)
@@ -28,6 +28,8 @@ use Friendica\Content\Text\Markdown;
 use Friendica\Core\Logger;
 use Friendica\Core\Protocol;
 use Friendica\Core\System;
+use Friendica\Core\Worker;
+use Friendica\Database\Database;
 use Friendica\DI;
 use Friendica\Model\Contact;
 use Friendica\Model\APContact;
@@ -36,6 +38,7 @@ use Friendica\Model\Post;
 use Friendica\Model\User;
 use Friendica\Protocol\Activity;
 use Friendica\Protocol\ActivityPub;
+use Friendica\Util\DateTimeFormat;
 use Friendica\Util\HTTPSignature;
 use Friendica\Util\JsonLD;
 use Friendica\Util\LDSignature;
@@ -80,12 +83,13 @@ class Receiver
        /**
         * Checks incoming message from the inbox
         *
-        * @param         $body
-        * @param         $header
+        * @param string  $body Body string
+        * @param array   $header Header lines
         * @param integer $uid User ID
+        * @return void
         * @throws \Exception
         */
-       public static function processInbox($body, $header, $uid)
+       public static function processInbox(string $body, array $header, int $uid)
        {
                $activity = json_decode($body, true);
                if (empty($activity)) {
@@ -95,35 +99,44 @@ class Receiver
 
                $ldactivity = JsonLD::compact($activity);
 
-               $actor = JsonLD::fetchElement($ldactivity, 'as:actor', '@id');
+               $actor = JsonLD::fetchElement($ldactivity, 'as:actor', '@id') ?? '';
 
                $apcontact = APContact::getByURL($actor);
+
                if (empty($apcontact)) {
                        Logger::notice('Unable to retrieve AP contact for actor - message is discarded', ['actor' => $actor]);
                        return;
-               } elseif ($apcontact['type'] == 'Application' && $apcontact['nick'] == 'relay') {
+               } elseif (APContact::isRelay($apcontact)) {
                        self::processRelayPost($ldactivity, $actor);
                        return;
                } else {
                        APContact::unmarkForArchival($apcontact);
                }
 
+               $sig_contact = HTTPSignature::getKeyIdContact($header);
+               if (APContact::isRelay($sig_contact)) {
+                       Logger::info('Message from a relay', ['url' => $sig_contact['url']]);
+                       self::processRelayPost($ldactivity, $sig_contact['url']);
+                       return;
+               }
+
                $http_signer = HTTPSignature::getSigner($body, $header);
                if ($http_signer === false) {
-                       Logger::warning('Invalid HTTP signature, message will be discarded.');
-                       return;
+                       Logger::notice('Invalid HTTP signature, message will not be trusted.', ['uid' => $uid, 'actor' => $actor, 'header' => $header, 'body' => $body]);
+                       $signer = [];
                } elseif (empty($http_signer)) {
                        Logger::info('Signer is a tombstone. The message will be discarded, the signer account is deleted.');
                        return;
                } else {
                        Logger::info('Valid HTTP signature', ['signer' => $http_signer]);
+                       $signer = [$http_signer];
                }
 
-               $signer = [$http_signer];
-
                Logger::info('Message for user ' . $uid . ' is from actor ' . $actor);
 
-               if (LDSignature::isSigned($activity)) {
+               if ($http_signer === false) {
+                       $trust_source = false;
+               } elseif (LDSignature::isSigned($activity)) {
                        $ld_signer = LDSignature::getSigner($activity);
                        if (empty($ld_signer)) {
                                Logger::info('Invalid JSON-LD signature from ' . $actor);
@@ -151,7 +164,7 @@ class Receiver
                        $trust_source = false;
                }
 
-               self::processActivity($ldactivity, $body, $uid, $trust_source, true, $signer);
+               self::processActivity($ldactivity, $body, $uid, $trust_source, true, $signer, $http_signer);
        }
 
        /**
@@ -165,18 +178,43 @@ class Receiver
        {
                $type = JsonLD::fetchElement($activity, '@type');
                if (!$type) {
-                       Logger::info('Empty type', ['activity' => $activity]);
+                       Logger::notice('Empty type', ['activity' => $activity, 'actor' => $actor]);
                        return;
                }
 
-               if ($type != 'as:Announce') {
-                       Logger::info('Not an announcement', ['activity' => $activity]);
-                       return;
-               }
+               $object_type = JsonLD::fetchElement($activity, 'as:object', '@type') ?? '';
 
                $object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
                if (empty($object_id)) {
-                       Logger::info('No object id found', ['activity' => $activity]);
+                       Logger::notice('No object id found', ['type' => $type, 'object_type' => $object_type, 'actor' => $actor, 'activity' => $activity]);
+                       return;
+               }
+
+               $handle = ($type == 'as:Announce');
+
+               if (!$handle && in_array($type, ['as:Create', 'as:Update'])) {
+                       $handle = in_array($object_type, self::CONTENT_TYPES);
+               }
+
+               if (!$handle) {
+                       $trust_source = false;
+                       $object_data = self::prepareObjectData($activity, 0, false, $trust_source);
+
+                       if (!$trust_source) {
+                               Logger::notice('Activity trust could not be achieved.',  ['type' => $type, 'object_type' => $object_type, 'object_id' => $object_id, 'actor' => $actor, 'activity' => $activity]);
+                               return;
+                       }
+
+                       if (empty($object_data)) {
+                               Logger::notice('No object data found', ['type' => $type, 'object_type' => $object_type, 'object_id' => $object_id, 'actor' => $actor, 'activity' => $activity]);
+                               return;
+                       }
+       
+                       if (self::routeActivities($object_data, $type, true)) {
+                               Logger::debug('Handled activity', ['type' => $type, 'object_type' => $object_type, 'object_id' => $object_id, 'actor' => $actor]);
+                       } else {
+                               Logger::info('Unhandled activity', ['type' => $type, 'object_type' => $object_type, 'object_id' => $object_id, 'actor' => $actor, 'activity' => $activity]);
+                       }
                        return;
                }
 
@@ -191,26 +229,19 @@ class Receiver
                        return;
                }
 
-               Logger::info('Got relayed message id', ['id' => $object_id]);
+               Logger::debug('Got relayed message id', ['id' => $object_id, 'actor' => $actor]);
 
                $item_id = Item::searchByLink($object_id);
                if ($item_id) {
-                       Logger::info('Relayed message already exists', ['id' => $object_id, 'item' => $item_id]);
+                       Logger::info('Relayed message already exists', ['id' => $object_id, 'item' => $item_id, 'actor' => $actor]);
                        return;
                }
 
                $id = Processor::fetchMissingActivity($object_id, [], $actor, self::COMPLETION_RELAY);
                if (empty($id)) {
-                       Logger::notice('Relayed message had not been fetched', ['id' => $object_id]);
+                       Logger::notice('Relayed message had not been fetched', ['id' => $object_id, 'actor' => $actor]);
                        return;
                }
-
-               $item_id = Item::searchByLink($object_id);
-               if ($item_id) {
-                       Logger::info('Relayed message had been fetched and stored', ['id' => $object_id, 'item' => $item_id]);
-               } else {
-                       Logger::notice('Relayed message had not been stored', ['id' => $object_id]);
-               }
        }
 
        /**
@@ -220,11 +251,11 @@ class Receiver
         * @param string  $object_id Object ID of the the provided object
         * @param integer $uid       User ID
         *
-        * @return string with object type
+        * @return string with object type or NULL
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       private static function fetchObjectType($activity, $object_id, $uid = 0)
+       private static function fetchObjectType(array $activity, string $object_id, int $uid = 0)
        {
                if (!empty($activity['as:object'])) {
                        $object_type = JsonLD::fetchElement($activity['as:object'], '@type');
@@ -244,7 +275,7 @@ class Receiver
                        return 'as:' . $profile['type'];
                }
 
-               $data = ActivityPub::fetchContent($object_id, $uid);
+               $data = Processor::fetchCachedActivity($object_id, $uid);
                if (!empty($data)) {
                        $object = JsonLD::compact($data);
                        $type = JsonLD::fetchElement($object, '@type');
@@ -268,20 +299,41 @@ class Receiver
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function prepareObjectData($activity, $uid, $push, &$trust_source)
+       public static function prepareObjectData(array $activity, int $uid, bool $push, bool &$trust_source): array
        {
-               $id = JsonLD::fetchElement($activity, '@id');
+               $id        = JsonLD::fetchElement($activity, '@id');
+               $type      = JsonLD::fetchElement($activity, '@type');
+               $object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
+
+               if (!empty($object_id) && in_array($type, ['as:Create', 'as:Update'])) {
+                       $fetch_id = $object_id;
+               } else {
+                       $fetch_id = $id;
+               }
+
+               if (!empty($activity['as:object'])) {
+                       $object_type = JsonLD::fetchElement($activity['as:object'], '@type');
+               }
+
                if (!empty($id) && !$trust_source) {
                        $fetch_uid = $uid ?: self::getBestUserForActivity($activity);
 
-                       $fetched_activity = ActivityPub::fetchContent($id, $fetch_uid);
+                       $fetched_activity = Processor::fetchCachedActivity($fetch_id, $fetch_uid);
                        if (!empty($fetched_activity)) {
                                $object = JsonLD::compact($fetched_activity);
-                               $fetched_id = JsonLD::fetchElement($object, '@id');
-                               if ($fetched_id == $id) {
+
+                               $fetched_id   = JsonLD::fetchElement($object, '@id');
+                               $fetched_type = JsonLD::fetchElement($object, '@type');
+
+                               if (($fetched_id == $id) && !empty($fetched_type) && ($fetched_type == $type)) {
                                        Logger::info('Activity had been fetched successfully', ['id' => $id]);
                                        $trust_source = true;
                                        $activity = $object;
+                               } elseif (($fetched_id == $object_id) && !empty($fetched_type) && ($fetched_type == $object_type)) {
+                                       Logger::info('Fetched data is the object instead of the activity', ['id' => $id]);
+                                       $trust_source = true;
+                                       unset($object['@context']);
+                                       $activity['as:object'] = $object;
                                } else {
                                        Logger::info('Activity id is not equal', ['id' => $id, 'fetched' => $fetched_id]);
                                }
@@ -340,7 +392,8 @@ class Receiver
 
                // Fetch the activity on Lemmy "Announce" messages (announces of activities)
                if (($type == 'as:Announce') && in_array($object_type, array_merge(self::ACTIVITY_TYPES, ['as:Delete', 'as:Undo', 'as:Update']))) {
-                       $data = ActivityPub::fetchContent($object_id, $fetch_uid);
+                       Logger::debug('Fetch announced activity', ['object' => $object_id]);
+                       $data = Processor::fetchCachedActivity($object_id, $fetch_uid);
                        if (!empty($data)) {
                                $type = $object_type;
                                $activity = JsonLD::compact($data);
@@ -361,6 +414,10 @@ class Receiver
                        $object_data['object_object'] = JsonLD::fetchElement($activity['as:object'], 'as:object');
                        $object_data['object_type'] = JsonLD::fetchElement($activity['as:object'], '@type');
                        $object_data['push'] = $push;
+                       if (!$trust_source && ($type == 'as:Delete')) {
+                               $apcontact = APContact::getByURL($object_data['object_id'], true);
+                               $trust_source = empty($apcontact) || ($apcontact['type'] == 'Tombstone') || $apcontact['suspended'];
+                       }
                } elseif (in_array($type, ['as:Create', 'as:Update', 'as:Announce', 'as:Invite']) || strpos($type, '#emojiReaction')) {
                        // Fetch the content only on activities where this matters
                        // We can receive "#emojiReaction" when fetching content from Hubzilla systems
@@ -415,6 +472,13 @@ class Receiver
                        if (($type == 'as:Undo') && !empty($object_data['object_object'])) {
                                $object_data['object_object_type'] = self::fetchObjectType([], $object_data['object_object'], $fetch_uid);
                        }
+
+                       if (!$trust_source && ($type == 'as:Delete') && in_array($object_data['object_type'], array_merge(['as:Tombstone', ''], self::CONTENT_TYPES))) {
+                               $trust_source = Processor::isActivityGone($object_data['object_id']);
+                               if (!$trust_source) {
+                                       $trust_source = !empty(APContact::getByURL($object_data['object_id'], false));
+                               }
+                       }
                }
 
                $object_data = self::addActivityFields($object_data, $activity);
@@ -435,19 +499,23 @@ class Receiver
                $object_data['receiver'] = array_replace($object_data['receiver'] ?? [], $receivers);
                $object_data['reception_type'] = array_replace($object_data['reception_type'] ?? [], $reception_types);
 
-               $author = $object_data['author'] ?? $actor;
-               if (!empty($author) && !empty($object_data['id'])) {
-                       $author_host = parse_url($author, PHP_URL_HOST);
-                       $id_host = parse_url($object_data['id'], PHP_URL_HOST);
-                       if ($author_host == $id_host) {
-                               Logger::info('Valid hosts', ['type' => $type, 'host' => $id_host]);
-                       } else {
-                               Logger::notice('Differing hosts on author and id', ['type' => $type, 'author' => $author_host, 'id' => $id_host]);
-                               $trust_source = false;
-                       }
-               }
+//             This check here interferes with Hubzilla posts where the author host differs from the host the post was created
+//             $author = $object_data['author'] ?? $actor;
+//             if (!empty($author) && !empty($object_data['id'])) {
+//                     $author_host = parse_url($author, PHP_URL_HOST);
+//                     $id_host = parse_url($object_data['id'], PHP_URL_HOST);
+//                     if ($author_host == $id_host) {
+//                             Logger::info('Valid hosts', ['type' => $type, 'host' => $id_host]);
+//                     } else {
+//                             Logger::notice('Differing hosts on author and id', ['type' => $type, 'author' => $author_host, 'id' => $id_host]);
+//                             $trust_source = false;
+//                     }
+//             }
 
-               Logger::info('Processing ' . $object_data['type'] . ' ' . $object_data['object_type'] . ' ' . $object_data['id']);
+               $account = Contact::selectFirstAccount(['platform'], ['nurl' => Strings::normaliseLink($actor)]);
+               $platform = $account['platform'] ?? '';
+
+               Logger::info('Processing', ['type' => $object_data['type'], 'object_type' => $object_data['object_type'], 'id' => $object_data['id'], 'actor' => $actor, 'platform' => $platform]);
 
                return $object_data;
        }
@@ -458,7 +526,7 @@ class Receiver
         * @param array $receivers Array with receivers
         * @return integer user id;
         */
-       public static function getFirstUserFromReceivers($receivers)
+       public static function getFirstUserFromReceivers(array $receivers): int
        {
                foreach ($receivers as $receiver) {
                        if (!empty($receiver)) {
@@ -471,31 +539,35 @@ class Receiver
        /**
         * Processes the activity object
         *
-        * @param array   $activity     Array with activity data
-        * @param string  $body         The unprocessed body
-        * @param integer $uid          User ID
-        * @param boolean $trust_source Do we trust the source?
-        * @param boolean $push         Message had been pushed to our system
-        * @param array   $signer       The signer of the post
-        * @throws \Exception
+        * @param array      $activity     Array with activity data
+        * @param string     $body         The unprocessed body
+        * @param int|null   $uid          User ID
+        * @param boolean    $trust_source Do we trust the source?
+        * @param boolean    $push         Message had been pushed to our system
+        * @param array      $signer       The signer of the post
+        *
+        * @return bool
+        *
+        * @throws \Friendica\Network\HTTPException\InternalServerErrorException
+        * @throws \ImagickException
         */
-       public static function processActivity($activity, string $body = '', int $uid = null, bool $trust_source = false, bool $push = false, array $signer = [])
+       public static function processActivity(array $activity, string $body = '', int $uid = null, bool $trust_source = false, bool $push = false, array $signer = [], string $http_signer = '', int $completion = Receiver::COMPLETION_AUTO): bool
        {
                $type = JsonLD::fetchElement($activity, '@type');
                if (!$type) {
                        Logger::info('Empty type', ['activity' => $activity]);
-                       return;
+                       return true;
                }
 
                if (!JsonLD::fetchElement($activity, 'as:object', '@id')) {
                        Logger::info('Empty object', ['activity' => $activity]);
-                       return;
+                       return true;
                }
 
                $actor = JsonLD::fetchElement($activity, 'as:actor', '@id');
                if (empty($actor)) {
                        Logger::info('Empty actor', ['activity' => $activity]);
-                       return;
+                       return true;
                }
 
                if (is_array($activity['as:object'])) {
@@ -517,20 +589,16 @@ class Receiver
                $object_data = self::prepareObjectData($activity, $uid, $push, $trust_source);
                if (empty($object_data)) {
                        Logger::info('No object data found', ['activity' => $activity]);
-                       return;
+                       return true;
                }
 
                // Lemmy is announcing activities.
                // We are changing the announces into regular activities.
                if (($type == 'as:Announce') && in_array($object_data['type'] ?? '', array_merge(self::ACTIVITY_TYPES, ['as:Delete', 'as:Undo', 'as:Update']))) {
+                       Logger::debug('Change type of announce to activity', ['type' => $object_data['type']]);
                        $type = $object_data['type'];
                }
 
-               if (!$trust_source) {
-                       Logger::info('Activity trust could not be achieved.',  ['id' => $object_data['object_id'], 'type' => $type, 'signer' => $signer, 'actor' => $actor, 'attributedTo' => $attributed_to]);
-                       return;
-               }
-
                if (!empty($body) && empty($object_data['raw'])) {
                        $object_data['raw'] = $body;
                }
@@ -553,28 +621,93 @@ class Receiver
                        $object_data['from-relay'] = $activity['from-relay'];
                }
 
+               if ($type == 'as:Announce') {
+                       $object_data['object_activity'] = $activity;
+               }
+
+               if (($type == 'as:Create') && $trust_source) {
+                       if (self::hasArrived($object_data['object_id'])) {
+                               Logger::info('The activity already arrived.', ['id' => $object_data['object_id']]);
+                               return true;
+                       }
+                       self::addArrivedId($object_data['object_id']);
+
+                       if (Queue::exists($object_data['object_id'], $type)) {
+                               Logger::info('The activity is already added.', ['id' => $object_data['object_id']]);
+                               return true;
+                       }
+               }
+
+               if (DI::config()->get('system', 'decoupled_receiver') && ($trust_source || DI::config()->get('debug', 'ap_inbox_store_untrusted'))) {
+                       $object_data = Queue::add($object_data, $type, $uid, $http_signer, $push, $trust_source);
+               }
+
+               if (!$trust_source) {
+                       Logger::info('Activity trust could not be achieved.',  ['id' => $object_data['object_id'], 'type' => $type, 'signer' => $signer, 'actor' => $actor, 'attributedTo' => $attributed_to]);
+                       return true;
+               }
+
+               if (!empty($object_data['entry-id']) && DI::config()->get('system', 'decoupled_receiver') && ($push || ($completion == self::COMPLETION_RELAY))) {
+                       if (Queue::isProcessable($object_data['entry-id'])) {
+                               // We delay by 5 seconds to allow to accumulate all receivers
+                               $delayed = date(DateTimeFormat::MYSQL, time() + 5);
+                               Logger::debug('Initiate processing', ['id' => $object_data['entry-id'], 'uri' => $object_data['object_id']]);
+                               $wid = Worker::add(['priority' => PRIORITY_HIGH, 'delayed' => $delayed], 'ProcessQueue', $object_data['entry-id']);
+                               Queue::setWorkerId($object_data['entry-id'], $wid);
+                       } else {
+                               Logger::debug('Other queue entries need to be processed first.', ['id' => $object_data['entry-id']]);
+                       }
+                       return false;
+               }
+
+               if (!empty($activity['recursion-depth'])) {
+                       $object_data['recursion-depth'] = $activity['recursion-depth'];
+               }
+
                if (in_array('as:Question', [$object_data['object_type'] ?? '', $object_data['object_object_type'] ?? ''])) {
                        self::storeUnhandledActivity(false, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
                }
 
+               if (!self::routeActivities($object_data, $type, $push)) {
+                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                       Queue::remove($object_data);
+               }
+               return true;
+       }
+
+       /**
+        * Route activities
+        *
+        * @param array  $object_data
+        * @param string $type
+        * @param bool   $push
+        * @param bool   $fetch_parents
+        *
+        * @return boolean Could the activity be routed?
+        */
+       public static function routeActivities(array $object_data, string $type, bool $push, bool $fetch_parents = true): bool
+       {
+               $activity = $object_data['object_activity']     ?? [];
+
                switch ($type) {
                        case 'as:Create':
                                if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
-                                       $item = ActivityPub\Processor::createItem($object_data);
+                                       $item = ActivityPub\Processor::createItem($object_data, $fetch_parents);
                                        ActivityPub\Processor::postItem($object_data, $item);
                                } elseif (in_array($object_data['object_type'], ['pt:CacheFile'])) {
                                        // Unhandled Peertube activity
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
                        case 'as:Invite':
                                if (in_array($object_data['object_type'], ['as:Event'])) {
-                                       $item = ActivityPub\Processor::createItem($object_data);
+                                       $item = ActivityPub\Processor::createItem($object_data, $fetch_parents);
                                        ActivityPub\Processor::postItem($object_data, $item);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -585,38 +718,52 @@ class Receiver
                                        ActivityPub\Processor::addToFeaturedCollection($object_data);
                                } elseif ($object_data['object_type'] == '') {
                                        // The object type couldn't be determined. We don't have it and we can't fetch it. We ignore this activity.
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
                        case 'as:Announce':
                                if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
+                                       $actor = JsonLD::fetchElement($activity, 'as:actor', '@id');
                                        $object_data['thread-completion'] = Contact::getIdForURL($actor);
                                        $object_data['completion-mode']   = self::COMPLETION_ANNOUCE;
 
-                                       $item = ActivityPub\Processor::createItem($object_data);
-                                       if (empty($item)) {
-                                               return;
-                                       }
-
-                                       $item['post-reason'] = Item::PR_ANNOUNCEMENT;
-                                       ActivityPub\Processor::postItem($object_data, $item);
-
-                                       $announce_object_data = self::processObject($activity);
-                                       $announce_object_data['name'] = $type;
-                                       $announce_object_data['author'] = JsonLD::fetchElement($activity, 'as:actor', '@id');
-                                       $announce_object_data['object_id'] = $object_data['object_id'];
-                                       $announce_object_data['object_type'] = $object_data['object_type'];
-                                       $announce_object_data['push'] = $push;
+                                       if (!Post::exists(['uri' => $object_data['id'], 'uid' => 0])) {
+                                               $item = ActivityPub\Processor::createItem($object_data, $fetch_parents);
+                                               if (empty($item)) {
+                                                       Logger::debug('announced id was not created', ['id' => $object_data['id']]);
+                                                       return false;
+                                               }
 
-                                       if (!empty($body)) {
-                                               $announce_object_data['raw'] = $body;
+                                               $item['post-reason'] = Item::PR_ANNOUNCEMENT;
+                                               ActivityPub\Processor::postItem($object_data, $item);
+                                               Logger::debug('Created announced id', ['id' => $object_data['id']]);
+                                       } else {
+                                               Logger::info('Announced id already exists', ['id' => $object_data['id']]);
+                                               Queue::remove($object_data);
                                        }
 
-                                       ActivityPub\Processor::createActivity($announce_object_data, Activity::ANNOUNCE);
+                                       if (!empty($activity)) {
+                                               $announce_object_data = self::processObject($activity);
+                                               $announce_object_data['name'] = $type;
+                                               $announce_object_data['author'] = $actor;
+                                               $announce_object_data['object_id'] = $object_data['id'];
+                                               $announce_object_data['object_type'] = $object_data['object_type'];
+                                               $announce_object_data['push'] = $push;
+                                               Logger::debug('Create announce activity', ['id' => $announce_object_data['id'], 'object_data' => $announce_object_data]);
+
+                                               if (!empty($object_data['raw'])) {
+                                                       $announce_object_data['raw'] = $object_data['raw'];
+                                               }
+                                               if (!empty($object_data['raw-object'])) {
+                                                       $announce_object_data['raw-object'] = $object_data['raw-object'];
+                                               }
+                                               ActivityPub\Processor::createActivity($announce_object_data, Activity::ANNOUNCE);
+                                       }
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -625,8 +772,9 @@ class Receiver
                                        ActivityPub\Processor::createActivity($object_data, Activity::LIKE);
                                } elseif ($object_data['object_type'] == '') {
                                        // The object type couldn't be determined. We don't have it and we can't fetch it. We ignore this activity.
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -635,8 +783,9 @@ class Receiver
                                        ActivityPub\Processor::createActivity($object_data, Activity::DISLIKE);
                                } elseif ($object_data['object_type'] == '') {
                                        // The object type couldn't be determined. We don't have it and we can't fetch it. We ignore this activity.
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -644,7 +793,7 @@ class Receiver
                                if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
                                        ActivityPub\Processor::createActivity($object_data, Activity::ATTENDMAYBE);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -655,8 +804,9 @@ class Receiver
                                        ActivityPub\Processor::updatePerson($object_data);
                                } elseif (in_array($object_data['object_type'], ['pt:CacheFile'])) {
                                        // Unhandled Peertube activity
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -667,8 +817,9 @@ class Receiver
                                        ActivityPub\Processor::deletePerson($object_data);
                                } elseif ($object_data['object_type'] == '') {
                                        // The object type couldn't be determined. Most likely we don't have it here. We ignore this activity.
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -676,17 +827,18 @@ class Receiver
                                if (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
                                        ActivityPub\Processor::blockAccount($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
                        case 'as:Remove':
                                if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
-                                       ActivityPub\Processor::removeFromFeaturedCollection($object_data);                                      
+                                       ActivityPub\Processor::removeFromFeaturedCollection($object_data);
                                } elseif ($object_data['object_type'] == '') {
                                        // The object type couldn't be determined. We don't have it and we can't fetch it. We ignore this activity.
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -697,17 +849,21 @@ class Receiver
                                        $object_data['reply-to-id'] = $object_data['object_id'];
                                        ActivityPub\Processor::createActivity($object_data, Activity::FOLLOW);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
                        case 'as:Accept':
                                if ($object_data['object_type'] == 'as:Follow') {
-                                       ActivityPub\Processor::acceptFollowUser($object_data);
+                                       if (!empty($object_data['object_actor'])) {
+                                               ActivityPub\Processor::acceptFollowUser($object_data);
+                                       } else {
+                                               Logger::notice('Unhandled "accept follow" message.', ['object_data' => $object_data]);
+                                       }
                                } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
                                        ActivityPub\Processor::createActivity($object_data, Activity::ATTEND);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -717,7 +873,7 @@ class Receiver
                                } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
                                        ActivityPub\Processor::createActivity($object_data, Activity::ATTENDNO);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -734,17 +890,19 @@ class Receiver
                                } elseif (($object_data['object_type'] == 'as:Block') &&
                                        in_array($object_data['object_object_type'], self::ACCOUNT_TYPES)) {
                                        ActivityPub\Processor::unblockAccount($object_data);
-                               } elseif (in_array($object_data['object_type'], array_merge(self::ACTIVITY_TYPES, ['as:Announce'])) &&
-                                       in_array($object_data['object_object_type'], array_merge(['as:Tombstone'], self::CONTENT_TYPES))) {
-                                       ActivityPub\Processor::undoActivity($object_data);
                                } elseif (in_array($object_data['object_type'], array_merge(self::ACTIVITY_TYPES, ['as:Announce', 'as:Create', ''])) &&
                                        empty($object_data['object_object_type'])) {
                                        // We cannot detect the target object. So we can ignore it.
+                                       Queue::remove($object_data);
+                               } elseif (in_array($object_data['object_type'], array_merge(self::ACTIVITY_TYPES, ['as:Announce'])) &&
+                                       in_array($object_data['object_object_type'], array_merge(['as:Tombstone'], self::CONTENT_TYPES))) {
+                                       ActivityPub\Processor::undoActivity($object_data);
                                } elseif (in_array($object_data['object_type'], ['as:Create']) &&
                                        in_array($object_data['object_object_type'], ['pt:CacheFile'])) {
                                        // Unhandled Peertube activity
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -753,8 +911,9 @@ class Receiver
                                        ActivityPub\Processor::createActivity($object_data, Activity::VIEW);
                                } elseif ($object_data['object_type'] == '') {
                                        // The object type couldn't be determined. Most likely we don't have it here. We ignore this activity.
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
 
@@ -763,16 +922,17 @@ class Receiver
                                        ActivityPub\Processor::createActivity($object_data, Activity::EMOJIREACT);
                                } elseif ($object_data['object_type'] == '') {
                                        // The object type couldn't be determined. We don't have it and we can't fetch it. We ignore this activity.
+                                       Queue::remove($object_data);
                                } else {
-                                       self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
+                                       return false;
                                }
                                break;
-       
+
                        default:
                                Logger::info('Unknown activity: ' . $type . ' ' . $object_data['object_type']);
-                               self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
-                               break;
+                               return false;
                }
+               return true;
        }
 
        /**
@@ -796,7 +956,7 @@ class Receiver
                }
 
                $file = ($unknown  ? 'unknown-' : 'unhandled-') . str_replace(':', '-', $type) . '-';
-       
+
                if (!empty($object_data['object_type'])) {
                        $file .= str_replace(':', '-', $object_data['object_type']) . '-';
                }
@@ -818,7 +978,7 @@ class Receiver
         *
         * @return int   user id
         */
-       public static function getBestUserForActivity(array $activity)
+       public static function getBestUserForActivity(array $activity): int
        {
                $uid = 0;
                $actor = JsonLD::fetchElement($activity, 'as:actor', '@id') ?? '';
@@ -844,7 +1004,8 @@ class Receiver
                return $uid;
        }
 
-       public static function getReceiverURL($activity)
+       // @TODO Missing documentation
+       public static function getReceiverURL(array $activity): array
        {
                $urls = [];
 
@@ -876,9 +1037,9 @@ class Receiver
         * @return array with receivers (user id)
         * @throws \Exception
         */
-       private static function getReceivers($activity, $actor, $tags = [], $fetch_unlisted = false)
+       private static function getReceivers(array $activity, string $actor, array $tags = [], bool $fetch_unlisted = false): array
        {
-               $reply = $receivers = [];
+               $reply = $receivers = $profile = [];
 
                // When it is an answer, we inherite the receivers from the parent
                $replyto = JsonLD::fetchElement($activity, 'as:inReplyTo', '@id');
@@ -899,7 +1060,7 @@ class Receiver
                }
 
                if (!empty($reply)) {
-                       $parents = Post::select(['uid'], ['uri' => $reply]);
+                       $parents = Post::select(['uid'], DBA::mergeConditions(['uri' => $reply], ["`uid` != ?", 0]));
                        while ($parent = Post::fetch($parents)) {
                                $receivers[$parent['uid']] = ['uid' => $parent['uid'], 'type' => self::TARGET_ANSWER];
                        }
@@ -990,6 +1151,17 @@ class Receiver
 
                self::switchContacts($receivers, $actor);
 
+               // "birdsitelive" is a service that mirrors tweets into the fediverse
+               // These posts can be fetched without authentification, but are not marked as public
+               // We treat them as unlisted posts to be able to handle them.
+               if (empty($receivers) && $fetch_unlisted && Contact::isPlatform($actor, 'birdsitelive')) {
+                       $receivers[0]  = ['uid' => 0, 'type' => self::TARGET_GLOBAL];
+                       $receivers[-1] = ['uid' => -1, 'type' => self::TARGET_GLOBAL];
+                       Logger::notice('Post from "birdsitelive" is set to "unlisted"', ['id' => JsonLD::fetchElement($activity, '@id')]);
+               } elseif (empty($receivers)) {
+                       Logger::notice('Post has got no receivers', ['fetch_unlisted' => $fetch_unlisted, 'actor' => $actor, 'id' => JsonLD::fetchElement($activity, '@id'), 'type' => JsonLD::fetchElement($activity, '@type')]);
+               }
+
                return $receivers;
        }
 
@@ -1005,7 +1177,7 @@ class Receiver
         * @return array with receivers (user id)
         * @throws \Exception
         */
-       private static function getReceiverForActor($actor, $tags, $receivers, $target_type, $profile)
+       private static function getReceiverForActor(string $actor, array $tags, array $receivers, int $target_type, array $profile): array
        {
                $basecondition = ['rel' => [Contact::SHARING, Contact::FRIEND, Contact::FOLLOWER],
                        'network' => Protocol::FEDERATED, 'archive' => false, 'pending' => false];
@@ -1047,13 +1219,12 @@ class Receiver
         * Tests if the contact is a valid receiver for this actor
         *
         * @param array  $contact
-        * @param string $actor
         * @param array  $tags
         *
         * @return bool with receivers (user id)
         * @throws \Exception
         */
-       private static function isValidReceiverForActor($contact, $tags)
+       private static function isValidReceiverForActor(array $contact, array $tags): bool
        {
                // Are we following the contact? Then this is a valid receiver
                if (in_array($contact['rel'], [Contact::SHARING, Contact::FRIEND])) {
@@ -1086,10 +1257,11 @@ class Receiver
         * @param integer $cid Contact ID
         * @param integer $uid User ID
         * @param string  $url Profile URL
+        * @return void
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function switchContact($cid, $uid, $url)
+       public static function switchContact(int $cid, int $uid, string $url)
        {
                if (DBA::exists('contact', ['id' => $cid, 'network' => Protocol::ACTIVITYPUB])) {
                        Logger::info('Contact is already ActivityPub', ['id' => $cid, 'uid' => $uid, 'url' => $url]);
@@ -1108,10 +1280,11 @@ class Receiver
        }
 
        /**
-        *
+        * @TODO Fix documentation and type-hints
         *
         * @param $receivers
         * @param $actor
+        * @return void
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
@@ -1135,14 +1308,14 @@ class Receiver
        }
 
        /**
-        *
+        * @TODO Fix documentation and type-hints
         *
         * @param       $object_data
         * @param array $activity
         *
         * @return mixed
         */
-       private static function addActivityFields($object_data, $activity)
+       private static function addActivityFields($object_data, array $activity)
        {
                if (!empty($activity['published']) && empty($object_data['published'])) {
                        $object_data['published'] = JsonLD::fetchElement($activity, 'as:published', '@value');
@@ -1185,7 +1358,7 @@ class Receiver
                $type = JsonLD::fetchElement($object, '@type');
 
                if (!$trust_source || empty($type)) {
-                       $data = ActivityPub::fetchContent($object_id, $uid);
+                       $data = Processor::fetchCachedActivity($object_id, $uid);
                        if (!empty($data)) {
                                $object = JsonLD::compact($data);
                                Logger::info('Fetched content for ' . $object_id);
@@ -1239,7 +1412,7 @@ class Receiver
                        $object_data = self::processObject($object);
 
                        if (!empty($data)) {
-                               $object_data['raw'] = json_encode($data);
+                               $object_data['raw-object'] = json_encode($data);
                        }
                        return $object_data;
                }
@@ -1262,7 +1435,7 @@ class Receiver
         * @param array $languages
         * @return array Languages
         */
-       public static function processLanguages(array $languages)
+       public static function processLanguages(array $languages): array
        {
                if (empty($languages)) {
                        return [];
@@ -1285,7 +1458,7 @@ class Receiver
         *
         * @return array with tags in a simplified format
         */
-       public static function processTags(array $tags)
+       public static function processTags(array $tags): array
        {
                $taglist = [];
 
@@ -1317,7 +1490,7 @@ class Receiver
         * @param array $emojis
         * @return array with emojis in a simplified format
         */
-       private static function processEmojis(array $emojis)
+       private static function processEmojis(array $emojis): array
        {
                $emojilist = [];
 
@@ -1343,7 +1516,7 @@ class Receiver
         *
         * @return array Attachments in a simplified format
         */
-       private static function processAttachments(array $attachments)
+       private static function processAttachments(array $attachments): array
        {
                $attachlist = [];
 
@@ -1460,7 +1633,7 @@ class Receiver
         *
         * @return array Questions in a simplified format
         */
-       private static function processQuestion(array $object)
+       private static function processQuestion(array $object): array
        {
                $question = [];
 
@@ -1518,10 +1691,10 @@ class Receiver
         * @param array $object
         * @param array $object_data
         *
-        * @return array
+        * @return array Object data (?)
         * @throws \Exception
         */
-       private static function getSource($object, $object_data)
+       private static function getSource(array $object, array $object_data): array
        {
                $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/bbcode');
                $object_data['source'] = JsonLD::fetchElement($object_data, 'source', '@value');
@@ -1650,10 +1823,10 @@ class Receiver
         *
         * @param array $object
         *
-        * @return array
+        * @return array|bool Object data or FALSE if $object does not contain @id element
         * @throws \Exception
         */
-       private static function processObject($object)
+       private static function processObject(array $object)
        {
                if (!JsonLD::fetchElement($object, '@id')) {
                        return false;
@@ -1714,8 +1887,10 @@ class Receiver
                $object_data['diaspora:comment'] = JsonLD::fetchElement($object, 'diaspora:comment', '@value');
                $object_data['diaspora:like'] = JsonLD::fetchElement($object, 'diaspora:like', '@value');
                $object_data['actor'] = $object_data['author'] = $actor;
-               $object_data['context'] = JsonLD::fetchElement($object, 'as:context', '@id');
-               $object_data['conversation'] = JsonLD::fetchElement($object, 'ostatus:conversation', '@id');
+               $element = JsonLD::fetchElement($object, 'as:context', '@id');
+               $object_data['context'] = $element != './' ? $element : null;
+               $element = JsonLD::fetchElement($object, 'ostatus:conversation', '@id');
+               $object_data['conversation'] = $element != './' ? $element : null;
                $object_data['sensitive'] = JsonLD::fetchElement($object, 'as:sensitive');
                $object_data['name'] = JsonLD::fetchElement($object, 'as:name', '@value');
                $object_data['summary'] = JsonLD::fetchElement($object, 'as:summary', '@value');
@@ -1755,6 +1930,24 @@ class Receiver
                        $object_data['attachments'] = array_merge($object_data['attachments'], self::processAttachmentUrls($object['as:url'] ?? []));
                }
 
+               // Support for quoted posts (Pleroma, Fedibird and Misskey)
+               $object_data['quote-url'] = JsonLD::fetchElement($object, 'as:quoteUrl', '@value');
+               if (empty($object_data['quote-url'])) {
+                       $object_data['quote-url'] = JsonLD::fetchElement($object, 'fedibird:quoteUri', '@value');
+               }
+               if (empty($object_data['quote-url'])) {
+                       $object_data['quote-url'] = JsonLD::fetchElement($object, 'misskey:_misskey_quote', '@value');
+               }
+
+               // Misskey adds some data to the standard "content" value for quoted posts for backwards compatibility.
+               // Their own "_misskey_content" value does then contain the content without this extra data.
+               if (!empty($object_data['quote-url'])) {
+                       $misskey_content = JsonLD::fetchElement($object, 'misskey:_misskey_content', '@value');
+                       if (!empty($misskey_content)) {
+                               $object_data['content'] = $misskey_content;
+                       }
+               }
+
                // For page types we expect that the alternate url posts to some page.
                // So we add this to the attachments if it differs from the id.
                // Currently only Lemmy is using the page type.
@@ -1767,7 +1960,7 @@ class Receiver
                        $object_data['question'] = self::processQuestion($object);
                }
 
-               $receiverdata = self::getReceivers($object, $object_data['actor'], $object_data['tags'], true);
+               $receiverdata = self::getReceivers($object, $object_data['actor'] ?? '', $object_data['tags'], true);
                $receivers = $reception_types = [];
                foreach ($receiverdata as $key => $data) {
                        $receivers[$key] = $data['uid'];
@@ -1782,29 +1975,31 @@ class Receiver
                unset($object_data['receiver'][-1]);
                unset($object_data['reception_type'][-1]);
 
-               // Common object data:
-
-               // Unhandled
-               // @context, type, actor, signature, mediaType, duration, replies, icon
-
-               // Also missing: (Defined in the standard, but currently unused)
-               // audience, preview, endTime, startTime, image
-
-               // Data in Notes:
-
-               // Unhandled
-               // contentMap, announcement_count, announcements, context_id, likes, like_count
-               // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
-
-               // Data in video:
-
-               // To-Do?
-               // category, licence, language, commentsEnabled
+               return $object_data;
+       }
 
-               // Unhandled
-               // views, waitTranscoding, state, support, subtitleLanguage
-               // likes, dislikes, shares, comments
+       /**
+        * Add an object id to the list of arrived activities
+        *
+        * @param string $id
+        *
+        * @return void
+        */
+       private static function addArrivedId(string $id)
+       {
+               DBA::delete('arrived-activity', ["`received` < ?", DateTimeFormat::utc('now - 5 minutes')]);
+               DBA::insert('arrived-activity', ['object-id' => $id, 'received' => DateTimeFormat::utcNow()], Database::INSERT_IGNORE);
+       }
 
-               return $object_data;
+       /**
+        * Checks if the given object already arrived before
+        *
+        * @param string $id
+        *
+        * @return boolean
+        */
+       private static function hasArrived(string $id): bool
+       {
+               return DBA::exists('arrived-activity', ['object-id' => $id]);
        }
 }