<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social 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.
//
// GNU social 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 GNU social. If not, see <http://www.gnu.org/licenses/>.
/**
* ActivityPub implementation for GNU social
*
* @package GNUsocial
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @copyright 2018-2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
* @link http://www.gnu.org/software/social/
*/
defined('GNUSOCIAL') || die();
/**
* ActivityPub notice representation
*
* @category Plugin
* @package GNUsocial
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
class Activitypub_notice
{
/**
* Generates a pretty notice from a Notice object
*
* @param Notice $notice
* @return array array to be used in a response
* @throws EmptyPkeyValueException
* @throws InvalidUrlException
* @throws ServerException
* @throws Exception
* @author Diogo Cordeiro <diogo@fc.up.pt>
*/
public static function notice_to_array(Notice $notice): array
{
$profile = $notice->getProfile();
$attachments = [];
foreach ($notice->attachments() as $attachment) {
$attachments[] = Activitypub_attachment::attachment_to_array($attachment);
}
$tags = [];
foreach ($notice->getTags() as $tag) {
if ($tag != "") { // Hacky workaround to avoid stupid outputs
$tags[] = Activitypub_tag::tag_to_array($tag);
}
}
if ($notice->isPublic()) {
$to = ['https://www.w3.org/ns/activitystreams#Public'];
$cc = [common_local_url('apActorFollowers', ['id' => $profile->getID()])];
} else {
// Since we currently don't support sending unlisted/followers-only
// notices, arriving here means we're instead answering to that type
// of posts. Not having subscription policy working, its safer to
// always send answers of type unlisted.
$to = [];
$cc = ['https://www.w3.org/ns/activitystreams#Public'];
}
foreach ($notice->getAttentionProfiles() as $to_profile) {
$to[] = $href = $to_profile->getUri();
$tags[] = Activitypub_mention_tag::mention_tag_to_array_from_values($href, $to_profile->getNickname() . '@' . parse_url($href, PHP_URL_HOST));
}
if (ActivityUtils::compareVerbs($notice->getVerb(), ActivityVerb::DELETE)) {
$item = [
'@context' => 'https://www.w3.org/ns/activitystreams',
'id' => self::getUri($notice),
'type' => 'Delete',
// XXX: A bit of ugly code here
'object' => array_merge(Activitypub_tombstone::tombstone_to_array((int)substr(explode(':', $notice->getUri())[2],9)), ['deleted' => str_replace(' ', 'T', $notice->getCreated()) . 'Z']),
'url' => $notice->getUrl(),
'actor' => $profile->getUri(),
'to' => $to,
'cc' => $cc,
'conversationId' => $notice->getConversationUrl(false),
'conversationUrl' => $notice->getConversationUrl(),
'content' => $notice->getRendered(),
'isLocal' => $notice->isLocal(),
'attachment' => $attachments,
'tag' => $tags
];
} else { // Note
$item = [
'@context' => 'https://www.w3.org/ns/activitystreams',
'id' => self::note_uri($notice->getID()),
'type' => 'Note',
'published' => str_replace(' ', 'T', $notice->getCreated()) . 'Z',
'url' => $notice->getUrl(),
'attributedTo' => $profile->getUri(),
'to' => $to,
'cc' => $cc,
'conversationId' => $notice->getConversationUrl(false),
'conversationUrl' => $notice->getConversationUrl(),
'content' => $notice->getRendered(),
'isLocal' => $notice->isLocal(),
'attachment' => $attachments,
'tag' => $tags
];
}
// Is this a reply?
if (!empty($notice->reply_to)) {
$item['inReplyTo'] = self::getUri(Notice::getById($notice->reply_to));
}
// Do we have a location for this notice?
try {
$location = Notice_location::locFromStored($notice);
$item['latitude'] = $location->lat;
$item['longitude'] = $location->lon;
} catch (Exception $e) {
// Apparently no.
}
return $item;
}
/**
* Create a Notice via ActivityPub Note Object.
* Returns created Notice.
*
* @param array $object
* @param Profile $actor_profile
* @param bool $directMessage
* @return Notice
* @throws Exception
* @author Diogo Cordeiro <diogo@fc.up.pt>
*/
public static function create_notice(array $object, Profile $actor_profile, bool $directMessage = false): Notice
{
$id = $object['id']; // int
$url = isset($object['url']) ? $object['url'] : $id; // string
$content = $object['content']; // string
// possible keys: ['inReplyTo', 'latitude', 'longitude']
$settings = [];
if (isset($object['inReplyTo'])) {
$settings['inReplyTo'] = $object['inReplyTo'];
}
if (isset($object['latitude'])) {
$settings['latitude'] = $object['latitude'];
}
if (isset($object['longitude'])) {
$settings['longitude'] = $object['longitude'];
}
$act = new Activity();
$act->verb = ActivityVerb::POST;
$act->time = time();
$act->actor = $actor_profile->asActivityObject();
$act->context = new ActivityContext();
$options = ['source' => 'ActivityPub',
'uri' => $id,
'url' => $url,
'is_local' => self::getNotePolicyType($object, $actor_profile)];
if ($directMessage) {
$options['scope'] = Notice::MESSAGE_SCOPE;
}
// Is this a reply?
if (isset($settings['inReplyTo'])) {
try {
$inReplyTo = ActivityPubPlugin::grab_notice_from_url($settings['inReplyTo']);
$act->context->replyToID = $inReplyTo->getUri();
$act->context->replyToUrl = $inReplyTo->getUrl();
} catch (Exception $e) {
// It failed to grab, maybe we got this note from another source
// (e.g.: OStatus) that handles this differently or we really
// failed to get it...
// Welp, nothing that we can do about, let's
// just fake we don't have such notice.
}
} else {
$inReplyTo = null;
}
// Mentions
$mentions = [];
if (isset($object['tag']) && is_array($object['tag'])) {
foreach ($object['tag'] as $tag) {
if (array_key_exists('type', $tag) && $tag['type'] == 'Mention') {
$mentions[] = $tag['href'];
}
}
}
$mentions_profiles = [];
$discovery = new Activitypub_explorer;
foreach ($mentions as $mention) {
try {
$mentioned_profile = $discovery->lookup($mention);
if (!empty($mentioned_profile)) {
$mentions_profiles[] = $mentioned_profile[0];
}
} catch (Exception $e) {
// Invalid actor found, just let it go, it will eventually be handled by some other federation plugin like OStatus.
}
}
unset($discovery);
foreach ($mentions_profiles as $mp) {
if (!$mp->hasBlocked($actor_profile)) {
$act->context->attention[$mp->getUri()] = 'http://activitystrea.ms/schema/1.0/person';
}
}
// Add location if that is set
if (isset($settings['latitude'], $settings['longitude'])) {
$act->context->location = Location::fromLatLon($settings['latitude'], $settings['longitude']);
}
/* Reject notice if it is too long (without the HTML)
if (Notice::contentTooLong($content)) {
throw new Exception('That\'s too long. Maximum notice size is %d character.');
}*/
// Attachments (first part)
$attachments = [];
if (isset($object['attachment']) && is_array($object['attachment'])) {
foreach ($object['attachment'] as $attachment) {
if (array_key_exists('type', $attachment) && $attachment['type'] == 'Document') {
try {
// throws exception on failure
$attachment = MediaFile::fromUrl($attachment['url'], $actor_profile, $attachment['name']);
$act->enclosures[] = $attachment->getEnclosure();
$attachments[] = $attachment;
} catch (Exception $e) {
// Whatever.
}
}
}
}
$actobj = new ActivityObject();
$actobj->type = ActivityObject::NOTE;
$actobj->content = strip_tags($content, '<p><b><i><u><a><ul><ol><li>');
// Finally add the activity object to our activity
$act->objects[] = $actobj;
$note = Notice::saveActivity($act, $actor_profile, $options);
// Attachments (last part)
foreach($attachments as $attachment) {
$attachment->attachToNotice($note);
}
return $note;
}
/**
* Validates a note.
*
* @param array $object
* @return bool false if unacceptable for GS but valid ActivityPub object
* @throws Exception if invalid ActivityPub object
* @author Diogo Cordeiro <diogo@fc.up.pt>
*/
public static function validate_note(array $object): bool
{
if (!isset($object['id'])) {
common_debug('ActivityPub Notice Validator: Rejected because Object ID was not specified.');
throw new Exception('Object ID not specified.');
} elseif (!filter_var($object['id'], FILTER_VALIDATE_URL)) {
common_debug('ActivityPub Notice Validator: Rejected because Object ID is invalid.');
throw new Exception('Invalid Object ID.');
}
if (!isset($object['type']) || $object['type'] !== 'Note') {
common_debug('ActivityPub Notice Validator: Rejected because of Type.');
throw new Exception('Invalid Object type.');
}
if (isset($object['url']) && !filter_var($object['url'], FILTER_VALIDATE_URL)) {
common_debug('ActivityPub Notice Validator: Rejected because Object URL is invalid.');
throw new Exception('Invalid Object URL.');
}
if (!(isset($object['to']) && isset($object['cc']))) {
common_debug('ActivityPub Notice Validator: Rejected because either Object CC or TO wasn\'t specified.');
throw new Exception('Either Object CC or TO wasn\'t specified.');
}
if (!isset($object['content'])) {
common_debug('ActivityPub Notice Validator: Rejected because Content was not specified (GNU social requires content in notes).');
return false;
}
return true;
}
/**
* Get the original representation URL of a given notice.
*
* @param Notice $notice notice from which to retrieve the URL
* @return string URL
* @throws InvalidUrlException
* @throws Exception
* @author Bruno Casteleiro <brunoccast@fc.up.pt>
* @see note_uri when it's not a generic activity but a object type note
*/
public static function getUri(Notice $notice): string
{
if ($notice->isLocal()) {
return common_local_url('apNotice', ['id' => $notice->getID()]);
} else {
return $notice->getUrl();
}
}
/**
* Use this if your Notice is in fact a note
*
* @param int $id
* @return string it's uri
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @see getUri for every other activity that aren't objects of a certain type like note
*/
public static function note_uri(int $id): string
{
return common_root_url() . 'object/note/' . $id;
}
/**
* Extract note policy type from note targets.
*
* @param array $note received Note
* @param Profile $actor_profile Note author
* @return int Notice policy type
* @author Bruno Casteleiro <brunoccast@fc.up.pt>
*/
public static function getNotePolicyType(array $note, Profile $actor_profile): int
{
$addressee = array_unique(array_merge($note['to'], $note['cc']));
if (in_array('https://www.w3.org/ns/activitystreams#Public', $addressee)) {
return $actor_profile->isLocal() ? Notice::LOCAL_PUBLIC : Notice::REMOTE;
} else {
// either an unlisted or followers-only note, we'll handle
// both as a GATEWAY notice since this type is not visible
// from the public timelines, hence partially enough while
// we don't have subscription_policy working.
return Notice::GATEWAY;
}
}
}