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gnu-social-v2-archive-activ.../utils/explorer.php
Diogo Cordeiro edb3633bcd Proper AP Notices (fixed #46)
Explorer now works both for local and remote URIs
Fixed various serious errors (most of them in Explorer
and some in AP Profiles)
2018-07-29 02:35:04 +01:00

309 lines
11 KiB
PHP
Executable File

<?php
/**
* GNU social - a federating social network
*
* ActivityPubPlugin implementation for GNU Social
*
* LICENCE: 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/>.
*
* @category Plugin
* @package GNUsocial
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @author Daniel Supernault <danielsupernault@gmail.com>
* @copyright 2018 Free Software Foundation http://fsf.org
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link https://www.gnu.org/software/social/
*/
if (!defined('GNUSOCIAL')) {
exit(1);
}
/**
* ActivityPub's own Explorer
*
* Allows to discovery new (or the same) Profiles (both local or remote)
*
* @category Plugin
* @package GNUsocial
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://www.gnu.org/software/social/
*/
class Activitypub_explorer
{
private $discovered_actor_profiles = array();
/**
* Get every profile from the given URL
* This function cleans the $this->discovered_actor_profiles array
* so that there is no erroneous data
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param string $url User's url
* @return array of Profile objects
*/
public function lookup($url)
{
common_debug("Explorer started now looking for ".$url);
$this->discovered_actor_profiles = array();
return $this->_lookup($url);
}
/**
* Get every profile from the given URL
* This is a recursive function that will accumulate the results on
* $discovered_actor_profiles array
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param string $url User's url
* @return array of Profile objects
*/
private function _lookup($url)
{
// First check if we already have it locally and, if so, return it
// If the local fetch fails: grab it remotely, store locally and return
if (! ($this->grab_local_user($url) || $this->grab_remote_user($url))) {
throw new Exception("User not found.");
}
return $this->discovered_actor_profiles;
}
/**
* This ensures that we are using a valid ActivityPub URI
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param string $url
* @return boolean success state (related to the response)
* @throws Exception (If the HTTP request fails)
*/
private function ensure_proper_remote_uri($url)
{
$client = new HTTPClient();
$headers = [];
$headers[] = 'Accept: application/ld+json; profile="https://www.w3.org/ns/activitystreams"';
$headers[] = 'User-Agent: GNUSocialBot v0.1 - https://gnu.io/social';
$response = $client->get($url, $headers);
$res = json_decode($response->getBody(), JSON_UNESCAPED_SLASHES);
if (self::validate_remote_response($res)) {
$this->temp_res = $res;
return true;
}
return false;
}
/**
* Get a local user profile from its URL and joins it on
* $this->discovered_actor_profiles
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param string $uri Actor's uri
* @return boolean success state
*/
private function grab_local_user($uri, $online = false)
{
if ($online) {
common_debug("Explorer is searching locally for ".$uri. " online.");
} else {
common_debug("Explorer is searching locally for ".$uri. " offline.");
}
// Ensure proper remote URI
// If an exception occurs here it's better to just leave everything
// break than to continue processing
if ($online && $this->ensure_proper_remote_uri($uri)) {
$uri = $this->temp_res["id"];
}
// Try standard ActivityPub route
// Is this a known filthy little mudblood?
$aprofile = self::get_aprofile_by_url($uri);
if ($aprofile instanceof Activitypub_profile) {
$profile = $aprofile->local_profile();
common_debug("Explorer found a local Aprofile for ".$uri);
// We found something!
$this->discovered_actor_profiles[]= $profile;
unset($this->temp_res); // IMPORTANT to avoid _dangerous_ noise in the Explorer system
return true;
} else {
common_debug("Explorer didn't find a local Aprofile for ".$uri);
// Well, maybe it is a pure blood?
// Iff, we are in the same instance:
$ACTIVITYPUB_BASE_INSTANCE_URI_length = strlen(ACTIVITYPUB_BASE_INSTANCE_URI);
if (substr($uri, 0, $ACTIVITYPUB_BASE_INSTANCE_URI_length) == ACTIVITYPUB_BASE_INSTANCE_URI) {
try {
$profile = Profile::getByID(intval(substr($uri, $ACTIVITYPUB_BASE_INSTANCE_URI_length)));
// We found something!
$this->discovered_actor_profiles[]= $profile;
unset($this->temp_res); // IMPORTANT to avoid _dangerous_ noise in the Explorer system
return true;
} catch (Exception $e) {
// Let the exception go on its merry way.
}
}
}
// If offline grabbing failed, attempt again with online resources
if (!$online) {
return $this->grab_local_user($uri, true);
}
return false;
}
/**
* Get a remote user(s) profile(s) from its URL and joins it on
* $this->discovered_actor_profiles
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param string $url User's url
* @return boolean success state
*/
private function grab_remote_user($url)
{
common_debug("Explorer is grabbing a remote profile for ".$url);
if (!isset($this->temp_res)) {
$client = new HTTPClient();
$headers = array();
$headers[] = 'Accept: application/ld+json; profile="https://www.w3.org/ns/activitystreams"';
$headers[] = 'User-Agent: GNUSocialBot v0.1 - https://gnu.io/social';
$response = $client->get($url, $headers);
$res = json_decode($response->getBody(), JSON_UNESCAPED_SLASHES);
} else {
$res = $this->temp_res;
unset($this->temp_res);
}
if (isset($res["orderedItems"])) { // It's a potential collection of actors!!!
foreach ($res["orderedItems"] as $profile) {
if ($this->_lookup($profile) == false) {
// XXX: Invalid actor found, not sure how we handle those
}
}
// Go through entire collection
if (!is_null($res["next"])) {
$this->_lookup($res["next"]);
}
return true;
} elseif (self::validate_remote_response($res)) {
$this->discovered_actor_profiles[]= $this->store_profile($res);
return true;
}
return false;
}
/**
* Save remote user profile in local instance
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param array $res remote response
* @return Profile remote Profile object
*/
private function store_profile($res)
{
// ActivityPub Profile
$aprofile = new Activitypub_profile;
$aprofile->uri = $res['id'];
$aprofile->nickname = $res['preferredUsername'];
$aprofile->fullname = $res['name'];
$aprofile->bio = substr($res['summary'], 0, 1000);
$aprofile->inboxuri = $res['inbox'];
$aprofile->sharedInboxuri = isset($res['endpoints']['sharedInbox']) ? $res['endpoints']['sharedInbox'] : $res['inbox'];
$aprofile->do_insert();
$profile = $aprofile->local_profile();
// Public Key
$apRSA = new Activitypub_rsa();
$apRSA->profile_id = $profile->getID();
$apRSA->public_key = $res['publicKey']['publicKeyPem'];
$apRSA->store_keys();
return $profile;
}
/**
* Validates a remote response in order to determine whether this
* response is a valid profile or not
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param array $res remote response
* @return boolean success state
*/
public static function validate_remote_response($res)
{
if (!isset($res['id'], $res['preferredUsername'], $res['name'], $res['summary'], $res['inbox'], $res['publicKey']['publicKeyPem'])) {
return false;
}
return true;
}
/**
* Get a ActivityPub Profile from it's uri
* Unfortunately GNU Social cache is not truly reliable when handling
* potential ActivityPub remote profiles, as so it is important to use
* this hacky workaround (at least for now)
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param string $v URL
* @return boolean|Activitypub_profile false if fails | Aprofile object if successful
*/
public static function get_aprofile_by_url($v)
{
$i = Managed_DataObject::getcached("Activitypub_profile", "uri", $v);
if (empty($i)) { // false = cache miss
$i = new Activitypub_profile;
$result = $i->get("uri", $v);
if ($result) {
// Hit!
$i->encache();
} else {
return false;
}
}
return $i;
}
/**
* Given a valid actor profile url returns its inboxes
*
* @author Diogo Cordeiro <diogo@fc.up.pt>
* @param string $url of Actor profile
* @return boolean|array false if fails | array with inbox and shared inbox if successful
*/
public static function get_actor_inboxes_uri($url)
{
$client = new HTTPClient();
$headers = array();
$headers[] = 'Accept: application/ld+json; profile="https://www.w3.org/ns/activitystreams"';
$headers[] = 'User-Agent: GNUSocialBot v0.1 - https://gnu.io/social';
$response = $client->get($url, $headers);
if (!$response->isOk()) {
throw new Exception('Invalid Actor URL.');
}
$res = json_decode($response->getBody(), JSON_UNESCAPED_SLASHES);
if (self::validate_remote_response($res)) {
return [
'inbox' => $res['inbox'],
'sharedInbox' => isset($res['endpoints']['sharedInbox']) ? $res['endpoints']['sharedInbox'] : $res['inbox']
];
}
return false;
}
}