gnu-social/plugins/OStatus/lib/salmon.php
2014-05-05 19:06:22 +02:00

166 lines
5.8 KiB
PHP

<?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/
*/
class Salmon
{
const REL_SALMON = 'salmon';
const REL_MENTIONED = 'mentioned';
// XXX: these are deprecated
const NS_REPLIES = "http://salmon-protocol.org/ns/salmon-replies";
const NS_MENTIONS = "http://salmon-protocol.org/ns/salmon-mention";
/**
* Sign and post the given Atom entry as a Salmon message.
*
* Side effects: may generate a keypair on-demand for the given user,
* which can be very slow on some systems.
*
* @param string $endpoint_uri
* @param string $xml string representation of payload
* @param Profile $actor local user profile whose keys to sign with
* @return boolean success
*/
public function post($endpoint_uri, $xml, Profile $actor)
{
if (empty($endpoint_uri)) {
return false;
}
foreach ($this->formatClasses() as $class) {
try {
$envelope = $this->createMagicEnv($xml, $actor, $class);
} catch (Exception $e) {
common_log(LOG_ERR, "Salmon unable to sign: " . $e->getMessage());
return false;
}
$headers = array('Content-Type: application/magic-envelope+xml');
try {
$client = new HTTPClient();
$client->setBody($envelope);
$response = $client->post($endpoint_uri, $headers);
} catch (HTTP_Request2_Exception $e) {
common_log(LOG_ERR, "Salmon ($class) post to $endpoint_uri failed: " . $e->getMessage());
continue;
}
if ($response->getStatus() != 200) {
common_log(LOG_ERR, "Salmon ($class) at $endpoint_uri returned status " .
$response->getStatus() . ': ' . $response->getBody());
continue;
}
// Success!
return true;
}
return false;
}
/**
* List the magic envelope signature class variants in the order we try them.
* Multiples are needed for backwards-compat with StatusNet prior to 0.9.7,
* which used a draft version of the magic envelope spec.
*/
protected function formatClasses() {
return array('MagicEnvelope', 'MagicEnvelopeCompat');
}
/**
* Encode the given string as a signed MagicEnvelope XML document,
* using the keypair for the given local user profile.
*
* Side effects: will create and store a keypair on-demand if one
* hasn't already been generated for this user. This can be very slow
* on some systems.
*
* @param string $text XML fragment to sign, assumed to be Atom
* @param Profile $actor Profile of a local user to use as signer
* @param string $class to override the magic envelope signature version, pass a MagicEnvelope subclass here
*
* @return string XML string representation of magic envelope
*
* @throws Exception on bad profile input or key generation problems
* @fixme if signing fails, this seems to return the original text without warning. Is there a reason for this?
*/
public function createMagicEnv($text, $actor, $class='MagicEnvelope')
{
$magic_env = new $class();
$user = User::getKV('id', $actor->id);
if ($user->id) {
// Use local key
$magickey = Magicsig::getKV('user_id', $user->id);
if (!$magickey) {
// No keypair yet, let's generate one.
$magickey = new Magicsig();
$magickey->generate($user->id);
}
} else {
// TRANS: Exception.
throw new Exception(_m('Salmon invalid actor for signing.'));
}
try {
$env = $magic_env->signMessage($text, 'application/atom+xml', $magickey->toString());
} catch (Exception $e) {
return $text;
}
return $magic_env->toXML($env);
}
/**
* Check if the given magic envelope is well-formed and correctly signed.
* Needs to have network access to fetch public keys over the web.
* Both current and back-compat signature formats will be checked.
*
* Side effects: exceptions and caching updates may occur during network
* fetches.
*
* @param string $text XML fragment of magic envelope
* @return boolean
*
* @throws Exception on bad profile input or key generation problems
* @fixme could hit fatal errors or spew output on invalid XML
*/
public function verifyMagicEnv($text)
{
foreach ($this->formatClasses() as $class) {
$magic_env = new $class();
$env = $magic_env->parse($text);
if ($magic_env->verify($env)) {
return true;
}
}
return false;
}
}