diff options
Diffstat (limited to 'plugins/OStatus/lib/magicenvelope.php')
| -rw-r--r-- | plugins/OStatus/lib/magicenvelope.php | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/plugins/OStatus/lib/magicenvelope.php b/plugins/OStatus/lib/magicenvelope.php new file mode 100644 index 000000000..fb8c57c71 --- /dev/null +++ b/plugins/OStatus/lib/magicenvelope.php @@ -0,0 +1,215 @@ +<?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 MagicEnvelope +{ + const ENCODING = 'base64url'; + + const NS = 'http://salmon-protocol.org/ns/magic-env'; + + private function normalizeUser($user_id) + { + if (substr($user_id, 0, 5) == 'http:' || + substr($user_id, 0, 6) == 'https:' || + substr($user_id, 0, 5) == 'acct:') { + return $user_id; + } + + if (strpos($user_id, '@') !== FALSE) { + return 'acct:' . $user_id; + } + + return 'http://' . $user_id; + } + + public function getKeyPair($signer_uri) + { + $disco = new Discovery(); + + try { + $xrd = $disco->lookup($signer_uri); + } catch (Exception $e) { + return false; + } + if ($xrd->links) { + if ($link = Discovery::getService($xrd->links, Magicsig::PUBLICKEYREL)) { + list($type, $keypair) = explode(';', $link['href']); + return $keypair; + } + } + throw new Exception('Unable to locate signer public key'); + } + + + public function signMessage($text, $mimetype, $keypair) + { + $signature_alg = Magicsig::fromString($keypair); + $armored_text = base64_encode($text); + + return array( + 'data' => $armored_text, + 'encoding' => MagicEnvelope::ENCODING, + 'data_type' => $mimetype, + 'sig' => $signature_alg->sign($armored_text), + 'alg' => $signature_alg->getName() + ); + + + } + + public function toXML($env) { + $dom = new DOMDocument(); + + $envelope = $dom->createElementNS(MagicEnvelope::NS, 'me:env'); + $envelope->setAttribute('xmlns:me', MagicEnvelope::NS); + $data = $dom->createElementNS(MagicEnvelope::NS, 'me:data', $env['data']); + $data->setAttribute('type', $env['data_type']); + $envelope->appendChild($data); + $enc = $dom->createElementNS(MagicEnvelope::NS, 'me:encoding', $env['encoding']); + $envelope->appendChild($enc); + $alg = $dom->createElementNS(MagicEnvelope::NS, 'me:alg', $env['alg']); + $envelope->appendChild($alg); + $sig = $dom->createElementNS(MagicEnvelope::NS, 'me:sig', $env['sig']); + $envelope->appendChild($sig); + + $dom->appendChild($envelope); + + + return $dom->saveXML(); + } + + + public function unfold($env) + { + $dom = new DOMDocument(); + $dom->loadXML(base64_decode($env['data'])); + + if ($dom->documentElement->tagName != 'entry') { + return false; + } + + $prov = $dom->createElementNS(MagicEnvelope::NS, 'me:provenance'); + $prov->setAttribute('xmlns:me', MagicEnvelope::NS); + $data = $dom->createElementNS(MagicEnvelope::NS, 'me:data', $env['data']); + $data->setAttribute('type', $env['data_type']); + $prov->appendChild($data); + $enc = $dom->createElementNS(MagicEnvelope::NS, 'me:encoding', $env['encoding']); + $prov->appendChild($enc); + $alg = $dom->createElementNS(MagicEnvelope::NS, 'me:alg', $env['alg']); + $prov->appendChild($alg); + $sig = $dom->createElementNS(MagicEnvelope::NS, 'me:sig', $env['sig']); + $prov->appendChild($sig); + + $dom->documentElement->appendChild($prov); + + return $dom->saveXML(); + } + + public function getAuthor($text) { + $doc = new DOMDocument(); + if (!$doc->loadXML($text)) { + return FALSE; + } + + if ($doc->documentElement->tagName == 'entry') { + $authors = $doc->documentElement->getElementsByTagName('author'); + foreach ($authors as $author) { + $uris = $author->getElementsByTagName('uri'); + foreach ($uris as $uri) { + return $this->normalizeUser($uri->nodeValue); + } + } + } + } + + public function checkAuthor($text, $signer_uri) + { + return ($this->getAuthor($text) == $signer_uri); + } + + public function verify($env) + { + if ($env['alg'] != 'RSA-SHA256') { + common_log(LOG_DEBUG, "Salmon error: bad algorithm"); + return false; + } + + if ($env['encoding'] != MagicEnvelope::ENCODING) { + common_log(LOG_DEBUG, "Salmon error: bad encoding"); + return false; + } + + $text = base64_decode($env['data']); + $signer_uri = $this->getAuthor($text); + + try { + $keypair = $this->getKeyPair($signer_uri); + } catch (Exception $e) { + common_log(LOG_DEBUG, "Salmon error: ".$e->getMessage()); + return false; + } + + $verifier = Magicsig::fromString($keypair); + + if (!$verifier) { + common_log(LOG_DEBUG, "Salmon error: unable to parse keypair"); + return false; + } + + return $verifier->verify($env['data'], $env['sig']); + } + + public function parse($text) + { + $dom = DOMDocument::loadXML($text); + return $this->fromDom($dom); + } + + public function fromDom($dom) + { + if ($dom->documentElement->tagName == 'entry') { + $env_element = $dom->getElementsByTagNameNS(MagicEnvelope::NS, 'provenance')->item(0); + } else if ($dom->documentElement->tagName == 'me:env') { + $env_element = $dom->documentElement; + } else { + return false; + } + + $data_element = $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'data')->item(0); + + return array( + 'data' => trim($data_element->nodeValue), + 'data_type' => $data_element->getAttribute('type'), + 'encoding' => $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'encoding')->item(0)->nodeValue, + 'alg' => $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'alg')->item(0)->nodeValue, + 'sig' => $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'sig')->item(0)->nodeValue, + ); + } + +} |