friendica/src/Protocol/Salmon.php
Hypolite Petovan 55640eec87 [Composer] Upgrade to phpseclib version 3
- Create custom Key file format for Salmon Magic key
- Remove obsolete pemToME and MEtoPem Crypto methods
- Remove unused newECKeypair Crypto method
- Switch to constant-time Base64 encode/decode in Base64Url Strings methods
2022-11-25 08:13:05 -05:00

264 lines
7.4 KiB
PHP

<?php
/**
* @copyright Copyright (C) 2010-2022, the Friendica project
*
* @license GNU AGPL version 3 or any later version
*
* 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 <https://www.gnu.org/licenses/>.
*
*/
namespace Friendica\Protocol;
use Friendica\Core\Logger;
use Friendica\DI;
use Friendica\Network\HTTPClient\Client\HttpClientAccept;
use Friendica\Network\Probe;
use Friendica\Protocol\Salmon\Format\Magic;
use Friendica\Util\Crypto;
use Friendica\Util\Strings;
use Friendica\Util\XML;
use phpseclib3\Crypt\PublicKeyLoader;
/**
* Salmon Protocol class
*
* The Salmon Protocol is a message exchange protocol running over HTTP designed to decentralize commentary
* and annotations made against newsfeed articles such as blog posts.
*/
class Salmon
{
/**
* @param string $uri Uniform Resource Identifier
* @param string $keyhash encoded key
* @return string Key or empty string on any errors
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
public static function getKey(string $uri, string $keyhash): string
{
$ret = [];
Logger::info('Fetching salmon key for '.$uri);
$arr = Probe::lrdd($uri);
if (is_array($arr)) {
foreach ($arr as $a) {
if ($a['@attributes']['rel'] === 'magic-public-key') {
$ret[] = $a['@attributes']['href'];
}
}
} else {
return '';
}
// We have found at least one key URL
// If it's inline, parse it - otherwise get the key
if (count($ret) > 0) {
for ($x = 0; $x < count($ret); $x ++) {
if (substr($ret[$x], 0, 5) === 'data:') {
if (strstr($ret[$x], ',')) {
$ret[$x] = substr($ret[$x], strpos($ret[$x], ',') + 1);
} else {
$ret[$x] = substr($ret[$x], 5);
}
} elseif (Strings::normaliseLink($ret[$x]) == 'http://') {
$ret[$x] = DI::httpClient()->fetch($ret[$x], HttpClientAccept::MAGIC_KEY);
Logger::debug('Fetched public key', ['url' => $ret[$x]]);
}
}
}
Logger::notice('Key located', ['ret' => $ret]);
if (count($ret) == 1) {
/* We only found one one key so we don't care if the hash matches.
* If it's the wrong key we'll find out soon enough because
* message verification will fail. This also covers some older
* software which don't supply a keyhash. As long as they only
* have one key we'll be right.
*/
return (string) $ret[0];
} else {
foreach ($ret as $a) {
$hash = Strings::base64UrlEncode(hash('sha256', $a));
if ($hash == $keyhash) {
return $a;
}
}
}
return '';
}
/**
* @param array $owner owner
* @param string $url url
* @param string $slap slap
* @return integer
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
public static function slapper(array $owner, string $url, string $slap): int
{
// does contact have a salmon endpoint?
if (!strlen($url)) {
return -1;
}
if (!$owner['sprvkey']) {
Logger::notice(sprintf("user '%s' (%d) does not have a salmon private key. Send failed.",
$owner['name'], $owner['uid']));
return -1;
}
Logger::info('slapper called for '.$url.'. Data: ' . $slap);
// create a magic envelope
$data = Strings::base64UrlEncode($slap);
$data_type = 'application/atom+xml';
$encoding = 'base64url';
$algorithm = 'RSA-SHA256';
$keyhash = Strings::base64UrlEncode(hash('sha256', self::salmonKey($owner['spubkey'])), true);
$precomputed = '.' . Strings::base64UrlEncode($data_type) . '.' . Strings::base64UrlEncode($encoding) . '.' . Strings::base64UrlEncode($algorithm);
// GNU Social format
$signature = Strings::base64UrlEncode(Crypto::rsaSign($data . $precomputed, $owner['sprvkey']));
// Compliant format
$signature2 = Strings::base64UrlEncode(Crypto::rsaSign(str_replace('=', '', $data . $precomputed), $owner['sprvkey']));
// Old Status.net format
$signature3 = Strings::base64UrlEncode(Crypto::rsaSign($data, $owner['sprvkey']));
// At first try the non compliant method that works for GNU Social
$xmldata = [
'me:env' => [
'me:data' => $data,
'@attributes' => ['type' => $data_type],
'me:encoding' => $encoding,
'me:alg' => $algorithm,
'me:sig' => $signature,
'@attributes2' => ['key_id' => $keyhash],
]
];
$namespaces = ['me' => ActivityNamespace::SALMON_ME];
$salmon = XML::fromArray($xmldata, $xml, false, $namespaces);
// slap them
$postResult = DI::httpClient()->post($url, $salmon, [
'Content-type' => 'application/magic-envelope+xml',
'Content-length' => strlen($salmon),
]);
$return_code = $postResult->getReturnCode();
// check for success, e.g. 2xx
if ($return_code > 299) {
Logger::notice('GNU Social salmon failed. Falling back to compliant mode');
// Now try the compliant mode that normally isn't used for GNU Social
$xmldata = [
'me:env' => [
'me:data' => $data,
'@attributes' => ['type' => $data_type],
'me:encoding' => $encoding,
'me:alg' => $algorithm,
'me:sig' => $signature2,
'@attributes2' => ['key_id' => $keyhash]
]
];
$namespaces = ['me' => ActivityNamespace::SALMON_ME];
$salmon = XML::fromArray($xmldata, $xml, false, $namespaces);
// slap them
$postResult = DI::httpClient()->post($url, $salmon, [
'Content-type' => 'application/magic-envelope+xml',
'Content-length' => strlen($salmon),
]);
$return_code = $postResult->getReturnCode();
}
if ($return_code > 299) {
Logger::notice('compliant salmon failed. Falling back to old status.net');
// Last try. This will most likely fail as well.
$xmldata = [
'me:env' => [
'me:data' => $data,
'@attributes' => ['type' => $data_type],
'me:encoding' => $encoding,
'me:alg' => $algorithm,
'me:sig' => $signature3,
'@attributes2' => ['key_id' => $keyhash],
]
];
$namespaces = ['me' => ActivityNamespace::SALMON_ME];
$salmon = XML::fromArray($xmldata, $xml, false, $namespaces);
// slap them
$postResult = DI::httpClient()->post($url, $salmon, [
'Content-type' => 'application/magic-envelope+xml',
'Content-length' => strlen($salmon)]);
$return_code = $postResult->getReturnCode();
}
Logger::info('slapper for '.$url.' returned ' . $return_code);
if (! $return_code) {
return -1;
}
if (($return_code == 503) && $postResult->inHeader('retry-after')) {
return -1;
}
return (($return_code >= 200) && ($return_code < 300)) ? 0 : 1;
}
/**
* @param string $pubkey public key
* @return string
* @throws \Exception
*/
public static function salmonKey(string $pubkey): string
{
\phpseclib3\Crypt\RSA::addFileFormat(Magic::class);
return PublicKeyLoader::load($pubkey)->toString('Magic');
}
/**
* @param string $magic Magic key format starting with "RSA."
* @return string
*/
public static function magicKeyToPem(string $magic): string
{
\phpseclib3\Crypt\RSA::addFileFormat(Magic::class);
return (string) PublicKeyLoader::load($magic);
}
}