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Signature check added

pull/5794/head
Michael 3 years ago
parent
commit
67fa0ed433
  1. 13
      src/Module/Inbox.php
  2. 157
      src/Protocol/ActivityPub.php

13
src/Module/Inbox.php

@ -5,10 +5,7 @@
namespace Friendica\Module;
use Friendica\BaseModule;
use Friendica\Database\DBA;
use Friendica\Model\Contact;
use Friendica\Util\HTTPSignature;
use Friendica\Util\Network;
use Friendica\Protocol\ActivityPub;
use Friendica\Core\System;
/**
@ -26,7 +23,13 @@ class Inbox extends BaseModule
System::httpExit(400);
}
$tempfile = tempnam(get_temppath(), 'activitypub');
if (ActivityPub::verifySignature($postdata, $_SERVER)) {
$filename = 'signed-activitypub';
} else {
$filename = 'failed-activitypub';
}
$tempfile = tempnam(get_temppath(), filename);
file_put_contents($tempfile, json_encode(['header' => $_SERVER, 'body' => $postdata]));
System::httpExit(200);

157
src/Protocol/ActivityPub.php

@ -53,16 +53,11 @@ class ActivityPub
$headers[] = 'Signature: keyId="' . $owner['url'] . '#main-key' . '",headers="(request-target) host date",signature="' . $signature . '"';
$headers[] = 'Content-Type: application/activity+json';
//print_r($headers);
//die($signed_data);
//$headers = [];
// $headers = HTTPSignature::createSig('', $headers, $owner['uprvkey'], $owner['url'] . '#main-key', false, false, 'sha256');
Network::post($target, $content, $headers);
$return_code = BaseObject::getApp()->get_curl_code();
echo $return_code."\n";
print_r(BaseObject::getApp()->get_curl_headers());
print_r($headers);
echo $return_code."\n";
}
/**
@ -226,6 +221,154 @@ echo $return_code."\n";
return false;
}
public static function verifySignature($content, $http_headers)
{
$object = json_decode($content, true);
if (empty($object)) {
return false;
}
$actor = self::processElement($object, 'actor', 'id');
$headers = [];
$headers['(request-target)'] = strtolower($http_headers['REQUEST_METHOD']) . ' ' . $http_headers['REQUEST_URI'];
// First take every header
foreach ($http_headers as $k => $v) {
$field = str_replace('_', '-', strtolower($k));
$headers[$field] = $v;
}
// Now add every http header
foreach ($http_headers as $k => $v) {
if (strpos($k, 'HTTP_') === 0) {
$field = str_replace('_', '-', strtolower(substr($k, 5)));
$headers[$field] = $v;
}
}
$sig_block = ActivityPub::parseSigHeader($http_headers['HTTP_SIGNATURE']);
if (empty($sig_block) || empty($sig_block['headers']) || empty($sig_block['keyId'])) {
return false;
}
$signed_data = '';
foreach ($sig_block['headers'] as $h) {
if (array_key_exists($h, $headers)) {
$signed_data .= $h . ': ' . $headers[$h] . "\n";
}
}
$signed_data = rtrim($signed_data, "\n");
if (empty($signed_data)) {
return false;
}
$algorithm = null;
if ($sig_block['algorithm'] === 'rsa-sha256') {
$algorithm = 'sha256';
}
if ($sig_block['algorithm'] === 'rsa-sha512') {
$algorithm = 'sha512';
}
if (empty($algorithm)) {
return false;
}
$key = self::fetchKey($sig_block['keyId'], $actor);
if (empty($key)) {
return false;
}
if (!Crypto::rsaVerify($signed_data, $sig_block['signature'], $key, $algorithm)) {
return false;
}
// Check the digest if it was part of the signed data
if (in_array('digest', $sig_block['headers'])) {
$digest = explode('=', $headers['digest'], 2);
if ($digest[0] === 'SHA-256') {
$hashalg = 'sha256';
}
if ($digest[0] === 'SHA-512') {
$hashalg = 'sha512';
}
/// @todo addd all hashes from the rfc
if (!empty($hashalg) && base64_encode(hash($hashalg, $content, true)) != $digest[1]) {
return false;
}
}
// Check the content-length if it was part of the signed data
if (in_array('content-length', $sig_block['headers'])) {
if (strlen($content) != $headers['content-length']) {
return false;
}
}
return true;
}
private static function fetchKey($id, $actor)
{
$url = (strpos($id, '#') ? substr($id, 0, strpos($id, '#')) : $id);
$profile = self::fetchProfile($url);
if (!empty($profile)) {
return $profile['pubkey'];
} elseif ($url != $actor) {
$profile = self::fetchProfile($actor);
if (!empty($profile)) {
return $profile['pubkey'];
}
}
return false;
}
/**
* @brief
*
* @param string $header
* @return array associate array with
* - \e string \b keyID
* - \e string \b algorithm
* - \e array \b headers
* - \e string \b signature
*/
private static function parseSigHeader($header)
{
$ret = [];
$matches = [];
if (preg_match('/keyId="(.*?)"/ism',$header,$matches)) {
$ret['keyId'] = $matches[1];
}
if (preg_match('/algorithm="(.*?)"/ism',$header,$matches)) {
$ret['algorithm'] = $matches[1];
}
if (preg_match('/headers="(.*?)"/ism',$header,$matches)) {
$ret['headers'] = explode(' ', $matches[1]);
}
if (preg_match('/signature="(.*?)"/ism',$header,$matches)) {
$ret['signature'] = base64_decode(preg_replace('/\s+/','',$matches[1]));
}
return $ret;
}
/**
* Fetches a profile from the given url
*

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