. * */ namespace Friendica\Util; use Friendica\Core\Logger; use Friendica\Core\Protocol; use Friendica\Database\Database; use Friendica\Database\DBA; use Friendica\DI; use Friendica\Model\APContact; use Friendica\Model\Contact; use Friendica\Model\GServer; use Friendica\Model\ItemURI; use Friendica\Model\User; use Friendica\Network\HTTPClient\Capability\ICanHandleHttpResponses; use Friendica\Network\HTTPClient\Client\HttpClientAccept; use Friendica\Network\HTTPClient\Client\HttpClientOptions; /** * Implements HTTP Signatures per draft-cavage-http-signatures-07. * * Ported from Hubzilla: https://framagit.org/hubzilla/core/blob/master/Zotlabs/Web/HTTPSig.php * * Other parts of the code for HTTP signing are taken from the Osada project. * https://framagit.org/macgirvin/osada * * @see https://tools.ietf.org/html/draft-cavage-http-signatures-07 */ class HTTPSignature { // See draft-cavage-http-signatures-08 /** * Verifies a magic request * * @param $key * * @return array with verification data * @throws \Friendica\Network\HTTPException\InternalServerErrorException */ public static function verifyMagic(string $key): array { $headers = null; $spoofable = false; $result = [ 'signer' => '', 'header_signed' => false, 'header_valid' => false ]; // Decide if $data arrived via controller submission or curl. $headers = []; $headers['(request-target)'] = strtolower(DI::args()->getMethod()).' '.$_SERVER['REQUEST_URI']; foreach ($_SERVER as $k => $v) { if (strpos($k, 'HTTP_') === 0) { $field = str_replace('_', '-', strtolower(substr($k, 5))); $headers[$field] = $v; } } $sig_block = null; $sig_block = self::parseSigheader($headers['authorization']); if (!$sig_block) { Logger::notice('no signature provided.'); return $result; } $result['header_signed'] = true; $signed_headers = $sig_block['headers']; if (!$signed_headers) { $signed_headers = ['date']; } $signed_data = ''; foreach ($signed_headers as $h) { if (array_key_exists($h, $headers)) { $signed_data .= $h . ': ' . $headers[$h] . "\n"; } if (strpos($h, '.')) { $spoofable = true; } } $signed_data = rtrim($signed_data, "\n"); $algorithm = 'sha512'; if ($key && function_exists($key)) { $result['signer'] = $sig_block['keyId']; $key = $key($sig_block['keyId']); } Logger::info('Got keyID ' . $sig_block['keyId']); if (!$key) { return $result; } $x = Crypto::rsaVerify($signed_data, $sig_block['signature'], $key, $algorithm); Logger::info('verified: ' . $x); if (!$x) { return $result; } if (!$spoofable) { $result['header_valid'] = true; } return $result; } /** * @param array $head * @param string $prvkey * @param string $keyid (optional, default 'Key') * * @return array */ public static function createSig(array $head, string $prvkey, string $keyid = 'Key'): array { $return_headers = []; if (!empty($head)) { $return_headers = $head; } $alg = 'sha512'; $algorithm = 'rsa-sha512'; $x = self::sign($head, $prvkey, $alg); $headerval = 'keyId="' . $keyid . '",algorithm="' . $algorithm . '",headers="' . $x['headers'] . '",signature="' . $x['signature'] . '"'; $return_headers['Authorization'] = ['Signature ' . $headerval]; return $return_headers; } /** * @param array $head * @param string $prvkey * @param string $alg (optional) default 'sha256' * * @return array */ private static function sign(array $head, string $prvkey, string $alg = 'sha256'): array { $ret = []; $headers = ''; $fields = ''; foreach ($head as $k => $v) { if (is_array($v)) { $v = implode(', ', $v); } $headers .= strtolower($k) . ': ' . trim($v) . "\n"; if ($fields) { $fields .= ' '; } $fields .= strtolower($k); } // strip the trailing linefeed $headers = rtrim($headers, "\n"); $sig = base64_encode(Crypto::rsaSign($headers, $prvkey, $alg)); $ret['headers'] = $fields; $ret['signature'] = $sig; return $ret; } /** * @param string $header * @return array associative array with * - \e string \b keyID * - \e string \b created * - \e string \b expires * - \e string \b algorithm * - \e array \b headers * - \e string \b signature * @throws \Friendica\Network\HTTPException\InternalServerErrorException */ public static function parseSigheader(string $header): array { // Remove obsolete folds $header = preg_replace('/\n\s+/', ' ', $header); $token = "[!#$%&'*+.^_`|~0-9A-Za-z-]"; $quotedString = '"(?:\\\\.|[^"\\\\])*"'; $regex = "/($token+)=($quotedString|$token+)/ism"; $matches = []; preg_match_all($regex, $header, $matches, PREG_SET_ORDER); $headers = []; foreach ($matches as $match) { $headers[$match[1]] = trim($match[2] ?: $match[3], '"'); } // if the header is encrypted, decrypt with (default) site private key and continue if (!empty($headers['iv'])) { $header = self::decryptSigheader($headers, DI::config()->get('system', 'prvkey')); return self::parseSigheader($header); } $return = [ 'keyId' => $headers['keyId'] ?? '', 'algorithm' => $headers['algorithm'] ?? 'rsa-sha256', 'created' => $headers['created'] ?? null, 'expires' => $headers['expires'] ?? null, 'headers' => explode(' ', $headers['headers'] ?? ''), 'signature' => base64_decode(preg_replace('/\s+/', '', $headers['signature'] ?? '')), ]; if (!empty($return['signature']) && !empty($return['algorithm']) && empty($return['headers'])) { $return['headers'] = ['date']; } return $return; } /** * @param array $headers Signature headers * @param string $prvkey The site private key * @return string Decrypted signature string * @throws \Friendica\Network\HTTPException\InternalServerErrorException */ private static function decryptSigheader(array $headers, string $prvkey): string { if (!empty($headers['iv']) && !empty($headers['key']) && !empty($headers['data'])) { return Crypto::unencapsulate($headers, $prvkey); } return ''; } /* * Functions for ActivityPub */ /** * Post given data to a target for a user, returns the result class * * @param array $data Data that is about to be sent * @param string $target The URL of the inbox * @param array $owner Sender owner-view record * * @return ICanHandleHttpResponses */ public static function post(array $data, string $target, array $owner): ICanHandleHttpResponses { $content = json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE); // Header data that is about to be signed. $host = parse_url($target, PHP_URL_HOST); $path = parse_url($target, PHP_URL_PATH); $digest = 'SHA-256=' . base64_encode(hash('sha256', $content, true)); $content_length = strlen($content); $date = DateTimeFormat::utcNow(DateTimeFormat::HTTP); $headers = [ 'Date' => $date, 'Content-Length' => $content_length, 'Digest' => $digest, 'Host' => $host ]; $signed_data = "(request-target): post " . $path . "\ndate: ". $date . "\ncontent-length: " . $content_length . "\ndigest: " . $digest . "\nhost: " . $host; $signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256')); $headers['Signature'] = 'keyId="' . $owner['url'] . '#main-key' . '",algorithm="rsa-sha256",headers="(request-target) date content-length digest host",signature="' . $signature . '"'; $headers['Content-Type'] = 'application/activity+json'; $postResult = DI::httpClient()->post($target, $content, $headers, DI::config()->get('system', 'curl_timeout')); $return_code = $postResult->getReturnCode(); Logger::info('Transmit to ' . $target . ' returned ' . $return_code); self::setInboxStatus($target, ($return_code >= 200) && ($return_code <= 299)); return $postResult; } /** * Transmit given data to a target for a user * * @param array $data Data that is about to be sent * @param string $target The URL of the inbox * @param array $owner Sender owner-vew record * * @return boolean Was the transmission successful? */ public static function transmit(array $data, string $target, array $owner): bool { $postResult = self::post($data, $target, $owner); $return_code = $postResult->getReturnCode(); return ($return_code >= 200) && ($return_code <= 299); } /** * Set the delivery status for a given inbox * * @param string $url The URL of the inbox * @param boolean $success Transmission status * @param boolean $shared The inbox is a shared inbox * @param int $gsid Server ID * @throws \Exception */ static public function setInboxStatus(string $url, bool $success, bool $shared = false, int $gsid = null) { $now = DateTimeFormat::utcNow(); $status = DBA::selectFirst('inbox-status', [], ['url' => $url]); if (!DBA::isResult($status)) { $insertFields = ['url' => $url, 'uri-id' => ItemURI::getIdByURI($url), 'created' => $now, 'shared' => $shared]; if (!empty($gsid)) { $insertFields['gsid'] = $gsid; } DBA::insert('inbox-status', $insertFields, Database::INSERT_IGNORE); $status = DBA::selectFirst('inbox-status', [], ['url' => $url]); if (empty($status)) { Logger::warning('Unable to insert inbox-status row', $insertFields); return; } } if ($success) { $fields = ['success' => $now]; } else { $fields = ['failure' => $now]; } if (!empty($gsid)) { $fields['gsid'] = $gsid; } if ($status['failure'] > DBA::NULL_DATETIME) { $new_previous_stamp = strtotime($status['failure']); $old_previous_stamp = strtotime($status['previous']); // Only set "previous" with at least one day difference. // We use this to assure to not accidentally archive too soon. if (($new_previous_stamp - $old_previous_stamp) >= 86400) { $fields['previous'] = $status['failure']; } } if (!$success) { if ($status['success'] <= DBA::NULL_DATETIME) { $stamp1 = strtotime($status['created']); } else { $stamp1 = strtotime($status['success']); } $stamp2 = strtotime($now); $previous_stamp = strtotime($status['previous']); // Archive the inbox when there had been failures for five days. // Additionally ensure that at least one previous attempt has to be in between. if ((($stamp2 - $stamp1) >= 86400 * 5) && ($previous_stamp > $stamp1)) { $fields['archive'] = true; } } else { $fields['archive'] = false; } if (empty($status['uri-id'])) { $fields['uri-id'] = ItemURI::getIdByURI($url); } DBA::update('inbox-status', $fields, ['url' => $url]); if (!empty($status['gsid'])) { if ($success) { GServer::setReachableById($status['gsid'], Protocol::ACTIVITYPUB); } elseif ($status['shared']) { GServer::setFailureById($status['gsid']); } } } /** * Fetches JSON data for a user * * @param string $request request url * @param integer $uid User id of the requester * * @return array JSON array * @throws \Friendica\Network\HTTPException\InternalServerErrorException */ public static function fetch(string $request, int $uid = 0): array { try { $curlResult = self::fetchRaw($request, $uid); } catch (\Exception $exception) { Logger::notice('Error fetching url', ['url' => $request, 'exception' => $exception]); return []; } if (empty($curlResult)) { return []; } if (!$curlResult->isSuccess() || empty($curlResult->getBodyString())) { Logger::debug('Fetching was unsuccessful', ['url' => $request, 'return-code' => $curlResult->getReturnCode(), 'error-number' => $curlResult->getErrorNumber(), 'error' => $curlResult->getError()]); return []; } $content = json_decode($curlResult->getBodyString(), true); if (empty($content) || !is_array($content)) { return []; } if (!self::isValidContentType($curlResult->getContentType(), $request)) { return []; } return $content; } /** * Check if the provided content type is a valid LD JSON mime type * * @param string $contentType * @return boolean */ public static function isValidContentType(string $contentType, string $url = ''): bool { if (in_array(current(explode(';', $contentType)), ['application/activity+json', 'application/ld+json'])) { return true; } if (current(explode(';', $contentType)) == 'application/json') { Logger::notice('Unexpected content type, possibly from a remote system that is not standard compliant.', ['content-type' => $contentType, 'url' => $url]); } return false; } /** * Fetches raw data for a user * * @param string $request request url * @param integer $uid User id of the requester * @param boolean $binary TRUE if asked to return binary results (file download) (default is "false") * @param array $opts (optional parameters) associative array with: * 'accept_content' => supply Accept: header with 'accept_content' as the value * 'timeout' => int Timeout in seconds, default system config value or 60 seconds * 'nobody' => only return the header * 'cookiejar' => path to cookie jar file * * @return \Friendica\Network\HTTPClient\Capability\ICanHandleHttpResponses CurlResult * @throws \Friendica\Network\HTTPException\InternalServerErrorException */ public static function fetchRaw(string $request, int $uid = 0, array $opts = [HttpClientOptions::ACCEPT_CONTENT => [HttpClientAccept::JSON_AS]]) { $header = []; if (!empty($uid)) { $owner = User::getOwnerDataById($uid); if (!$owner) { return; } } else { $owner = User::getSystemAccount(); if (!$owner) { return; } } if (!empty($owner['uprvkey'])) { // Header data that is about to be signed. $host = parse_url($request, PHP_URL_HOST); $path = parse_url($request, PHP_URL_PATH); $date = DateTimeFormat::utcNow(DateTimeFormat::HTTP); $header['Date'] = $date; $header['Host'] = $host; $signed_data = "(request-target): get " . $path . "\ndate: ". $date . "\nhost: " . $host; $signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256')); $header['Signature'] = 'keyId="' . $owner['url'] . '#main-key' . '",algorithm="rsa-sha256",headers="(request-target) date host",signature="' . $signature . '"'; } $curl_opts = $opts; $curl_opts[HttpClientOptions::HEADERS] = $header; if (!empty($opts['nobody'])) { $curlResult = DI::httpClient()->head($request, $curl_opts); } else { $curlResult = DI::httpClient()->get($request, HttpClientAccept::JSON_AS, $curl_opts); } $return_code = $curlResult->getReturnCode(); Logger::info('Fetched for user ' . $uid . ' from ' . $request . ' returned ' . $return_code); return $curlResult; } /** * Fetch the apcontact entry of the keyId in the given header * * @param array $http_headers * * @return array APContact entry */ public static function getKeyIdContact(array $http_headers): array { if (empty($http_headers['HTTP_SIGNATURE'])) { Logger::debug('No HTTP_SIGNATURE header', ['header' => $http_headers]); return []; } $sig_block = self::parseSigHeader($http_headers['HTTP_SIGNATURE']); if (empty($sig_block['keyId'])) { Logger::debug('No keyId', ['sig_block' => $sig_block]); return []; } $url = (strpos($sig_block['keyId'], '#') ? substr($sig_block['keyId'], 0, strpos($sig_block['keyId'], '#')) : $sig_block['keyId']); return APContact::getByURL($url); } /** * Gets a signer from a given HTTP request * * @param string $content * @param array $http_headers * * @return string|null|false Signer * @throws \Friendica\Network\HTTPException\InternalServerErrorException */ public static function getSigner(string $content, array $http_headers) { if (empty($http_headers['HTTP_SIGNATURE'])) { Logger::debug('No HTTP_SIGNATURE header'); return false; } if (!empty($content)) { $object = json_decode($content, true); if (empty($object)) { Logger::info('No object'); return false; } $actor = JsonLD::fetchElement($object, 'actor', 'id') ?? ''; } else { $actor = ''; } $headers = []; $headers['(request-target)'] = strtolower(DI::args()->getMethod()) . ' ' . parse_url($http_headers['REQUEST_URI'], PHP_URL_PATH); // 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; } } $sig_block = self::parseSigHeader($http_headers['HTTP_SIGNATURE']); // Add fields from the signature block to the header. See issue 8845 if (!empty($sig_block['created']) && empty($headers['(created)'])) { $headers['(created)'] = $sig_block['created']; } if (!empty($sig_block['expires']) && empty($headers['(expires)'])) { $headers['(expires)'] = $sig_block['expires']; } if (empty($sig_block) || empty($sig_block['headers']) || empty($sig_block['keyId'])) { Logger::info('No headers or keyId'); return false; } $signed_data = ''; foreach ($sig_block['headers'] as $h) { if (array_key_exists($h, $headers)) { $signed_data .= $h . ': ' . $headers[$h] . "\n"; } else { Logger::info('Requested header field not found', ['field' => $h, 'header' => $headers]); } } $signed_data = rtrim($signed_data, "\n"); if (empty($signed_data)) { Logger::info('Signed data is empty'); return false; } $algorithm = null; // Wildcard value where signing algorithm should be derived from keyId // @see https://tools.ietf.org/html/draft-ietf-httpbis-message-signatures-00#section-4.1 // Defaulting to SHA256 as it seems to be the prevalent implementation // @see https://arewehs2019yet.vpzom.click if ($sig_block['algorithm'] === 'hs2019') { $algorithm = 'sha256'; } if ($sig_block['algorithm'] === 'rsa-sha256') { $algorithm = 'sha256'; } if ($sig_block['algorithm'] === 'rsa-sha512') { $algorithm = 'sha512'; } if (empty($algorithm)) { Logger::info('No algorithm'); return false; } $key = self::fetchKey($sig_block['keyId'], $actor); if (empty($key)) { Logger::info('Empty key'); return false; } if (!empty($key['url']) && !empty($key['type']) && ($key['type'] == 'Tombstone')) { Logger::info('Actor is a tombstone', ['key' => $key]); if (!Contact::isLocal($key['url'])) { // We now delete everything that we possibly knew from this actor Contact::deleteContactByUrl($key['url']); } return null; } if (empty($key['pubkey'])) { Logger::info('Empty pubkey'); return false; } if (!Crypto::rsaVerify($signed_data, $sig_block['signature'], $key['pubkey'], $algorithm)) { Logger::info('Verification failed', ['signed_data' => $signed_data, 'algorithm' => $algorithm, 'header' => $sig_block['headers'], 'http_headers' => $http_headers]); return false; } $hasGoodSignedContent = false; // Check the digest when it is part of the signed data if (!empty($content) && in_array('digest', $sig_block['headers'])) { $digest = explode('=', $headers['digest'], 2); if ($digest[0] === 'SHA-256') { $hashalg = 'sha256'; } if ($digest[0] === 'SHA-512') { $hashalg = 'sha512'; } /// @todo add all hashes from the rfc if (!empty($hashalg) && base64_encode(hash($hashalg, $content, true)) != $digest[1]) { Logger::info('Digest does not match'); return false; } $hasGoodSignedContent = true; } if (in_array('date', $sig_block['headers']) && !empty($headers['date'])) { $created = strtotime($headers['date']); } elseif (in_array('(created)', $sig_block['headers']) && !empty($sig_block['created'])) { $created = $sig_block['created']; } else { $created = 0; } if (in_array('(expires)', $sig_block['headers']) && !empty($sig_block['expires'])) { $expired = min($sig_block['expires'], $created + 300); } else { $expired = $created + 300; } // Check if the signed date field is in an acceptable range if (!empty($created)) { $current = time(); // Calculate with a grace period of 60 seconds to avoid slight time differences between the servers if (($created - 60) > $current) { Logger::notice('Signature created in the future', ['created' => date(DateTimeFormat::MYSQL, $created), 'expired' => date(DateTimeFormat::MYSQL, $expired), 'current' => date(DateTimeFormat::MYSQL, $current)]); return false; } if ($current > $expired) { Logger::notice('Signature expired', ['created' => date(DateTimeFormat::MYSQL, $created), 'expired' => date(DateTimeFormat::MYSQL, $expired), 'current' => date(DateTimeFormat::MYSQL, $current)]); return false; } Logger::debug('Valid creation date', ['created' => date(DateTimeFormat::MYSQL, $created), 'expired' => date(DateTimeFormat::MYSQL, $expired), 'current' => date(DateTimeFormat::MYSQL, $current)]); $hasGoodSignedContent = true; } // Check the content-length when it is part of the signed data if (in_array('content-length', $sig_block['headers'])) { if (strlen($content) != $headers['content-length']) { Logger::info('Content length does not match'); return false; } } // Ensure that the authentication had been done with some content // Without this check someone could authenticate with fakeable data if (!$hasGoodSignedContent) { Logger::info('No good signed content'); return false; } return $key['url']; } /** * fetches a key for a given id and actor * * @param string $id * @param string $actor * * @return array with actor url and public key * @throws \Exception */ private static function fetchKey(string $id, string $actor): array { $url = (strpos($id, '#') ? substr($id, 0, strpos($id, '#')) : $id); $profile = APContact::getByURL($url); if (!empty($profile)) { Logger::info('Taking key from id', ['id' => $id]); return ['url' => $url, 'pubkey' => $profile['pubkey'], 'type' => $profile['type']]; } elseif ($url != $actor) { $profile = APContact::getByURL($actor); if (!empty($profile)) { Logger::info('Taking key from actor', ['actor' => $actor]); return ['url' => $actor, 'pubkey' => $profile['pubkey'], 'type' => $profile['type']]; } } Logger::notice('Key could not be fetched', ['url' => $url, 'actor' => $actor]); return []; } }