src/Module/Owa.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Module;
  23
  24 use Friendica\BaseModule;
  25 use Friendica\Core\Logger;
  26 use Friendica\Core\System;
  27 use Friendica\Database\DBA;
  28 use Friendica\Model\Contact;
  29 use Friendica\Model\OpenWebAuthToken;
  30 use Friendica\Util\HTTPSignature;
  31 use Friendica\Util\Strings;
  32
  33 /**
  34  * OpenWebAuth verifier and token generator
  35  *
  36  * See https://macgirvin.com/wiki/mike/OpenWebAuth/Home
  37  * Requests to this endpoint should be signed using HTTP Signatures
  38  * using the 'Authorization: Signature' authentication method
  39  * If the signature verifies a token is returned.
  40  *
  41  * This token may be exchanged for an authenticated cookie.
  42  *
  43  * Ported from Hubzilla: https://framagit.org/hubzilla/core/blob/master/Zotlabs/Module/Owa.php
  44  */
  45 class Owa extends BaseModule
  46 {
  47         public static function init(array $parameters = [])
  48         {
  49
  50                 $ret = [ 'success' => false ];
  51
  52                 foreach (['REDIRECT_REMOTE_USER', 'HTTP_AUTHORIZATION'] as $head) {
  53                         if (array_key_exists($head, $_SERVER) && substr(trim($_SERVER[$head]), 0, 9) === 'Signature') {
  54                                 if ($head !== 'HTTP_AUTHORIZATION') {
  55                                         $_SERVER['HTTP_AUTHORIZATION'] = $_SERVER[$head];
  56                                         continue;
  57                                 }
  58
  59                                 $sigblock = HTTPSignature::parseSigheader($_SERVER[$head]);
  60                                 if ($sigblock) {
  61                                         $keyId = $sigblock['keyId'];
  62
  63                                         if ($keyId) {
  64                                                 // Try to find the public contact entry of the handle.
  65                                                 $handle = str_replace('acct:', '', $keyId);
  66
  67                                                 $cid       = Contact::getIdForURL($handle);
  68                                                 $fields    = ['id', 'url', 'addr', 'pubkey'];
  69                                                 $condition = ['id' => $cid];
  70
  71                                                 $contact = DBA::selectFirst('contact', $fields, $condition);
  72
  73                                                 if (DBA::isResult($contact)) {
  74                                                         // Try to verify the signed header with the public key of the contact record
  75                                                         // we have found.
  76                                                         $verified = HTTPSignature::verifyMagic($contact['pubkey']);
  77
  78                                                         if ($verified && $verified['header_signed'] && $verified['header_valid']) {
  79                                                                 Logger::debug('OWA header', ['addr' => $contact['addr'], 'data' => $verified]);
  80
  81                                                                 $ret['success'] = true;
  82                                                                 $token = Strings::getRandomHex(32);
  83
  84                                                                 // Store the generated token in the databe.
  85                                                                 OpenWebAuthToken::create('owt', 0, $token, $contact['addr']);
  86
  87                                                                 $result = '';
  88
  89                                                                 // Encrypt the token with the public contacts publik key.
  90                                                                 // Only the specific public contact will be able to encrypt it.
  91                                                                 // At a later time, we will compare weather the token we're getting
  92                                                                 // is really the same token we have stored in the database.
  93                                                                 openssl_public_encrypt($token, $result, $contact['pubkey']);
  94                                                                 $ret['encrypted_token'] = Strings::base64UrlEncode($result);
  95                                                         } else {
  96                                                                 Logger::info('OWA fail', ['id' => $contact['id'], 'addr' => $contact['addr'], 'url' => $contact['url']]);
  97                                                         }
  98                                                 } else {
  99                                                         Logger::info('Contact not found', ['handle' => $handle]);
 100                                                 }
 101                                         }
 102                                 }
 103                         }
 104                 }
 105                 System::jsonExit($ret, 'application/x-zot+json');
 106         }
 107 }