mod/lti/OAuthBody.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16 //
  17 // This file is part of BasicLTI4Moodle
  18 //
  19 // BasicLTI4Moodle is an IMS BasicLTI (Basic Learning Tools for Interoperability)
  20 // consumer for Moodle 1.9 and Moodle 2.0. BasicLTI is a IMS Standard that allows web
  21 // based learning tools to be easily integrated in LMS as native ones. The IMS BasicLTI
  22 // specification is part of the IMS standard Common Cartridge 1.1 Sakai and other main LMS
  23 // are already supporting or going to support BasicLTI. This project Implements the consumer
  24 // for Moodle. Moodle is a Free Open source Learning Management System by Martin Dougiamas.
  25 // BasicLTI4Moodle is a project iniciated and leaded by Ludo(Marc Alier) and Jordi Piguillem
  26 // at the GESSI research group at UPC.
  27 // SimpleLTI consumer for Moodle is an implementation of the early specification of LTI
  28 // by Charles Severance (Dr Chuck) htp://dr-chuck.com , developed by Jordi Piguillem in a
  29 // Google Summer of Code 2008 project co-mentored by Charles Severance and Marc Alier.
  30 //
  31 // BasicLTI4Moodle is copyright 2009 by Marc Alier Forment, Jordi Piguillem and Nikolas Galanis
  32 // of the Universitat Politecnica de Catalunya http://www.upc.edu
  33 // Contact info: Marc Alier Forment granludo @ gmail.com or marc.alier @ upc.edu.
  34
  35 namespace moodle\mod\lti; // Using a namespace as the basicLTI module imports classes with the same names.
  36
  37 defined('MOODLE_INTERNAL') || die;
  38
  39 require_once($CFG->dirroot . '/mod/lti/OAuth.php');
  40 require_once($CFG->dirroot . '/mod/lti/TrivialStore.php');
  41
  42 /**
  43  *
  44  * @param int $typeid LTI type ID.
  45  * @param string[] $scopes  Array of scopes which give permission for the current request.
  46  *
  47  * @return string|int|boolean  The OAuth consumer key, the LTI type ID for the validated bearer token,
  48                                true for requests not requiring a scope, otherwise false.
  49  */
  50 function get_oauth_key_from_headers($typeid = null, $scopes = null) {
  51     global $DB;
  52
  53     $now = time();
  54
  55     $requestheaders = OAuthUtil::get_headers();
  56
  57     if (isset($requestheaders['Authorization'])) {
  58         if (substr($requestheaders['Authorization'], 0, 6) == "OAuth ") {
  59             $headerparameters = OAuthUtil::split_header($requestheaders['Authorization']);
  60
  61             return format_string($headerparameters['oauth_consumer_key']);
  62         } else if (empty($scopes)) {
  63             return true;
  64         } else if (substr($requestheaders['Authorization'], 0, 7) == 'Bearer ') {
  65             $tokenvalue = trim(substr($requestheaders['Authorization'], 7));
  66             $conditions = array('token' => $tokenvalue);
  67             if (!empty($typeid)) {
  68                 $conditions['typeid'] = intval($typeid);
  69             }
  70             $token = $DB->get_record('lti_access_tokens', $conditions);
  71             if ($token) {
  72                 // Log token access.
  73                 $DB->set_field('lti_access_tokens', 'lastaccess', $now, array('id' => $token->id));
  74                 $permittedscopes = json_decode($token->scope);
  75                 if ((intval($token->validuntil) > $now) && !empty(array_intersect($scopes, $permittedscopes))) {
  76                     return intval($token->typeid);
  77                 }
  78             }
  79         }
  80     }
  81     return false;
  82 }
  83
  84 function handle_oauth_body_post($oauthconsumerkey, $oauthconsumersecret, $body, $requestheaders = null) {
  85
  86     if ($requestheaders == null) {
  87         $requestheaders = OAuthUtil::get_headers();
  88     }
  89
  90     // Must reject application/x-www-form-urlencoded.
  91     if (isset($requestheaders['Content-type'])) {
  92         if ($requestheaders['Content-type'] == 'application/x-www-form-urlencoded' ) {
  93             throw new OAuthException("OAuth request body signing must not use application/x-www-form-urlencoded");
  94         }
  95     }
  96
  97     if (isset($requestheaders['Authorization']) && (substr($requestheaders['Authorization'], 0, 6) == "OAuth ")) {
  98         $headerparameters = OAuthUtil::split_header($requestheaders['Authorization']);
  99         $oauthbodyhash = $headerparameters['oauth_body_hash'];
 100     }
 101
 102     if ( ! isset($oauthbodyhash)  ) {
 103         throw new OAuthException("OAuth request body signing requires oauth_body_hash body");
 104     }
 105
 106     // Verify the message signature.
 107     $store = new TrivialOAuthDataStore();
 108     $store->add_consumer($oauthconsumerkey, $oauthconsumersecret);
 109
 110     $server = new OAuthServer($store);
 111
 112     $method = new OAuthSignatureMethod_HMAC_SHA1();
 113     $server->add_signature_method($method);
 114     $request = OAuthRequest::from_request();
 115
 116     try {
 117         $server->verify_request($request);
 118     } catch (\Exception $e) {
 119         $message = $e->getMessage();
 120         throw new OAuthException("OAuth signature failed: " . $message);
 121     }
 122
 123     $postdata = $body;
 124
 125     $hash = base64_encode(sha1($postdata, true));
 126
 127     if ( $hash != $oauthbodyhash ) {
 128         throw new OAuthException("OAuth oauth_body_hash mismatch");
 129     }
 130
 131     return $postdata;
 132 }