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 function get_oauth_key_from_headers() {
  43     $requestheaders = OAuthUtil::get_headers();
  44
  45     if (@substr($requestheaders['Authorization'], 0, 6) == "OAuth ") {
  46         $headerparameters = OAuthUtil::split_header($requestheaders['Authorization']);
  47
  48         return format_string($headerparameters['oauth_consumer_key']);
  49     }
  50     return false;
  51 }
  52
  53 function handle_oauth_body_post($oauthconsumerkey, $oauthconsumersecret, $body, $requestheaders = null) {
  54
  55     if ($requestheaders == null) {
  56         $requestheaders = OAuthUtil::get_headers();
  57     }
  58
  59     // Must reject application/x-www-form-urlencoded.
  60     if (isset($requestheaders['Content-type'])) {
  61         if ($requestheaders['Content-type'] == 'application/x-www-form-urlencoded' ) {
  62             throw new OAuthException("OAuth request body signing must not use application/x-www-form-urlencoded");
  63         }
  64     }
  65
  66     if (@substr($requestheaders['Authorization'], 0, 6) == "OAuth ") {
  67         $headerparameters = OAuthUtil::split_header($requestheaders['Authorization']);
  68         $oauthbodyhash = $headerparameters['oauth_body_hash'];
  69     }
  70
  71     if ( ! isset($oauthbodyhash)  ) {
  72         throw new OAuthException("OAuth request body signing requires oauth_body_hash body");
  73     }
  74
  75     // Verify the message signature.
  76     $store = new TrivialOAuthDataStore();
  77     $store->add_consumer($oauthconsumerkey, $oauthconsumersecret);
  78
  79     $server = new OAuthServer($store);
  80
  81     $method = new OAuthSignatureMethod_HMAC_SHA1();
  82     $server->add_signature_method($method);
  83     $request = OAuthRequest::from_request();
  84
  85     try {
  86         $server->verify_request($request);
  87     } catch (\Exception $e) {
  88         $message = $e->getMessage();
  89         throw new OAuthException("OAuth signature failed: " . $message);
  90     }
  91
  92     $postdata = $body;
  93
  94     $hash = base64_encode(sha1($postdata, true));
  95
  96     if ( $hash != $oauthbodyhash ) {
  97         throw new OAuthException("OAuth oauth_body_hash mismatch");
  98     }
  99
 100     return $postdata;
 101 }