mod/lti/locallib.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 /**
  36  * This file contains the library of functions and constants for the lti module
  37  *
  38  * @package    mod
  39  * @subpackage lti
  40  * @copyright  2009 Marc Alier, Jordi Piguillem, Nikolas Galanis
  41  *  marc.alier@upc.edu
  42  * @copyright  2009 Universitat Politecnica de Catalunya http://www.upc.edu
  43  * @author     Marc Alier
  44  * @author     Jordi Piguillem
  45  * @author     Nikolas Galanis
  46  * @author     Chris Scribner
  47  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  48  */
  49
  50 defined('MOODLE_INTERNAL') || die;
  51
  52 // TODO: Switch to core oauthlib once implemented - MDL-30149
  53 use moodle\mod\lti as lti;
  54
  55 require_once($CFG->dirroot.'/mod/lti/OAuth.php');
  56
  57 define('LTI_URL_DOMAIN_REGEX', '/(?:https?:\/\/)?(?:www\.)?([^\/]+)(?:\/|$)/i');
  58
  59 define('LTI_LAUNCH_CONTAINER_DEFAULT', 1);
  60 define('LTI_LAUNCH_CONTAINER_EMBED', 2);
  61 define('LTI_LAUNCH_CONTAINER_EMBED_NO_BLOCKS', 3);
  62 define('LTI_LAUNCH_CONTAINER_WINDOW', 4);
  63 define('LTI_LAUNCH_CONTAINER_REPLACE_MOODLE_WINDOW', 5);
  64
  65 define('LTI_TOOL_STATE_ANY', 0);
  66 define('LTI_TOOL_STATE_CONFIGURED', 1);
  67 define('LTI_TOOL_STATE_PENDING', 2);
  68 define('LTI_TOOL_STATE_REJECTED', 3);
  69
  70 define('LTI_SETTING_NEVER', 0);
  71 define('LTI_SETTING_ALWAYS', 1);
  72 define('LTI_SETTING_DELEGATE', 2);
  73
  74 /**
  75  * Prints a Basic LTI activity
  76  *
  77  * $param int $basicltiid       Basic LTI activity id
  78  */
  79 function lti_view($instance) {
  80     global $PAGE, $CFG;
  81
  82     if (empty($instance->typeid)) {
  83         $tool = lti_get_tool_by_url_match($instance->toolurl, $instance->course);
  84         if ($tool) {
  85             $typeid = $tool->id;
  86         } else {
  87             $typeid = null;
  88         }
  89     } else {
  90         $typeid = $instance->typeid;
  91     }
  92
  93     if ($typeid) {
  94         $typeconfig = lti_get_type_config($typeid);
  95     } else {
  96         //There is no admin configuration for this tool. Use configuration in the lti instance record plus some defaults.
  97         $typeconfig = (array)$instance;
  98
  99         $typeconfig['sendname'] = $instance->instructorchoicesendname;
 100         $typeconfig['sendemailaddr'] = $instance->instructorchoicesendemailaddr;
 101         $typeconfig['customparameters'] = $instance->instructorcustomparameters;
 102         $typeconfig['acceptgrades'] = $instance->instructorchoiceacceptgrades;
 103         $typeconfig['allowroster'] = $instance->instructorchoiceallowroster;
 104         $typeconfig['forcessl'] = '0';
 105     }
 106
 107     //Default the organizationid if not specified
 108     if (empty($typeconfig['organizationid'])) {
 109         $urlparts = parse_url($CFG->wwwroot);
 110
 111         $typeconfig['organizationid'] = $urlparts['host'];
 112     }
 113
 114     if (!empty($instance->resourcekey)) {
 115         $key = $instance->resourcekey;
 116     } else if (!empty($typeconfig['resourcekey'])) {
 117         $key = $typeconfig['resourcekey'];
 118     } else {
 119         $key = '';
 120     }
 121
 122     if (!empty($instance->password)) {
 123         $secret = $instance->password;
 124     } else if (!empty($typeconfig['password'])) {
 125         $secret = $typeconfig['password'];
 126     } else {
 127         $secret = '';
 128     }
 129
 130     $endpoint = !empty($instance->toolurl) ? $instance->toolurl : $typeconfig['toolurl'];
 131     $endpoint = trim($endpoint);
 132
 133     //If the current request is using SSL and a secure tool URL is specified, use it
 134     if (lti_request_is_using_ssl() && !empty($instance->securetoolurl)) {
 135         $endpoint = trim($instance->securetoolurl);
 136     }
 137
 138     //If SSL is forced, use the secure tool url if specified. Otherwise, make sure https is on the normal launch URL.
 139     if ($typeconfig['forcessl'] == '1') {
 140         if (!empty($instance->securetoolurl)) {
 141             $endpoint = trim($instance->securetoolurl);
 142         }
 143
 144         $endpoint = lti_ensure_url_is_https($endpoint);
 145     } else {
 146         if (!strstr($endpoint, '://')) {
 147             $endpoint = 'http://' . $endpoint;
 148         }
 149     }
 150
 151     $orgid = $typeconfig['organizationid'];
 152
 153     $course = $PAGE->course;
 154     $requestparams = lti_build_request($instance, $typeconfig, $course);
 155
 156     $launchcontainer = lti_get_launch_container($instance, $typeconfig);
 157     $returnurlparams = array('course' => $course->id, 'launch_container' => $launchcontainer, 'instanceid' => $instance->id);
 158
 159     if ( $orgid ) {
 160         $requestparams["tool_consumer_instance_guid"] = $orgid;
 161     }
 162
 163     if (empty($key) || empty($secret)) {
 164         $returnurlparams['unsigned'] = '1';
 165
 166         //Add the return URL. We send the launch container along to help us avoid frames-within-frames when the user returns
 167         $url = new moodle_url('/mod/lti/return.php', $returnurlparams);
 168         $returnurl = $url->out(false);
 169
 170         if ($typeconfig['forcessl'] == '1') {
 171             $returnurl = lti_ensure_url_is_https($returnurl);
 172         }
 173
 174         $requestparams['launch_presentation_return_url'] = $returnurl;
 175     }
 176
 177     if (!empty($key) && !empty($secret)) {
 178         $parms = lti_sign_parameters($requestparams, $endpoint, "POST", $key, $secret);
 179     } else {
 180         //If no key and secret, do the launch unsigned.
 181         $parms = $requestparams;
 182     }
 183
 184     $debuglaunch = ( $instance->debuglaunch == 1 );
 185
 186     $content = lti_post_launch_html($parms, $endpoint, $debuglaunch);
 187
 188     echo $content;
 189 }
 190
 191 function lti_build_sourcedid($instanceid, $userid, $launchid = null, $servicesalt) {
 192     $data = new stdClass();
 193
 194     $data->instanceid = $instanceid;
 195     $data->userid = $userid;
 196     if (!empty($launchid)) {
 197         $data->launchid = $launchid;
 198     } else {
 199         $data->launchid = mt_rand();
 200     }
 201
 202     $json = json_encode($data);
 203
 204     $hash = hash('sha256', $json . $servicesalt, false);
 205
 206     $container = new stdClass();
 207     $container->data = $data;
 208     $container->hash = $hash;
 209
 210     return $container;
 211 }
 212
 213 /**
 214  * This function builds the request that must be sent to the tool producer
 215  *
 216  * @param object    $instance       Basic LTI instance object
 217  * @param object    $typeconfig     Basic LTI tool configuration
 218  * @param object    $course         Course object
 219  *
 220  * @return array    $request        Request details
 221  */
 222 function lti_build_request($instance, $typeconfig, $course) {
 223     global $USER, $CFG;
 224
 225     if (empty($instance->cmid)) {
 226         $instance->cmid = 0;
 227     }
 228
 229     $role = lti_get_ims_role($USER, $instance->cmid, $instance->course);
 230
 231     $locale = $course->lang;
 232     if ( strlen($locale) < 1 ) {
 233          $locale = $CFG->lang;
 234     }
 235
 236     $requestparams = array(
 237         'resource_link_id' => $instance->id,
 238         'resource_link_title' => $instance->name,
 239         'resource_link_description' => $instance->intro,
 240         'user_id' => $USER->id,
 241         'roles' => $role,
 242         'context_id' => $course->id,
 243         'context_label' => $course->shortname,
 244         'context_title' => $course->fullname,
 245         'launch_presentation_locale' => $locale,
 246     );
 247
 248     $placementsecret = $instance->servicesalt;
 249
 250     if ( isset($placementsecret) ) {
 251         $sourcedid = json_encode(lti_build_sourcedid($instance->id, $USER->id, null, $placementsecret));
 252     }
 253
 254     if ( isset($placementsecret) &&
 255          ( $typeconfig['acceptgrades'] == LTI_SETTING_ALWAYS ||
 256          ( $typeconfig['acceptgrades'] == LTI_SETTING_DELEGATE && $instance->instructorchoiceacceptgrades == LTI_SETTING_ALWAYS ) ) ) {
 257         $requestparams['lis_result_sourcedid'] = $sourcedid;
 258
 259         //Add outcome service URL
 260         $serviceurl = new moodle_url('/mod/lti/service.php');
 261         $serviceurl = $serviceurl->out();
 262
 263         if ($typeconfig['forcessl'] == '1') {
 264             $serviceurl = lti_ensure_url_is_https($serviceurl);
 265         }
 266
 267         $requestparams['lis_outcome_service_url'] = $serviceurl;
 268     }
 269
 270     // Send user's name and email data if appropriate
 271     if ( $typeconfig['sendname'] == LTI_SETTING_ALWAYS ||
 272          ( $typeconfig['sendname'] == LTI_SETTING_DELEGATE && $instance->instructorchoicesendname == LTI_SETTING_ALWAYS ) ) {
 273         $requestparams['lis_person_name_given'] =  $USER->firstname;
 274         $requestparams['lis_person_name_family'] =  $USER->lastname;
 275         $requestparams['lis_person_name_full'] =  $USER->firstname." ".$USER->lastname;
 276     }
 277
 278     if ( $typeconfig['sendemailaddr'] == LTI_SETTING_ALWAYS ||
 279          ( $typeconfig['sendemailaddr'] == LTI_SETTING_DELEGATE && $instance->instructorchoicesendemailaddr == LTI_SETTING_ALWAYS ) ) {
 280         $requestparams['lis_person_contact_email_primary'] = $USER->email;
 281     }
 282
 283     // Concatenate the custom parameters from the administrator and the instructor
 284     // Instructor parameters are only taken into consideration if the administrator
 285     // has giver permission
 286     $customstr = $typeconfig['customparameters'];
 287     $instructorcustomstr = $instance->instructorcustomparameters;
 288     $custom = array();
 289     $instructorcustom = array();
 290     if ($customstr) {
 291         $custom = lti_split_custom_parameters($customstr);
 292     }
 293     if (!isset($typeconfig['allowinstructorcustom']) || $typeconfig['allowinstructorcustom'] == LTI_SETTING_NEVER) {
 294         $requestparams = array_merge($custom, $requestparams);
 295     } else {
 296         if ($instructorcustomstr) {
 297             $instructorcustom = lti_split_custom_parameters($instructorcustomstr);
 298         }
 299         foreach ($instructorcustom as $key => $val) {
 300             // Ignore the instructor's parameter
 301             if (!array_key_exists($key, $custom)) {
 302                 $custom[$key] = $val;
 303             }
 304         }
 305         $requestparams = array_merge($custom, $requestparams);
 306     }
 307
 308     // Make sure we let the tool know what LMS they are being called from
 309     $requestparams["ext_lms"] = "moodle-2";
 310     $requestparams['tool_consumer_info_product_family_code'] = 'moodle';
 311     $requestparams['tool_consumer_info_version'] = strval($CFG->version);
 312
 313     // Add oauth_callback to be compliant with the 1.0A spec
 314     $requestparams['oauth_callback'] = 'about:blank';
 315
 316     //The submit button needs to be part of the signature as it gets posted with the form.
 317     //This needs to be here to support launching without javascript.
 318     $submittext = get_string('press_to_submit', 'lti');
 319     $requestparams['ext_submit'] = $submittext;
 320
 321     $requestparams['lti_version'] = 'LTI-1p0';
 322     $requestparams['lti_message_type'] = 'basic-lti-launch-request';
 323
 324     return $requestparams;
 325 }
 326
 327 function lti_get_tool_table($tools, $id) {
 328     global $CFG, $USER;
 329     $html = '';
 330
 331     $typename = get_string('typename', 'lti');
 332     $baseurl = get_string('baseurl', 'lti');
 333     $action = get_string('action', 'lti');
 334     $createdon = get_string('createdon', 'lti');
 335
 336     if ($id == 'lti_configured') {
 337         $html .= '<div><a style="margin-top:.25em" href="'.$CFG->wwwroot.'/mod/lti/typessettings.php?action=add&amp;sesskey='.$USER->sesskey.'">'.get_string('addtype', 'lti').'</a></div>';
 338     }
 339
 340     if (!empty($tools)) {
 341         $html .= "
 342         <div id=\"{$id}_container\" style=\"margin-top:.5em;margin-bottom:.5em\">
 343             <table id=\"{$id}_tools\">
 344                 <thead>
 345                     <tr>
 346                         <th>$typename</th>
 347                         <th>$baseurl</th>
 348                         <th>$createdon</th>
 349                         <th>$action</th>
 350                     </tr>
 351                 </thead>
 352         ";
 353
 354         foreach ($tools as $type) {
 355             $date = userdate($type->timecreated);
 356             $accept = get_string('accept', 'lti');
 357             $update = get_string('update', 'lti');
 358             $delete = get_string('delete', 'lti');
 359
 360             $accepthtml = "
 361                 <a class=\"editing_accept\" href=\"{$CFG->wwwroot}/mod/lti/typessettings.php?action=accept&amp;id={$type->id}&amp;sesskey={$USER->sesskey}&amp;tab={$id}\" title=\"{$accept}\">
 362                     <img class=\"iconsmall\" alt=\"{$accept}\" src=\"{$CFG->wwwroot}/pix/t/clear.gif\"/>
 363                 </a>
 364             ";
 365
 366             $deleteaction = 'delete';
 367
 368             if ($type->state == LTI_TOOL_STATE_CONFIGURED) {
 369                 $accepthtml = '';
 370             }
 371
 372             if ($type->state != LTI_TOOL_STATE_REJECTED) {
 373                 $deleteaction = 'reject';
 374                 $delete = get_string('reject', 'lti');
 375             }
 376
 377             $html .= "
 378             <tr>
 379                 <td>
 380                     {$type->name}
 381                 </td>
 382                 <td>
 383                     {$type->baseurl}
 384                 </td>
 385                 <td>
 386                     {$date}
 387                 </td>
 388                 <td align=\"center\">
 389                     {$accepthtml}
 390                     <a class=\"editing_update\" href=\"{$CFG->wwwroot}/mod/lti/typessettings.php?action=update&amp;id={$type->id}&amp;sesskey={$USER->sesskey}&amp;tab={$id}\" title=\"{$update}\">
 391                         <img class=\"iconsmall\" alt=\"{$update}\" src=\"{$CFG->wwwroot}/pix/t/edit.gif\"/>
 392                     </a>
 393                     <a class=\"editing_delete\" href=\"{$CFG->wwwroot}/mod/lti/typessettings.php?action={$deleteaction}&amp;id={$type->id}&amp;sesskey={$USER->sesskey}&amp;tab={$id}\" title=\"{$delete}\">
 394                         <img class=\"iconsmall\" alt=\"{$delete}\" src=\"{$CFG->wwwroot}/pix/t/delete.gif\"/>
 395                     </a>
 396                 </td>
 397             </tr>
 398             ";
 399         }
 400         $html .= '</table></div>';
 401     } else {
 402         $html .= get_string('no_' . $id, 'lti');
 403     }
 404
 405     return $html;
 406 }
 407
 408 /**
 409  * Splits the custom parameters field to the various parameters
 410  *
 411  * @param string $customstr     String containing the parameters
 412  *
 413  * @return Array of custom parameters
 414  */
 415 function lti_split_custom_parameters($customstr) {
 416     $lines = preg_split("/[\n;]/", $customstr);
 417     $retval = array();
 418     foreach ($lines as $line) {
 419         $pos = strpos($line, "=");
 420         if ( $pos === false || $pos < 1 ) {
 421             continue;
 422         }
 423         $key = trim(textlib::substr($line, 0, $pos));
 424         $val = trim(textlib::substr($line, $pos+1, strlen($line)));
 425         $key = lti_map_keyname($key);
 426         $retval['custom_'.$key] = $val;
 427     }
 428     return $retval;
 429 }
 430
 431 /**
 432  * Used for building the names of the different custom parameters
 433  *
 434  * @param string $key   Parameter name
 435  *
 436  * @return string       Processed name
 437  */
 438 function lti_map_keyname($key) {
 439     $newkey = "";
 440     $key = textlib::strtolower(trim($key));
 441     foreach (str_split($key) as $ch) {
 442         if ( ($ch >= 'a' && $ch <= 'z') || ($ch >= '0' && $ch <= '9') ) {
 443             $newkey .= $ch;
 444         } else {
 445             $newkey .= '_';
 446         }
 447     }
 448     return $newkey;
 449 }
 450
 451 /**
 452  * Gets the IMS role string for the specified user and LTI course module.
 453  *
 454  * @param mixed $user User object or user id
 455  * @param int $cmid The course module id of the LTI activity
 456  * @return string A role string suitable for passing with an LTI launch
 457  */
 458 function lti_get_ims_role($user, $cmid, $courseid) {
 459     $roles = array();
 460
 461     if (empty($cmid)) {
 462         //If no cmid is passed, check if the user is a teacher in the course
 463         //This allows other modules to programmatically "fake" a launch without
 464         //a real LTI instance
 465         $coursecontext = get_context_instance(CONTEXT_COURSE, $courseid);
 466
 467         if (has_capability('moodle/course:manageactivities', $coursecontext)) {
 468             array_push($roles, 'Instructor');
 469         } else {
 470             array_push($roles, 'Learner');
 471         }
 472     } else {
 473         $context = get_context_instance(CONTEXT_MODULE, $cmid);
 474
 475         if (has_capability('mod/lti:manage', $context)) {
 476             array_push($roles, 'Instructor');
 477         } else {
 478             array_push($roles, 'Learner');
 479         }
 480     }
 481
 482     if (is_siteadmin($user)) {
 483         array_push($roles, 'urn:lti:sysrole:ims/lis/Administrator');
 484     }
 485
 486     return join(',', $roles);
 487 }
 488
 489 /**
 490  * Returns configuration details for the tool
 491  *
 492  * @param int $typeid   Basic LTI tool typeid
 493  *
 494  * @return array        Tool Configuration
 495  */
 496 function lti_get_type_config($typeid) {
 497     global $DB;
 498
 499     $query = "SELECT name, value
 500                 FROM {lti_types_config}
 501                WHERE typeid = :typeid1
 502            UNION ALL
 503               SELECT 'toolurl' AS name, baseurl AS value
 504                 FROM {lti_types}
 505                WHERE id = :typeid2";
 506
 507     $typeconfig = array();
 508     $configs = $DB->get_records_sql($query, array('typeid1' => $typeid, 'typeid2' => $typeid));
 509
 510     if (!empty($configs)) {
 511         foreach ($configs as $config) {
 512             $typeconfig[$config->name] = $config->value;
 513         }
 514     }
 515
 516     return $typeconfig;
 517 }
 518
 519 function lti_get_tools_by_url($url, $state, $courseid = null) {
 520     $domain = lti_get_domain_from_url($url);
 521
 522     return lti_get_tools_by_domain($domain, $state, $courseid);
 523 }
 524
 525 function lti_get_tools_by_domain($domain, $state = null, $courseid = null) {
 526     global $DB, $SITE;
 527
 528     $filters = array('tooldomain' => $domain);
 529
 530     $statefilter = '';
 531     $coursefilter = '';
 532
 533     if ($state) {
 534         $statefilter = 'AND state = :state';
 535     }
 536
 537     if ($courseid && $courseid != $SITE->id) {
 538         $coursefilter = 'OR course = :courseid';
 539     }
 540
 541     $query = "SELECT *
 542                 FROM {lti_types}
 543                WHERE tooldomain = :tooldomain
 544                  AND (course = :siteid $coursefilter)
 545                  $statefilter";
 546
 547     return $DB->get_records_sql($query, array(
 548         'courseid' => $courseid,
 549         'siteid' => $SITE->id,
 550         'tooldomain' => $domain,
 551         'state' => $state
 552     ));
 553 }
 554
 555 /**
 556  * Returns all basicLTI tools configured by the administrator
 557  *
 558  */
 559 function lti_filter_get_types($course) {
 560     global $DB;
 561
 562     if (!empty($course)) {
 563         $filter = array('course' => $course);
 564     } else {
 565         $filter = array();
 566     }
 567
 568     return $DB->get_records('lti_types', $filter);
 569 }
 570
 571 function lti_get_types_for_add_instance() {
 572     global $DB, $SITE, $COURSE;
 573
 574     $query = "SELECT *
 575                 FROM {lti_types}
 576                WHERE coursevisible = 1
 577                  AND (course = :siteid OR course = :courseid)
 578                  AND state = :active";
 579
 580     $admintypes = $DB->get_records_sql($query, array('siteid' => $SITE->id, 'courseid' => $COURSE->id, 'active' => LTI_TOOL_STATE_CONFIGURED));
 581
 582     $types = array();
 583     $types[0] = (object)array('name' => get_string('automatic', 'lti'), 'course' => $SITE->id);
 584
 585     foreach ($admintypes as $type) {
 586         $types[$type->id] = $type;
 587     }
 588
 589     return $types;
 590 }
 591
 592 function lti_get_domain_from_url($url) {
 593     $matches = array();
 594
 595     if (preg_match(LTI_URL_DOMAIN_REGEX, $url, $matches)) {
 596         return $matches[1];
 597     }
 598 }
 599
 600 function lti_get_tool_by_url_match($url, $courseid = null, $state = LTI_TOOL_STATE_CONFIGURED) {
 601     $possibletools = lti_get_tools_by_url($url, $state, $courseid);
 602
 603     return lti_get_best_tool_by_url($url, $possibletools, $courseid);
 604 }
 605
 606 function lti_get_url_thumbprint($url) {
 607     $urlparts = parse_url(strtolower($url));
 608     if (!isset($urlparts['path'])) {
 609         $urlparts['path'] = '';
 610     }
 611
 612     if (!isset($urlparts['host'])) {
 613         $urlparts['host'] = '';
 614     }
 615
 616     if (substr($urlparts['host'], 0, 4) === 'www.') {
 617         $urlparts['host'] = substr($urlparts['host'], 4);
 618     }
 619
 620     return $urllower = $urlparts['host'] . '/' . $urlparts['path'];
 621 }
 622
 623 function lti_get_best_tool_by_url($url, $tools, $courseid = null) {
 624     if (count($tools) === 0) {
 625         return null;
 626     }
 627
 628     $urllower = lti_get_url_thumbprint($url);
 629
 630     foreach ($tools as $tool) {
 631         $tool->_matchscore = 0;
 632
 633         $toolbaseurllower = lti_get_url_thumbprint($tool->baseurl);
 634
 635         if ($urllower === $toolbaseurllower) {
 636             //100 points for exact thumbprint match
 637             $tool->_matchscore += 100;
 638         } else if (substr($urllower, 0, strlen($toolbaseurllower)) === $toolbaseurllower) {
 639             //50 points if tool thumbprint starts with the base URL thumbprint
 640             $tool->_matchscore += 50;
 641         }
 642
 643         //Prefer course tools over site tools
 644         if (!empty($courseid)) {
 645             //Minus 10 points for not matching the course id (global tools)
 646             if ($tool->course != $courseid) {
 647                 $tool->_matchscore -= 10;
 648             }
 649         }
 650     }
 651
 652     $bestmatch = array_reduce($tools, function($value, $tool) {
 653         if ($tool->_matchscore > $value->_matchscore) {
 654             return $tool;
 655         } else {
 656             return $value;
 657         }
 658
 659     }, (object)array('_matchscore' => -1));
 660
 661     //None of the tools are suitable for this URL
 662     if ($bestmatch->_matchscore <= 0) {
 663         return null;
 664     }
 665
 666     return $bestmatch;
 667 }
 668
 669 function lti_get_shared_secrets_by_key($key) {
 670     global $DB;
 671
 672     //Look up the shared secret for the specified key in both the types_config table (for configured tools)
 673     //And in the lti resource table for ad-hoc tools
 674     $query = "SELECT t2.value
 675                 FROM {lti_types_config} t1
 676                 JOIN {lti_types_config} t2 ON t1.typeid = t2.typeid
 677                 JOIN {lti_types} type ON t2.typeid = type.id
 678               WHERE t1.name = 'resourcekey'
 679                 AND t1.value = :key1
 680                 AND t2.name = 'password'
 681                 AND type.state = :configured
 682               UNION
 683              SELECT password AS value
 684                FROM {lti}
 685               WHERE resourcekey = :key2";
 686
 687     $sharedsecrets = $DB->get_records_sql($query, array('configured' => LTI_TOOL_STATE_CONFIGURED, 'key1' => $key, 'key2' => $key));
 688
 689     $values = array_map(function($item) {
 690         return $item->value;
 691     }, $sharedsecrets);
 692
 693     //There should really only be one shared secret per key. But, we can't prevent
 694     //more than one getting entered. For instance, if the same key is used for two tool providers.
 695     return $values;
 696 }
 697
 698 /**
 699  * Delete a Basic LTI configuration
 700  *
 701  * @param int $id   Configuration id
 702  */
 703 function lti_delete_type($id) {
 704     global $DB;
 705
 706     //We should probably just copy the launch URL to the tool instances in this case... using a single query
 707     /*
 708     $instances = $DB->get_records('lti', array('typeid' => $id));
 709     foreach ($instances as $instance) {
 710         $instance->typeid = 0;
 711         $DB->update_record('lti', $instance);
 712     }*/
 713
 714     $DB->delete_records('lti_types', array('id' => $id));
 715     $DB->delete_records('lti_types_config', array('typeid' => $id));
 716 }
 717
 718 function lti_set_state_for_type($id, $state) {
 719     global $DB;
 720
 721     $DB->update_record('lti_types', array('id' => $id, 'state' => $state));
 722 }
 723
 724 /**
 725  * Transforms a basic LTI object to an array
 726  *
 727  * @param object $ltiobject    Basic LTI object
 728  *
 729  * @return array Basic LTI configuration details
 730  */
 731 function lti_get_config($ltiobject) {
 732     $typeconfig = array();
 733     $typeconfig = (array)$ltiobject;
 734     $additionalconfig = lti_get_type_config($ltiobject->typeid);
 735     $typeconfig = array_merge($typeconfig, $additionalconfig);
 736     return $typeconfig;
 737 }
 738
 739 /**
 740  *
 741  * Generates some of the tool configuration based on the instance details
 742  *
 743  * @param int $id
 744  *
 745  * @return Instance configuration
 746  *
 747  */
 748 function lti_get_type_config_from_instance($id) {
 749     global $DB;
 750
 751     $instance = $DB->get_record('lti', array('id' => $id));
 752     $config = lti_get_config($instance);
 753
 754     $type = new stdClass();
 755     $type->lti_fix = $id;
 756     if (isset($config['toolurl'])) {
 757         $type->lti_toolurl = $config['toolurl'];
 758     }
 759     if (isset($config['instructorchoicesendname'])) {
 760         $type->lti_sendname = $config['instructorchoicesendname'];
 761     }
 762     if (isset($config['instructorchoicesendemailaddr'])) {
 763         $type->lti_sendemailaddr = $config['instructorchoicesendemailaddr'];
 764     }
 765     if (isset($config['instructorchoiceacceptgrades'])) {
 766         $type->lti_acceptgrades = $config['instructorchoiceacceptgrades'];
 767     }
 768     if (isset($config['instructorchoiceallowroster'])) {
 769         $type->lti_allowroster = $config['instructorchoiceallowroster'];
 770     }
 771
 772     if (isset($config['instructorcustomparameters'])) {
 773         $type->lti_allowsetting = $config['instructorcustomparameters'];
 774     }
 775     return $type;
 776 }
 777
 778 /**
 779  * Generates some of the tool configuration based on the admin configuration details
 780  *
 781  * @param int $id
 782  *
 783  * @return Configuration details
 784  */
 785 function lti_get_type_type_config($id) {
 786     global $DB;
 787
 788     $basicltitype = $DB->get_record('lti_types', array('id' => $id));
 789     $config = lti_get_type_config($id);
 790
 791     $type = new stdClass();
 792
 793     $type->lti_typename = $basicltitype->name;
 794
 795     $type->typeid = $basicltitype->id;
 796
 797     $type->lti_toolurl = $basicltitype->baseurl;
 798
 799     if (isset($config['resourcekey'])) {
 800         $type->lti_resourcekey = $config['resourcekey'];
 801     }
 802     if (isset($config['password'])) {
 803         $type->lti_password = $config['password'];
 804     }
 805
 806     if (isset($config['sendname'])) {
 807         $type->lti_sendname = $config['sendname'];
 808     }
 809     if (isset($config['instructorchoicesendname'])) {
 810         $type->lti_instructorchoicesendname = $config['instructorchoicesendname'];
 811     }
 812     if (isset($config['sendemailaddr'])) {
 813         $type->lti_sendemailaddr = $config['sendemailaddr'];
 814     }
 815     if (isset($config['instructorchoicesendemailaddr'])) {
 816         $type->lti_instructorchoicesendemailaddr = $config['instructorchoicesendemailaddr'];
 817     }
 818     if (isset($config['acceptgrades'])) {
 819         $type->lti_acceptgrades = $config['acceptgrades'];
 820     }
 821     if (isset($config['instructorchoiceacceptgrades'])) {
 822         $type->lti_instructorchoiceacceptgrades = $config['instructorchoiceacceptgrades'];
 823     }
 824     if (isset($config['allowroster'])) {
 825         $type->lti_allowroster = $config['allowroster'];
 826     }
 827     if (isset($config['instructorchoiceallowroster'])) {
 828         $type->lti_instructorchoiceallowroster = $config['instructorchoiceallowroster'];
 829     }
 830
 831     if (isset($config['customparameters'])) {
 832         $type->lti_customparameters = $config['customparameters'];
 833     }
 834
 835     if (isset($config['forcessl'])) {
 836         $type->lti_forcessl = $config['forcessl'];
 837     }
 838
 839     if (isset($config['organizationid'])) {
 840         $type->lti_organizationid = $config['organizationid'];
 841     }
 842     if (isset($config['organizationurl'])) {
 843         $type->lti_organizationurl = $config['organizationurl'];
 844     }
 845     if (isset($config['organizationdescr'])) {
 846         $type->lti_organizationdescr = $config['organizationdescr'];
 847     }
 848     if (isset($config['launchcontainer'])) {
 849         $type->lti_launchcontainer = $config['launchcontainer'];
 850     }
 851
 852     if (isset($config['coursevisible'])) {
 853         $type->lti_coursevisible = $config['coursevisible'];
 854     }
 855
 856     if (isset($config['debuglaunch'])) {
 857         $type->lti_debuglaunch = $config['debuglaunch'];
 858     }
 859
 860     if (isset($config['module_class_type'])) {
 861         $type->lti_module_class_type = $config['module_class_type'];
 862     }
 863
 864     return $type;
 865 }
 866
 867 function lti_prepare_type_for_save($type, $config) {
 868     $type->baseurl = $config->lti_toolurl;
 869     $type->tooldomain = lti_get_domain_from_url($config->lti_toolurl);
 870     $type->name = $config->lti_typename;
 871
 872     $type->coursevisible = !empty($config->lti_coursevisible) ? $config->lti_coursevisible : 0;
 873     $config->lti_coursevisible = $type->coursevisible;
 874
 875     $type->forcessl = !empty($config->lti_forcessl) ? $config->lti_forcessl : 0;
 876     $config->lti_forcessl = $type->forcessl;
 877
 878     $type->timemodified = time();
 879
 880     unset ($config->lti_typename);
 881     unset ($config->lti_toolurl);
 882 }
 883
 884 function lti_update_type($type, $config) {
 885     global $DB;
 886
 887     lti_prepare_type_for_save($type, $config);
 888
 889     if ($DB->update_record('lti_types', $type)) {
 890         foreach ($config as $key => $value) {
 891             if (substr($key, 0, 4)=='lti_' && !is_null($value)) {
 892                 $record = new StdClass();
 893                 $record->typeid = $type->id;
 894                 $record->name = substr($key, 4);
 895                 $record->value = $value;
 896
 897                 lti_update_config($record);
 898             }
 899         }
 900     }
 901 }
 902
 903 function lti_add_type($type, $config) {
 904     global $USER, $SITE, $DB;
 905
 906     lti_prepare_type_for_save($type, $config);
 907
 908     if (!isset($type->state)) {
 909         $type->state = LTI_TOOL_STATE_PENDING;
 910     }
 911
 912     if (!isset($type->timecreated)) {
 913         $type->timecreated = time();
 914     }
 915
 916     if (!isset($type->createdby)) {
 917         $type->createdby = $USER->id;
 918     }
 919
 920     if (!isset($type->course)) {
 921         $type->course = $SITE->id;
 922     }
 923
 924     //Create a salt value to be used for signing passed data to extension services
 925     //The outcome service uses the service salt on the instance. This can be used
 926     //for communication with services not related to a specific LTI instance.
 927     $config->lti_servicesalt = uniqid('', true);
 928
 929     $id = $DB->insert_record('lti_types', $type);
 930
 931     if ($id) {
 932         foreach ($config as $key => $value) {
 933             if (substr($key, 0, 4)=='lti_' && !is_null($value)) {
 934                 $record = new StdClass();
 935                 $record->typeid = $id;
 936                 $record->name = substr($key, 4);
 937                 $record->value = $value;
 938
 939                 lti_add_config($record);
 940             }
 941         }
 942     }
 943
 944     return $id;
 945 }
 946
 947 /**
 948  * Add a tool configuration in the database
 949  *
 950  * @param $config   Tool configuration
 951  *
 952  * @return int Record id number
 953  */
 954 function lti_add_config($config) {
 955     global $DB;
 956
 957     return $DB->insert_record('lti_types_config', $config);
 958 }
 959
 960 /**
 961  * Updates a tool configuration in the database
 962  *
 963  * @param $config   Tool configuration
 964  *
 965  * @return Record id number
 966  */
 967 function lti_update_config($config) {
 968     global $DB;
 969
 970     $return = true;
 971     $old = $DB->get_record('lti_types_config', array('typeid' => $config->typeid, 'name' => $config->name));
 972
 973     if ($old) {
 974         $config->id = $old->id;
 975         $return = $DB->update_record('lti_types_config', $config);
 976     } else {
 977         $return = $DB->insert_record('lti_types_config', $config);
 978     }
 979     return $return;
 980 }
 981
 982 /**
 983  * Signs the petition to launch the external tool using OAuth
 984  *
 985  * @param $oldparms     Parameters to be passed for signing
 986  * @param $endpoint     url of the external tool
 987  * @param $method       Method for sending the parameters (e.g. POST)
 988  * @param $oauth_consumoer_key          Key
 989  * @param $oauth_consumoer_secret       Secret
 990  * @param $submittext  The text for the submit button
 991  * @param $orgid       LMS name
 992  * @param $orgdesc     LMS key
 993  */
 994 function lti_sign_parameters($oldparms, $endpoint, $method, $oauthconsumerkey, $oauthconsumersecret) {
 995     //global $lastbasestring;
 996     $parms = $oldparms;
 997
 998     $testtoken = '';
 999
1000     // TODO: Switch to core oauthlib once implemented - MDL-30149
1001     $hmacmethod = new lti\OAuthSignatureMethod_HMAC_SHA1();
1002     $testconsumer = new lti\OAuthConsumer($oauthconsumerkey, $oauthconsumersecret, null);
1003     $accreq = lti\OAuthRequest::from_consumer_and_token($testconsumer, $testtoken, $method, $endpoint, $parms);
1004     $accreq->sign_request($hmacmethod, $testconsumer, $testtoken);
1005
1006     // Pass this back up "out of band" for debugging
1007     //$lastbasestring = $accreq->get_signature_base_string();
1008
1009     $newparms = $accreq->get_parameters();
1010
1011     return $newparms;
1012 }
1013
1014 /**
1015  * Posts the launch petition HTML
1016  *
1017  * @param $newparms     Signed parameters
1018  * @param $endpoint     URL of the external tool
1019  * @param $debug        Debug (true/false)
1020  */
1021 function lti_post_launch_html($newparms, $endpoint, $debug=false) {
1022     $r = "<form action=\"".$endpoint."\" name=\"ltiLaunchForm\" id=\"ltiLaunchForm\" method=\"post\" encType=\"application/x-www-form-urlencoded\">\n";
1023
1024     $submittext = $newparms['ext_submit'];
1025
1026     // Contruct html for the launch parameters
1027     foreach ($newparms as $key => $value) {
1028         $key = htmlspecialchars($key);
1029         $value = htmlspecialchars($value);
1030         if ( $key == "ext_submit" ) {
1031             $r .= "<input type=\"submit\" name=\"";
1032         } else {
1033             $r .= "<input type=\"hidden\" name=\"";
1034         }
1035         $r .= $key;
1036         $r .= "\" value=\"";
1037         $r .= $value;
1038         $r .= "\"/>\n";
1039     }
1040
1041     if ( $debug ) {
1042         $r .= "<script language=\"javascript\"> \n";
1043         $r .= "  //<![CDATA[ \n";
1044         $r .= "function basicltiDebugToggle() {\n";
1045         $r .= "    var ele = document.getElementById(\"basicltiDebug\");\n";
1046         $r .= "    if (ele.style.display == \"block\") {\n";
1047         $r .= "        ele.style.display = \"none\";\n";
1048         $r .= "    }\n";
1049         $r .= "    else {\n";
1050         $r .= "        ele.style.display = \"block\";\n";
1051         $r .= "    }\n";
1052         $r .= "} \n";
1053         $r .= "  //]]> \n";
1054         $r .= "</script>\n";
1055         $r .= "<a id=\"displayText\" href=\"javascript:basicltiDebugToggle();\">";
1056         $r .= get_string("toggle_debug_data", "lti")."</a>\n";
1057         $r .= "<div id=\"basicltiDebug\" style=\"display:none\">\n";
1058         $r .=  "<b>".get_string("basiclti_endpoint", "lti")."</b><br/>\n";
1059         $r .= $endpoint . "<br/>\n&nbsp;<br/>\n";
1060         $r .=  "<b>".get_string("basiclti_parameters", "lti")."</b><br/>\n";
1061         foreach ($newparms as $key => $value) {
1062             $key = htmlspecialchars($key);
1063             $value = htmlspecialchars($value);
1064             $r .= "$key = $value<br/>\n";
1065         }
1066         $r .= "&nbsp;<br/>\n";
1067         //$r .= "<p><b>".get_string("basiclti_base_string", "lti")."</b><br/>\n".$lastbasestring."</p>\n";
1068         $r .= "</div>\n";
1069     }
1070     $r .= "</form>\n";
1071
1072     if ( ! $debug ) {
1073         $ext_submit = "ext_submit";
1074         $ext_submit_text = $submittext;
1075         $r .= " <script type=\"text/javascript\"> \n" .
1076             "  //<![CDATA[ \n" .
1077             "    document.getElementById(\"ltiLaunchForm\").style.display = \"none\";\n" .
1078             "    nei = document.createElement('input');\n" .
1079             "    nei.setAttribute('type', 'hidden');\n" .
1080             "    nei.setAttribute('name', '".$ext_submit."');\n" .
1081             "    nei.setAttribute('value', '".$ext_submit_text."');\n" .
1082             "    document.getElementById(\"ltiLaunchForm\").appendChild(nei);\n" .
1083             "    document.ltiLaunchForm.submit(); \n" .
1084             "  //]]> \n" .
1085             " </script> \n";
1086     }
1087     return $r;
1088 }
1089
1090 function lti_get_type($typeid) {
1091     global $DB;
1092
1093     return $DB->get_record('lti_types', array('id' => $typeid));
1094 }
1095
1096 function lti_get_launch_container($lti, $toolconfig) {
1097     if (empty($lti->launchcontainer)) {
1098         $lti->launchcontainer = LTI_LAUNCH_CONTAINER_DEFAULT;
1099     }
1100
1101     if ($lti->launchcontainer == LTI_LAUNCH_CONTAINER_DEFAULT) {
1102         if (isset($toolconfig['launchcontainer'])) {
1103             $launchcontainer = $toolconfig['launchcontainer'];
1104         }
1105     } else {
1106         $launchcontainer = $lti->launchcontainer;
1107     }
1108
1109     if (empty($launchcontainer) || $launchcontainer == LTI_LAUNCH_CONTAINER_DEFAULT) {
1110         $launchcontainer = LTI_LAUNCH_CONTAINER_EMBED_NO_BLOCKS;
1111     }
1112
1113     $devicetype = get_device_type();
1114
1115     //Scrolling within the object element doesn't work on iOS or Android
1116     //Opening the popup window also had some issues in testing
1117     //For mobile devices, always take up the entire screen to ensure the best experience
1118     if ($devicetype === 'mobile' || $devicetype === 'tablet' ) {
1119         $launchcontainer = LTI_LAUNCH_CONTAINER_REPLACE_MOODLE_WINDOW;
1120     }
1121
1122     return $launchcontainer;
1123 }
1124
1125 function lti_request_is_using_ssl() {
1126     global $CFG;
1127     return (stripos($CFG->httpswwwroot, 'https://') === 0);
1128 }
1129
1130 function lti_ensure_url_is_https($url) {
1131     if (!strstr($url, '://')) {
1132         $url = 'https://' . $url;
1133     } else {
1134         //If the URL starts with http, replace with https
1135         if (stripos($url, 'http://') === 0) {
1136             $url = 'https://' . substr($url, 8);
1137         }
1138     }
1139
1140     return $url;
1141 }