moodle/mod/lti/token.php
carlos 32591786d9 MDL-66920 mod_lti: Allow usage of both JWKS URI and Public Key
- Changed mod_lti edit_form.php to add necessary fields.
- Added configuration field 'keytype' that can be RSA_KEY or JWK_KEYSET, defaulting to RSA_KEY if none is found.
- Changed mod_lti locallib.php to add the usage of jwk in the verifications of jwt's.
- Changed mod_lti token.php to call the verification function from locallib.php.
- Caches the keyset endpoint content of any given lti tool.
- Updated language files to accommodate new functionalities.
- Added test method for JWK functionalities.
- Added test_keyset file in the fixtures folder.
- Bumped the mod_lti version to 2020022200.
2020-04-16 08:53:53 -03:00

116 lines
3.4 KiB
PHP

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This file contains a service for issuing access tokens
*
* @package mod_lti
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
define('NO_DEBUG_DISPLAY', true);
define('NO_MOODLE_COOKIES', true);
use Firebase\JWT\JWT;
require_once(__DIR__ . '/../../config.php');
require_once($CFG->dirroot . '/mod/lti/locallib.php');
$response = new \mod_lti\local\ltiservice\response();
$contenttype = isset($_SERVER['CONTENT_TYPE']) ? explode(';', $_SERVER['CONTENT_TYPE'], 2)[0] : '';
$ok = ($_SERVER['REQUEST_METHOD'] === 'POST') && ($contenttype === 'application/x-www-form-urlencoded');
$error = 'invalid_request';
$clientassertion = optional_param('client_assertion', '', PARAM_TEXT);
$clientassertiontype = optional_param('client_assertion_type', '', PARAM_TEXT);
$granttype = optional_param('grant_type', '', PARAM_TEXT);
$scope = optional_param('scope', '', PARAM_TEXT);
if ($ok) {
$ok = !empty($clientassertion) && !empty($clientassertiontype) &&
!empty($granttype) && !empty($scope);
}
if ($ok) {
$ok = ($clientassertiontype === 'urn:ietf:params:oauth:client-assertion-type:jwt-bearer') &&
($granttype === 'client_credentials');
$error = 'unsupported_grant_type';
}
if ($ok) {
$parts = explode('.', $clientassertion);
$ok = (count($parts) === 3);
if ($ok) {
$payload = JWT::urlsafeB64Decode($parts[1]);
$claims = json_decode($payload, true);
$ok = !is_null($claims) && !empty($claims['sub']);
}
$error = 'invalid_request';
}
if ($ok) {
$tool = $DB->get_record('lti_types', array('clientid' => $claims['sub']));
if ($tool) {
try {
lti_verify_jwt_signature($tool->id, $claims['sub'], $clientassertion);
$ok = true;
} catch (Exception $e) {
$error = $e->getMessage();
$ok = false;
}
} else {
$error = 'invalid_client';
$ok = false;
}
}
if ($ok) {
$scopes = array();
$requestedscopes = explode(' ', $scope);
$typeconfig = lti_get_type_config($tool->id);
$permittedscopes = lti_get_permitted_service_scopes($tool, $typeconfig);
$scopes = array_intersect($requestedscopes, $permittedscopes);
$ok = !empty($scopes);
$error = 'invalid_scope';
}
if ($ok) {
$token = lti_new_access_token($tool->id, $scopes);
$expiry = LTI_ACCESS_TOKEN_LIFE;
$permittedscopes = implode(' ', $scopes);
$body = <<< EOD
{
"access_token" : "{$token->token}",
"token_type" : "Bearer",
"expires_in" : {$expiry},
"scope" : "{$permittedscopes}"
}
EOD;
} else {
$response->set_code(400);
$body = <<< EOD
{
"error" : "{$error}"
}
EOD;
}
$response->set_body($body);
$response->send();