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See Release Notes

  • Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
  • Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
  • PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
<?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/>.

/**
 * Configurable oauth2 client class.
 *
 * @package    core
 * @copyright  2017 Damyon Wiese
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
namespace core\oauth2;

defined('MOODLE_INTERNAL') || die();

require_once($CFG->libdir . '/oauthlib.php');
require_once($CFG->libdir . '/filelib.php');

use moodle_url;
use moodle_exception;
use stdClass;

/**
 * Configurable oauth2 client class. URLs come from DB and access tokens from either DB (system accounts) or session (users').
 *
 * @copyright  2017 Damyon Wiese
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class client extends \oauth2_client {

    /** @var \core\oauth2\issuer $issuer */
    private $issuer;

    /** @var bool $system */
    protected $system = false;

    /** @var bool $autorefresh whether this client will use a refresh token to automatically renew access tokens.*/
    protected $autorefresh = false;

> /** @var array $rawuserinfo Keep rawuserinfo from . */ /** > protected $rawuserinfo = []; * Constructor. >
* * @param issuer $issuer * @param moodle_url|null $returnurl * @param string $scopesrequired * @param boolean $system * @param boolean $autorefresh whether refresh_token grants are used to allow continued access across sessions. */ public function __construct(issuer $issuer, $returnurl, $scopesrequired, $system = false, $autorefresh = false) { $this->issuer = $issuer; $this->system = $system; $this->autorefresh = $autorefresh; $scopes = $this->get_login_scopes(); $additionalscopes = explode(' ', $scopesrequired); foreach ($additionalscopes as $scope) { if (!empty($scope)) { if (strpos(' ' . $scopes . ' ', ' ' . $scope . ' ') === false) { $scopes .= ' ' . $scope; } } } if (empty($returnurl)) { $returnurl = new moodle_url('/'); } $this->basicauth = $issuer->get('basicauth'); parent::__construct($issuer->get('clientid'), $issuer->get('clientsecret'), $returnurl, $scopes); } /** * Returns the auth url for OAuth 2.0 request * @return string the auth url */ protected function auth_url() { return $this->issuer->get_endpoint_url('authorization'); } /** * Get the oauth2 issuer for this client. * * @return \core\oauth2\issuer Issuer */ public function get_issuer() { return $this->issuer; } /** * Override to append additional params to a authentication request. * * @return array (name value pairs). */ public function get_additional_login_parameters() { $params = ''; if ($this->system || $this->can_autorefresh()) { // System clients and clients supporting the refresh_token grant (provided the user is authenticated) add // extra params to the login request, depending on the issuer settings. The extra params allow a refresh // token to be returned during the authorization_code flow. if (!empty($this->issuer->get('loginparamsoffline'))) { $params = $this->issuer->get('loginparamsoffline'); } } else { // This is not a system client, nor a client supporting the refresh_token grant type, so just return the // vanilla login params. if (!empty($this->issuer->get('loginparams'))) { $params = $this->issuer->get('loginparams'); } } if (empty($params)) { return []; } $result = []; parse_str($params, $result); return $result; } /** * Override to change the scopes requested with an authentiction request. * * @return string */ protected function get_login_scopes() { if ($this->system || $this->can_autorefresh()) { // System clients and clients supporting the refresh_token grant (provided the user is authenticated) add // extra scopes to the login request, depending on the issuer settings. The extra params allow a refresh // token to be returned during the authorization_code flow. return $this->issuer->get('loginscopesoffline'); } else { // This is not a system client, nor a client supporting the refresh_token grant type, so just return the // vanilla login scopes. return $this->issuer->get('loginscopes'); } } /** * Returns the token url for OAuth 2.0 request * * We are overriding the parent function so we get this from the configured endpoint. * * @return string the auth url */ protected function token_url() { return $this->issuer->get_endpoint_url('token'); } /** * We want a unique key for each issuer / and a different key for system vs user oauth. * * @return string The unique key for the session value. */ protected function get_tokenname() { $name = 'oauth2-state-' . $this->issuer->get('id'); if ($this->system) { $name .= '-system'; } return $name; } /** * Store a token between requests. Uses session named by get_tokenname for user account tokens * and a database record for system account tokens. * * @param stdClass|null $token token object to store or null to clear */ protected function store_token($token) { if (!$this->system) { parent::store_token($token); return; } $this->accesstoken = $token; // Create or update a DB record with the new token. $persistedtoken = access_token::get_record(['issuerid' => $this->issuer->get('id')]); if ($token !== null) { if (!$persistedtoken) { $persistedtoken = new access_token(); $persistedtoken->set('issuerid', $this->issuer->get('id')); } // Update values from $token. Don't use from_record because that would skip validation. $persistedtoken->set('token', $token->token); if (isset($token->expires)) { $persistedtoken->set('expires', $token->expires); } else { // Assume an arbitrary time span of 1 week for access tokens without expiration. // The "refresh_system_tokens_task" is run hourly (by default), so the token probably won't last that long. $persistedtoken->set('expires', time() + WEEKSECS); } $persistedtoken->set('scope', $token->scope); $persistedtoken->save(); } else { if ($persistedtoken) { $persistedtoken->delete(); } } } /** * Retrieve a stored token from session (user accounts) or database (system accounts). * * @return stdClass|null token object */ protected function get_stored_token() { if ($this->system) { $token = access_token::get_record(['issuerid' => $this->issuer->get('id')]); if ($token !== false) { return $token->to_record(); } return null; } return parent::get_stored_token(); } /** * Get a list of the mapping user fields in an associative array. * * @return array */ protected function get_userinfo_mapping() { $fields = user_field_mapping::get_records(['issuerid' => $this->issuer->get('id')]); $map = []; foreach ($fields as $field) { $map[$field->get('externalfield')] = $field->get('internalfield'); } return $map; } /** * Override which upgrades the authorization code to an access token and stores any refresh token in the DB. * * @param string $code the authorisation code * @return bool true if the token could be upgraded * @throws moodle_exception */ public function upgrade_token($code) { $upgraded = parent::upgrade_token($code); if (!$this->can_autorefresh()) { return $upgraded; } // For clients supporting auto-refresh, try to store a refresh token. if (!empty($this->refreshtoken)) { $refreshtoken = (object) [ 'token' => $this->refreshtoken, 'scope' => $this->scope ]; $this->store_user_refresh_token($refreshtoken); } return $upgraded; } /** * Override which in addition to auth code upgrade, also attempts to exchange a refresh token for an access token. * * @return bool true if the user is logged in as a result, false otherwise. */ public function is_logged_in() { global $DB, $USER; $isloggedin = parent::is_logged_in(); // Attempt to exchange a user refresh token, but only if required and supported. if ($isloggedin || !$this->can_autorefresh()) { return $isloggedin; } // Autorefresh is supported. Try to negotiate a login by exchanging a stored refresh token for an access token. $issuerid = $this->issuer->get('id'); $refreshtoken = $DB->get_record('oauth2_refresh_token', ['userid' => $USER->id, 'issuerid' => $issuerid]); if ($refreshtoken) { try { $tokensreceived = $this->exchange_refresh_token($refreshtoken->token); if (empty($tokensreceived)) { // No access token was returned, so invalidate the refresh token and return false. $DB->delete_records('oauth2_refresh_token', ['id' => $refreshtoken->id]); return false; } // Otherwise, save the access token and, if provided, the new refresh token. $this->store_token($tokensreceived['access_token']); if (!empty($tokensreceived['refresh_token'])) { $this->store_user_refresh_token($tokensreceived['refresh_token']); } return true; } catch (\moodle_exception $e) { // The refresh attempt failed either due to an error or a bad request. A bad request could be received // for a number of reasons including expired refresh token (lifetime is not specified in OAuth 2 spec), // scope change or if app access has been revoked manually by the user (tokens revoked). // Remove the refresh token and suppress the exception, allowing the user to be taken through the // authorization_code flow again. $DB->delete_records('oauth2_refresh_token', ['id' => $refreshtoken->id]); } } return false; } /** * Whether this client should automatically exchange a refresh token for an access token as part of login checks. * * @return bool true if supported, false otherwise. */ protected function can_autorefresh(): bool { global $USER; // Auto refresh is only supported when the follow criteria are met: // a) The client is not a system client. The exchange process for system client refresh tokens is handled // externally, via a call to client->upgrade_refresh_token(). // b) The user is authenticated. // c) The client has been configured with autorefresh enabled. return !$this->system && ($this->autorefresh && !empty($USER->id)); } /** * Store the user's refresh token for later use. * * @param stdClass $token a refresh token. */ protected function store_user_refresh_token(stdClass $token): void { global $DB, $USER; $id = $DB->get_field('oauth2_refresh_token', 'id', ['userid' => $USER->id, 'scopehash' => sha1($token->scope), 'issuerid' => $this->issuer->get('id')]); $time = time(); if ($id) { $record = [ 'id' => $id, 'timemodified' => $time, 'token' => $token->token ]; $DB->update_record('oauth2_refresh_token', $record); } else { $record = [ 'timecreated' => $time, 'timemodified' => $time, 'userid' => $USER->id, 'issuerid' => $this->issuer->get('id'), 'token' => $token->token, 'scopehash' => sha1($token->scope) ]; $DB->insert_record('oauth2_refresh_token', $record); } } /** * Attempt to exchange a refresh token for a new access token. * * If successful, will return an array of token objects in the form: * Array * ( * [access_token] => stdClass object * ( * [token] => 'the_token_string' * [expires] => 123456789 * [scope] => 'openid files etc' * ) * [refresh_token] => stdClass object * ( * [token] => 'the_refresh_token_string' * [scope] => 'openid files etc' * ) * ) * where the 'refresh_token' will only be provided if supplied by the auth server in the response. * * @param string $refreshtoken the refresh token to exchange. * @return null|array array containing access token and refresh token if provided, null if the exchange was denied. * @throws moodle_exception if an invalid response is received or if the response contains errors. */ protected function exchange_refresh_token(string $refreshtoken): ?array { $params = array('refresh_token' => $refreshtoken, 'grant_type' => 'refresh_token' ); if ($this->basicauth) { $idsecret = urlencode($this->issuer->get('clientid')) . ':' . urlencode($this->issuer->get('clientsecret')); $this->setHeader('Authorization: Basic ' . base64_encode($idsecret)); } else { $params['client_id'] = $this->issuer->get('clientid'); $params['client_secret'] = $this->issuer->get('clientsecret'); } // Requests can either use http GET or POST. if ($this->use_http_get()) { $response = $this->get($this->token_url(), $params); } else { $response = $this->post($this->token_url(), $this->build_post_data($params)); } if ($this->info['http_code'] !== 200) {
< throw new moodle_exception('Could not upgrade oauth token');
> $debuginfo = !empty($this->error) ? $this->error : $response; > throw new moodle_exception('oauth2refreshtokenerror', 'core_error', '', $this->info['http_code'], $debuginfo);
} $r = json_decode($response); if (!empty($r->error)) { throw new moodle_exception($r->error . ' ' . $r->error_description); } if (!isset($r->access_token)) { return null; } // Store the token an expiry time. $accesstoken = new stdClass(); $accesstoken->token = $r->access_token; if (isset($r->expires_in)) { // Expires 10 seconds before actual expiry. $accesstoken->expires = (time() + ($r->expires_in - 10)); } $accesstoken->scope = $this->scope; $tokens = ['access_token' => $accesstoken]; if (isset($r->refresh_token)) { $this->refreshtoken = $r->refresh_token; $newrefreshtoken = new stdClass(); $newrefreshtoken->token = $this->refreshtoken; $newrefreshtoken->scope = $this->scope; $tokens['refresh_token'] = $newrefreshtoken; } return $tokens; } /** * Override which, in addition to deleting access tokens, also deletes any stored refresh token. */ public function log_out() { global $DB, $USER; parent::log_out(); if (!$this->can_autorefresh()) { return; } // For clients supporting autorefresh, delete the stored refresh token too. $issuerid = $this->issuer->get('id'); $refreshtoken = $DB->get_record('oauth2_refresh_token', ['userid' => $USER->id, 'issuerid' => $issuerid, 'scopehash' => sha1($this->scope)]); if ($refreshtoken) { $DB->delete_records('oauth2_refresh_token', ['id' => $refreshtoken->id]); } } /** * Upgrade a refresh token from oauth 2.0 to an access token, for system clients only. * * @param \core\oauth2\system_account $systemaccount * @return boolean true if token is upgraded succesfully */ public function upgrade_refresh_token(system_account $systemaccount) { $receivedtokens = $this->exchange_refresh_token($systemaccount->get('refreshtoken')); // No access token received, so return false. if (empty($receivedtokens)) { return false; } // Store the access token and, if provided by the server, the new refresh token. $this->store_token($receivedtokens['access_token']); if (isset($receivedtokens['refresh_token'])) { $systemaccount->set('refreshtoken', $receivedtokens['refresh_token']->token); $systemaccount->update(); } return true; } /**
< * Fetch the user info from the user info endpoint and map all < * the fields back into moodle fields.
> * Fetch the user info from the user info endpoint.
*
< * @return array|false Moodle user fields for the logged in user (or false if request failed)
> * @return stdClass|false Moodle user fields for the logged in user (or false if request failed) > * @throws moodle_exception if the response is empty after decoding it.
*/
< public function get_userinfo() {
> public function get_raw_userinfo() { > if (!empty($this->rawuserinfo)) { > return $this->rawuserinfo; > }
$url = $this->get_issuer()->get_endpoint_url('userinfo');
> if (empty($url)) { $response = $this->get($url); > return false; if (!$response) { > } return false; >
} $userinfo = new stdClass(); try { $userinfo = json_decode($response); } catch (\Exception $e) {
> return false; return false; > } } > > if (is_null($userinfo)) { return $this->map_userinfo_to_fields($userinfo); > // Throw an exception displaying the original response, because, at this point, $userinfo shouldn't be empty. } > throw new moodle_exception($response); > } /** > $this->rawuserinfo = $userinfo; * Maps the oauth2 response to userfields. > return $userinfo; * > } * @param stdClass $userinfo > * @return array > /** */ > * Fetch the user info from the user info endpoint and map all protected function map_userinfo_to_fields(stdClass $userinfo): array { > * the fields back into moodle fields. $map = $this->get_userinfo_mapping(); > * > * @return stdClass|false Moodle user fields for the logged in user (or false if request failed) $user = new stdClass(); > * @throws moodle_exception if the response is empty after decoding it. foreach ($map as $openidproperty => $moodleproperty) { > */ // We support nested objects via a-b-c syntax. > public function get_userinfo() { $getfunc = function($obj, $prop) use (&$getfunc) { > $userinfo = $this->get_raw_userinfo(); $proplist = explode('-', $prop, 2); > if ($userinfo === false) {
// The value of proplist[0] can be falsey, so just check if not set. if (empty($obj) || !isset($proplist[0])) { return false; } if (preg_match('/^(.*)\[([0-9]*)\]$/', $proplist[0], $matches) && count($matches) == 3) { $property = $matches[1]; $index = $matches[2]; $obj = $obj->{$property}[$index] ?? null; } else if (!empty($obj->{$proplist[0]})) { $obj = $obj->{$proplist[0]}; } else if (is_array($obj) && !empty($obj[$proplist[0]])) { $obj = $obj[$proplist[0]]; } else { // Nothing found after checking all possible valid combinations, return false. return false; } if (count($proplist) > 1) { return $getfunc($obj, $proplist[1]); } return $obj; }; $resolved = $getfunc($userinfo, $openidproperty); if (!empty($resolved)) { $user->$moodleproperty = $resolved; } } if (empty($user->username) && !empty($user->email)) { $user->username = $user->email; } if (!empty($user->picture)) { $user->picture = download_file_content($user->picture, null, null, false, 10, 10, true, null, false); } else { $pictureurl = $this->issuer->get_endpoint_url('userpicture'); if (!empty($pictureurl)) { $user->picture = $this->get($pictureurl); } } if (!empty($user->picture)) { // If it doesn't look like a picture lets unset it. if (function_exists('imagecreatefromstring')) { $img = @imagecreatefromstring($user->picture); if (empty($img)) { unset($user->picture); } else { imagedestroy($img); } } } return (array)$user; } }