moodle/lib/externallib.php

644 lines
24 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/>.
/**
* Support for external API
*
* @package core_webservice
* @copyright 2009 Petr Skodak
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
class_alias(\core_external\external_api::class, 'external_api');
class_alias(\core_external\restricted_context_exception::class, 'restricted_context_exception');
class_alias(\core_external\external_description::class, 'external_description');
class_alias(\core_external\external_value::class, 'external_value');
class_alias(\core_external\external_single_structure::class, 'external_single_structure');
class_alias(\core_external\external_multiple_structure::class, 'external_multiple_structure');
class_alias(\core_external\external_function_parameters::class, 'external_function_parameters');
class_alias(\core_external\util::class, 'external_util');
class_alias(\core_external\external_files::class, 'external_files');
class_alias(\core_external\external_warnings::class, 'external_warnings');
/**
* Generate a token
*
* @param string $tokentype EXTERNAL_TOKEN_EMBEDDED|EXTERNAL_TOKEN_PERMANENT
* @param stdClass|int $serviceorid service linked to the token
* @param int $userid user linked to the token
* @param stdClass|int $contextorid
* @param int $validuntil date when the token expired
* @param string $iprestriction allowed ip - if 0 or empty then all ips are allowed
* @return string generated token
* @author 2010 Jamie Pratt
* @since Moodle 2.0
*/
function external_generate_token($tokentype, $serviceorid, $userid, $contextorid, $validuntil=0, $iprestriction=''){
global $DB, $USER;
// make sure the token doesn't exist (even if it should be almost impossible with the random generation)
$numtries = 0;
do {
$numtries ++;
$generatedtoken = md5(uniqid(rand(),1));
if ($numtries > 5){
throw new moodle_exception('tokengenerationfailed');
}
} while ($DB->record_exists('external_tokens', array('token'=>$generatedtoken)));
$newtoken = new stdClass();
$newtoken->token = $generatedtoken;
if (!is_object($serviceorid)){
$service = $DB->get_record('external_services', array('id' => $serviceorid));
} else {
$service = $serviceorid;
}
if (!is_object($contextorid)){
$context = context::instance_by_id($contextorid, MUST_EXIST);
} else {
$context = $contextorid;
}
if (empty($service->requiredcapability) || has_capability($service->requiredcapability, $context, $userid)) {
$newtoken->externalserviceid = $service->id;
} else {
throw new moodle_exception('nocapabilitytousethisservice');
}
$newtoken->tokentype = $tokentype;
$newtoken->userid = $userid;
if ($tokentype == EXTERNAL_TOKEN_EMBEDDED){
$newtoken->sid = session_id();
}
$newtoken->contextid = $context->id;
$newtoken->creatorid = $USER->id;
$newtoken->timecreated = time();
$newtoken->validuntil = $validuntil;
if (!empty($iprestriction)) {
$newtoken->iprestriction = $iprestriction;
}
// Generate the private token, it must be transmitted only via https.
$newtoken->privatetoken = random_string(64);
$DB->insert_record('external_tokens', $newtoken);
return $newtoken->token;
}
/**
* Create and return a session linked token. Token to be used for html embedded client apps that want to communicate
* with the Moodle server through web services. The token is linked to the current session for the current page request.
* It is expected this will be called in the script generating the html page that is embedding the client app and that the
* returned token will be somehow passed into the client app being embedded in the page.
*
* @param string $servicename name of the web service. Service name as defined in db/services.php
* @param int $context context within which the web service can operate.
* @return int returns token id.
* @since Moodle 2.0
*/
function external_create_service_token($servicename, $context){
global $USER, $DB;
$service = $DB->get_record('external_services', array('name'=>$servicename), '*', MUST_EXIST);
return external_generate_token(EXTERNAL_TOKEN_EMBEDDED, $service, $USER->id, $context, 0);
}
/**
* Delete all pre-built services (+ related tokens) and external functions information defined in the specified component.
*
* @param string $component name of component (moodle, mod_assignment, etc.)
*/
function external_delete_descriptions($component) {
global $DB;
$params = array($component);
$DB->delete_records_select('external_tokens',
"externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
$DB->delete_records_select('external_services_users',
"externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
$DB->delete_records_select('external_services_functions',
"functionname IN (SELECT name FROM {external_functions} WHERE component = ?)", $params);
$DB->delete_records('external_services', array('component'=>$component));
$DB->delete_records('external_functions', array('component'=>$component));
}
/**
* A pre-filled external_value class for text format.
*
* Default is FORMAT_HTML
* This should be used all the time in external xxx_params()/xxx_returns functions
* as it is the standard way to implement text format param/return values.
*
* @package core_webservice
* @copyright 2012 Jerome Mouneyrac
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.3
*/
class external_format_value extends external_value {
/**
* Constructor
*
* @param string $textfieldname Name of the text field
* @param int $required if VALUE_REQUIRED then set standard default FORMAT_HTML
* @param int $default Default value.
* @since Moodle 2.3
*/
public function __construct($textfieldname, $required = VALUE_REQUIRED, $default = null) {
if ($default == null && $required == VALUE_DEFAULT) {
$default = FORMAT_HTML;
}
$desc = $textfieldname . ' format (' . FORMAT_HTML . ' = HTML, '
. FORMAT_MOODLE . ' = MOODLE, '
. FORMAT_PLAIN . ' = PLAIN or '
. FORMAT_MARKDOWN . ' = MARKDOWN)';
parent::__construct(PARAM_INT, $desc, $required, $default);
}
}
/**
* Validate text field format against known FORMAT_XXX
*
* @param array $format the format to validate
* @return the validated format
* @throws coding_exception
* @since Moodle 2.3
*/
function external_validate_format($format) {
$allowedformats = array(FORMAT_HTML, FORMAT_MOODLE, FORMAT_PLAIN, FORMAT_MARKDOWN);
if (!in_array($format, $allowedformats)) {
throw new moodle_exception('formatnotsupported', 'webservice', '' , null,
'The format with value=' . $format . ' is not supported by this Moodle site');
}
return $format;
}
/**
* Format the string to be returned properly as requested by the either the web service server,
* either by an internally call.
* The caller can change the format (raw) with the external_settings singleton
* All web service servers must set this singleton when parsing the $_GET and $_POST.
*
* <pre>
* Options are the same that in {@link format_string()} with some changes:
* filter : Can be set to false to force filters off, else observes {@link external_settings}.
* </pre>
*
* @param string $str The string to be filtered. Should be plain text, expect
* possibly for multilang tags.
* @param boolean $striplinks To strip any link in the result text. Moodle 1.8 default changed from false to true! MDL-8713
* @param context|int $contextorid The id of the context for the string or the context (affects filters).
* @param array $options options array/object or courseid
* @return string text
* @since Moodle 3.0
*/
function external_format_string($str, $contextorid, $striplinks = true, $options = array()) {
// Get settings (singleton).
$settings = external_settings::get_instance();
if (empty($contextorid)) {
throw new coding_exception('contextid is required');
}
if (!$settings->get_raw()) {
if (is_object($contextorid) && is_a($contextorid, 'context')) {
$context = $contextorid;
} else {
$context = context::instance_by_id($contextorid);
}
$options['context'] = $context;
$options['filter'] = isset($options['filter']) && !$options['filter'] ? false : $settings->get_filter();
$str = format_string($str, $striplinks, $options);
}
return $str;
}
/**
* Format the text to be returned properly as requested by the either the web service server,
* either by an internally call.
* The caller can change the format (raw, filter, file, fileurl) with the external_settings singleton
* All web service servers must set this singleton when parsing the $_GET and $_POST.
*
* <pre>
* Options are the same that in {@link format_text()} with some changes in defaults to provide backwards compatibility:
* trusted : If true the string won't be cleaned. Default false.
* noclean : If true the string won't be cleaned only if trusted is also true. Default false.
* nocache : If true the string will not be cached and will be formatted every call. Default false.
* filter : Can be set to false to force filters off, else observes {@link external_settings}.
* para : If true then the returned string will be wrapped in div tags. Default (different from format_text) false.
* Default changed because div tags are not commonly needed.
* newlines : If true then lines newline breaks will be converted to HTML newline breaks. Default true.
* context : Not used! Using contextid parameter instead.
* overflowdiv : If set to true the formatted text will be encased in a div with the class no-overflow before being
* returned. Default false.
* allowid : If true then id attributes will not be removed, even when using htmlpurifier. Default (different from
* format_text) true. Default changed id attributes are commonly needed.
* blanktarget : If true all <a> tags will have target="_blank" added unless target is explicitly specified.
* </pre>
*
* @param string $text The content that may contain ULRs in need of rewriting.
* @param int $textformat The text format.
* @param context|int $contextorid This parameter and the next two identify the file area to use.
* @param string $component
* @param string $filearea helps identify the file area.
* @param int $itemid helps identify the file area.
* @param object/array $options text formatting options
* @return array text + textformat
* @since Moodle 2.3
* @since Moodle 3.2 component, filearea and itemid are optional parameters
*/
function external_format_text($text, $textformat, $contextorid, $component = null, $filearea = null, $itemid = null,
$options = null) {
global $CFG;
// Get settings (singleton).
$settings = external_settings::get_instance();
if (is_object($contextorid) && is_a($contextorid, 'context')) {
$context = $contextorid;
$contextid = $context->id;
} else {
$context = null;
$contextid = $contextorid;
}
if ($component and $filearea and $settings->get_fileurl()) {
require_once($CFG->libdir . "/filelib.php");
$text = file_rewrite_pluginfile_urls($text, $settings->get_file(), $contextid, $component, $filearea, $itemid);
}
// Note that $CFG->forceclean does not apply here if the client requests for the raw database content.
// This is consistent with web clients that are still able to load non-cleaned text into editors, too.
if (!$settings->get_raw()) {
$options = (array)$options;
// If context is passed in options, check that is the same to show a debug message.
if (isset($options['context'])) {
if ((is_object($options['context']) && $options['context']->id != $contextid)
|| (!is_object($options['context']) && $options['context'] != $contextid)) {
debugging('Different contexts found in external_format_text parameters. $options[\'context\'] not allowed.
Using $contextid parameter...', DEBUG_DEVELOPER);
}
}
$options['filter'] = isset($options['filter']) && !$options['filter'] ? false : $settings->get_filter();
$options['para'] = isset($options['para']) ? $options['para'] : false;
$options['context'] = !is_null($context) ? $context : context::instance_by_id($contextid);
$options['allowid'] = isset($options['allowid']) ? $options['allowid'] : true;
$text = format_text($text, $textformat, $options);
$textformat = FORMAT_HTML; // Once converted to html (from markdown, plain... lets inform consumer this is already HTML).
}
return array($text, $textformat);
}
/**
* Generate or return an existing token for the current authenticated user.
* This function is used for creating a valid token for users authenticathing via login/token.php or admin/tool/mobile/launch.php.
*
* @param stdClass $service external service object
* @return stdClass token object
* @since Moodle 3.2
* @throws moodle_exception
*/
function external_generate_token_for_current_user($service) {
global $DB, $USER, $CFG;
core_user::require_active_user($USER, true, true);
// Check if there is any required system capability.
if ($service->requiredcapability and !has_capability($service->requiredcapability, context_system::instance())) {
throw new moodle_exception('missingrequiredcapability', 'webservice', '', $service->requiredcapability);
}
// Specific checks related to user restricted service.
if ($service->restrictedusers) {
$authoriseduser = $DB->get_record('external_services_users',
array('externalserviceid' => $service->id, 'userid' => $USER->id));
if (empty($authoriseduser)) {
throw new moodle_exception('usernotallowed', 'webservice', '', $service->shortname);
}
if (!empty($authoriseduser->validuntil) and $authoriseduser->validuntil < time()) {
throw new moodle_exception('invalidtimedtoken', 'webservice');
}
if (!empty($authoriseduser->iprestriction) and !address_in_subnet(getremoteaddr(), $authoriseduser->iprestriction)) {
throw new moodle_exception('invalidiptoken', 'webservice');
}
}
// Check if a token has already been created for this user and this service.
$conditions = array(
'userid' => $USER->id,
'externalserviceid' => $service->id,
'tokentype' => EXTERNAL_TOKEN_PERMANENT
);
$tokens = $DB->get_records('external_tokens', $conditions, 'timecreated ASC');
// A bit of sanity checks.
foreach ($tokens as $key => $token) {
// Checks related to a specific token. (script execution continue).
$unsettoken = false;
// If sid is set then there must be a valid associated session no matter the token type.
if (!empty($token->sid)) {
if (!\core\session\manager::session_exists($token->sid)) {
// This token will never be valid anymore, delete it.
$DB->delete_records('external_tokens', array('sid' => $token->sid));
$unsettoken = true;
}
}
// Remove token is not valid anymore.
if (!empty($token->validuntil) and $token->validuntil < time()) {
$DB->delete_records('external_tokens', array('token' => $token->token, 'tokentype' => EXTERNAL_TOKEN_PERMANENT));
$unsettoken = true;
}
// Remove token if its IP is restricted.
if (isset($token->iprestriction) and !address_in_subnet(getremoteaddr(), $token->iprestriction)) {
$unsettoken = true;
}
if ($unsettoken) {
unset($tokens[$key]);
}
}
// If some valid tokens exist then use the most recent.
if (count($tokens) > 0) {
$token = array_pop($tokens);
} else {
$context = context_system::instance();
$isofficialservice = $service->shortname == MOODLE_OFFICIAL_MOBILE_SERVICE;
if (($isofficialservice and has_capability('moodle/webservice:createmobiletoken', $context)) or
(!is_siteadmin($USER) && has_capability('moodle/webservice:createtoken', $context))) {
// Create a new token.
$token = new stdClass;
$token->token = md5(uniqid(rand(), 1));
$token->userid = $USER->id;
$token->tokentype = EXTERNAL_TOKEN_PERMANENT;
$token->contextid = context_system::instance()->id;
$token->creatorid = $USER->id;
$token->timecreated = time();
$token->externalserviceid = $service->id;
// By default tokens are valid for 12 weeks.
$token->validuntil = $token->timecreated + $CFG->tokenduration;
$token->iprestriction = null;
$token->sid = null;
$token->lastaccess = null;
// Generate the private token, it must be transmitted only via https.
$token->privatetoken = random_string(64);
$token->id = $DB->insert_record('external_tokens', $token);
$eventtoken = clone $token;
$eventtoken->privatetoken = null;
$params = array(
'objectid' => $eventtoken->id,
'relateduserid' => $USER->id,
'other' => array(
'auto' => true
)
);
$event = \core\event\webservice_token_created::create($params);
$event->add_record_snapshot('external_tokens', $eventtoken);
$event->trigger();
} else {
throw new moodle_exception('cannotcreatetoken', 'webservice', '', $service->shortname);
}
}
return $token;
}
/**
* Set the last time a token was sent and trigger the \core\event\webservice_token_sent event.
*
* This function is used when a token is generated by the user via login/token.php or admin/tool/mobile/launch.php.
* In order to protect the privatetoken, we remove it from the event params.
*
* @param stdClass $token token object
* @since Moodle 3.2
*/
function external_log_token_request($token) {
global $DB, $USER;
$token->privatetoken = null;
// Log token access.
$DB->set_field('external_tokens', 'lastaccess', time(), array('id' => $token->id));
$params = array(
'objectid' => $token->id,
);
$event = \core\event\webservice_token_sent::create($params);
$event->add_record_snapshot('external_tokens', $token);
$event->trigger();
// Check if we need to notify the user about the new login via token.
$loginip = getremoteaddr();
if ($USER->lastip != $loginip &&
((!WS_SERVER && !CLI_SCRIPT && NO_MOODLE_COOKIES) || PHPUNIT_TEST)) {
$logintime = time();
$useragent = \core_useragent::get_user_agent_string();
$ismoodleapp = \core_useragent::is_moodle_app();
// Schedule adhoc task to sent a login notification to the user.
$task = new \core\task\send_login_notifications();
$task->set_userid($USER->id);
$task->set_custom_data(compact('ismoodleapp', 'useragent', 'loginip', 'logintime'));
$task->set_component('core');
// We need sometime so the mobile app will send to Moodle the device information after login.
$task->set_next_run_time($logintime + (2 * MINSECS));
\core\task\manager::reschedule_or_queue_adhoc_task($task);
}
}
/**
* Singleton to handle the external settings.
*
* We use singleton to encapsulate the "logic"
*
* @package core_webservice
* @copyright 2012 Jerome Mouneyrac
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.3
*/
class external_settings {
/** @var object the singleton instance */
public static $instance = null;
/** @var boolean Should the external function return raw text or formatted */
private $raw = false;
/** @var boolean Should the external function filter the text */
private $filter = false;
/** @var boolean Should the external function rewrite plugin file url */
private $fileurl = true;
/** @var string In which file should the urls be rewritten */
private $file = 'webservice/pluginfile.php';
/** @var string The session lang */
private $lang = '';
/** @var string The timezone to use during this WS request */
private $timezone = '';
/**
* Constructor - protected - can not be instanciated
*/
protected function __construct() {
if ((AJAX_SCRIPT == false) && (CLI_SCRIPT == false) && (WS_SERVER == false)) {
// For normal pages, the default should match the default for format_text.
$this->filter = true;
// Use pluginfile.php for web requests.
$this->file = 'pluginfile.php';
}
}
/**
* Return only one instance
*
* @return \external_settings
*/
public static function get_instance() {
if (self::$instance === null) {
self::$instance = new external_settings;
}
return self::$instance;
}
/**
* Set raw
*
* @param boolean $raw
*/
public function set_raw($raw) {
$this->raw = $raw;
}
/**
* Get raw
*
* @return boolean
*/
public function get_raw() {
return $this->raw;
}
/**
* Set filter
*
* @param boolean $filter
*/
public function set_filter($filter) {
$this->filter = $filter;
}
/**
* Get filter
*
* @return boolean
*/
public function get_filter() {
return $this->filter;
}
/**
* Set fileurl
*
* @param boolean $fileurl
*/
public function set_fileurl($fileurl) {
$this->fileurl = $fileurl;
}
/**
* Get fileurl
*
* @return boolean
*/
public function get_fileurl() {
return $this->fileurl;
}
/**
* Set file
*
* @param string $file
*/
public function set_file($file) {
$this->file = $file;
}
/**
* Get file
*
* @return string
*/
public function get_file() {
return $this->file;
}
/**
* Set lang
*
* @param string $lang
*/
public function set_lang($lang) {
$this->lang = $lang;
}
/**
* Get lang
*
* @return string
*/
public function get_lang() {
return $this->lang;
}
/**
* Set timezone
*
* @param string $timezone
*/
public function set_timezone($timezone) {
$this->timezone = $timezone;
}
/**
* Get timezone
*
* @return string
*/
public function get_timezone() {
return $this->timezone;
}
}