618 lines
26 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/>.
namespace core_external;
use context;
use context_course;
use context_helper;
use context_system;
use core_user;
use moodle_exception;
use moodle_url;
use stdClass;
/**
* Utility functions for the external API.
*
* @package core_webservice
* @copyright 2015 Juan Leyva
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 3.0
*/
class util {
/**
* Validate a list of courses, returning the complete course objects for valid courses.
*
* Each course has an additional 'contextvalidated' field, this will be set to true unless
* you set $keepfails, in which case it will be false if validation fails for a course.
*
* @param array $courseids A list of course ids
* @param array $courses An array of courses already pre-fetched, indexed by course id.
* @param bool $addcontext True if the returned course object should include the full context object.
* @param bool $keepfails True to keep all the course objects even if validation fails
* @return array An array of courses and the validation warnings
*/
public static function validate_courses($courseids, $courses = array(), $addcontext = false,
$keepfails = false) {
global $DB;
// Delete duplicates.
$courseids = array_unique($courseids);
$warnings = array();
// Remove courses which are not even requested.
$courses = array_intersect_key($courses, array_flip($courseids));
// For any courses NOT loaded already, get them in a single query (and preload contexts)
// for performance. Preserve ordering because some tests depend on it.
$newcourseids = [];
foreach ($courseids as $cid) {
if (!array_key_exists($cid, $courses)) {
$newcourseids[] = $cid;
}
}
if ($newcourseids) {
list ($listsql, $listparams) = $DB->get_in_or_equal($newcourseids);
// Load list of courses, and preload associated contexts.
$contextselect = context_helper::get_preload_record_columns_sql('x');
$newcourses = $DB->get_records_sql("
SELECT c.*, $contextselect
FROM {course} c
JOIN {context} x ON x.instanceid = c.id
WHERE x.contextlevel = ? AND c.id $listsql",
array_merge([CONTEXT_COURSE], $listparams));
foreach ($newcourseids as $cid) {
if (array_key_exists($cid, $newcourses)) {
$course = $newcourses[$cid];
context_helper::preload_from_record($course);
$courses[$course->id] = $course;
}
}
}
foreach ($courseids as $cid) {
// Check the user can function in this context.
try {
$context = context_course::instance($cid);
external_api::validate_context($context);
if ($addcontext) {
$courses[$cid]->context = $context;
}
$courses[$cid]->contextvalidated = true;
} catch (Exception $e) {
if ($keepfails) {
$courses[$cid]->contextvalidated = false;
} else {
unset($courses[$cid]);
}
$warnings[] = array(
'item' => 'course',
'itemid' => $cid,
'warningcode' => '1',
'message' => 'No access rights in course context'
);
}
}
return array($courses, $warnings);
}
/**
* Returns all area files (optionally limited by itemid).
*
* @param int $contextid context ID
* @param string $component component
* @param string $filearea file area
* @param int $itemid item ID or all files if not specified
* @param bool $useitemidinurl wether to use the item id in the file URL (modules intro don't use it)
* @return array of files, compatible with the external_files structure.
* @since Moodle 3.2
*/
public static function get_area_files($contextid, $component, $filearea, $itemid = false, $useitemidinurl = true) {
$files = array();
$fs = get_file_storage();
if ($areafiles = $fs->get_area_files($contextid, $component, $filearea, $itemid, 'itemid, filepath, filename', false)) {
foreach ($areafiles as $areafile) {
$file = array();
$file['filename'] = $areafile->get_filename();
$file['filepath'] = $areafile->get_filepath();
$file['mimetype'] = $areafile->get_mimetype();
$file['filesize'] = $areafile->get_filesize();
$file['timemodified'] = $areafile->get_timemodified();
$file['isexternalfile'] = $areafile->is_external_file();
if ($file['isexternalfile']) {
$file['repositorytype'] = $areafile->get_repository_type();
}
$fileitemid = $useitemidinurl ? $areafile->get_itemid() : null;
$file['fileurl'] = moodle_url::make_webservice_pluginfile_url($contextid, $component, $filearea,
$fileitemid, $areafile->get_filepath(), $areafile->get_filename())->out(false);
$files[] = $file;
}
}
return $files;
}
/**
* 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 int $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 context $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
*/
public static function generate_token(
int $tokentype,
stdClass $service,
int $userid,
context $context,
int $validuntil = 0,
string $iprestriction = ''
): string {
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 ++;
$generatedtoken = md5(uniqid((string) rand(), true));
if ($numtries > 5) {
throw new moodle_exception('tokengenerationfailed');
}
} while ($DB->record_exists('external_tokens', ['token' => $generatedtoken]));
$newtoken = (object) [
'token' => $generatedtoken,
];
if (empty($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;
}
/**
* Get a service by its id.
*
* @param int $serviceid
* @return stdClass
*/
public static function get_service_by_id(int $serviceid): stdClass {
global $DB;
return $DB->get_record('external_services', ['id' => $serviceid], '*', MUST_EXIST);
}
/**
* Get a service by its name.
*
* @param string $name The service name.
* @return stdClass
*/
public static function get_service_by_name(string $name): stdClass {
global $DB;
return $DB->get_record('external_services', ['name' => $name], '*', MUST_EXIST);
}
/**
* 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
*/
public static function log_token_request(stdClass $token): void {
global $DB, $USER;
$token->privatetoken = null;
// Log token access.
$DB->set_field('external_tokens', 'lastaccess', time(), ['id' => $token->id]);
$event = \core\event\webservice_token_sent::create([
'objectid' => $token->id,
]);
$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) {
return;
}
$shouldskip = WS_SERVER || CLI_SCRIPT || !NO_MOODLE_COOKIES;
if ($shouldskip && !PHPUNIT_TEST) {
return;
}
$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);
$logintime = time();
$task->set_custom_data([
'useragent' => \core_useragent::get_user_agent_string(),
'ismoodleapp' => \core_useragent::is_moodle_app(),
'loginip' => $loginip,
'logintime' => $logintime,
]);
$task->set_component('core');
// We need sometime so the mobile app will send to Moodle the device information after login.
$task->set_next_run_time(time() + (2 * MINSECS));
\core\task\manager::reschedule_or_queue_adhoc_task($task);
}
/**
* Generate or return an existing token for the current authenticated user.
* This function is used for creating a valid token for users authenticathing via places, including:
* - login/token.php
* - admin/tool/mobile/launch.php.
*
* @param stdClass $service external service object
* @return stdClass token object
* @throws moodle_exception
*/
public static function generate_token_for_current_user(stdClass $service) {
global $DB, $USER, $CFG;
core_user::require_active_user($USER, true, true);
// Check if there is any required system capability.
if ($service->requiredcapability && !has_capability($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', [
'externalserviceid' => $service->id,
'userid' => $USER->id,
]);
if (empty($authoriseduser)) {
throw new moodle_exception('usernotallowed', 'webservice', '', $service->shortname);
}
if (!empty($authoriseduser->validuntil) && $authoriseduser->validuntil < time()) {
throw new moodle_exception('invalidtimedtoken', 'webservice');
}
if (!empty($authoriseduser->iprestriction) && !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 = [
'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', ['sid' => $token->sid]);
$unsettoken = true;
}
}
// Remove token is not valid anymore.
if (!empty($token->validuntil) && $token->validuntil < time()) {
$DB->delete_records('external_tokens', ['token' => $token->token, 'tokentype' => EXTERNAL_TOKEN_PERMANENT]);
$unsettoken = true;
}
// Remove token if its IP is restricted.
if (isset($token->iprestriction) && !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 && has_capability('moodle/webservice:createmobiletoken', $context)) ||
(!is_siteadmin($USER) && has_capability('moodle/webservice:createtoken', $context))
) {
// Create a new token.
$token = new stdClass;
$token->token = md5(uniqid((string) rand(), true));
$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 = [
'objectid' => $eventtoken->id,
'relateduserid' => $USER->id,
'other' => [
'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;
}
/**
* 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 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 settings}.
* </pre>
*
* @param string|null $content 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 $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
*/
public static function format_string(
$content,
$context,
$striplinks = true,
$options = []
) {
if ($content === null || $content === '') {
// Nothing to return.
// Note: It's common for the DB to return null, so we allow format_string to take a null,
// even though it is counter-intuitive.
return '';
}
// Get settings (singleton).
$settings = external_settings::get_instance();
if (!$settings->get_raw()) {
$options['context'] = $context;
$options['filter'] = isset($options['filter']) && !$options['filter'] ? false : $settings->get_filter();
return format_string($content, $striplinks, $options);
}
return $content;
}
/**
* 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 \core_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 \core_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|null $text The content that may contain ULRs in need of rewriting.
* @param string|int|null $textformat The text format.
* @param context $context This parameter and the next two identify the file area to use.
* @param string|null $component
* @param string|null $filearea helps identify the file area.
* @param int|string|null $itemid helps identify the file area.
* @param array|stdClass|null $options text formatting options
* @return array text + textformat
*/
public static function format_text(
$text,
$textformat,
$context,
$component = null,
$filearea = null,
$itemid = null,
$options = null
) {
global $CFG;
if ($text === null || $text === '') {
// Nothing to return.
// Note: It's common for the DB to return null, so we allow format_string to take nulls,
// even though it is counter-intuitive.
return ['', $textformat ?? FORMAT_MOODLE];
}
if (empty($itemid)) {
$itemid = null;
}
// Get settings (singleton).
$settings = external_settings::get_instance();
if ($component && $filearea && $settings->get_fileurl()) {
require_once($CFG->libdir . "/filelib.php");
$text = file_rewrite_pluginfile_urls($text, $settings->get_file(), $context->id, $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_int($options['context'])) {
if ($options['context'] != $context->id) {
debugging(
'Different contexts found in external_format_text parameters. $options[\'context\'] not allowed. ' .
'Using $contextid parameter...',
DEBUG_DEVELOPER
);
}
} else if ($options['context'] instanceof context) {
if ($options['context']->id != $context->id) {
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'] = $context;
$options['allowid'] = isset($options['allowid']) ? $options['allowid'] : true;
$text = format_text($text, $textformat, $options);
// Once converted to html (from markdown, plain... lets inform consumer this is already HTML).
$textformat = FORMAT_HTML;
}
// Note: The formats defined in weblib are strings.
return [$text, $textformat];
}
/**
* Validate text field format against known FORMAT_XXX
*
* @param array $format the format to validate
* @return the validated format
* @throws coding_exception
* @since Moodle 2.3
*/
public static function validate_format($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;
}
/**
* Delete all pre-built services (+ related tokens) and external functions information defined in the specified component.
*
* @param string $component name of component (moodle, mod_assignment, etc.)
*/
public static function delete_service_descriptions($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));
}
}