Proyectos de Subversion Moodle

<?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/>.

/**

 * Base class for antivirus integration.

 *

 * @package    core_antivirus

 * @copyright  2015 Ruslan Kabalin, Lancaster University.

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace core\antivirus;

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

require_once($CFG->dirroot . '/iplookup/lib.php');

/**

 * Base abstract antivirus scanner class.

 *

 * @package    core

 * @subpackage antivirus

 * @copyright  2015 Ruslan Kabalin, Lancaster University.

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

abstract class scanner {

    /** Scanning result indicating no virus found. */

    const SCAN_RESULT_OK = 0;

    /** Scanning result indicating that virus is found. */

    const SCAN_RESULT_FOUND = 1;

    /** Scanning result indicating the error. */

    const SCAN_RESULT_ERROR = 2;

    /** @var \stdClass the config for antivirus */

    protected $config;

    /** @var string scanning notice */

    protected $scanningnotice = '';

    /** @var array any admin messages generated by a plugin. */

    protected $messages = [];

    /**

     * Class constructor.

     *

     * @return void.

     */

    public function __construct() {

        // Populate config variable, inheriting class namespace is matching

        // full plugin name, so we can use it directly to retrieve plugin

        // configuration.

        $ref = new \ReflectionClass(get_class($this));

        $this->config = get_config($ref->getNamespaceName());

    }

    /**

     * Config get method.

     *

     * @param string $property config property to get.

     * @return mixed

     * @throws \coding_exception

     */

    public function get_config($property) {

        if (property_exists($this->config, $property)) {

            return $this->config->$property;

        }

        throw new \coding_exception('Config property "' . $property . '" doesn\'t exist');

    }

    /**

     * Get scanning notice.

     *

     * @return string

     */

    public function get_scanning_notice() {

        return $this->scanningnotice;

    }

    /**

     * Set scanning notice.

     *

     * @param string $notice notice to set.

     * @return void

     */

    protected function set_scanning_notice($notice) {

        $this->scanningnotice = $notice;

    }

    /**

     * Are the antivirus settings configured?

     *

     * @return bool True if plugin has been configured.

     */

    abstract public function is_configured();

    /**

     * Scan file.

     *

     * @param string $file Full path to the file.

     * @param string $filename Name of the file (could be different from physical file if temp file is used).

     * @return int Scanning result constants.

     */

    abstract public function scan_file($file, $filename);

    /**

     * Scan data.

     *

     * By default it saves data variable content to file and then scans it using

     * scan_file method, however if antivirus plugin permits scanning data directly,

     * the method can be overridden.

     *

     * @param string $data The variable containing the data to scan.

     * @return int Scanning result constants.

     */

    public function scan_data($data) {

        // Prepare temp file.

        $tempdir = make_request_directory();

        $tempfile = $tempdir . DIRECTORY_SEPARATOR . rand();

        file_put_contents($tempfile, $data);

        // Perform a virus scan now.

        return $this->scan_file($tempfile, get_string('datastream', 'antivirus'));

    }

    /**

     * This function pushes given messages into the message queue, which will be sent by the antivirus manager.

     *

     * @param string $notice The body of the email to be sent.

     * @param string $format The body format.

     * @param string $eventname event name

     * @return void

     * @throws \coding_exception

     * @throws \moodle_exception

     */

    public function message_admins($notice, $format = FORMAT_PLAIN, $eventname = 'errors') {

        $noticehtml = $format !== FORMAT_PLAIN ? format_text($notice, $format) : '';

        $site = get_site();

        $subject = get_string('emailsubject', 'antivirus', format_string($site->fullname));

        $notifyemail = get_config('antivirus', 'notifyemail');

        // If one email address is specified, construct a message to fake account.

        if (!empty($notifyemail)) {

            $user = new \stdClass();

            $user->id = -1;

            $user->email = $notifyemail;

            $user->mailformat = 1;

            $admins = [$user];

        } else {

            // Otherwise, we message all admins.

            $admins = get_admins();

        }

        foreach ($admins as $admin) {

            $eventdata = new \core\message\message();

            $eventdata->courseid          = SITEID;

            $eventdata->component         = 'moodle';

            $eventdata->name              = $eventname;

            $eventdata->userfrom          = get_admin();

            $eventdata->userto            = $admin;

            $eventdata->subject           = $subject;

            $eventdata->fullmessage       = $notice;

            $eventdata->fullmessageformat = $format;

            $eventdata->fullmessagehtml   = $noticehtml;

            $eventdata->smallmessage      = '';

            // Now add the message to an array to be sent by the antivirus manager.

            $this->messages[] = $eventdata;

        }

    }

    /**

     * Return incident details

     *

     * @param string $file full path to the file

     * @param string $filename original name of the file

     * @param string $notice notice from antivirus

     * @param string $virus if this template is due to a virus found.

     * @return string the incident details

     * @throws \coding_exception

     */

    public function get_incident_details($file = '', $filename = '', $notice = '', $virus = true) {

        global $OUTPUT, $USER;

        if (empty($notice)) {

            $notice = $this->get_scanning_notice();

        }

        $classname = get_class($this);

        $component = explode('\\', $classname)[0];

        $content = new \stdClass();

        $unknown = get_string('unknown', 'antivirus');

        $content->header = get_string('emailinfectedfiledetected', 'antivirus');

        $content->filename = !empty($filename) ? $filename : $unknown;

        $content->scanner = $component;

        // Check for empty file, or file not uploaded.

        if (!empty($file) && filesize($file) !== false) {

            $content->filesize = display_size(filesize($file));

            $content->contenthash = \file_storage::hash_from_path($file);

            $content->contenttype = mime_content_type($file);

        } else {

            $content->filesize = $unknown;

            $content->contenthash = $unknown;

            $content->contenttype = $unknown;

        }

        $content->author = \core_user::is_real_user($USER->id) ? fullname($USER) . " ($USER->username)" : $unknown;

        $content->ipaddress = getremoteaddr();

        $geoinfo = iplookup_find_location(getremoteaddr());

        $content->geoinfo = $geoinfo['city'] . ', ' . $geoinfo['country'];

        $content->date = userdate(time(), get_string('strftimedatetimeshort'));

        $content->referer = isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : $unknown;

        $content->notice = $notice;

        $report = new \moodle_url('/report/infectedfiles/index.php');

        $content->report = $report->out();

        // If this is not due to a virus, we need to change the header line.

        if (!$virus) {

            $content->header = get_string('emailscannererrordetected', 'antivirus');

        }

        return $OUTPUT->render_from_template('core/infected_file_email', $content);

    }

    /**

     * Getter method for messages queued by the antivirus scanner.

     *

     * @return array

     */

    public function get_messages(): array {

        return $this->messages;

    }

    /**

     * Getter method for the antivirus message displayed in the exception.

     *

     * @return array array of string and component to pass to exception constructor.

     */

    public function get_virus_found_message() {

        // Base antivirus found string.

        return ['string' => 'virusfound', 'component' => 'antivirus', 'placeholders' => []];

    }

}