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/>.

 // 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 is a PHP library that handles calling reCAPTCHA v2.

 *

 *    - Documentation

 *          {@link https://developers.google.com/recaptcha/docs/display}

 *    - Get a reCAPTCHA API Key

 *          {@link https://www.google.com/recaptcha/admin}

 *    - Discussion group

 *          {@link http://groups.google.com/group/recaptcha}

 *

 * @package core

 * @copyright 2018 Jeff Webster

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

 */

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

/**

 * The reCAPTCHA URL's

 */

define('RECAPTCHA_API_URL', 'https://www.recaptcha.net/recaptcha/api.js');

define('RECAPTCHA_VERIFY_URL', 'https://www.recaptcha.net/recaptcha/api/siteverify');

/**

 * Returns the language code the reCAPTCHA element should use.

 * Google reCAPTCHA uses different language codes than Moodle so we must convert.

 * https://developers.google.com/recaptcha/docs/language

 *

 * @param string $lang Language to use. If not provided, get current language.

 * @return string A language code

 */

function recaptcha_lang($lang = null) {

    if (empty($lang)) {

        $lang = current_language();

    }

    $glang = $lang;

    switch ($glang) {

        case 'en':

            $glang = 'en-GB';

            break;

        case 'en_us':

            $glang = 'en';

            break;

        case 'zh_cn':

            $glang = 'zh-CN';

            break;

        case 'zh_tw':

            $glang = 'zh-TW';

            break;

        case 'fr_ca':

            $glang = 'fr-CA';

            break;

        case 'pt_br':

            $glang = 'pt-BR';

            break;

        case 'he':

            $glang = 'iw';

            break;

    }

    // For any language code that didn't change reduce down to the base language.

    if (($lang === $glang) and (strpos($lang, '_') !== false)) {

        list($glang, $trash) = explode('_', $lang, 2);

    }

    return $glang;

}

/**

 * Gets the challenge HTML

 * This is called from the browser, and the resulting reCAPTCHA HTML widget

 * is embedded within the HTML form it was called from.

 *

 * @param string $apiurl URL for reCAPTCHA API

 * @param string $pubkey The public key for reCAPTCHA

 * @param string $lang Language to use. If not provided, get current language.

 * @param bool $compactmode If true, use the compact widget.

 * @return string - The HTML to be embedded in the user's form.

 */

function recaptcha_get_challenge_html($apiurl, $pubkey, $lang = null, bool $compactmode = false) {

    global $CFG, $PAGE;

    // To use reCAPTCHA you must have an API key.

    if ($pubkey === null || $pubkey === '') {

        return get_string('getrecaptchaapi', 'auth');

    }

    $jscode = "

        var recaptchacallback = function() {

            grecaptcha.render('recaptcha_element', {

              'sitekey' : '$pubkey'

            });

        }";

    $lang = recaptcha_lang($lang);

    $apicode = "\n<script type=\"text/javascript\" ";

    $apicode .= "src=\"$apiurl?onload=recaptchacallback&render=explicit&hl=$lang\" async defer>";

    $apicode .= "</script>\n";

    $return = html_writer::script($jscode, '');

    $return .= html_writer::div('', 'recaptcha_element', [

        'id' => 'recaptcha_element',

        'data-size' => ($compactmode ? 'compact' : 'normal'),

    ]);

    $return .= $apicode;

    return $return;

}

/**

 * Calls an HTTP POST function to verify if the user's response was correct

 *

 * @param string $verifyurl URL for reCAPTCHA verification

 * @param string $privkey The private key for reCAPTCHA

 * @param string $remoteip The user's IP

 * @param string $response The response from reCAPTCHA

 * @return array

 */

function recaptcha_check_response($verifyurl, $privkey, $remoteip, $response) {

    global $CFG;

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

    // Check response - isvalid boolean, error string.

    $checkresponse = array('isvalid' => false, 'error' => 'check-not-started');

    // To use reCAPTCHA you must have an API key.

    if ($privkey === null || $privkey === '') {

        $checkresponse['isvalid'] = false;

        $checkresponse['error'] = 'no-apikey';

        return $checkresponse;

    }

    // For security reasons, you must pass the remote ip to reCAPTCHA.

    if ($remoteip === null || $remoteip === '') {

        $checkresponse['isvalid'] = false;

        $checkresponse['error'] = 'no-remoteip';

        return $checkresponse;

    }

    // Discard spam submissions.

    if ($response === null || strlen($response) === 0) {

        $checkresponse['isvalid'] = false;

        $checkresponse['error'] = 'incorrect-captcha-sol';

        return $checkresponse;

    }

    $params = array('secret' => $privkey, 'remoteip' => $remoteip, 'response' => $response);

    $curl = new curl();

    $curlresponse = $curl->post($verifyurl, $params);

    if ($curl->get_errno() === 0) {

        $curldata = json_decode($curlresponse);

        if (isset($curldata->success) && $curldata->success === true) {

            $checkresponse['isvalid'] = true;

            $checkresponse['error'] = '';

        } else {

            $checkresponse['isvalid'] = false;

            $checkresponse['error'] = $curldata->{'error-codes'};

        }

    } else {

        $checkresponse['isvalid'] = false;

        $checkresponse['error'] = 'check-failed';

    }

    return $checkresponse;

}