lib/form/recaptcha.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 /**
  19  * recaptcha type form element
  20  *
  21  * Contains HTML class for a recaptcha type element
  22  *
  23  * @package   core_form
  24  * @copyright 2008 Nicolas Connault <nicolasconnault@gmail.com>
  25  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26  */
  27
  28 require_once('HTML/QuickForm/input.php');
  29
  30 /**
  31  * recaptcha type form element
  32  *
  33  * HTML class for a recaptcha type element
  34  *
  35  * @package   core_form
  36  * @category  form
  37  * @copyright 2008 Nicolas Connault <nicolasconnault@gmail.com>
  38  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  39  */
  40 class MoodleQuickForm_recaptcha extends HTML_QuickForm_input {
  41
  42     /** @var string html for help button, if empty then no help */
  43     var $_helpbutton='';
  44
  45     /** @var bool if true, recaptcha will be servered from https */
  46     var $_https=false;
  47
  48     /**
  49      * constructor
  50      *
  51      * @param string $elementName (optional) name of the recaptcha element
  52      * @param string $elementLabel (optional) label for recaptcha element
  53      * @param mixed $attributes (optional) Either a typical HTML attribute string
  54      *              or an associative array
  55      */
  56     function MoodleQuickForm_recaptcha($elementName = null, $elementLabel = null, $attributes = null) {
  57         global $CFG;
  58         parent::HTML_QuickForm_input($elementName, $elementLabel, $attributes);
  59         $this->_type = 'recaptcha';
  60         if (is_https()) {
  61             $this->_https = true;
  62         } else {
  63             $this->_https = false;
  64         }
  65     }
  66
  67     /**
  68      * Returns the recaptcha element in HTML
  69      *
  70      * @return string
  71      */
  72     function toHtml() {
  73         global $CFG, $PAGE;
  74         require_once $CFG->libdir . '/recaptchalib.php';
  75
  76         $recaptureoptions = Array('theme'=>'custom', 'custom_theme_widget'=>'recaptcha_widget');
  77         $html = html_writer::script(js_writer::set_variable('RecaptchaOptions', $recaptureoptions));
  78
  79         $attributes = $this->getAttributes();
  80         if (empty($attributes['error_message'])) {
  81             $attributes['error_message'] = null;
  82             $this->setAttributes($attributes);
  83         }
  84         $error = $attributes['error_message'];
  85         unset($attributes['error_message']);
  86
  87         $strincorrectpleasetryagain = get_string('incorrectpleasetryagain', 'auth');
  88         $strenterthewordsabove = get_string('enterthewordsabove', 'auth');
  89         $strenterthenumbersyouhear = get_string('enterthenumbersyouhear', 'auth');
  90         $strgetanothercaptcha = get_string('getanothercaptcha', 'auth');
  91         $strgetanaudiocaptcha = get_string('getanaudiocaptcha', 'auth');
  92         $strgetanimagecaptcha = get_string('getanimagecaptcha', 'auth');
  93
  94         $html .= '
  95 <div id="recaptcha_widget" style="display:none">
  96
  97 <div id="recaptcha_image"></div>
  98 <div class="recaptcha_only_if_incorrect_sol" style="color:red">' . $strincorrectpleasetryagain . '</div>
  99
 100 <span class="recaptcha_only_if_image"><label for="recaptcha_response_field">' . $strenterthewordsabove . '</label></span>
 101 <span class="recaptcha_only_if_audio"><label for="recaptcha_response_field">' . $strenterthenumbersyouhear . '</label></span>
 102
 103 <input type="text" id="recaptcha_response_field" name="recaptcha_response_field" />
 104 <input type="hidden" name="recaptcha_element" value="dummyvalue" /> <!-- Dummy value to fool formslib -->
 105 <div><a href="javascript:Recaptcha.reload()">' . $strgetanothercaptcha . '</a></div>
 106 <div class="recaptcha_only_if_image"><a href="javascript:Recaptcha.switch_type(\'audio\')">' . $strgetanaudiocaptcha . '</a></div>
 107 <div class="recaptcha_only_if_audio"><a href="javascript:Recaptcha.switch_type(\'image\')">' . $strgetanimagecaptcha . '</a></div>
 108 </div>';
 109
 110         return $html . recaptcha_get_html($CFG->recaptchapublickey, $error, $this->_https);
 111     }
 112
 113     /**
 114      * get html for help button
 115      *
 116      * @return string html for help button
 117      */
 118     function getHelpButton(){
 119         return $this->_helpbutton;
 120     }
 121
 122     /**
 123      * Checks input and challenged field
 124      *
 125      * @param string $challenge_field recaptcha shown  to user
 126      * @param string $response_field input value by user
 127      * @return bool
 128      */
 129     function verify($challenge_field, $response_field) {
 130         global $CFG;
 131         require_once $CFG->libdir . '/recaptchalib.php';
 132         $response = recaptcha_check_answer($CFG->recaptchaprivatekey,
 133                                            getremoteaddr(),
 134                                            $challenge_field,
 135                                            $response_field,
 136                                            $this->_https);
 137         if (!$response->is_valid) {
 138             $attributes = $this->getAttributes();
 139             $attributes['error_message'] = $response->error;
 140             $this->setAttributes($attributes);
 141             return $response->error;
 142         }
 143         return true;
 144     }
 145 }