application/libraries/Captcha.php

   1 <?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2
   3 /**
   4  * A library which simplifies the insertion and verification of CATCHAs.
   5  *
   6  * @author Călin-Andrei Burloiu
   7  * @category Library
   8  */
   9 class Captcha {
  10
  11         private $ci = NULL;
  12         private $db;
  13         private $params = NULL;
  14
  15         public function __construct($params = NULL)
  16         {
  17                 $this->ci =& get_instance();
  18                 $this->ci->config->load('captcha');
  19                 $this->ci->load->library('Singleton_db');
  20                 $this->db = $this->ci->singleton_db->connect();
  21
  22                 // Configuration parameters.
  23                 if (!$params)
  24                 {
  25                         $this->params = $this->ci->config->item('captcha_params');
  26                 }
  27                 else
  28                         $this->params = $params;
  29
  30                 if (!$this->params)
  31                         die('Cannot load CAPTCHA config file.');
  32         }
  33
  34         public function get_params()
  35         {
  36                 return $this->params;
  37         }
  38
  39         public function set_params($params)
  40         {
  41                 $this->params = $params;
  42         }
  43
  44         /**
  45          * Generates a CAPTCHA image and returns an array of associative data
  46          * about the image.
  47          *
  48          * @param string $word
  49          * @return array
  50          */
  51         public function get_captcha($word = NULL)
  52         {
  53                 $this->ci->load->helper('captcha');
  54
  55                 if ($word)
  56                         $this->params['captcha_params']['word'] = $word;
  57
  58                 // Creating the CAPTCHA.
  59                 $cap = create_captcha($this->params['captcha_params']);
  60
  61                 $data = array(
  62                         'captcha_time' => $cap['time'],
  63                         'ip_address' => $this->ci->input->ip_address(),
  64                         'word' => $cap['word']
  65                         );
  66
  67                 // Remember in DB the CAPTCHA - user mapping.
  68                 $str_query = $this->db->insert_string('captcha', $data);
  69                 $this->db->query($str_query);
  70
  71                 return $cap;
  72         }
  73
  74         /**
  75          * Check againt the DB if the word(s) entered by the user ($word) matches
  76          * the CAPTCHA and if the CAPTCHA did not expired.
  77          *
  78          * @param string $word
  79          * @return boolean
  80          */
  81         public function check_captcha($word)
  82         {
  83                 // First, delete old captchas
  84                 $expiration_limit = (!$this->params['captcha_params']['expiration']
  85                                 ? 7200 : $this->params['captcha_params']['expiration']);
  86                 $expiration = time() - $expiration_limit; // Two hour limit
  87                 $this->db->query("DELETE FROM captcha WHERE captcha_time < ".$expiration);
  88                 // TODO also delete the CAPTCHA image file
  89
  90                 // Then see if a captcha exists:
  91                 $sql = "SELECT COUNT(*) AS count FROM captcha WHERE word = ? AND ip_address = ? AND captcha_time > ?";
  92                 $binds = array($word, $this->ci->input->ip_address(), $expiration);
  93                 $query = $this->db->query($sql, $binds);
  94                 $row = $query->row();
  95
  96                 if ($row->count == 0)
  97                 {
  98                         return FALSE;
  99                 }
 100
 101                 return TRUE;
 102         }
 103 }
 104
 105 /* End of file Captcha.php */
 106 /* Location: ./application/libraries/Captcha.php */