application/libraries/Captcha.php

   1 <?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2
   3 class Captcha {
   4
   5         private $ci = NULL;
   6         private $db;
   7         private $params = NULL;
   8
   9         public function __construct()
  10         {
  11                 $this->ci =& get_instance();
  12                 $this->ci->config->load('captcha');
  13                 $this->ci->load->library('Singleton_db');
  14                 $this->db = $this->ci->singleton_db->connect();
  15
  16                 $this->params = $this->ci->config->item('captcha_params');
  17
  18                 if (!$this->params)
  19                         die('Cannot load CAPTCHA config file.');
  20         }
  21
  22         /**
  23          * Generates a CAPTCHA image and returns an HTML image tag for it.
  24          *
  25          * @param string $word
  26          * @return string
  27          */
  28         public function get_captcha_tag($word = NULL)
  29         {
  30                 $this->load->helper('captcha');
  31
  32                 if ($word)
  33                         $this->params['word'] = $word;
  34
  35                 $cap = create_captcha($this->params);
  36
  37                 $data = array(
  38                         'captcha_time' => $cap['time'],
  39                         'ip_address' => $this->input->ip_address(),
  40                         'word' => $cap['word']
  41                         );
  42
  43                 $str_query = $this->db->insert_string('captcha', $data);
  44                 $this->db->query($str_query);
  45
  46                 return $cap['image'];
  47         }
  48
  49         /**
  50          * Check againt the DB if the word(s) entered by the user ($word) matches
  51          * the CAPTCHA and if the CAPTCHA did not expired.
  52          */
  53         public function check_captcha($word)
  54         {
  55                 // First, delete old captchas
  56                 $expiration_limit = (!$this->params['expiration']
  57                                 ? 7200 : $this->params['expiration']);
  58                 $expiration = time() - $expiration_limit; // Two hour limit
  59                 $this->db->query("DELETE FROM captcha WHERE captcha_time < ".$expiration);
  60                 // TODO also delete the CAPTCHA image file
  61
  62                 // Then see if a captcha exists:
  63                 $sql = "SELECT COUNT(*) AS count FROM captcha WHERE word = ? AND ip_address = ? AND captcha_time > ?";
  64                 $binds = array($word, $this->input->ip_address(), $expiration);
  65                 $query = $this->db->query($sql, $binds);
  66                 $row = $query->row();
  67
  68                 if ($row->count == 0)
  69                 {
  70                         return FALSE;
  71                 }
  72
  73                 return TRUE;
  74         }
  75 }
  76
  77 /* End of file Captcha.php */
  78 /* Location: ./application/libraries/Captcha.php */