File Source for antispam.inc.php

<?php
/**
* @author Matthias Reuter ($LastChangedBy: matthias $)
* @version $LastChangedDate: 2009-08-26 19:19:41 +0200 (Mi, 26 Aug 2009) $
* @package antispam
* @copyright 2007-2010 IPBWI development team
* @link http://ipbwi.com/examples/attachment.php
* @since 2.0
* @license http://www.gnu.org/licenses/gpl-3.0.html GNU General Public License
*/
class ipbwi_antispam extends ipbwi {
private $ipbwi = null;
private $captchaClass = null;
private $captcha = null;
private $uniqueId = null;
private $recaptchaPrivateKey = ipbwi_RECAPTCHA_PRIVATE_KEY;
private $recaptchaPublicKey = ipbwi_RECAPTCHA_PUBLIC_KEY;
/**
* @desc Loads and checks different vars when class is initiating
* @param object $ipbwi The ipbwi class object
* @author Matthias Reuter
* @since 2.0
* @ignore
*/
public function __construct($ipbwi){
// loads common classes
$this->ipbwi = $ipbwi;
// loads recaptcha lib
require_once(ipbwi_ROOT_PATH.'lib/third_party/recaptchalib.inc.php');
// loads IP.Board Captcha Class
require_once(ipbwi_BOARD_PATH.'ips_kernel/classCaptcha.php');
$this->captcha = new classCaptcha($this->ipbwi->ips_wrapper->registry,$this->ipbwi->ips_wrapper->settings['bot_antispam_type']);
// if the captcha mode is auto, and the board uses recaptcha we have
// to use the public and private key that is set in the board
if(ipbwi_CAPTCHA_MODE == 'auto'){
if($this->ipbwi->ips_wrapper->settings['bot_antispam_type'] == 'recaptcha'){
$this->recaptchaPrivateKey = $this->ipbwi->ips_wrapper->settings['recaptcha_private_key'];
$this->recaptchaPublicKey = $this->ipbwi->ips_wrapper->settings['recaptcha_public_key'];
}
}
}
/**
* @desc Returns the Captcha HTML Code
* @param string $ajaxUrl The URL that should be called to renew the captcha Image (only for GD Based captchas)
* @return string captcha html code
* @author Jan Ecker
* @since 2.0
*/
public function getHTML($ajaxUrl = false){
if(isset($ajaxUrl)){
$ajaxUrl = urlencode($ajaxUrl);
}
switch(ipbwi_CAPTCHA_MODE){
case 'gd':
return $this->getGdHtml($ajaxUrl);
break;
case 'recaptcha':
return $this->getRecaptchaHtml();
break;
case 'auto':
if($this->ipbwi->ips_wrapper->settings['bot_antispam_type'] == 'recaptcha'){
return $this->getRecaptchaHtml();
}else{
return $this->getGdHtml($ajaxUrl);
}
break;
default:
die('Wrong config Value, please check ipbwi_CAPTCHA_MODE');
}
}
/**
* @desc Checks weather the entered string was correct
* @return bool True if the entered string was correct, otherwise false
* @author Jan Ecker
* @since 2.0
*/
public function validate(){
$result = false;
// Checks which captcha mode was used and than validate it
if(isset($_POST['ipbwiCaptchaString']) && isset($_POST['ipbwiCaptchaUniqueId'])){
$result = $this->validateGd($_POST['ipbwiCaptchaUniqueId'], $_POST['ipbwiCaptchaString']);
}elseif(isset($_POST['recaptcha_response_field'])){
$result = $this->validateRecaptcha($_POST['recaptcha_response_field'], $_POST['recaptcha_challenge_field']);
}
return $result;
}
/**
* @desc Generates a new GD Based Captcha
* @return string The unique id of the new GD based captcha
* @author Jan Ecker
* @since 2.0
*/
public function renewGdImage(){
// Clean up database
$this->clearGdDatabase();
$captchaString = $this->createRandomString();
$uniqueId = $this->createUniqueId();
$this->uniqueId = $uniqueId;
// Save the new captcha data in Database
$this->ipbwi->ips_wrapper->DB->insert('captcha', array('captcha_unique_id' => $uniqueId, 'captcha_string' => $captchaString, 'captcha_ipaddress' => $_SERVER['REMOTE_ADDR'], 'captcha_date' => time()));
return $uniqueId;
}
/**
* @desc Checks if the entered string in the recaptcha was correct
* @param string $responseField The entered captcha string
* @param string $challengeField The unique id of the captcha image
* @return bool True if the entered string was correct, otherwise false
* @author Jan Ecker
* @since 2.0
*/
private function validateRecaptcha($responseField, $challengeField){
// Send the entered string to the recaptcha server and listen if it was correct
$resp = recaptcha_check_answer($this->recaptchaPrivateKey, $_SERVER['REMOTE_ADDR'], $challengeField, $responseField);
if($resp->is_valid){
return true;
}else{
return false;
}
}
/**
* @desc Checks if the entered string in the GD Based captcha was correct
* @param string $uniqueId The unique id of the GD based captcha
* @param string $userCaptchaString The entered captcha string
* @return bool True if the entered String was correct, otherwise false
* @author Jan Ecker
* @since 2.0
*/
private function validateGd($uniqueId, $userCaptchaString){
// Get the correct Captcha String from the database, using the unique id
$this->ipbwi->ips_wrapper->DB->query('SELECT captcha_string FROM '.$this->ipbwi->board['sql_tbl_prefix'].'captcha WHERE captcha_unique_id="'.addslashes($uniqueId).'"');
$row = $this->ipbwi->ips_wrapper->DB->fetch();
if(isset($row) && !empty($row)){
// Is not case sesetive! Maybe change later?
if(strtoupper($row['captcha_string']) == strtoupper($userCaptchaString)){
// Captcha was correct! Clear seassion and return true
$this->clearGdDatabase();
return true;
}else{
// Captcha was not correct! Report the error
$this->ipbwi->addSystemMessage('Error',$this->ipbwi->getLibLang('badKey'),'Located in file '.__FILE__.' at class '.__CLASS__.' in function '.'Located in file <strong>'.__FILE__.'</strong> at class <strong>'.__CLASS__.'</strong> in function <strong>'.__FUNCTION__.'</strong> on line #<strong>'.__LINE__.'</strong>');
return false;
}
}else{
return false;
}
}
/**
* @desc Get the HTML code from the recaptcha server and returns it
* @return string The HTML code to display the recaptcha
* @author Jan Ecker
* @since 2.0
*/
private function getRecaptchaHtml(){
$error = null;
// Get the HTML data from the recaptcha server
return recaptcha_get_html($this->recaptchaPublicKey, $error);
}
/**
* @desc Creates the HTML code for the GD Based captchas and returns it
* @param string $ajaxUrl If given it will additionally return ajax code to refresh the GD based Captcha
* @return string The HTML code to display the GD based captcha
* @author Jan Ecker
* @author Matthias Reuter
* @since 2.0
*/
private function getGdHtml($ajaxUrl = false){
// Create a new image and get the unique id
$uniqueId = $this->renewGdImage();
// ajax support for on demand reloading of anti_spam-Image
$ajaxCode = false;
$ajaxLink = false;
if(isset($ajaxUrl) && !empty($ajaxUrl)){
$ajaxCode =
<<<AJAXCODE
<script type="text/javascript">
var keycode_id = '{$uniqueId}';
function get_new_hash(){
var url = unescape('{$ajaxUrl}');
var xmlHttp = window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest();
if(xmlHttp){
xmlHttp.open('GET', url, true);
xmlHttp.onreadystatechange = function (){
if(xmlHttp.readyState == 4){
keycode_id = xmlHttp.responseText;
document.getElementById("anti_spam_image").src = unescape('{$this->ipbwi->getBoardVar('url')}index.php%3Fact%3Dcaptcha%26do%3DshowImage%26captcha_unique_id%3D') + keycode_id;
document.getElementById("anti_spam_session_id").value = keycode_id;
}
}
xmlHttp.send(null);
}
}
</script>
AJAXCODE;
$ajaxLink = ' onclick="get_new_hash();" style="cursor:pointer;" title="Click here to refresh Spam-Image"';
}
$html = '<p>'.$ajaxCode.'<img'.$ajaxLink.' src="'.$this->ipbwi->getBoardVar('url').'index.php?act=captcha&do=showImage&captcha_unique_id='.$uniqueId.'" alt="Code Bit" id="anti_spam_image" /></p>';
$html .= '<p><input type="hidden" name="ipbwiCaptchaUniqueId" value="'.$this->uniqueId.'" id="anti_spam_session_id" /></p>';
$html .= '<p><strong>Insert Code</strong></p>';
$html .= '<p><input type="text" name="ipbwiCaptchaString" value="" id="keycode" /></p>';
return $html;
}
/**
* @desc Clears the database for the GD Based captchas
* @param string $ajaxUrl If given it will additionally return ajax code to refresh the GD based Captcha
* @return bool Always returns true
* @author Jan Ecker
* @since 2.0
*/
private function clearGdDatabase(){
$time = time() - 60*3600;
// Delete all old entries and the seassion of the actual user
$this->ipbwi->ips_wrapper->DB->query('DELETE FROM '.$this->ipbwi->board['sql_tbl_prefix'].'captcha WHERE captcha_date < "'.$time.'" OR captcha_ipaddress = "'.$_SERVER['REMOTE_ADDR'].'"');
return true;
}
/**
* @desc Generates and returns an unique id
* @return string The generated unique id
* @author Jan Ecker
* @since 2.0
*/
private function createUniqueId(){
srand(microtime()*1000000);
return md5(uniqid(rand(), true));
}
/**
* @desc Generates a random string and returns it
* @param int $length The length of the generated random string
* @return string The generated string
* @author Jan Ecker
* @since 2.0
*/
private function createRandomString($length = 6){
srand(microtime()*1000000);
$captchaString = '';
// Generate an array of all letters and numbers
$chars = array();
$smallLetter = 'a';
$bigLetter = 'A';
for($i = 0;$i <= 25;$i++){
$chars[] = $smallLetter++;
$chars[] = $bigLetter++;
}
for($i = 0;$i <= 9;$i++){
$chars[] = $i;
}
// Generate a string of the given length with randomly taken letters and numbers
for($i = 0;$i < $length;$i++){
$index = rand(0, count($chars)-1);
$captchaString .= $chars[$index];
}
return $captchaString;
}
}
?>

Source for file antispam.inc.php