This tiny captcha code is kind of weird. Only works in Firefox but not IE (6,8)
Hope someone may figure it out what's going on?
Or you may download this code from Author. (demo included)
Click Here
exmple.php
<?php
if(isset($_POST['setCaptcha'])){
include_once('./captcha/cf.captcha.php');
if(!check_captcha($_POST['setCaptcha'])){
echo 'CAPTCHA CHECK: <span style="color:red">'.$error_captcha.'</span>';
//exit();
}else{
echo 'CAPTCHA CHECK: <span style="color:green">Correct</span>';
//proceed
}
}
?>
<form method="post" action="" class="center">
<br/><img id="captcha_img" src="./captcha/cf.captcha.php?img=<?=time();?>" /><br/>
<a href="#" onclick="document.getElementById('captcha_img').src = './captcha/cf.captcha.php?img=' + Math.random(); return false">Reload Captcha</a><br/>
<label for="setCaptcha">Verification code: </label><br/>
<input name="setCaptcha" type="text" id="setCaptcha" size="24" class="textbox" /><br/><br/>
<input type="submit" value="Send" /><br/>
</form>
cf.captcha.php
<?php
//
// CF Captcha v0.9
// -------------------------------
//
// Author: codefuture.co.uk
// Version: 0.9
// Date: 28-Apr-10
//
// download the latest version from - http://codefuture.co.uk/projects/captcha/
// Copyright (c) 2010 codefuture.co.uk
//
//////////////////////////////////////////////////////////////////////////////////////////////////
//debug
// error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);
//////////////////////////////////////////////////////////////////////////////////////////////////
// settings
// Cookie timer
define('COOKIE_TIMER', 5 );
// Cookie Salting Pick a random code
define('SALTING', 'aeb1021e49282375948ac10004c2eb53ef9070e0');
// check_captcha() Error Messages
define('ERROR_MESSAGE_CAPTCHA', 'Verification code can\'t be blank');
define('ERROR_MESSAGE_CAPTCHA_INVALID', 'Verification code is invalid');
define('ERROR_MESSAGE_CAPTCHA_TIMED_OUT', 'Sorry the verification code is only valid for '.COOKIE_TIMER.' minutes');
define('ERROR_MESSAGE_CAPTCHA_COOKIE', 'No captcha cookie given. Make sure cookies are enabled.');
//////////////////////////////////////////////////////////////////////////////////////////////////
// Check Captcha
/**
* Holds any errors from check_captcha
* you could use it like this
* <div style="color:red"><?=$error_captcha;?></div>
*/
$captcha_error = null;
/**
* check_captcha()
*
* @param string $captcha
* @param boolean $timer (on|off)(true|false)
* @return boolean
*/
function check_captcha($captcha,$timer = true){
global $error_captcha;
$captcha = htmlspecialchars(stripslashes(trim($captcha)));
if(empty($captcha)){
$error_captcha = ERROR_MESSAGE_CAPTCHA;
remove_cookie();
return false;
}elseif (isset($_COOKIE['Captcha']) ){
list($Hash, $Time) = explode('.', $_COOKIE['Captcha']);
if ( md5(SALTING.$captcha.$_SERVER['REMOTE_ADDR'].$Time) != $Hash ){
$error_captcha = ERROR_MESSAGE_CAPTCHA_INVALID;
remove_cookie();
return false;
}elseif( (time() - COOKIE_TIMER*60) > $Time && $timer){
$error_captcha = ERROR_MESSAGE_CAPTCHA_TIMED_OUT;
remove_cookie();
return false;
}
}else{
$error_captcha = ERROR_MESSAGE_CAPTCHA_COOKIE;
return false;
}
return true;
}
function remove_cookie(){
$domain = $_SERVER['HTTP_HOST'];
if ( strtolower( substr($domain, 0, 4) ) == 'www.' )
$domain = substr($domain, 4);
if ( substr($domain, 0, 1) != '.' )
$domain = '.'.$domain;
setcookie('Captcha', '', time() - 3600, '/',$domain);
unset($_COOKIE['Captcha']);
}
//////////////////////////////////////////////////////////////////////////////////////////////////
// make image
/**
* the time() at the end of the address is just to keep the image from being cached
* <img id="captcha_img" src="./captcha/cf.captcha.php?img=<?=time();?>" />
*
*/
if(isset($_GET['img'])){
$capt = new captcha;
// $capt->transparent_bg(false);
// $capt->bg_color('cccccc');
$capt->display();
exit();
}
//////////////////////////////////////////////////////////////////////////////////////////////////
// captcha Class
class captcha {
private $UserString;
private $transparent = true;
private $bg_color = 'ffffff';
private function font(){
switch(rand(1,2)){
case 1: return dirname(__FILE__).'/font/arial.ttf'; break;
case 2: return dirname(__FILE__).'/font/verdana.ttf'; break;
default : return dirname(__FILE__).'/font/arial.ttf'; break;
}
}
public function transparent_bg($var){$this->transparent = ($var != true ? false : true);}
public function bg_color($var){$this->bg_color = $var;}
private function LoadPNG(){
$im = imagecreatetruecolor(130, 35);
$rgb = $this->html2rgb($this->bg_color);
$bgcolor = imagecolorallocate($im, $rgb[0], $rgb[1], $rgb[2]);
imagefill($im, 0, 0, $bgcolor);
if($this->transparent)imagecolortransparent($im, $bgcolor);
return $im;
}
private function task_string(){
$image = $this->LoadPNG();
$string_a = array("a","b","c","d","e","f","g","h","j","k",
"m","n","p","r","s","t","u","v","w","x",
"y","z","2","3","4","5","6","7","8","9");
$x = 0;
for($i = 0; $i < 5; $i++){
$x += rand(16,18);
$temp = $string_a[rand(0,29)];
$this->UserString .= $temp;
imagettftext($image, $this->rand_fontsize(), $this->rand_angle(), $x, $this->rand_Y(), $this->rand_color($image), $this->font(), $temp);
}
return $image;
}
private function rand_color($im){return imagecolorallocate($im, rand(0,155), rand(0,155), rand(0,155));}
private function rand_angle(){return rand(-15,15);}
private function rand_Y(){return rand(25,30);}
private function rand_fontsize(){return rand(14,20);}
private function task_sum(){
$image = $this->LoadPNG();
$x = rand(10,20);
$sum = rand(1,3);
$number1= $sum != 3 ? rand(10,99) : rand(1,9);
$number2= rand(1,9);
imagettftext($image, $this->rand_fontsize(), $this->rand_angle(), $x, $this->rand_Y(), $this->rand_color($image), $this->font(),($sum ==3?'':substr($number1, 0,1)));
imagettftext($image, $this->rand_fontsize(), $this->rand_angle(), ($x += 15), $this->rand_Y(), $this->rand_color($image), $this->font(),($sum ==3?$number1:substr($number1, -1)) );
imagettftext($image, $this->rand_fontsize(), 0, ($x += 20), $this->rand_Y(), $this->rand_color($image), $this->font(),($sum ==1?'+':($sum ==2?'-':'*')));
imagettftext($image, $this->rand_fontsize(), $this->rand_angle(), ($x += 18), $this->rand_Y(), $this->rand_color($image), $this->font(), $number2);
imagettftext($image, $this->rand_fontsize(), $this->rand_angle(), ($x += 18), $this->rand_Y(), $this->rand_color($image), $this->font(),'=');
imagettftext($image, $this->rand_fontsize(), $this->rand_angle(), ($x += 18), $this->rand_Y(), $this->rand_color($image), $this->font(),'?');
$this->UserString = ($sum ==1?$number1+$number2:($sum == 2?$number1-$number2:$number1*$number2));
return $image;
}
private function cookie(){
$time = time();
$domain = $_SERVER['HTTP_HOST'];
if ( strtolower( substr($domain, 0, 4) ) == 'www.' )
$domain = substr($domain, 4); // Fix the domain to accept domains with and without 'www.'.
if ( substr($domain, 0, 1) != '.' )
$domain = '.'.$domain; // Add the dot prefix to ensure compatibility with subdomains
setcookie('Captcha', md5(SALTING.$this->UserString.$_SERVER['REMOTE_ADDR'].$time).'.'.$time, null, '/',$domain);
}
public function display(){
switch(rand(1,2)){
case 1: $image = $this->task_string(); break;
case 2: $image = $this->task_sum(); break;
default: $image = $this->task_sum(); break;
}
$this->cookie();
header("Content-type: image/png");
imagepng($image);
}
private function html2rgb($color){
if ($color[0] == '#')
$color = substr($color, 1);
if (strlen($color) == 6)
list($r, $g, $b) = array($color[0].$color[1],$color[2].$color[3],$color[4].$color[5]);
elseif (strlen($color) == 3)
list($r, $g, $b) = array($color[0].$color[0], $color[1].$color[1], $color[2].$color[2]);
else
return false;
$r = hexdec($r); $g = hexdec($g); $b = hexdec($b);
return array($r, $g, $b);
}
}
?>
