Adding Captcha

[Greg]

Hi guys, have been trying to add Captcha and came across some code that may help but I cannot get it working properly, hope someone can help, it is based on a post at http://www.osticket.com/forums/showthread.php?t=2153&highlight=captcha

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Create a file named : randomImage.php in the same folder where process.php resides:

<?php
session_start();

// generate 5 digit random number
$rand = rand(10000, 99999);

// create the hash for the random number and put it in the session
$_SESSION['image_random_value'] = md5($rand);

// create the image
$image = imagecreate(60, 25);

// use white as the background image
$bgColor = imagecolorallocate ($image, 255, 255, 255);

// the text color is black
$textColor = imagecolorallocate ($image, 0, 0, 0);

// write the random number
imagestring ($image, 5, 5, 8, $rand, $textColor);

// send several headers to make sure the image is not cached
// taken directly from the PHP Manual

// Date in the past
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");

// always modified
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");

// HTTP/1.1
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);

// HTTP/1.0
header("Pragma: no-cache");

// send the content type header so the image is displayed properly
header('Content-type: image/jpeg');

// send the image to the browser
imagejpeg($image);

// destroy the image to free up the memory
imagedestroy($image);
?>

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Add into form form field

Verify: <img src="randomImage.php">
<input id="txtNumber" name="txtNumber" type="text" value ="<-- type this number" onClick="document.forms[0].txtNumber.value='';"/>

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Add into process.php file (not sure where or if this is correct code

$number = $_POST['txtNumber'];
if (md5($number) != $_SESSION['image_random_value']) {
$error .="You have provided an invalid security code.<br>";
$errors=1;
}

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Not sure how to get it working but hope the above will be a start to get someone with more knowledge to provide the chnages needed to get it to work.

Cheers

Greg

[Musawir Ali]

having image verification is a good idea, i think it would help considerably against spam. I will add this as a feature to the new phpFormGenerator version. My only concern is that all ISPs don't have gd support, which might cause problems with the image generation.