Question

I’m trying to implement a simple captcha into a form I’m building but I’ve run up against an issue I can’t seem to sort out by myself.

I’m using simple code to generate a random number like so ….

$randomnr = rand(1000, 9999);
$_SESSION['randomnr2'] = md5($randomnr);

…. and then some more code to generate an image of the random number and display it on the page. I’m against it for validity like this ….

if (strlen($captcha) !== ($_SESSION['randomnr2'])) { 
    $error['captcha'] = "CAPTCHA error. Please try again";
}

How do I go about checking the value that’s been input into the captcha input field against the random number that’s stored in the session randomnr2?

Answer 1

I’m not sure why you are checking the length of the string against an md5 hash of the string here, but assuming $captcha is the number from the user, you can just do this:

if(md5($captcha) !== $_SESSION['randomnr2']) {
  $error['captcha'] = "CAPTCHA error. Please try again";
}