public static function recaptcha_mailhide_url($pubkey, $privkey, $email) { if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) { die("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " . "you can do so at <a href='http://www.google.com/recaptcha/mailhide/apikey'>http://www.google.com/recaptcha/mailhide/apikey</a>"); } $ky = pack('H*', $privkey); $cryptmail = RecaptchaForDekoBoko::_recaptcha_aes_encrypt($email, $ky); return "http://www.google.com/recaptcha/mailhide/d?k=" . $pubkey . "&c=" . RecaptchaForDekoBoko::_recaptcha_mailhide_urlbase64($cryptmail); }