How to add recaptcha to mailform - php

Question

The website of the wife of a deceased friend has been misused for sending spam. This is probably because ReCaptcha is not used with the registration form. The site uses Joomla 3.9.
I would like to add ReCaptcha but I have no idea how I can do that.
I hope someone can help.
I have not tried anything myself because my knowledge of PHP is not good enough to get this done.
Here is the form:
<form id="form1" action="/script/mailforms/mailsend.php" enctype="multipart/form-data" method="post"><input name="redirect" type="hidden" value="/bedankt" />
<table border="0" width="200">
<tbody>
<tr>
<td> </td>
<td><strong>Gegevens ouder/verzorger</strong></td>
<td> </td>
<td> </td>
<td><strong>Gegevens kind</strong></td>
</tr>
<tr>
<td>Voornaam</td>
<td><span id="sprytextfield1"> <label for="Naam"></label> <input id="Naam" name="Naam" type="text" /> </span></td>
<td> </td>
<td>Naam kind</td>
<td><span id="sprytextfield9"> <label for="Naam Kind"></label> <input id="Naam Kind" name="Naam Kind" type="text" /> </span></td>
</tr>
<tr>
<td>Achternaam</td>
<td><span id="sprytextfield2"> <label for="Achternaam"></label> <input id="Achternaam" name="Achternaam" type="text" /> </span></td>
<td> </td>
<td>Geslacht</td>
<td><span id="spryradio1"> <label> <input id="Geslacht_0" name="Geslacht" type="radio" value="Jongen" /> jongen</label> <br /> <label> <input id="Geslacht_1" name="Geslacht" type="radio" value="Meisje" /> meisje</label> <br /> </span></td>
</tr>
<tr>
<td>Straat + nr</td>
<td><span id="sprytextfield3"> <label for="Straat en nr"></label> <input id="Straat en nr" name="Straat en nr" type="text" /> </span></td>
<td> </td>
<td>Geboortedatum</td>
<td><span id="sprytextfield10"> <label for="Geboortedatum"></label> <input id="Geboortedatum" name="Geboortedatum" type="text" /> </span></td>
</tr>
<tr>
<td>Postcode</td>
<td><span id="sprytextfield4"> <label for="Postcode"></label> <input id="Postcode" name="Postcode" type="text" /> </span></td>
<td> </td>
<td>Schoolnaam</td>
<td><span id="sprytextfield11"> <label for="Schoolnaam"></label> <input id="Schoolnaam" name="Schoolnaam" type="text" /> </span></td>
</tr>
<tr>
<td>Woonplaats</td>
<td><span id="sprytextfield5"> <label for="Woonplaats"></label> <input id="Woonplaats" name="Woonplaats" type="text" /> </span></td>
<td> </td>
<td>Voorkeur</td>
<td><span id="spryradio2"> <br /> <label> <input id="Voorkeur_1" name="Voorkeur" type="radio" value="Woensdag" /> Woensdagmiddag (Zonnestudio)</label> <br /> </span></td>
</tr>
<tr>
<td>Telefoonnr</td>
<td><span id="sprytextfield6"> <label for="Telefoonnr"></label> <input id="Telefoonnr" name="Telefoonnr" type="text" /> </span></td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>Email</td>
<td><span id="sprytextfield7"> <label for="Email"></label> <input id="Email" name="Email" type="text" /> </span></td>
<td> </td>
<td>Bijzonderheden</td>
<td><span id="sprytextarea1"> <label for="Bijzonderheden"></label> <textarea id="Bijzonderheden" cols="45" name="Bijzonderheden" rows="5"> </textarea> </span></td>
</tr>
<tr>
<td>Bank/gironr</td>
<td><span id="sprytextfield8"> <label for="Bankgiro"></label> <input id="Bankgiro" name="Bankgiro" type="text" /> </span></td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td colspan="4"><br /><span id="sprycheckbox1"> <input id="Algemene Voorwaarden" name="Algemene Voorwaarden" type="checkbox" /> </span>Ik heb de de <strong>algemene voorwaarden</strong> gelezen en ga hiermee akkoord</td>
</tr>
<tr>
<td> </td>
<td><input id="Verzenden" name="Verzenden" type="submit" value="Verzenden" /></td>
<td> </td>
<td> </td>
<td> </td>
</tr>
</tbody>
</table>
</form>
Here is the mailsend.php:
<?php
require('class.mailer.info.php');
//phpinfo();
/* Vaste post waarden vastleggen */
// ontvanger
if(empty($_POST['redirect']))
{
die("error: geen ontvanger vastgelegd en redirect pad.");
}
// Instantiate your new class
$mail = new HeartmedicalMailer;
/*
Verwerken post informatie
*/
$body_text = '';
// waardes die je niet wilt tonen wegfilteren als redirect / receipient etc.
$excluded = array('redirect');
// html opmaak formulier voor loop
$body_text .= "<style>body{ font-family:Verdana, Arial; font-size:11px; color:#000000; }</style>";
// loop doorlopen met opmaak
foreach($_POST as $key => $value)
{
// vaste waardes wegfilteren
if(!in_array($key, $excluded))
{
if(!empty($value))
{
$key = preg_replace('#_#',' ', $key);
$body_text .= '<strong>'.$key.'</strong>: '.$value.'<br>';
}
}
}
// Now you only need to add the necessary stuff
$mail->Body = $body_text;
if(!$mail->Send())
{
echo "Mailer Error: " . $mail->ErrorInfo;
die("There was an error sending the message #code1");
}
// redirect
header("Location: ".$_POST['redirect']." ");
?>
Here is the class.mailer.info.php:
<?php
// class phpmailer
require("../phpmailer/class.phpmailer.php");
class HeartmedicalMailer extends PHPMailer
{
// Set default variables for all new objects
var $From = "xxxxx#xxxxx.nl";
var $FromName = "De Zwemschool";
var $Host = "localhost";
/* smtp auth */
var $Mailer = "smtp"; // Alternative to IsSMTP()
var $SMTPAuth = false; // turn on SMTP authentication
var $Username = ""; // SMTP username
var $Password = ""; // SMTP password
var $WordWrap = 75;
var $Subject = "Inschrijving De Zwemschool";
function HeartmedicalMailer()
{
$this->AddAddress('xxxx#xxxx.nl', 'Name');
$this->IsHTML(true);
}
// Replace the default error_handler
function error_handler($msg) {
print("Mailer Error");
print("Description:");
printf("%s", $msg);
exit;
}
}
?>
I would like the form to be sent with recaptcha

Answer 1

You could use Google reCAPTCHA.
I personally use the reCAPTACHA V2 invisible one so you'll find an example below.
First get the keys here: link
Then replace your submit input with this:
<button class="g-recaptcha form-control" data-sitekey="YOUR_RECAPTCHA_KEY" data-callback='onSubmit'>Send</button>
Then add these scripts to your HTML page:
<script src="https://www.google.com/recaptcha/api.js" async defer></script>
<script>
function onSubmit(token) {
document.getElementById("form1").submit();
}
</script>
And finally add this at the begining of your mailsend.php:
function get_ip() {
// IP if shared network
if (isset($_SERVER['HTTP_CLIENT_IP'])) {
return $_SERVER['HTTP_CLIENT_IP'];
}
// IP behind proxy
elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
return $_SERVER['HTTP_X_FORWARDED_FOR'];
}
// Sinon : normal IP
else {
return (isset($_SERVER['REMOTE_ADDR']) ? $_SERVER['REMOTE_ADDR'] : '');
}
}
// Anti spam using google Captcha
$post_params = [
'secret' => "YOUR",
'response' => $_POST['g-recaptcha-response'],
'remoteip' => get_ip()
];
# Create a connection
$url = 'https://www.google.com/recaptcha/api/siteverify';
$ch = curl_init($url);
# Form data string
$post_string = http_build_query($post_params, '', '&');
# Setting our options
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_string);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
# Get the response
$response = curl_exec($ch);
$response = json_decode($response);
curl_close($ch);
if(!$response->success){
exit();
}
Hope it helps ;)