How to Verify Google Recaptcha V3 Response?

Karthik picture Karthik · May 18, 2018 · Viewed 61.4k times · Source

How to integrate Google reCAPTCHA Version 3 in Client Side and Server Side(php). following code use to display recaptcha but its not working good. How to do this integration.

Verify.php

<?php

    if(isset($_POST['g-recaptcha-response']) && !empty($_POST['g-recaptcha-response'])) {
        //your site secret key
        $secret = 'XXXX-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX';
        //get verify response data
        $verifyResponse = file_get_contents('https://www.google.com/recaptcha/api/siteverify?secret='.$secret.'&response='.$_POST['g-recaptcha-response']);
        $responseData = json_decode($verifyResponse);
        if($responseData->success):

             print_r("Working Fine"); exit;
        else:
             print_r("No valid Key"); exit;
        endif;
    } else {
        print_r("Not Working Captcha"); exit;
    }

?>

Answer

bsbak picture bsbak · Jun 7, 2018
<html>
    <head>
        <script src='https://www.google.com/recaptcha/api.js?render=6Le7-FkUAAAAADDSsTVBvpoUB5MkesNKgPVemFf-UD'></script>
    </head>
    <body> 
    <script>
    // when form is submit
    $('form').submit(function() { 
        // we stoped it
        event.preventDefault();
        // needs for recaptacha ready
        grecaptcha.ready(function() {
            // do request for recaptcha token
            // response is promise with passed token
            grecaptcha.execute('6Le7-FkUAAAAADDSsTVBvpoUB5MkesNKgPVemFf-UD', {action: 'create_comment'}).then(function(token) {
                // add token to form
                $('form').prepend('<input type="hidden" name="token" value="' + token + '">');
                $('form').prepend('<input type="hidden" name="action" value="create_comment">');
                // submit form now
                $('form').unbind('submit').submit();
            });;
        });
    });

    </script>

    <form action="verify.php" method="post">
        <input type="text" name="name" placeholder="Your name" required >
        <input type="email" name="email" placeholder="Your email address" required>
        <textarea name="message" placeholder="Type your message here...." required></textarea>   

        <input type="submit" name="submit" value="SUBMIT">

    </form>

    </body>

</html>

php

$token = $_POST['token'];
$secret = 'ur secret';
$action = $_POST['action'];
// now you need do a POST requst to google recaptcha server.
// url: https://www.google.com/recaptcha/api/siteverify.
// with data secret:$secret and response:$token 

At this point in the code, you will need to do a post request to ReCAPTCHA to verify the token, as documented here: https://www.google.com/recaptcha/api/siteverify. The response will be a json object with field "success" (true/false) and "action" for comparison (==) and score (number from 0.0 - 1.0)

https://developers.google.com/recaptcha/docs/v3#api-response.

You can also specify action name for each request (create_post, update_post, create_comment ...)