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How to verify Google reCAPTCHA v3 on the server side?

P粉904191507 2023-08-27 16:48:47

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I just set up the new Google Captcha with checkboxes and it works fine on the front end, but I don't know how to handle it on the server side using PHP. I tried using the old code below but the form is sent even though the verification code is invalid. <pre class="brush:php;toolbar:false;">require_once('recaptchalib.php'); $privatekey = "my key"; $resp = recaptcha_check_answer ($privatekey, $_SERVER["REMOTE_ADDR"], $_POST["recaptcha_challenge_field"], $_POST["recaptcha_response_field"]); if (!$resp->is_valid) { $errCapt='The CAPTCHA Code was not entered correctly.';}</pre>

P粉904191507

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P粉2974349092023-08-28 12:23:43 2 floor

Private Key Security

While the answers here certainly work, they use GET requests, which exposes your private key (even with https ). On Google Developers, the specified method is POST.

For more details: https://stackoverflow.com/a/323286/1680919

Verify via POST

function isValid() 
{
    try {

        $url = 'https://www.google.com/recaptcha/api/siteverify';
        $data = ['secret'   => '[YOUR SECRET KEY]',
                 'response' => $_POST['g-recaptcha-response'],
                 'remoteip' => $_SERVER['REMOTE_ADDR']];
                 
        $options = [
            'http' => [
                'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
                'method'  => 'POST',
                'content' => http_build_query($data) 
            ]
        ];
    
        $context  = stream_context_create($options);
        $result = file_get_contents($url, false, $context);
        return json_decode($result)->success;
    }
    catch (Exception $e) {
        return null;
    }
}

Array syntax: I use the "new" array syntax ([ and ] instead of array(..)). If your version of php doesn't support this yet, you will have to edit these 3 array definitions accordingly (see comments).

Return value: If the user is valid, this function returns true; if it is invalid, it returns false; if the user is valid, it returns nullIf an error occurs. For example, you can use it simply by writing if (isValid()) { ... }

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P粉2621135692023-08-28 10:59:16 1 floor

This is the solution

index.html


  
    Google recapcha demo - Codeforgeek
    
  

  
    Google reCAPTHA Demo

verification.php

Please check the the captcha form.';
        exit;
    }

    $response = json_decode(file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=YOUR SECRET KEY&response=".$captcha."&remoteip=".$_SERVER['REMOTE_ADDR']), true);
    if($response['success'] == false)
    {
        echo 'You are spammer ! Get the @$%K out';
    }
    else
    {
        echo 'Thanks for posting comment.';
    }
?>

http://codeforgeek.com/2014/12/google-recaptcha-tutorial /

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