Recently, Google completely overhauled their reCaptcha API and simplified it to a single checkbox.
The problem is, I can submit a form with the reCaptcha included without checking it and the form will ignore the reCaptcha.
Before you had to send the form to a PHP file with the private key et al, but I'm not seeing any mention of that in their Developer's Guide. I have no idea how to validate the form to be sure the new reCaptcha was filled by the user.
Am I missing something? Is that PHP file with the private key still required?
All I have for the reCaptcha so far is:
<div data-type="image" class="g-recaptcha" data-sitekey="My Public Key"></div>
From a UX perspective, it can help to visibly let the user know when they can proceed to submit the form - either by enabling a disabled button, or simply making the button visible.
Here's a simple example...
<form>
<div class="g-recaptcha" data-sitekey="YOUR_PRIVATE_KEY" data-callback="recaptchaCallback"></div>
<button type="submit" class="btn btn-default hidden" id="btnSubmit">Submit</button>
</form>
<script>
function recaptchaCallback() {
var btnSubmit = document.getElementById("btnSubmit");
if ( btnSubmit.classList.contains("hidden") ) {
btnSubmit.classList.remove("hidden");
btnSubmitclassList.add("show");
}
}
</script>
You can verify the response in 3 ways as per the Google reCAPTCHA documentation:
g-recaptcha-response
: Once user checks the checkbox (I am not a robot), a field with id g-recaptcha-response
gets populated in your HTML.
You can now use the value of this field to know if the user is a bot or not, using the below mentioed lines:-
var captchResponse = $('#g-recaptcha-response').val();
if(captchResponse.length == 0 )
//user has not yet checked the 'I am not a robot' checkbox
else
//user is a verified human and you are good to submit your form now
Before you are about to submit your form, you can make a call as follows:-
var isCaptchaValidated = false;
var response = grecaptcha.getResponse();
if(response.length == 0) {
isCaptchaValidated = false;
toast('Please verify that you are a Human.');
} else {
isCaptchaValidated = true;
}
if (isCaptchaValidated ) {
//you can now submit your form
}
You can display your reCAPTCHA as follows:-
<div class="col s12 g-recaptcha" data-sitekey="YOUR_PRIVATE_KEY" data-callback='doSomething'></div>
And then define the function in your JavaScript, which can also be used to submit your form.
function doSomething() { alert(1); }
Now, once the checkbox (I am not a robot) is checked, you will get a callback to the defined callback, which is doSomething
in your case.
var googleResponse = $('#g-recaptcha-response').val();
if(googleResponse=='')
{
$("#texterr").html("<span>Please check reCaptcha to continue.</span>");
return false;
}
Try this link: https://github.com/google/ReCAPTCHA/tree/master/php
A link to that page is posted at the very bottom of this page: https://developers.google.com/recaptcha/intro
One issue I came up with that prevented these two files from working correctly was with my php.ini file for the website. Make sure this property is setup properly, as follows: allow_url_fopen = On
Verify Google reCapcha is valid or not after form submit
if ($post['g-recaptcha-response']) {
$captcha = $post['g-recaptcha-response'];
$secretKey = 'type here private key';
$response = file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=" . $secretKey . "&response=" . $captcha);
$responseKeys = json_decode($response, true);
if (intval($responseKeys["success"]) !== 1) {
return "failed";
} else {
return "success";
}
}
else {
return "failed";
}
One issue I came up with that prevented these two files from working correctly was with my php.ini
file for the website. Make sure this property is properly set, as follows:
allow_url_fopen =
You can first verify in the frontend side that the checkbox is marked:
var recaptchaRes = grecaptcha.getResponse();
var message = "";
if(recaptchaRes.length == 0) {
// You can return the message to user
message = "Please complete the reCAPTCHA challenge!";
return false;
} else {
// Add reCAPTCHA response to the POST
form.recaptchaRes = recaptchaRes;
}
And then in the server side verify the received response using Google reCAPTCHA API:
$receivedRecaptcha = $_POST['recaptchaRes'];
$verifiedRecaptcha = file_get_contents('https://www.google.com/recaptcha/api/siteverify?secret='.$google_secret.'&response='.$receivedRecaptcha);
$verResponseData = json_decode($verifiedRecaptcha);
if(!$verResponseData->success)
{
return "reCAPTCHA is not valid; Please try again!";
}
For more info you can visit Google docs.
//validate
$receivedRecaptcha = $_POST['recaptchaRes'];
$google_secret = "Yoursecretgooglepapikey";
$verifiedRecaptchaUrl = 'https://www.google.com/recaptcha/api/siteverify?secret='.$google_secret.'&response='.$receivedRecaptcha;
$handle = curl_init($verifiedRecaptchaUrl);
curl_setopt($handle, CURLOPT_RETURNTRANSFER, TRUE);
curl_setopt($handle, CURLOPT_SSL_VERIFYPEER, false); // not safe but works
//curl_setopt($handle, CURLOPT_CAINFO, "./my_cert.pem"); // safe
$response = curl_exec($handle);
$httpCode = curl_getinfo($handle, CURLINFO_HTTP_CODE);
curl_close($handle);
if ($httpCode >= 200 && $httpCode < 300) {
if (strlen($response) > 0) {
$responseobj = json_decode($response);
if(!$responseobj->success) {
echo "reCAPTCHA is not valid. Please try again!";
}
else {
echo "reCAPTCHA is valid.";
}
}
} else {
echo "curl failed. http code is ".$httpCode;
}
when using JavaScript it will work for me
<script src='https://www.google.com/recaptcha/api.js'></script>_x000D_
<script>_x000D_
function submitUserForm() {_x000D_
var response = grecaptcha.getResponse();_x000D_
if(response.length == 0) {_x000D_
document.getElementById('g-recaptcha-error').innerHTML = '<span style="color:red;">This field is required.</span>';_x000D_
return false;_x000D_
}_x000D_
return true;_x000D_
}_x000D_
_x000D_
function verifyCaptcha() {_x000D_
document.getElementById('g-recaptcha-error').innerHTML = '';_x000D_
}_x000D_
</script>
_x000D_
<form method="post" onsubmit="return submitUserForm();">_x000D_
<div class="g-recaptcha" data-sitekey="YOUR_SITE_KEY" data-callback="verifyCaptcha"></div>_x000D_
<div id="g-recaptcha-error"></div>_x000D_
<input type="submit" name="submit" value="Submit" />_x000D_
</form>
_x000D_
var googleResponse = jQuery('#g-recaptcha-response').val();
if (!googleResponse) {
$('<p style="color:red !important" class=error-captcha"><span class="glyphicon glyphicon-remove " ></span> Please fill up the captcha.</p>" ').insertAfter("#html_element");
return false;
} else {
return true;
}
Put this in a function. Call this function on submit... #html_element
is my empty div.
While using Google reCaptcha with reCaptcha DLL file, we can validate it in C# as follows :
RecaptchaControl1.Validate();
bool _Varify = RecaptchaControl1.IsValid;
if (_Varify)
{
// Pice of code after validation.
}
Its works for me.
Source: Stackoverflow.com