Question

am trying to validate the recaptcha using some js code but am getting some permission Errors “Access is Denied”
Is it possible to achieve the validation using the javascript validation code alongside ajax across multiple browsers.

<script type="text/javascript">


    $(document).ready(function() {

        Recaptcha.create("var_public_key", recaptchadiv, {
            theme: "clean",
            callback: Recaptcha.focus_response_field
        });
    });


function submitFormData() {

var urlString = "http://www.google.com/recaptcha/api/verify";
var params = encodeURI("remoteip=" + $("#userIp").val() +"&privatekey=" + var_private_key + "&challenge=" + Recaptcha.get_challenge() + "&response=" +
Recaptcha.get_response());
        params = encodeURI(params);
        var status = document.getElementById("status");
        status.className = "";
        status.innerHTML = "<b>Submitting your data. Please wait...</b>";
        var html = $.ajax({
            type: "POST",
            url: urlString + "?" + params,
            async: false
        }).responseText;

        alert("ResponseText: " + html + ", Recaptcha.responseText: " + Recaptcha.responseText);

        var result = html.split("\n")[0];

        if (result == "true") {
            status.innerHTML = " ";
            return true;
        }
        else {
            status.className = "GlobalErrorText";
            status.innerHTML = "Your captcha is incorrect. Please try again";
            Recaptcha.reload();
            return false;
        }
    }
</script>

Answer 1

@Boug is right, this is called cross site ajax request, you can see this question to see if you can a find a solution Cross-site AJAX requests but….

I think putting your private key for recaptcha in javascript is a vulnerability, recaptcha should be validated on Server Side code, this question contain useful links about how to implement recaptcha in Asp.Net MVC How to implement reCaptcha for ASP.NET MVC? I used this approach and it works perfectly http://www.dotnetcurry.com/ShowArticle.aspx?ID=611&AspxAutoDetectCookieSupport=1