Captcha nuget package always Valid on ASP.NET MVC 5

Question

I've installed the captcha plugin and followed the setup instructions. The captcha renders perfectly on the page but when submit the form, the ModelState.IsValid is always true, no matter what I enter. Obviously, if captcha won't validate then it's not much good to me.

Here's my controller:

        [HttpPost]
    [CaptchaValidation("CaptchaCode", "SampleCaptcha", "Incorrect CAPTCHA code!")]
    public ActionResult Register(AccountModel model)
    {
        if (!ModelState.IsValid)
        {
            // TODO: Captcha validation failed, show error message
        }
        else
        {
            // TODO: Captcha validation passed, proceed with protected action
        }

        return View();
    }

And here's my view:

<link href="@BotDetect.Web.CaptchaUrls.Absolute.LayoutStyleSheetUrl" rel="stylesheet" type="text/css" />

<form class="form-horizointal" action="@Url.Action("Register", "Account")" method="POST">
    <div class="form-group">
        @Html.LabelFor(m => m.FirstName, new { @class = "col-sm-2 control-label" })
        @Html.TextBoxFor(m => m.FirstName, new { placeholder = "First Name"})
        @Html.LabelFor(m => m.LastName, new { @class = "control-label", placeholder = "Last Name" })
        @Html.TextBoxFor(m => m.LastName, new { placeholder = "Last Name" })
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.Email, new {@class = "col-sm-2 control-label", placeholder = "Email"})
        @Html.TextBoxFor(m => m.Email, new {placeholder = "Email"})
    </div>
    <div class="form-group">
        @{ MvcCaptcha sampleCaptcha = new MvcCaptcha("SampleCaptcha"); }
        @Html.Captcha(sampleCaptcha)
        @Html.TextBox("CaptchaCode")
    </div>
    <div class="form-group">
        captcha goes here
    </div>
    <div class="form-group">
        <input type="submit" class="btn btn-default" value="Register"/>
    </div>
</form>

Does anyone have any idea why this isn't working for me? Thanks for your help!

Answer 1

I'm not sure if it's the same problem. I've got a botdetect captcha in a modal popup. It' works ok until passes the first validation ok, after then it's always true so i added a samplecaptcha.Reset() and the Model.IsValid is false again when it's not valid.

@{
    Layout = null;
    MvcCaptcha sampleCaptcha = new MvcCaptcha("SampleCaptcha");
    sampleCaptcha.Reset();
}

[etc]

Answer 2

//I had the same problem with you, but i solved it with this way

    public ActionResult RegistrationComp(NewRegistration data, bool captchaValid)
    {
        try
        {
            captchaValid = MvcCaptcha.Validate(data.CaptchaID, data.CaptchaCode, data.CurrentInstanceID);

            MvcCaptcha.ResetCaptcha(data.CaptchaID);

            if (!captchaValid)
                return this.Json("false");
            else
                return this.Json("true");

        }
        catch (Exception ex)
        {
            return this.Json("false");
        }
    }

in RegistrationModel add properties : CaptchaID ,CaptchaCode the user input,CurrentInstanceID

cshtml

MvcCaptcha exampleCaptcha = new MvcCaptcha("C");

exampleCaptcha.UserInputID = "CC";

<script>
 $.post("@Url.Action("RegistrationComp", "Authentication")", { CaptchaCode: $("#CC").val() , CaptchaID: '@exampleCaptcha.CaptchaId',CurrentInstanceID: '@exampleCaptcha.CurrentInstanceId' }, function (data) {});
</script>