How to implement reCaptcha V3 in ASP.NET

Question

Does anyone have a full implementation demo of reCaptcha V3 in ASP.NET?

I found this article: Google Recaptcha v3 example demo

At the moment I am using reCap

Answer 1

The simplest:

a) in cshtml (at the top)

@section Scripts
{
    
    
}

b) in cshtml inside the form (just before /form>:

c) a function inside Pagemodel class:

public static bool ReCaptchaPassed(string gRecaptchaResponse)
{
    HttpClient httpClient = new HttpClient();
    
    var res = httpClient.GetAsync($"https://www.google.com/recaptcha/api/siteverify?secret=your secret key no quotes&response={gRecaptchaResponse}").Result;
    
    if (res.StatusCode != HttpStatusCode.OK)
        return false;

    string JSONres = res.Content.ReadAsStringAsync().Result;
    dynamic JSONdata = JObject.Parse(JSONres);
    
    if (JSONdata.success != "true")
        return false;

    return true;
}

Finally, inside OnPostAsync at the beginning:

if (!ModelState.IsValid) 
    return Page();
else
{
    if (!ReCaptchaPassed(Request.Form["foo"]))
    {
        ModelState.AddModelError(string.Empty, "You failed the CAPTCHA.");
        return Page();
    }
}