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

Edit : I have added a demo project . Check this github repository . https://github.com/NIHAR-SARKAR/GoogleRecaptchav3-example-In-asp.net

From frontend (.aspx page) you need to send ajax request to pass the token to backend server . Using "recaptcha.execute" U can get the response , and pass the token using ajax request .Please check the code block .

Reference link: https://developers.google.com/recaptcha/docs/verify https://developers.google.com/recaptcha/docs/display#js_api

Now in the aspx.cs you need to write a "[WebMethod]" to receive the token from Ajax request .

    [WebMethod]
    public static void CaptchaVerify(string token)
    {
            var responseString = RecaptchaVerify(token);
            ResponseToken response = new ResponseToken();
            response = Newtonsoft.Json.JsonConvert.DeserializeObject(responseString.Result);

    }

To get the response from google recapcha api u need to use async call using httpClient . you also need to create a class which will contain same properties like the response string . After getting the "responseString" u need to convert the response to ResponseToken object by using Newtonsoft.Json. response = Newtonsoft.Json.JsonConvert.DeserializeObject(responseString.Result);

private string apiAddress = "https://www.google.com/recaptcha/api/siteverify";

private string recaptchaSecret = googleRecaptchaSecret;

        public async Task RecaptchaVerify(string recaptchaToken)
        {
            string url = $"{apiAddress}?secret={recaptchaSecret}&response={recaptchaToken}";
            using (var httpClient = new HttpClient())
            {
                try
                {

                    string responseString=  httpClient.GetStringAsync(url).Result;
                    return responseString;

                }
                catch (Exception ex)
                {
                    throw new Exception(ex.Message);
                }
            }
        }


        public class ResponseToken
        {

            public DateTime challenge_ts { get; set; }
            public float score { get; set; }
            public List ErrorCodes { get; set; }
            public bool Success { get; set; }
            public string hostname { get; set; }
        }