在 ASP.NET 服务器端验证 Recaptcha 2（无 CAPTCHA reCAPTCHA）

新的验证码 2 http://googleonlinesecurity.blogspot.com/2014/12/are-you-robot-introducing-no-captcha.html看起来很有希望，但我没有找到在 ASP.NET 服务器端验证它的方法，

if(Page.IsValid) in 这个答案 https://stackoverflow.com/questions/5817690/validating-recaptcha-on-server-side，对旧 Recaptcha 有效，但对新 Recaptcha 无效，

如何在服务器端验证新的 reCAPTCHA？

在阅读了很多资源之后，我最终编写了这个类来处理验证新的验证码 http://googleonlinesecurity.blogspot.com/2014/12/are-you-robot-introducing-no-captcha.html :

如上所述Here https://developers.google.com/recaptcha/docs/verify：当最终用户解决 reCAPTCHA 时，将在 HTML 中填充一个新字段 (g-recaptcha-response)。

我们需要读取这个值并将其传递给下面的类来验证它：

In C#:

在页面后面的代码中：

string EncodedResponse = Request.Form["g-Recaptcha-Response"];
bool IsCaptchaValid = (ReCaptchaClass.Validate(EncodedResponse) == "true" ? true : false);

if (IsCaptchaValid) {
    //Valid Request
}

班上：

  using Newtonsoft.Json;

    public class ReCaptchaClass
    {
        public static string Validate(string EncodedResponse)
        {
            var client = new System.Net.WebClient();

            string PrivateKey = "6LcH-v8SerfgAPlLLffghrITSL9xM7XLrz8aeory";

            var GoogleReply = client.DownloadString(string.Format("https://www.google.com/recaptcha/api/siteverify?secret={0}&response={1}", PrivateKey, EncodedResponse));

            var captchaResponse = Newtonsoft.Json.JsonConvert.DeserializeObject<ReCaptchaClass>(GoogleReply);

            return captchaResponse.Success.ToLower();
        }

        [JsonProperty("success")]
        public string Success
        {
            get { return m_Success; }
            set { m_Success = value; }
        }

        private string m_Success;
        [JsonProperty("error-codes")]
        public List<string> ErrorCodes
        {
            get { return m_ErrorCodes; }
            set { m_ErrorCodes = value; }
        }


        private List<string> m_ErrorCodes;
    }

在 VB.NET 中：

在页面后面的代码中：

Dim EncodedResponse As String = Request.Form("g-Recaptcha-Response")
    Dim IsCaptchaValid As Boolean = IIf(ReCaptchaClass.Validate(EncodedResponse) = "True", True, False)

    If IsCaptchaValid Then
        'Valid Request
    End If

班上：

Imports Newtonsoft.Json


Public Class ReCaptchaClass
    Public Shared Function Validate(ByVal EncodedResponse As String) As String
        Dim client = New System.Net.WebClient()

        Dim PrivateKey As String = "6dsfH-v8SerfgAPlLLffghrITSL9xM7XLrz8aeory"

        Dim GoogleReply = client.DownloadString(String.Format("https://www.google.com/recaptcha/api/siteverify?secret={0}&response={1}", PrivateKey, EncodedResponse))

        Dim captchaResponse = Newtonsoft.Json.JsonConvert.DeserializeObject(Of ReCaptchaClass)(GoogleReply)

        Return captchaResponse.Success
    End Function

    <JsonProperty("success")> _
    Public Property Success() As String
        Get
            Return m_Success
        End Get
        Set(value As String)
            m_Success = value
        End Set
    End Property
    Private m_Success As String

    <JsonProperty("error-codes")> _
    Public Property ErrorCodes() As List(Of String)
        Get
            Return m_ErrorCodes
        End Get
        Set(value As List(Of String))
            m_ErrorCodes = value
        End Set
    End Property

    Private m_ErrorCodes As List(Of String)

End Class