通过 SSL 访问 Web 服务 - 未调用服务器证书验证回调

我需要通过https访问一个Web服务，它的证书有一些问题。在 chrome 中，它显示网站的身份已确认，但没有公开条目。

向该 URL 发出 httprequest 时，我收到错误 System.Net.WebExceptionStatus.SecureChannelFailure

"请求已中止：无法创建 SSL/TLS 安全通道。"

我尝试使用

ServicePointManager.ServerCertificateValidationCallback += ValidateRemoteCertificate;
private static bool ValidateRemoteCertificate(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors error)
{
    // If the certificate is a valid, signed certificate, return true.
    if (error == System.Net.Security.SslPolicyErrors.None)
    {
        return true;
    }
    Console.WriteLine("X509Certificate [{0}] Policy Error: '{1}'",
        cert.Subject,
        error.ToString());
    return false;
}

但是回调甚至没有命中。如果我请求不同的（有效）URL，则会命中回调。

有什么方法可以进一步调试问题吗？

下面是完整的示例代码：

    private void button1_Click(object sender, EventArgs e)
    {
        string url = "https://domainwithsslissues.";
        string method = "get";
        ServicePointManager.ServerCertificateValidationCallback += ValidateRemoteCertificate;
        HttpWebRequest ws = (HttpWebRequest)WebRequest.Create(url);
        ws.Credentials = CredentialCache.DefaultCredentials;
        ws.Method = method;
        using (HttpWebResponse webResponse = (HttpWebResponse)ws.GetResponse())
        {
            using (Stream responseStream = webResponse.GetResponseStream())
            {
                using (StreamReader responseStreamReader = new StreamReader(responseStream, true))
                {
                    string response = responseStreamReader.ReadToEnd();
                    Console.WriteLine(response);
                    responseStreamReader.Close();
                }
                responseStream.Close();
            }
            webResponse.Close();
        }
    }
    private static bool ValidateRemoteCertificate(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors error)
    {
        if (error == System.Net.Security.SslPolicyErrors.None)
        {
            return true;
        }
        Console.WriteLine("X509Certificate [{0}] Policy Error: '{1}'",
            cert.Subject,
            error.ToString());
        return false;
    }