WebRequest：请求已中止：无法创建SSL / TLS安全通道

Question

下面的curl请求工作正常，但是当我在C＃Web请求中转换此请求时，出现错误。我正在使用.net 4.6桌面应用程序。

卷曲请求工作正常：

  

curl --key private.pem --cert public.crt --data“ {\” branch_reference \“：\” 123 \“}”   --header“内容类型：application / json; profile = {https://realtime-listings.webservices.zpg.co.uk/docs/v1.2/schemas/listing/list.json”“   https://realtime-listings-api.webservices.zpg.co.uk/sandbox/v1/listing/list

C＃Web请求有错误

    ServicePointManager.Expect100Continue = true;
    ServicePointManager.DefaultConnectionLimit = 9999;
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12; 

    string certificateText = File.ReadAllText(@"D:\public.crt");
    string privateKeyText = File.ReadAllText(@"D:\private.pem");
    ICertificateProvider provider = new CertificateFromFileProvider(certificateText, privateKeyText);
    X509Certificate2 clientCertificate = provider.Certificate;

    var httpWebRequest = (HttpWebRequest)WebRequest.Create("https://realtime-listings-api.webservices.zpg.co.uk/sandbox/v1/listing/list");
    httpWebRequest.ContentType = "application/json; profile=https://realtime-listings.webservices.zpg.co.uk/docs/v1.2/schemas/listing/list.json";
    httpWebRequest.Method = "POST";
    httpWebRequest.ClientCertificates.Add(clientCertificate);

    ServicePointManager.ServerCertificateValidationCallback +=new RemoteCertificateValidationCallback((sender, certificate, chain, policyErrors) =>{ return true; });

    using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
    {
        string json = "{\"branch_reference\":\"123\"}";
    streamWriter.Write(json);
        streamWriter.Flush();
    }

    var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
    using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
    {
        var result = streamReader.ReadToEnd();
    }

错误详细信息： 请求已中止：无法创建SSL / TLS安全通道。

下面一行错误

var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();