C# making https request with httpclient

Question

UPD: This code work in windows server 2012, but dont work in windows 7,8,10. And i haven't any idea why

I am trying to make post request to some service that allows only https connection. But i get error

The request was aborted: Could not create SSL/TLS secure channel

My code

using (var client = new HttpClient())
{
    ServicePointManager.Expect100Continue = true;
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
    ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
    var response = await client.PostAsync(ApiAddress, content);
    var xml = await response.Content.ReadAsStringAsync();

    var transaction = DeserializeXml<StationsResponseTransaction>(xml);
    return transaction;
}

This service gave certificate (.crt) and private key (.pem) files. Maybe i need to use these files? But how?

UPDATE: I tried create pfx certificate and add it in WebRequestHandler

WebRequestHandler handler = new WebRequestHandler();
X509Certificate2 certificate = new X509Certificate2("Certificate.pfx", "password");
handler.ClientCertificates.Add(certificate);

and use handler in client new HttpClient(handler)

But i got same error

UPDATE: Just tested this request in postman - working fine, when server's certificate accepted from google crhome. But how to accept certificate from C# httpclient?

ServicePointManager's ServerCertificateValidationCallback event not called

Is the certificate signed with a trusted root certificate (even your own self-generated one)? — Jasen, Jun 08 '17 at 19:24
Maybe the server doesn't support the protocols or ciphers you need. You can check with ssllabs: https://www.ssllabs.com/ssltest/ — Julian, Jun 08 '17 at 19:27
You basically use Powershell to 1) create the signing cert 2) install the cert to your trusted certificates 3) create the (second) cert your application uses, **signed by the trusted cert**. — Jasen, Jun 08 '17 at 19:55
I used this guy's guide in the past: http://blog.davidchristiansen.com/2016/09/howto-create-self-signed-certificates-with-powershell/ — Jasen, Jun 08 '17 at 19:58
@ Kaushal yes, i am tried with WebRequestHandler.ServerCertificateValidationCallback - same situation, callback not even hitting — Stas Petrov, Jun 14 '17 at 14:29
@StasPetrov use X509Store() for more detail https://stackoverflow.com/questions/8448147/problems-with-x509store-certificates-find-findbythumbprint and https://msdn.microsoft.com/en-us/library/system.security.cryptography.x509certificates.x509store(v=vs.110).aspx — Kaushal, Jun 14 '17 at 14:48

score 0 · Answer 1 · answered Aug 17 '17 at 07:19

0

Make .cer file from your .pfx, and then install it to trusted folder in local. Then make client .cer from .pfc, and use it in solution (don't install it).

answered Aug 17 '17 at 07:19

Nenad

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C# making https request with httpclient

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