PHP/Curl-SSL operations alternative in C#

Question

I have this piece of code written in PHP, which adds, as i presume, some information about an SSL-certificate to a HTTP-request(It's just a simple http-request, isn't it?). It's added either to body-request or header, that i don't know for sure.

//some code before that
curl_setopt($curl,CURLOPT_SSLCERT,'cert.crt');
curl_setopt($curl,CURLOPT_SSLKEY,'cert.key');
//some code after

//the request itself
$json_response = curl_exec($curl);

The problem is - i don't know how to make this stuff in C#. It'd be easy if i had any knowledge how it's done in curl, like what it exactly does under it's cover.

My current request.

      //
            var request = CreateHttpRequest(url, method);
            var json = param?.ToJson();


            if (json != null)
            {
                var postData = Encoding.UTF8.GetBytes(json);
                request.ContentLength = postData.Length;
                using (var stream = request.GetRequestStream())
                    stream.Write(postData, 0, postData.Length);
            }

            using (var webResponse = request.GetResponse())
            using (var streamReader = new StreamReader(webResponse.GetResponseStream(), Encoding.UTF8))
             {
                    var result = streamReader.ReadToEnd();
                    return result.ParseJson(type);
             }

    //
    private HttpWebRequest CreateHttpRequest(string url, HttpMethod method)
    {
        var request = (HttpWebRequest)WebRequest.Create(url);
        request.ContentType = "application/json";
        request.Accept = "application/json, application/javascript, text/*";
        request.Headers.Add("Accept-Encoding", "gzip,deflate");
        request.Method = method.ToString().ToUpper();
        return request;
    }

Answer 1

In order to use client certificate (loaded from .crt and .key files) in your HTTP-request, add following lines in CreateHttpRequest method before return:

string certificateText = File.ReadAllText("cert.crt");
string privateKeyText = File.ReadAllText("cert.key");
ICertificateProvider provider =
    new CertificateFromFileProvider(certificateText, privateKeyText);

request.ClientCertificates.Add(provider.Certificate);

Taken from this answer. To have CertificateFromFileProvider install OpenSSL.X509Certificate2.Provider Nuget package.