title: Sending client certificate without installing its CA into the certificate store
body: <p>Is there a way to use a client certificate without installing its CA into the certificate store?  There is exactly one client certificate (as a pfx file) added to HttpWebRequest.ClientCertificates, and that single one should be used even if the corresponding CA certificate is not available in the certificate store.</p>
  
  <pre><code>HttpWebRequest req = WebRequest.Create("https://server/");
  X509Certificate2 cert = X509Certificate2("cert.p12", "secret");
  req.ClientCertificates.Add(cert);
  WebResponse resp = req.GetResponse();
  </code></pre>
  
  <p>Enabling detailed socket logging gives me this:</p>
  
  <pre><code>System.Net Information: 0 : [15136] SecureChannel#46104728 - We have user-provided certificates. The server has specified 8 issuer(s). Looking for certificates that match any of the issuers.
  System.Net Information: 0 : [15136] SecureChannel#46104728 - Left with 0 client certificates to choose from.
  </code></pre>
  
  <p>The client doesn't find any suitable client certificate since it doesn't recognize the CA that has signed it.  I don't care, I want to use it anyway.  Can this be achieved?</p>