(C# UWP/WinRT) Use a Smart Card Certificate + Private Key for SSL/TLS Authentication

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Demonstrates how to use a certificate + private key located on a smart card for the TLS client certificate in an HTTPS request.

Note: This functionality was introduced in Chilkat v9.5.0.87.

Note: The ScMinidriver functionality is for Windows-only because ScMinidriver DLLs only exist on Windows. In the next version, Chilkat will be releasing a Pkcs11 class to support Linux, MacOSX, and possibly other operating systems.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.ScMinidriver scmd = new Chilkat.ScMinidriver();

// Reader names (smart card readers or USB tokens) can be discovered
// via List Readers or Find Smart Cards
string readerName = "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0";
bool success = scmd.AcquireContext(readerName);
if (success == false) {
    Debug.WriteLine(scmd.LastErrorText);
    return;
}

// If successful, the name of the currently inserted smart card is available:
Debug.WriteLine("Card name: " + scmd.CardName);

// If desired, perform regular PIN authentication with the smartcard.
// For more details about smart card PIN authentication, see the Smart Card PIN Authentication Example
int retval = scmd.PinAuthenticate("user","000000");
if (retval != 0) {
    Debug.WriteLine("PIN Authentication failed.");
}

// You can find a cerficate using any of the following certificate parts:
// "subjectDN" -- The full distinguished name of the cert.
// "subjectDN_withTags" -- Same as above, but in a format that includes the subject part tags, such as the "CN=" in "CN=something"
// "subjectCN" -- The common name part (CN) of the certificate's subject.
// "serial" -- The certificate serial number.
// "serial:issuerCN" -- The certificate serial number + the issuer's common name, delimited with a colon char.
// These are the same certificate parts that can be retrieved by listing certificates on the smart card (or USB token).
// See List Certificates on Smart Card Example
string certPart = "subjectCN";
string partValue = "BadSSL Client Certificate";

// If the certificate is found, it is loaded into the cert object.
// Note: We imported this certificate from a .p12/.pfx using this Example to Import a .pfx/.p12 onto a Smart Card
Chilkat.Cert cert = new Chilkat.Cert();
success = scmd.FindCert(certPart,partValue,cert);
if (success == false) {
    Debug.WriteLine("Failed to find the certificate.");
    scmd.DeleteContext();
    return;
}

Debug.WriteLine("Successfully loaded the cert object from the smart card / USB token.");

// Note: When successful, the cert object is internally linked to the ScMinidriver object's authenticated session.
// The cert object can now be used to sign or do other cryptographic operations that occur on the smart card / USB token.
// If your application calls PinDeauthenticate or DeleteContext, the cert will no longer be able to sign on the smart card
// because the smart card ScMinidriver session will no longer be authenticated or deleted.

// ------------------------------------------------------------------------------------------------------------

// Send an HTTPS request to https://client.badssl.com
// https://client.badssl.com (part of the badssl.com service) lets you test authentication using client SSL certificates. 
// The client certificate can be downloaded from https://badssl.com/download/.
// This server returns 200 OK if the correct client certificate is provided, and 400 Bad Request otherwise.

Chilkat.Http http = new Chilkat.Http();

// Provide the client certificate (linked internally to our authenticated smartcard session)
success = http.SetSslClientCert(cert);
if (success == false) {
    Debug.WriteLine(http.LastErrorText);
    scmd.DeleteContext();
    return;
}

string responseBody = await http.QuickGetStrAsync("https://client.badssl.com/");
if (http.LastMethodSuccess == false) {
    Debug.WriteLine(http.LastErrorText);
    scmd.DeleteContext();
    return;
}

Debug.WriteLine("Response status code: " + Convert.ToString(http.LastStatus));
Debug.WriteLine("Response body: ");
Debug.WriteLine(responseBody);

// ------------------------------------------------------------------------------------------------------------
// Cleanup our ScMinidriver session...

// When finished with operations that required authentication, you may if you wish, deauthenticate the session.
success = scmd.PinDeauthenticate("user");
if (success == false) {
    Debug.WriteLine(scmd.LastErrorText);
}

// Delete the context when finished with the card.
success = scmd.DeleteContext();
if (success == false) {
    Debug.WriteLine(scmd.LastErrorText);
}