Delphi DLL

Load Certificate from Smart Card by Key Usage

See more Certificates Examples

You may have a smartcard or USB token that contains only 2 certificates, one for signing, and one for authentication, and you wish to load the certificate for signing. This example demonstrates how to load the 1st certificate found on a smartcard that matches the intended key usage. Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Cert;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
cert: HCkCert;

begin
success := False;

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

cert := CkCert_Create();

// If you know the smart card PIN, set it prior to loading from the smartcard/USB token.
CkCert_putSmartCardPin(cert,'12345678');

// To load a certificate matching an intended key usage, specify the type of usage as shown below.
// 
// The possible key usage keywords are:
// 
// digitalsignature
// Use when the public key is used with a digital signature mechanism to support security services other than non-repudiation, certificate signing, or CRL signing. 
// A digital signature is often used for entity authentication and data origin authentication with integrity.

// nonrepudiation
// When a digital certificate's key usage includes "nonrepudiation," it implies that the certificate and its associated private key can be used to 
// create digital signatures that provide proof of the origin and integrity of the signed data, and the signer cannot later deny having signed the data.

// Other less common usages:

// certificatesigning
// keyencipherment
// dataencipherment
// crlsigning
// secureemail
// serverauthentication
// clientauthentication
// codesigning
// timestamping

success := CkCert_LoadFromSmartcard(cert,'keyusage=nonrepudiation');
if (success = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Memo1.Lines.Add('Certificate not loaded.');
    Exit;
  end;

Memo1.Lines.Add('Found: ' + CkCert__subjectDN(cert) + ' serial=' + CkCert__serialNumber(cert));

CkCert_Dispose(cert);

end;