(Delphi ActiveX) DKIM Signature using Windows Current User Certificate Store

This is a Windows-specific example to load a certificate from the Current User (registry-based) certificate store, and then use the certificate's associated private key for a DKIM signature.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
cert: TChilkatCert;
success: Integer;
privKey: IPrivateKey;
dkim: TChilkatDkim;

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

cert := TChilkatCert.Create(Self);

// The LoadByCommonName method searches the Windows Local Machine and Current User 
// registry-based certificate stores for a certificate having the common name specified. 
// If found, the certificate is loaded and ready for use.
success := cert.LoadByCommonName('My Certificate ABC');
if (success <> 1) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

// The certificate must have an associated private key installed, and it must be a
// private key that has been marked "exportable" when it was originally installed.
if (not cert.HasPrivateKey()) then
  begin
    Memo1.Lines.Add('This certificate does not have a private key available.');
    Exit;
  end;

privKey := cert.ExportPrivateKey();
if (cert.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

dkim := TChilkatDkim.Create(Self);

// Load the private key into the DKIM object:
success := dkim.LoadDkimPk(privKey.GetPkcs8Pem(),'');
if (success <> 1) then
  begin
    Memo1.Lines.Add(dkim.LastErrorText);
    Exit;
  end;

// The private key has been loaded into the DKIM object.  See the other DKIM
// examples for guidance on how to create a DKIM signature...
end;