(Delphi ActiveX) Add S/MIME Signature using PFX

Add a digital signature to a MIME message using the certificate + private key from a PFX file.

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
mime: TChilkatMime;
cert: TChilkatCert;
pfxFilepath: WideString;
pfxPassword: WideString;
success: Integer;

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

mime := TChilkatMime.Create(Self);

// Load a PFX file into a certificate object.
cert := TChilkatCert.Create(Self);
pfxFilepath := 'pfxFiles/something.pfx';
pfxPassword := 'secret';
success := cert.LoadPfxFile(pfxFilepath,pfxPassword);
if (success = 0) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

success := mime.SetBodyFromPlainText('This is the plain-text MIME body.');

mime.Charset := 'utf-8';
mime.Encoding := 'quoted-printable';

// Sign the MIME (adds a PKCS7 detached signature)
success := mime.AddDetachedSignature(cert.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

// Save the S/MIME to a file.
success := mime.SaveMime('/temp/signedMime.txt');
if (success = 0) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('success!');
end;