Pascal (Lazarus/Delphi)

Sign PDF with Timestamp from TSA (Timestamp Server Authority)

See more PDF Signatures Examples

This example demonstrates how to a sign a PDF that is both long-term validation (LTV) enabled and includes a validating timestamp from a TSA (Timestamp Server Authority). Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Pdf,
  Chilkat.Cert,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  pdf: TPdf;
  json: TJsonObject;
  cert: TCert;

begin
  success := False;

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

  pdf := TPdf.Create;

  //  Load a PDF to be signed.
  //  The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
  success := pdf.LoadFile('qa_data/pdf/hello.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  //  Options for signing are specified in JSON.
  json := TJsonObject.Create;

  //  In most cases, the signingCertificateV2 and signingTime attributes are required.
  json.UpdateInt('signingCertificateV2',1);
  json.UpdateInt('signingTime',1);

  //  Tell Chilkat to create an LTV-enabled (long term validation) signature.
  //  See PDF Long-Term Validation (LTV) Signature Example for more detailed comments about "ltvOcsp".
  json.UpdateBool('ltvOcsp',True);

  //  Tell Chilkat to request a timestamp from a TSA server and include the timestamp token (1.2.840.113549.1.9.16.2.14)
  //  in the CMS signature's authentication attributes
  json.UpdateBool('timestampToken.enabled',True);

  //  In this example, we'll use a free TSA server (timestamp.digicert.com), but you may want to use your own timestamp authority server.
  json.UpdateString('timestampToken.tsaUrl','http://timestamp.digicert.com');

  //  If the timestamp server requires a username/password, do the following.  Otherwise omit the following few lines of code.
  json.UpdateString('timestampToken.tsaUsername','the_tsa_username');
  json.UpdateString('timestampToken.tsaPassword','the_tsa_password');

  //  When requesting the timestamp token, ask the server to include its certificate in the timestamp token response.
  //  This allows for the timestamp server's certificate to be included in the LTV validation (i.e. if the timestamp server
  //  has an OCSP URL, then Chilkat will also do the OCSP request for the timestamp server's certificate.)
  json.UpdateBool('timestampToken.requestTsaCert',True);

  //  Define the appearance of the signature.
  json.UpdateInt('page',1);
  json.UpdateString('appearance.y','top');
  json.UpdateString('appearance.x','left');
  json.UpdateString('appearance.fontScale','10.0');
  json.UpdateString('appearance.text[0]','Digitally signed by: cert_cn');
  json.UpdateString('appearance.text[1]','current_dt');
  json.UpdateString('appearance.text[2]','This is an LTV-enabled signature with a TSA timestamp.');

  //  Load the signing certificate. (Use your own certificate.)
  cert := TCert.Create;
  success := cert.LoadPfxFile('qa_data/pfx/myPdfSigningCert.pfx','pfxPassword');
  if (success = False) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  Tell the pdf object to use the certificate for signing.
  success := pdf.SetSigningCert(cert);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  success := pdf.SignPdf(json,'qa_output/hello_ltv_signed_with_timestamp.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  WriteLn('The PDF has been successfully cryptographically signed with TSA timestamp and long-term validation.');

  //  If you open the Signature Panel in Adobe Acrobat, it will indicate that the signature is LTV enabled
  //  and contains an embedded timestamp:
  //  (image:https://example-code.com/images/ltv_signature_with_timestamp.jpg/endImage)


  pdf.Free;
  json.Free;
  cert.Free;

end;

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

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.