Delphi ActiveX Requires Chilkat v11.7.0+

Encrypt a PDF for a Certificate Instead of a Password

See more PDF Protection Examples

Demonstrates certificate security, where a PDF is encrypted for one or more recipients and each opens it with their own certificate and private key. No password is involved. Only the public certificate of a recipient is needed to encrypt. Each recipient has its own permissions, and the changeSecurity permission gives a recipient owner rights. PreLoadCheck tells an application that a file is certificate-encrypted and which certificates can open it. A PDF that cannot be opened, because no matching certificate and private key were provided, fails to load. Delphi ActiveX

var
success: Integer;
recipient: TChilkatCert;
pdf: TChilkatPdf;
json: TChilkatJsonObject;
jsonOut: TChilkatJsonObject;
reader: TChilkatPdf;
info: TChilkatJsonObject;
myCert: TChilkatCert;
empty: TChilkatJsonObject;
loadedInfo: TChilkatJsonObject;

begin
success := 0;

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

//  The PDF used in this example is available at two_page_memo.pdf

//  The recipient's certificate.  Only the public certificate is needed to encrypt.
recipient := TChilkatCert.Create(Self);
success := recipient.LoadFromFile('qa_data/certs/recipient.cer');
if (success = 0) then
  begin
    Memo1.Lines.Add(recipient.LastErrorText);
    Exit;
  end;

pdf := TChilkatPdf.Create(Self);
success := pdf.LoadFile('qa_data/pdf/two_page_memo.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf.LastErrorText);
    Exit;
  end;

//  Call AddEncryptCert once for each recipient.
success := pdf.AddEncryptCert(recipient.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf.LastErrorText);
    Exit;
  end;

//  recipientPermissions[0] belongs to the first certificate added.  changeSecurity gives that
//  recipient owner rights, so the file can be managed later.
json := TChilkatJsonObject.Create(Self);
json.UpdateString('method','certificate');
json.UpdateBool('recipientPermissions[0].changeSecurity',1);

jsonOut := TChilkatJsonObject.Create(Self);
success := pdf.Protection('encrypt',json.ControlInterface,jsonOut.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('method: ' + jsonOut.StringOf('pending.method'));
Memo1.Lines.Add('algorithm: ' + jsonOut.StringOf('pending.algorithm'));
Memo1.Lines.Add('recipients: ' + IntToStr(jsonOut.SizeOfArray('pending.recipients')));

success := pdf.WriteFile('qa_output/memo_for_recipient.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf.LastErrorText);
    Exit;
  end;

//  PreLoadCheck says how the file is protected, without loading it.
reader := TChilkatPdf.Create(Self);
info := TChilkatJsonObject.Create(Self);
success := reader.PreLoadCheck('qa_output/memo_for_recipient.pdf',info.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(reader.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('saved file, method: ' + info.StringOf('method'));
Memo1.Lines.Add('saved file, recipients: ' + IntToStr(info.SizeOfArray('recipients')));

//  The recipient opens it with the certificate and its private key, here from a .pfx file.
//  (On Windows, a certificate that is installed in the Windows certificate store with its private
//  key is found automatically when the PDF is loaded, and SetDecryptCert is not needed for it.)
myCert := TChilkatCert.Create(Self);
success := myCert.LoadPfxFile('qa_data/pfx/recipient.pfx','pfx-password');
if (success = 0) then
  begin
    Memo1.Lines.Add(myCert.LastErrorText);
    Exit;
  end;
success := reader.SetDecryptCert(myCert.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(reader.LastErrorText);
    Exit;
  end;
success := reader.LoadFile('qa_output/memo_for_recipient.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(reader.LastErrorText);
    Exit;
  end;

empty := TChilkatJsonObject.Create(Self);
loadedInfo := TChilkatJsonObject.Create(Self);
success := reader.Protection('getInfo',empty.ControlInterface,loadedInfo.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(reader.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('opened with: ' + loadedInfo.StringOf('loaded.openedWith'));
Memo1.Lines.Add('pages: ' + IntToStr(reader.NumPages));

//  Sample output:

//  method: certificate
//  algorithm: aes-256
//  recipients: 1
//  saved file, method: certificate
//  saved file, recipients: 1
//  opened with: certificate
//  pages: 2