Delphi ActiveX Requires Chilkat v11.7.0+

Choose the PDF Encryption Algorithm: AES-256, AES-128 or RC4

See more PDF Protection Examples

Demonstrates the algorithmChoice option of the encrypt operation. aes-256 is the default and the one to use unless an older reader must open the file. aes-128 is for readers that predate AES-256. rc4-128 and rc4-40 are broken ciphers kept only for very old readers. Each algorithm needs a minimum PDF version, and the file header is raised to it when the PDF is saved, never lowered. A PDF saved with RC4 is written with a classic cross-reference table so that those old readers can parse it. Delphi ActiveX

var
success: Integer;
json: TChilkatJsonObject;
jsonOut: TChilkatJsonObject;
info: TChilkatJsonObject;
pdf1: TChilkatPdf;
pdf2: TChilkatPdf;
pdf3: TChilkatPdf;

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

json := TChilkatJsonObject.Create(Self);
jsonOut := TChilkatJsonObject.Create(Self);
info := TChilkatJsonObject.Create(Self);

//  AES-256, the default.  Saved as PDF 1.7 with Adobe extension level 8.
pdf1 := TChilkatPdf.Create(Self);
success := pdf1.LoadFile('qa_data/pdf/two_page_memo.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf1.LastErrorText);
    Exit;
  end;
pdf1.UserPassword := 'user-secret';
pdf1.OwnerPassword := 'owner-secret';
json.UpdateString('algorithmChoice','aes-256');
success := pdf1.Protection('encrypt',json.ControlInterface,jsonOut.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf1.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('aes-256 will be saved as PDF ' + jsonOut.StringOf('pending.pdfVersion') + ', Adobe extension level ' + IntToStr(jsonOut.IntOf('pending.adobeExtensionLevel')));
success := pdf1.WriteFile('qa_output/memo_aes256.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf1.LastErrorText);
    Exit;
  end;
success := pdf1.PreLoadCheck('qa_output/memo_aes256.pdf',info.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf1.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('  saved file: ' + info.StringOf('algorithm') + ', PDF ' + info.StringOf('pdfVersion'));

//  AES-128, for readers that predate AES-256.  Saved as PDF 1.6.
pdf2 := TChilkatPdf.Create(Self);
success := pdf2.LoadFile('qa_data/pdf/two_page_memo.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf2.LastErrorText);
    Exit;
  end;
pdf2.UserPassword := 'user-secret';
pdf2.OwnerPassword := 'owner-secret';
json.UpdateString('algorithmChoice','aes-128');
success := pdf2.Protection('encrypt',json.ControlInterface,jsonOut.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf2.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('aes-128 will be saved as PDF ' + jsonOut.StringOf('pending.pdfVersion'));
success := pdf2.WriteFile('qa_output/memo_aes128.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf2.LastErrorText);
    Exit;
  end;
success := pdf2.PreLoadCheck('qa_output/memo_aes128.pdf',info.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf2.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('  saved file: ' + info.StringOf('algorithm') + ', PDF ' + info.StringOf('pdfVersion'));

//  RC4-128, a broken cipher, only for readers too old for AES.  Saved as PDF 1.4.
pdf3 := TChilkatPdf.Create(Self);
success := pdf3.LoadFile('qa_data/pdf/two_page_memo.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf3.LastErrorText);
    Exit;
  end;
pdf3.UserPassword := 'user-secret';
pdf3.OwnerPassword := 'owner-secret';
json.UpdateString('algorithmChoice','rc4-128');
success := pdf3.Protection('encrypt',json.ControlInterface,jsonOut.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf3.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('rc4-128 will be saved as PDF ' + jsonOut.StringOf('pending.pdfVersion'));
success := pdf3.WriteFile('qa_output/memo_rc4_128.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf3.LastErrorText);
    Exit;
  end;
success := pdf3.PreLoadCheck('qa_output/memo_rc4_128.pdf',info.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf3.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('  saved file: ' + info.StringOf('algorithm') + ', PDF ' + info.StringOf('pdfVersion'));

//  Sample output:

//  aes-256 will be saved as PDF 1.7, Adobe extension level 8
//    saved file: aes-256, PDF 1.7
//  aes-128 will be saved as PDF 1.6
//    saved file: aes-128, PDF 1.6
//  rc4-128 will be saved as PDF 1.4
//    saved file: rc4-128, PDF 1.4