Delphi ActiveX Requires Chilkat v11.7.0+

Password-Protect a PDF with AES-256 Encryption

See more PDF Protection Examples

Demonstrates the simplest way to encrypt a PDF so that it needs a password to open. The passwords come from the UserPassword and OwnerPassword properties, and Protection with the encrypt operation and an empty JSON uses the defaults: AES-256, everything encrypted, every permission granted. Protection only records the security the PDF will be saved with. Nothing is encrypted until WriteFile is called. Delphi ActiveX

var
success: Integer;
pdf: TChilkatPdf;
json: TChilkatJsonObject;
jsonOut: TChilkatJsonObject;
checker: TChilkatPdf;
info: TChilkatJsonObject;
reader: 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

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;

//  The passwords are taken from these two properties at the time Protection is called.
//  The user password opens the PDF.  The owner password opens it too, and is the one needed
//  later to change or remove the protection.
pdf.UserPassword := 'user-secret';
pdf.OwnerPassword := 'owner-secret';

//  An empty JSON asks for the defaults: AES-256, everything encrypted, every permission granted.
json := TChilkatJsonObject.Create(Self);
jsonOut := TChilkatJsonObject.Create(Self);
success := pdf.Protection('encrypt',json.ControlInterface,jsonOut.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf.LastErrorText);
    Exit;
  end;

//  Nothing has been encrypted yet.  "pending" describes the security the PDF will be saved with.
Memo1.Lines.Add('algorithm: ' + jsonOut.StringOf('pending.algorithm'));
Memo1.Lines.Add('PDF version: ' + jsonOut.StringOf('pending.pdfVersion'));
Memo1.Lines.Add('password needed to open: ' + IntToStr(Ord(jsonOut.BoolOf('pending.userPasswordRequired'))));

//  Writing the file applies it.
success := pdf.WriteFile('qa_output/memo_encrypted.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf.LastErrorText);
    Exit;
  end;

//  PreLoadCheck reports a file's encryption without loading it, and needs no password.
checker := TChilkatPdf.Create(Self);
info := TChilkatJsonObject.Create(Self);
success := checker.PreLoadCheck('qa_output/memo_encrypted.pdf',info.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(checker.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('encrypted: ' + IntToStr(Ord(info.BoolOf('encrypted'))));
Memo1.Lines.Add('openPasswordRequired: ' + IntToStr(Ord(info.BoolOf('openPasswordRequired'))));

//  With the password, the PDF opens normally.
reader := TChilkatPdf.Create(Self);
reader.UserPassword := 'user-secret';
success := reader.LoadFile('qa_output/memo_encrypted.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(reader.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('pages: ' + IntToStr(reader.NumPages));

//  Sample output:

//  algorithm: aes-256
//  PDF version: 1.7
//  password needed to open: True
//  encrypted: True
//  openPasswordRequired: True
//  pages: 2