Pascal (Lazarus/Delphi)

Determine if a Zip is Encrypted or Password-Protected

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Determines whether or not a zip archive is AES encrypted or password-protected. 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.Zip;

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

procedure RunDemo;
var
  success: Boolean;
  zip: TZip;
  bPwdProt: Boolean;
  encValue: Integer;

begin
  success := False;

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

  zip := TZip.Create;

  //  An encrypted or password-protected zip can be opened
  //  without specifying the password.  However, the contents
  //  of the files cannot be unzipped without providing the correct
  //  password.

  success := zip.OpenZip('something.zip');
  if (success <> True) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  //  If the zip is password-protected, meaning that it uses
  //  the old (insecure) Zip 2.0 encryption, then the
  //  PasswordProtect property will be True
  bPwdProt := zip.PasswordProtect;
  if (bPwdProt) then
    begin
      WriteLn('This zip is password-protected.');
    end;

  //  If the zip is AES encrypted (WinZip compatible) then
  //  the Encryption property will be equal to 4.
  encValue := zip.Encryption;
  if (encValue = 4) then
    begin
      WriteLn('This zip is AES encrypted.');
    end;

  //  If the Encryption property = 0, then the zip is NOT
  //  strong encrypted, and is either password-protected or
  //  entirely unencrypted, depending on the value of the
  //  PasswordProtect property.

  zip.CloseZip();


  zip.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.