(Delphi ActiveX) Open a Zip Archive

See more Zip Examples

Demonstrates how to open a zip, or an encrypted .zip, or a legacy password-protected .zip.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
zip: TChilkatZip;
success: Integer;

begin
zip := TChilkatZip.Create(Self);

// Open a non-encrypted .zip
success := zip.OpenZip('qa_data/zips/sample.zip');
if (success <> 1) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('Num entries = ' + IntToStr(zip.NumEntries));

// ...
// ...

zip.CloseZip();

// ----------------------------------------------------------------------------
// Open an encrypted zip...

// The two main types of encryption used in ZIP archives are Password-Protected and AES.
// 

// ---------------------------------------
// 1. Legacy Password-Protected Zip
// 
// This is the older and less secure method of encrypting ZIP archives. 
// It provides a basic level of security, but is considered weak by modern standards. 
// It is vulnerable to various attacks, including known-plaintext attacks and brute force attacks.
// Although Chilkat allows it, you shouldn't create new zip archives using legacy password-protection.

// ---------------------------------------
// 2. AES Encrypted Zip
// 
// AES encryption is a more modern and secure method for encrypting ZIP archives. 
// It provides strong encryption based on the AES algorithm, which is widely regarded as secure. 
// AES supports different key lengths, typically 128-bit, 192-bit, and 256-bit.

// When opening an encrypted zip, your application only needs to provide the correct password.
// The information about the type of encryption and the key length (if AES) is already embedded within the encrypted .zip.

// Provide the decrypt password because we are opening an existing .zip (decrypting)
zip.DecryptPassword := 'thePassword';

success := zip.OpenZip('qa_data/zips/encryptedSamples/ziptest_256.zip');
if (success <> 1) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('Num entries = ' + IntToStr(zip.NumEntries));

// ...
// ...

zip.CloseZip();
end;