Extract from encrypted ZIP?

[PeterPanettone 157]

It seems that the Delphi RTL now supports ZIP encryption in Delphi 12?

 

Does anyone have an example code that shows how to extract a file from an encrypted ZIP file using the Delphi 12 RTL?

[Uwe Raabe 2057]

While Delphi 12 supports ZIP encryption, the actual encryption algorithm has to be provided by the developer itself or a library implementing the new IZipCryptor interface.

 

For the common PKWARE Zip 2.0 encryption (see APPNOTE.TXT) an implementation can be found in PKWAREZipCryptor.pas. The usage is shown in the following example, which extracts all files from an encrypted zip file:

var
  bytes: TBytes;
  fileName: string;
  zipFile: TZipFile;
begin
  zipFile := TZipFile.Create;
  try
    zipFile.Cryptor := TPKWAREZipCryptor.Create;
    zipFile.Password := cPassword;
    zipFile.Open(zipFileName, zmRead);
    for var I := 0 to zipfile.FileCount - 1 do begin
      fileName := zipFile.FileNames[I];
      zipFile.Read(I, bytes);
      TFile.WriteAllBytes(fileName, bytes);
    end;
    zipFile.Close;
  finally
    zipFile.Free;
  end;
end;

 

[PeterPanettone 157]

Uwe, you are my hero!