(Delphi DLL) Unzip an AES Encrypted Text File directly into a String Variable

A common need is to unzip from an AES encrypted Zip archive directly into a string variable, such that the unencrypted file never resides on disk, even temporarily. This example shows how to do it.

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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
zip: HCkZip;
success: Boolean;
entry: HCkZipEntry;
lineEndingBehavior: Integer;
srcCharset: PWideChar;
xmlText: PWideChar;

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

zip := CkZip_Create();

// This example opens a WinZip-compatible AES encrypted
// .zip that contains a single file: hamlet.xml.

// It decrypts and unzips hamlet.xml directly into a string
// variable.
CkZip_SetPassword(zip,'secret');
success := CkZip_OpenZip(zip,'qa_data/hamlet.zip');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;

entry := CkZip_GetEntryByName(zip,'hamlet.xml');
if (CkZip_getLastMethodSuccess(zip) = False) then
  begin
    Memo1.Lines.Add('Failed to find entry in zip');
    Exit;
  end;

// lineEndingBehavior:
// 0 = leave unchanged.
// 1 = convert all to bare LF's
// 2 = convert all to CRLF's
lineEndingBehavior := 0;
srcCharset := 'utf-8';
xmlText := CkZipEntry__unzipToString(entry,lineEndingBehavior,srcCharset);
Memo1.Lines.Add(xmlText);
CkZipEntry_Dispose(entry);

CkZip_Dispose(zip);

end;