untNtCompress by ErazerZ

unit untNtCompress;

//ErazerZ

interface

uses Windows;

const

  COMPRESSION_FORMAT_NONE          = $00000000;

  COMPRESSION_FORMAT_DEFAULT      = $00000001;

  COMPRESSION_FORMAT_LZNT1        = $00000002;

  COMPRESSION_FORMAT_NS3          = $00000003;

  COMPRESSION_FORMAT_NS15          = $0000000F;

  COMPRESSION_FORMAT_SPARSE        = $00004000;

  COMPRESSION_ENGINE_STANDARD      = $00000000;

  COMPRESSION_ENGINE_MAXIMUM      = $00000100;

  COMPRESSION_ENGINE_HIBER        = $00000200;

function CompressMemory(lpMemory: Pointer; var Size: Cardinal; dwCompression: DWORD = COMPRESSION_FORMAT_LZNT1): Pointer;

function DecompressMemory(lpMemory: Pointer; var Size: Cardinal; dwCompression: DWORD = COMPRESSION_FORMAT_LZNT1): Pointer;

function CompressFile(lpFilename, lpOutputfile: String; dwCompression: DWORD = COMPRESSION_FORMAT_LZNT1): Boolean;

function DecompressFile(lpFilename, lpOutputfile: String; dwCompression: DWORD = COMPRESSION_FORMAT_LZNT1): Boolean;

implementation

const

  ntdll = 'ntdll.dll';

function RtlGetCompressionWorkSpaceSize(CompressionFormatAndEngine: ULONG; CompressBufferWorkSpaceSize, CompressFragmentWorkSpaceSize : PULONG): Cardinal; stdcall; external ntdll name 'RtlGetCompressionWorkSpaceSize';

function RtlCompressBuffer(CompressionFormatAndEngine: ULONG; SourceBuffer: Pointer; SourceBufferLength: ULONG; DestinationBuffer: Pointer; DestinationBufferLength: ULONG;

                           SourceChunkSize: ULONG; pDestinationSize: PULONG; WorkspaceBuffer: Pointer): Cardinal; stdcall; external ntdll name 'RtlCompressBuffer';

function RtlDeCompressBuffer(CompressionFormatAndEngine:ULONG; DestinationBuffer: Pointer; DestinationBufferLength: ULONG; SourceBuffer: Pointer; SourceBufferLength: ULONG;

                             pDestinationSize: PULONG): Cardinal; stdcall; external ntdll name 'RtlDecompressBuffer';

function GetPointerSize(lpBuffer: Pointer): Cardinal;

begin

  if lpBuffer = nil then

    Result := Cardinal(-1)

  else

    Result := Cardinal(Pointer(Cardinal(lpBuffer) -4)^) and $7FFFFFFC -4;

end;

{

  Result: Pointer of the Compressed Buffer.

  lpMemory: Buffer that should be compressed.

  var Size: Length of how much should be compressed, later the compressed size.

  dwCompression: Compression type.

}

function CompressMemory(lpMemory: Pointer; var Size: Cardinal; dwCompression: DWORD = COMPRESSION_FORMAT_LZNT1): Pointer;

var

  lpWorkspace, lpOutput: Pointer;

  dwTemp, dwOutputSize: DWORD;

begin

  Result := nil;

  if Size = INVALID_HANDLE_VALUE then

    Size := GetPointerSize(lpMemory);

  dwOutputSize := Size;

  lpOutput := VirtualAlloc(nil, Size, MEM_COMMIT, PAGE_READWRITE);

  if lpOutput <> nil then

  begin

    RtlGetCompressionWorkSpaceSize(dwCompression, @dwTemp, @dwOutputSize);

    lpWorkspace := VirtualAlloc(nil, dwTemp, MEM_COMMIT, PAGE_READWRITE);

    if lpWorkspace <> nil then

    begin

      dwTemp := 0;

      RtlCompressBuffer(dwCompression, lpMemory, Size, lpOutput, Size, 0, @dwTemp, lpWorkspace);

      if dwTemp <> 0 then

      begin

        VirtualFree(lpWorkspace, 0, MEM_RELEASE);

        Size := dwTemp;

        Result := lpOutput;

      end;

    end;

  end;

end;

{

  Result: Pointer of the Decompressed Buffer.

  lpMemory: Buffer that should be decompressed.

  var Size: Length of how much should be decompressed (FileSize), later the decompressed size.

  dwCompression: Compression type.

}

function DecompressMemory(lpMemory: Pointer; var Size: Cardinal; dwCompression: DWORD = COMPRESSION_FORMAT_LZNT1): Pointer;

var

  lpOutput: Pointer;

  dwTemp, dwOutputSize: DWORD;

begin

  Result := nil;

  dwOutputSize := Round(Size * 12.5);

  lpOutput := VirtualAlloc(nil, dwOutputSize, MEM_COMMIT, PAGE_READWRITE);

  if lpOutput <> nil then

  begin

    begin

      dwTemp := 0;

      RtlDecompressBuffer(dwCompression, lpOutput, dwOutputSize, lpMemory, Size, @dwTemp);

      if dwTemp <> 0 then

      begin

        Size := dwTemp;

        Result := lpOutput;

      end;

    end;

  end;

end;

function CompressFile(lpFilename, lpOutputfile: String; dwCompression: DWORD = COMPRESSION_FORMAT_LZNT1): Boolean;

var

  hFileIn, hFileMappingObjectIn,

  hFileOut: THandle;

  dwFileSize, lpNumberOfBytesWritten: DWORD;

  lpBaseAddressIn, lpBuffer: Pointer;

begin

  Result := False;

  hFileIn := CreateFile(PChar(lpFilename), GENERIC_READ or GENERIC_WRITE, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_ALWAYS, 0, 0);

  if hFileIn = INVALID_HANDLE_VALUE then

    Exit;

  dwFileSize := GetFileSize(hFileIn, nil);

  hFileMappingObjectIn := CreateFileMapping(hFileIn, nil, PAGE_READWRITE, 0, 0, nil);

  lpBaseAddressIn := MapViewOfFile(hFileMappingObjectIn, FILE_MAP_READ or FILE_MAP_WRITE, 0, 0, 0);

  lpBuffer := CompressMemory(lpBaseAddressIn, dwFileSize, dwCompression);

  hFileOut := CreateFile(PChar(lpOutputfile), GENERIC_READ or GENERIC_WRITE, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, CREATE_ALWAYS, 0, 0);

  if hFileOut <> INVALID_HANDLE_VALUE then

  begin

    WriteFile(hFileOut, lpBuffer^, dwFileSize, lpNumberOfBytesWritten, nil);

    CloseHandle(hFileOut);

  end;

  UnmapViewOfFile(lpBaseAddressIn);

  CloseHandle(hFileMappingObjectIn);

  CloseHandle(hFileIn);

end;

function DecompressFile(lpFilename, lpOutputfile: String; dwCompression: DWORD = COMPRESSION_FORMAT_LZNT1): Boolean;

var

  hFileIn, hFileMappingObjectIn,

  hFileOut: THandle;

  dwFileSize, lpNumberOfBytesWritten: DWORD;

  lpBaseAddressIn, lpBuffer: Pointer;

begin

  Result := False;

  hFileIn := CreateFile(PChar(lpFilename), GENERIC_READ or GENERIC_WRITE, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_ALWAYS, 0, 0);

  if hFileIn = INVALID_HANDLE_VALUE then

    Exit;

  dwFileSize := GetFileSize(hFileIn, nil);

  hFileMappingObjectIn := CreateFileMapping(hFileIn, nil, PAGE_READWRITE, 0, 0, nil);

  lpBaseAddressIn := MapViewOfFile(hFileMappingObjectIn, FILE_MAP_READ or FILE_MAP_WRITE, 0, 0, 0);

  lpBuffer := DecompressMemory(lpBaseAddressIn, dwFileSize, dwCompression);

  hFileOut := CreateFile(PChar(lpOutputfile), GENERIC_READ or GENERIC_WRITE, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, CREATE_ALWAYS, 0, 0);

  if hFileOut <> INVALID_HANDLE_VALUE then

  begin

    WriteFile(hFileOut, lpBuffer^, dwFileSize, lpNumberOfBytesWritten, nil);

    CloseHandle(hFileOut);

  end;

  VirtualFree(lpBuffer, 0, MEM_RELEASE);

  UnmapViewOfFile(lpBaseAddressIn);

  CloseHandle(hFileMappingObjectIn);

  CloseHandle(hFileIn);

end;

end.