Realign PE

Post date: Jun 29, 2010 3:03:39 AM

After adding a section, you could use this unit, written by steve10120 of ic0de.org to realign your PE file to make it smaller. The unit also rebuilds section headers.

{ uReAlignPE

Author: steve10120

Description: Realign last section and rebuild section headers.

Website: http://www.ic0de.org

History: First try

Thanks: Cobein - mRealignPE.

CFF Explorer - I ripped(or tried to) your Realign PE Headers :P.

Todo:

Tidy RealignPEFromBytes

Total custom section realignment

unit uReAlignPE;

interface

uses Windows, SysUtils;

function RealignPEFromFile(sFile:string; sDestFile:string):Boolean;

implementation

type

TByteArray = array of Byte;

procedure Move(Destination, Source: Pointer; dLength:DWORD);

begin

CopyMemory(Destination, Source, dLength);

end;

function Align(dwValue:DWORD; dwAlign:DWORD):DWORD;

begin

if dwAlign <> 0 then

begin

if dwValue mod dwAlign <> 0 then

begin

Result := (dwValue + dwAlign) - (dwValue mod dwAlign);

Exit;

end;

end;

Result := dwValue;

end;

function RebuildHeaders(bFile:TByteArray):Boolean;

var

IDH: TImageDosHeader;

INH: TImageNtHeaders;

ISH: TImageSectionHeader;

i: integer;

ImageSize: DWORD;

SecName: array[0..7] of Char;

begin

Result := FALSE;

try

Move(@IDH, @bFile[0], 64);

if IDH.e_magic = IMAGE_DOS_SIGNATURE then

begin

Move(@INH, @bFile[IDH._lfanew], 248);

if INH.Signature = IMAGE_NT_SIGNATURE then

begin

Move(@ISH, @bFile[IDH._lfanew + 248], 40);

ImageSize := ISH.VirtualAddress;

for i := 0 to INH.FileHeader.NumberOfSections - 1 do

begin

Move(@ISH, @bFile[IDH._lfanew + 248 + (i * 40)], 40);

if i < INH.FileHeader.NumberOfSections - 1 then

begin

Move(@SecName[0], @ISH.Name[0], 8);

ISH.Misc.VirtualSize := Align(ISH.Misc.VirtualSize, INH.OptionalHeader.SectionAlignment);

ISH.SizeOfRawData := Align(ISH.SizeOfRawData, INH.OptionalHeader.FileAlignment);

if (SecName <> '.tls') and (SecName <> 'BSS') then

begin

if ISH.SizeOfRawData = 0 then

ISH.SizeOfRawData := ISH.Misc.VirtualSize;

if ISH.PointerToRawData = 0 then

ISH.PointerToRawData := ISH.VirtualAddress;

end;

end;

ImageSize := ImageSize + ISH.Misc.VirtualSize;

Move(@bFile[IDH._lfanew + 248 + (i * 40)], @ISH, 40);

end;

INH.OptionalHeader.SizeOfImage := ImageSize;

Move(@bFile[IDH._lfanew], @INH, 248);

Result := TRUE;

end;

end;

except

on E: Exception do

MessageBox(0, PChar('Error: ' + E.ClassName + #13#10#13#10'Message: ' + E.Message), PChar('Error'), MB_ICONHAND or MB_ICONSTOP or MB_ICONERROR);

end;

end;

function RealignPEFromBytes(bFile: TByteArray; var bResult:TByteArray):Boolean;

var

dSize: DWORD;

dLastSectPos: DWORD;

IDH: TImageDosHeader;

INH: TImageNtHeaders;

ISH: TImageSectionHeader;

dDataSize: DWORD;

dAlign: DWORD;

bExtraData: TByteArray;

begin

Result := FALSE;

try

Move(@IDH, @bFile[0], 64);

if IDH.e_magic = IMAGE_DOS_SIGNATURE then

begin

Move(@INH, @bFile[IDH._lfanew], 248);

if INH.Signature = IMAGE_NT_SIGNATURE then

begin

dLastSectPos := IDH._lfanew + 248 + ((INH.FileHeader.NumberOfSections - 1) * 40);

Move(@ISH, @bFile[dLastSectPos], 40);

dSize := ISH.SizeOfRawData;

dDataSize := Length(bFile) - ISH.SizeOfRawData - ISH.PointerToRawData;

if (dSize + dDataSize) mod INH.OptionalHeader.SectionAlignment = 0 then

begin

ISH.SizeOfRawData := ISH.SizeOfRawData + dSize;

Move(@bFile[dLastSectPos], @ISH, 40);

end

else

begin

SetLength(bExtraData, dDataSize);

Move(@bExtraData[0], @bFile[Length(bFile) - dDataSize], dDataSize);

SetLength(bFile, Length(bFile) - dDataSize);

dAlign := Align(dDataSize, INH.OptionalHeader.SectionAlignment);

SetLength(bFile, Length(bFile) + dAlign);

Move(@bFile[Length(bFile) - dDataSize], @bExtraData[0], dDataSize);

ISH.Misc.VirtualSize := ISH.Misc.VirtualSize + dAlign;

ISH.SizeOfRawData := ISH.SizeOfRawData + dAlign;

Move(@bFile[dLastSectPos], @ISH, 40);

Result := TRUE;

end;

RebuildHeaders(bFile);

bResult := bFile;

SetLength(bFile, 0);

end;

end;

except

on E: Exception do

MessageBox(0, PChar('Error: ' + E.ClassName + #13#10#13#10'Message: ' + E.Message), PChar('Error'), MB_ICONHAND or MB_ICONSTOP or MB_ICONERROR);

end;

end;

function RealignPEFromFile(sFile:string; sDestFile:string):Boolean;

var

bFile: TByteArray;

hFile: THandle;

dSize: DWORD;

dRead: DWORD;

dWritten: DWORD;

bResult: TByteArray;

begin

Result := FALSE;

hFile := CreateFile(PChar(sFile), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, 0, 0);

if hFile <> INVALID_HANDLE_VALUE then

begin

dSize := GetFileSize(hFile, nil);

SetLength(bFile, dSize);

SetFilePointer(hFile, 0, nil, FILE_BEGIN);

ReadFile(hFile, bFile[0], dSize, dRead, nil);

CloseHandle(hFile);

if RealignPEFromBytes(bFile, bResult) then

begin

if sDestFile = '' then

sDestFile := sFile;

hFile := CreateFile(PChar(sDestFile), GENERIC_WRITE, FILE_SHARE_WRITE, nil, CREATE_ALWAYS, 0, 0);

if hFile <> INVALID_HANDLE_VALUE then

begin

SetFilePointer(hFile, 0, nil, FILE_BEGIN);

WriteFile(hFile, bResult[0], Length(bResult), dWritten, nil);

CloseHandle(hFile);

Result := TRUE;

end;

end;

end;

end;

end.