[Delphi] Check if ASLR is enabled

[Agmcz]

Check if ASLR is enabled.

{************************************
* Coded by Agmcz                    *
* Hints by naquadria                *
* Date: 2018-01-07                  *
************************************}

unit uCheckASLR;

interface

uses
  Windows;

function CheckASLR(const FileName: string): Boolean;

implementation

const
  IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE = $0040;
  IMAGE_DIRECTORY_ENTRY_BASERELOC = 5;

function CheckASLR(const FileName: string): Boolean;
var
  hFile: THandle;
  hMapping: DWORD;
  pMap: Pointer;
  dwSize: DWORD;
  IDH: PImageDosHeader;
  INH: PImageNtHeaders;
  ISH: PImageSectionHeader;
  n: Word;
  dwRelocAddr, dwRelocSize: DWORD;
begin
  Result := False;
  hFile := CreateFile(PChar(FileName), GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0);
  if hFile <> INVALID_HANDLE_VALUE then
  begin
    dwSize := GetFileSize(hFile, nil);
    hMapping := CreateFileMapping(hFile, nil, PAGE_READONLY, 0, dwSize, nil);
    if hMapping <> 0 then
    begin
      pMap := MapViewOfFile(hMapping, FILE_MAP_READ, 0, 0, 0);
      if pMap <> nil then
      begin
        IDH := PImageDosHeader(pMap);
        if IDH.e_magic = IMAGE_DOS_SIGNATURE then
        begin
          INH := PImageNtHeaders(DWORD(pMap) + LongWord(IDH._lfanew));
          if INH.Signature = IMAGE_NT_SIGNATURE then
          begin
            if (INH.OptionalHeader.DllCharacteristics and IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE) = IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE then
            begin
              ISH := PImageSectionHeader(DWORD(pMap) + LongWord(IDH._lfanew) + SizeOf(DWORD) + SizeOf(INH.FileHeader) + INH.FileHeader.SizeOfOptionalHeader);
              dwRelocAddr := INH.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC].VirtualAddress;
              dwRelocSize := INH.OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC].Size;
              if (dwRelocAddr <> 0) and (dwRelocSize <> 0) then
              begin
                for n := 0 to INH.FileHeader.NumberOfSections - 1 do
                begin
                  if ISH.VirtualAddress = dwRelocAddr then
                  begin
                    if (ISH.Misc.VirtualSize <> 0) and  (ISH.PointerToRawData <> 0) and (ISH.SizeOfRawData <> 0) then
                      Result := True;
                    Break;
                  end;
                  Inc(ISH);
                end;
              end;
            end;
          end;
        end;
        UnmapViewOfFile(pMap);
      end;
      CloseHandle(hMapping);
    end;
    CloseHandle(hFile);
  end;
end;

end.