Delphi-PRAXiS - DLL aus RES in Speicher laden und direkt verwenden.

Hallo DP,

in diesem

Thread haben Himitsu und ich schon das Thema besprochen.

Es geht darum eine DLL direkt aus einer RES in den Speicher zu laden und dort zu verwenden. Der Umweg über das Filesystem würde also entfallen.

Hier habe ich das Thema gefunden und mal ausprobiert.

Es funktioniert fast. :-D

Mit der libmysql.dll mit der ich es getestet habe, schafft er die ersten paar Funktionen aber dann scheppert's.

Code:

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Zugriffsverletzung bei Adresse 776D8C19 in Modul 'ntdll.dll'. Schreiben von Adresse 00000014.

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Ich habe folgenden Code aus obiger Quelle verwendet, der ja angeblich D2010-tauglich sein soll.

Delphi-Quellcode:

			function BTMemoryLoadLibary(fp_data: Pointer;

  const f_size: int64): PBTMemoryModule;

var

  lp_result: PBTMemoryModule;

  l_dos_header: TImageDosHeader;

  l_old_header: TImageNtHeaders;

  l_code, l_headers: Pointer;

  l_locationdelta: Cardinal;

  lp_DllEntry: PDllEntryProc;

  l_successfull: boolean;

begin

  lp_result := nil;

  Result := nil;

  try

    CopyMemory(@l_dos_header, fp_data, SizeOf(_IMAGE_DOS_HEADER));

    if (l_dos_header.e_magic <> IMAGE_DOS_SIGNATURE) then

    begin

      lastErrStr := 'BTMemoryLoadLibary: dll dos header is not valid';

      exit;

    end;

    CopyMemory(@l_old_header, IncF(fp_data, l_dos_header._lfanew),

      SizeOf(_IMAGE_NT_HEADERS));

    if l_old_header.Signature <> IMAGE_NT_SIGNATURE then

    begin

      lastErrStr := 'BTMemoryLoadLibary: IMAGE_NT_SIGNATURE is not valid';

      exit;

    end;

    // reserve memory for image of library

    l_code := VirtualAlloc(Pointer(l_old_header.OptionalHeader.ImageBase),

      l_old_header.OptionalHeader.SizeOfImage, MEM_RESERVE, PAGE_READWRITE);

    if l_code = nil then

      // try to allocate memory at arbitrary position

      l_code := VirtualAlloc(nil, l_old_header.OptionalHeader.SizeOfImage,

        MEM_RESERVE, PAGE_READWRITE);

    if l_code = nil then

    begin

      lastErrStr := 'BTMemoryLoadLibary: VirtualAlloc failed';

      exit;

    end;

    // alloc space for the result record

    lp_result := PBTMemoryModule(HeapAlloc(GetProcessHeap(), 0,

        SizeOf(TBTMemoryModule)));

    lp_result^.codeBase := l_code;

    lp_result^.numModules := 0;

    lp_result^.modules := nil;

    lp_result^.initialized := false;

    // xy: is it correct to commit the complete memory region at once?

    // calling DllEntry raises an exception if we don't...

    VirtualAlloc(l_code, l_old_header.OptionalHeader.SizeOfImage, MEM_COMMIT,

      PAGE_READWRITE);

    // commit memory for headers

    l_headers := VirtualAlloc(l_code,

      l_old_header.OptionalHeader.SizeOfHeaders, MEM_COMMIT, PAGE_READWRITE);

    // copy PE header to code

    CopyMemory(l_headers, fp_data,

      (UInt64(l_dos_header._lfanew)

          + l_old_header.OptionalHeader.SizeOfHeaders));

    lp_result^.headers := PImageNtHeaders

      (UInt64(l_headers) + l_dos_header._lfanew);

    // update position

    lp_result^.headers^.OptionalHeader.ImageBase := UInt64(l_code);

    // copy sections from DLL file block to new memory location

    CopySections(fp_data, l_old_header, lp_result);

    // adjust base address of imported data

    l_locationdelta := Cardinal

      (UInt64(l_code) - l_old_header.OptionalHeader.ImageBase);

    if l_locationdelta <> 0 then

      PerformBaseRelocation(lp_result, l_locationdelta);

    // load required dlls and adjust function table of imports

    if not BuildImportTable(lp_result) then

    begin

      lastErrStr := lastErrStr + ' BTMemoryLoadLibary: BuildImportTable failed';

      Abort;

    end;

    // mark memory pages depending on section headers and release

    // sections that are marked as "discardable"

    FinalizeSections(lp_result);

    // get entry point of loaded library

    if (lp_result^.headers^.OptionalHeader.AddressOfEntryPoint) <> 0 then

    begin

      lp_DllEntry := Pointer

        (UInt64(l_code)

          + lp_result^.headers^.OptionalHeader.AddressOfEntryPoint);

      if lp_DllEntry = nil then

      begin

        lastErrStr := 'BTMemoryLoadLibary: Get DLLEntyPoint failed';

        Abort;

      end;

      l_successfull := TDllEntryProc(lp_DllEntry)(UInt64(l_code),

        DLL_PROCESS_ATTACH, nil);

      if not l_successfull then

      begin

        lastErrStr := 'BTMemoryLoadLibary: Can''t attach library';

        Abort;

      end;

      lp_result^.initialized := true;

    end;

  except

    BTMemoryFreeLibrary(lp_result);

    exit;

  end;

  Result := lp_result;

end;

function BTMemoryGetProcAddress(fp_module: PBTMemoryModule;

  const fp_name: PChar): Pointer;

var

  l_idx: Integer;

  l_i: DWORD;

  l_nameRef: PDWORD;

  l_ordinal: PWord;

  l_exports: PImageExportDirectory;

  l_directory: PImageDataDirectory;

begin

  Result := nil;

  l_idx := -1;

  l_directory := GetHeaderDictionary(fp_module, IMAGE_DIRECTORY_ENTRY_EXPORT);

  if l_directory^.Size = 0 then

  begin

    lastErrStr := 'BTMemoryGetProcAddress: no export table found';

    exit;

  end;

  l_exports := IncF(fp_module^.codeBase, l_directory^.VirtualAddress);

  if ((l_exports^.NumberOfNames = 0) or (l_exports^.NumberOfFunctions = 0)) then

  begin

    lastErrStr := 'BTMemoryGetProcAddress: DLL doesn''t export anything';

    exit;

  end;

  // search function name in list of exported names

  l_nameRef := IncF(fp_module^.codeBase, l_exports^.AddressOfNames);

  l_ordinal := IncF(fp_module^.codeBase, l_exports^.ADDressOfNameOrdinals);

  for l_i := 0 to l_exports^.NumberOfNames - 1 do

  begin

    if StrComp(fp_name, PAnsiCharToPChar(IncF(fp_module^.codeBase, l_nameRef^))

      ) = 0 then

    begin

      l_idx := l_ordinal^;

      break;

    end;

    Inc(l_nameRef);

    Inc(l_ordinal);

  end;

  if (l_idx = -1) then

  begin

    lastErrStr := 'BTMemoryGetProcAddress: exported symbol not found';

    exit;

  end;

  if (UInt64(l_idx) > l_exports^.NumberOfFunctions - 1) then

  begin

    lastErrStr :=

      'BTMemoryGetProcAddress: name <-> ordinal number don''t match';

    exit;

  end;

  // AddressOfFunctions contains the RVAs to the "real" functions

  Result := IncF(fp_module^.codeBase,

    PUInt64(IncF(fp_module^.codeBase, IncF(l_exports^.AddressOfFunctions,

          l_idx * 4)))^);

end;

Zum Debugging: Die AV kommt bei mir bei mysql_real_connect, es wurden also schon einige Funktionen erfolgreich durchlaufen (mysql_get_client_version, mysql_init, mysql_ssl_set). mysql_real_connect wird aber von BTMemoryGetProcAddress auch noch gefunden. Erst beim Aufruf von mysql_real_connect passiert's.

Hat jemand eine funktionierende Variante oder sieht einen offensichtlichen Fehler im Code?

Grüße,
Uwe

P.S.: Hat sich erledigt. Jetzt funktioniert es. ;)