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binary



Joined: 10 Oct 2009
Posts: 29
binary 27 Dec 2017, 10:21
I have a dll compiled with fasm and a c++ console program. When I load the function from the dll file I receive the error 127(0x7F) The specified procedure could not be found.

Dll code:
Code:
     ; DLL creation example

format PE GUI 4.0 DLL
entry DllEntryPoint

include 'win32a.inc'

section '.code' code readable executable

proc DllEntryPoint hinstDLL,fdwReason,lpvReserved
        mov     eax,123456
        ret
endp

proc Hello
       mov     eax,12345
       ret
endp

; VOID ShowErrorMessage(HWND hWnd,DWORD dwError);

proc ShowErrorMessage hWnd,dwError
  local lpBuffer:DWORD
        lea     eax,[lpBuffer]
        invoke  FormatMessage,FORMAT_MESSAGE_ALLOCATE_BUFFER+FORMAT_MESSAGE_FROM_SYSTEM,0,[dwError],LANG_NEUTRAL,eax,0,0
        invoke  MessageBox,[hWnd],[lpBuffer],NULL,MB_ICONERROR+MB_OK
        invoke  LocalFree,[lpBuffer]
        ret
endp

; VOID ShowLastError(HWND hWnd);

proc ShowLastError hWnd
        invoke  GetLastError
        stdcall ShowErrorMessage,[hWnd],eax
        ret
endp

section '.idata' import data readable writeable

  library kernel,'KERNEL32.DLL',\
          user,'USER32.DLL'

  import kernel,\
         GetLastError,'GetLastError',\
         SetLastError,'SetLastError',\
         FormatMessage,'FormatMessageA',\
         LocalFree,'LocalFree'

  import user,\
         MessageBox,'MessageBoxA'

section '.edata' export data readable

  export 'ERRORMSG.DLL',\
         ShowErrorMessage,'ShowErrorMessage',\
         ShowLastError,'ShowLastError'

section '.reloc' fixups data discardable

    


C++ code:
Code:
#include <windows.h>
#include <iostream>

using namespace std;
typedef int (__stdcall *f_funci)();

int main()
{
 HINSTANCE hGetProcIDDLL = LoadLibrary("dll.dll");

  if (!hGetProcIDDLL) {
    cout << "could not load the dynamic library" << endl;
    return EXIT_FAILURE;
  }

  // resolve function address here
  f_funci funci = (f_funci)GetProcAddress(hGetProcIDDLL, "Hello");
  if (!funci) {

    cout << "could not locate the function " << funci << GetLastError()<< endl;
    return EXIT_FAILURE;
  }

  cout << "funci() returned " << funci() << endl;


    return 0;
}    
Post 27 Dec 2017, 10:21
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 20445
Location: In your JS exploiting you and your system
revolution 27 Dec 2017, 10:41
You need to include the name "Hello" in the exports list.
Code:
  export 'ERRORMSG.DLL',\
         Hello,'Hello',\
         ShowErrorMessage,'ShowErrorMessage',\
         ShowLastError,'ShowLastError'    
Post 27 Dec 2017, 10:41
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binary



Joined: 10 Oct 2009
Posts: 29
binary 27 Dec 2017, 13:34
Thank you
Post 27 Dec 2017, 13:34
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