[Native/C] Reading keyboard input

I'm writing a native application in C (/SUBSYSTEM:NATIVE) and need to check if a key combination was pressed.

It works, but it only captures the first packet of keyboard input data (i.e only first key pressed), however I need to check 4 keys simultaneously.

Here's the code I used for testing:

UNICODE_STRING NtReadKeyboardInput()
{
  LARGE_INTEGER Interval;
  UNICODE_STRING input;
  UNICODE_STRING keyboardDeviceName;
  OBJECT_ATTRIBUTES objectAttributes;
  IO_STATUS_BLOCK ioStatusBlock;
  WCHAR show[200];
  NTSTATUS status;
  HANDLE keyboardHandle;
  UNICODE_STRING message;
  KEYBOARD_INPUT_DATA inputData[3]; 
  USHORT usMakeCode;
  USHORT usFlags;
//-----------------      "\\Device\\KeyboardClass0"      ------------------------
  NtPrint(L"\nReadKeyboardInput Start"); 
  NtSleep2();
//--------------------------------------------------------------------
  RtlInitUnicodeString(&keyboardDeviceName, L"\\Device\\KeyboardClass0");
  InitializeObjectAttributes(&objectAttributes, &keyboardDeviceName, OBJ_CASE_INSENSITIVE, NULL, NULL);
  memset(&ioStatusBlock, 0, sizeof(ioStatusBlock));
//-----------------------------   NtCreateFile   ---------------------------------
  status = NtCreateFile(&keyboardHandle,                 
                        GENERIC_READ|FILE_READ_ATTRIBUTES,
                        &objectAttributes,
                        &ioStatusBlock,
                        0,
                        FILE_ATTRIBUTE_NORMAL,
                        0,
                        FILE_OPEN,
                        FILE_DIRECTORY_FILE,
                        0,
                        0);  if (status == STATUS_SUCCESS) 
  {
     HANDLE hEvent;
     NtPrint(L"\nKeyboard created"); 
     NtSleep2();
//-------------------------------------------------------------------------------
     InitializeObjectAttributes(&objectAttributes, NULL, 0, NULL, NULL);
     status = NtCreateEvent(&hEvent,  
			   STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x03,
                           &objectAttributes,
                           NotificationEvent,
                           FALSE);    if (status == STATUS_SUCCESS) 
    {
      static char buffer[0x78];
      int i;
      static LARGE_INTEGER byteOffset;
      byteOffset.LowPart = 0;
      byteOffset.HighPart = 0;
      memset(&ioStatusBlock, 0, sizeof(ioStatusBlock));      NtPrint(L"\nEvent created");
      NtSleep2();
//------------------------------------------------------------------------------
      status = NtReadFile(keyboardHandle,
                          hEvent,  
                          NULL,
			  NULL,
                          &ioStatusBlock,
                          &inputData, 
                          sizeof(KEYBOARD_INPUT_DATA)*4, 
                          &byteOffset,
                          NULL);      if (status == STATUS_PENDING) 
      {
	int i;
	NtPrint(L"\nPlease Press any key...");        for (i=0; i<6; i++) 
        {
         // NtDisplayString(&message);//**************************
	  Interval.QuadPart = 2 * 10000 * 1000;
	  Interval.QuadPart = -Interval.QuadPart;
	  NtDelayExecution(FALSE, &Interval);
	  status = NtWaitForSingleObject(hEvent, TRUE, &Interval);           if (status == STATUS_SUCCESS)
          {
	    NtPrint(L"Success\n"); 
	    NtSleep2();	    usMakeCode = inputData[0].MakeCode;
	    usFlags = inputData[0].Flags;
	    swprintf(show, L"Key 0 MakeCode : %x, Flags : %x\n", usMakeCode, usFlags);
	    NtPrint(show);
	    NtSleep2();	    usMakeCode = inputData[1].MakeCode;
	    usFlags = inputData[1].Flags;
	    swprintf(show, L"Key 1 MakeCode : %x, Flags : %x\n", usMakeCode, usFlags);
	    NtPrint(show);
	    NtSleep2();	    usMakeCode = inputData[2].MakeCode;
	    usFlags = inputData[2].Flags;
	    swprintf(show, L"Key 2 MakeCode : %x, Flags : %x\n", usMakeCode, usFlags);
	    NtPrint(show);
	    NtSleep2();	    usMakeCode = inputData[3].MakeCode;
	    usFlags = inputData[3].Flags;
	    swprintf(show, L"Key 3 MakeCode : %x, Flags : %x\n", usMakeCode, usFlags);
	    NtPrint(show);
	    NtSleep2();
            break;
          }          else if (status == STATUS_TIMEOUT)
          {
	    swprintf(show,L"\nAttempt %d to get keyboard input, please press a key...\n",i+1);
	    NtPrint(show);
	    NtSleep2();
	    NtPrint(L"STATUS_TIMEOUT\n"); 
	    NtSleep2();	    if (i == 5) {
	      RtlInitUnicodeString(&message, L"\n\nFailed! You did not press any key.\n");
	      input = message;
	    }          }
        }        if (status != STATUS_SUCCESS) 
        {
            NtPrint(L"STATUS_UNSUCCESS"); 
	    NtSleep2();
        }
        else
        {
            RtlInitUnicodeString(&message, L"\n\nKey was pressed!!!\n");
            input = message;
        }      }
      else
      {
//--------------------------------------------------
		NtPrint(L"\nRead failed:"); 
		NtSleep2();
/////////////////////////////////////////////////
      }
      NtClose(hEvent);
    }
    else
    {
      NtPrint(L"\nCreate Event failed:");
    }
    NtClose(keyboardHandle);
  } 
  else 
  {
//-------------------------------------------------------------------
	NtPrint(L"\nUnable to open keyboard device:"); 
	NtSleep2();
//-------------------------------------------------------------------------
  } return input;}

Key 1,2 and 3 MakeCode is always zero and flags is some strange value.

NtPrint is a function I made that initializes the unicode string and calls NtDisplayString.

NtSleep2 calls NtDelayExecution with Interval of 2 seconds.

Anyway, this is irrelevant. What is important is why NtReadFile only reads the first pressed key?

It's a PS/2 keyboard it reads from.

Edited August 6, 201114 yr by Saduff