get the default string using EvtFormatMessage - c++

Question

I am trying to get the base string in the DLL using EvtFormatMessage but no matter what I do its not working. The windows help page made it sound like you can use the values and valuecount parameters to change the default behavior but when I change them nothing is printed.
Another attempt I made was to go through the publishers metadata and match it with the correct eventId and version but the EvtOpenEventMetadatEnum has no items for it to iterate through for all events publishers. It works for time change events but not for other events.
This is the code I have to return the message string. hMetadata is the publisher metadata and hEvent is the event metadata
LPWSTR GetMessageString(EVT_HANDLE hMetadata, EVT_HANDLE hEvent, EVT_FORMAT_MESSAGE_FLAGS FormatId, DWORD MsgID)
{
LPWSTR pBuffer = NULL;
DWORD dwBufferSize = 0;
DWORD dwBufferUsed = 0;
DWORD status = ERROR_SUCCESS;
if (!fpEvtFormatMessage(hMetadata, hEvent, MsgID, 0, NULL, FormatId, dwBufferSize, pBuffer, &dwBufferUsed))
{
status = GetLastError();
if (ERROR_INSUFFICIENT_BUFFER == status)
{
// An event can contain one or more keywords. The function returns keywords
// as a list of keyword strings. To process the list, you need to know the
// size of the buffer, so you know when you have read the last string, or you
// can terminate the list of strings with a second null terminator character
// as this example does.
if ((EvtFormatMessageKeyword == FormatId))
pBuffer[dwBufferSize - 1] = L'\0';
else
dwBufferSize = dwBufferUsed;
pBuffer = (LPWSTR)malloc(dwBufferSize * sizeof(WCHAR));
if (pBuffer)
{
fpEvtFormatMessage(hMetadata, hEvent, MsgID, 0, NULL, FormatId, dwBufferSize, pBuffer, &dwBufferUsed);
// Add the second null terminator character.
if ((EvtFormatMessageKeyword == FormatId))
pBuffer[dwBufferUsed - 1] = L'\0';
}
else
{
TRACE5(_T("malloc failed\n"));
}
}
else if (ERROR_EVT_MESSAGE_NOT_FOUND == status || ERROR_EVT_MESSAGE_ID_NOT_FOUND == status)
;
else
{
TRACE5(_T("EvtFormatMessage failed with %u\n"), status);
}
}
This is the code that is supposed to match the event I have with the template event in the dll
hEvents = fpEvtOpenEventMetadataEnum(g_hMetadata, 0);
if (NULL == hEvents)
{
TRACE5(_T("EvtOpenEventMetadataEnum failed with %lu\n"), GetLastError());
goto cleanup;
}
// Enumerate the events and print each event's metadata.
while (run)
{
hEvent = fpEvtNextEventMetadata(hEvents, 0);
if (NULL == hEvent)
{
if (ERROR_NO_MORE_ITEMS != (status = GetLastError()))
{
TRACE5(_T("EvtNextEventMetadata failed with %lu\n"), status);
}
break;
}
msgId = getEventID(g_hMetadata, hEvent, &tempVersion);
if (dwMsgID == msgId && tempVersion == version) {
PEVT_VARIANT pProperty = NULL; // Contains a metadata value
PEVT_VARIANT pTemp = NULL;
DWORD dwBufferSize = 0;
DWORD dwBufferUsed = 0;
DWORD status2 = ERROR_SUCCESS;
if (!fpEvtGetEventMetadataProperty(hEvent, EventMetadataEventMessageID, 0, dwBufferSize, pProperty, &dwBufferUsed))
{
status2 = GetLastError();
if (ERROR_INSUFFICIENT_BUFFER == status2)
{
dwBufferSize = dwBufferUsed;
pTemp = (PEVT_VARIANT)realloc(pProperty, dwBufferSize);
if (pTemp)
{
pProperty = pTemp;
pTemp = NULL;
fpEvtGetEventMetadataProperty(hEvent, EventMetadataEventMessageID, 0, dwBufferSize, pProperty, &dwBufferUsed);
}
else
{
TRACE5(_T("realloc failed\n"));
status2 = ERROR_OUTOFMEMORY;
goto cleanup;
}
}
if (ERROR_SUCCESS != (status2 = GetLastError()))
{
TRACE5(_T("EvtGetEventMetadataProperty failed with %d\n"), GetLastError());
goto cleanup;
}
}
if (-1 == pProperty->UInt32Val)
{
*pStrNonExpLibMsg = "Message string: \n";
}
else
{
*pStrNonExpLibMsg = GetMessageString(g_hMetadata, NULL, EvtFormatMessageId, pProperty->UInt32Val);
if (pMessage)
{
free(pMessage);
}
}
run = false;
break;
}
fpEvtClose(hEvent);
hEvent = NULL;
}
cleanup:
if (hEvents)
fpEvtClose(hEvents);
if (hEvent)
fpEvtClose(hEvent);
return status;
}
DWORD getEventID(EVT_HANDLE g_hMetadata, EVT_HANDLE hEvent, DWORD *evtVersion)
{
PEVT_VARIANT pProperty = NULL; // Contains a metadata value
PEVT_VARIANT pTemp = NULL;
DWORD dwBufferSize = 0;
DWORD dwBufferUsed = 0;
DWORD status = ERROR_SUCCESS;
DWORD retValue = NULL;
// Get the specified metadata property. If the pProperty buffer is not big enough, reallocate the buffer.
for (int i = 0; i < 2; i++)
{
if (!fpEvtGetEventMetadataProperty(hEvent, (EVT_EVENT_METADATA_PROPERTY_ID)i, 0, dwBufferSize, pProperty, &dwBufferUsed))
{
status = GetLastError();
if (ERROR_INSUFFICIENT_BUFFER == status)
{
dwBufferSize = dwBufferUsed;
pTemp = (PEVT_VARIANT)realloc(pProperty, dwBufferSize);
if (pTemp)
{
pProperty = pTemp;
pTemp = NULL;
fpEvtGetEventMetadataProperty(hEvent, (EVT_EVENT_METADATA_PROPERTY_ID)i, 0, dwBufferSize, pProperty, &dwBufferUsed);
}
else
{
TRACE5(_T("realloc failed\n"));
status = ERROR_OUTOFMEMORY;
goto cleanup;
}
}
if (ERROR_SUCCESS != (status = GetLastError()))
{
TRACE5(_T("EvtGetEventMetadataProperty failed with %d\n"), GetLastError());
goto cleanup;
}
}
if (i == 0)
{
retValue = pProperty->UInt32Val;
}
else
{
*evtVersion = pProperty->UInt32Val;
}
RtlZeroMemory(pProperty, dwBufferUsed);
}