void* sspi_SecureHandleGetLowerPointer(SecHandle* handle)
{
	void* pointer;

	if (!handle)
		return NULL;

	pointer = (void*) ~((size_t) handle->dwLower);

	return pointer;
}
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.