who is the real tobi?

I didn't realize that it was confirmed that he only had one eye. I just thought that he chose to reveal only one eye. Furthermore, because of that safeguard that Itachi left to make sure that he doesn't approach Sasuke and live. But I'm pretty sure that it's Madara since that was confirmed in the manga. I just wonder if everytime sasuke sees his sharingan if it's going to trigger that attack. it probably will since he had decided to put back on his mask, but still I would like that to be confirmed.