The Key To Success

To secure me, you need no key 

I don't let anyone, even my master come in freely

Opening me requires more than shaking my hand

Insert your magic wand and you shall proceed. 

Enter the Exit

Push to enter, pull to leave
Door still opens whether you press or heave.
Crawl, walk or run will allow to enter and never fall
But running into a sliding door is like charging a brick wall.