It seems to me the most logical thing to do is ask your boss if you can keep a knife at work or if he will supply one. If he won't oblige and you run into a situation where you need a knife, you can ask him to reconsider. If he won't, then you do the best you can.
I carry a knife everywhere everyday, but when I had to go into the courthouse the other day guess what...no knives allowed. I left it in my truck and went and did my business. You have a zero tolerance policy at school, so no knives...end of story. You won't be in school forever, so for now make do the best you can with the rules that are in place.