Rights, by definition exist outside of any law. They are yours because you exist. It is up to you to enforce and defend your rights. When you are able to do this, then you exist as sovereign over your domain and your domain stretches as far as you are able to enforce your rights.
See the contradiction there, "Rights" are only yours if you can "Enforce" them... this is a law of the jungle.
A contract is a means of enforcing your rights. You recognize that your fellow man also wants the same thing you want and thus you agree where the boundary is. Without this agreement you are left to fight to establish your rights.