3.3V Dallas one-wire bus on a 5V system

Use standard bidirectional a level shifter like this:

R1 and R2 ARE the pull-up resistors. The MOSFET a small signal one like the BSS138.

The boards as sold by Adafruit, Sparkfiun and the rest of the usual suspects use 10k resistors. Add a 10k in parallel and you're within spec for the one wire bus.