I have a couple of models that are both "password" centric models. They don't belong in a single inheritance table and need to be tracked in separate tables. Logically they are both completely different types of models, but both have password and password confirmation tracking. They also use the same business logic for the password rules such as number of characters in the password etc.
What's the best way in Rails to make sure that the code is DRY and not being repeated in Rails? What should I look into doing?