I think you should roll your own whenever you feel you wish too and as far as this stuff about re-inventing the wheel.. well.. there are no wheels in programming. And you may come up with a better/cleaner way of doing something, or you may only improve your own spell casting level. I don't feel its over hubris, I think its just the right amount.
Besides, why load a whole module if you only need the small hash ripper from it?? Keep on keeping on. If it gets too weird then use the CGI module and come back to it later.
webadept