CRC: rationale and request for professional check

From: Daryle Walker (darylew_at_[hidden])
Date: 2001-02-14 00:04:58

I just posted version 2 of the CRC tool classes to the vault (as "crc.zip").
I was wondering if there is anyone who is expert in use CRCs around here.
If so, then could they check if my code is correct and usable in real-world
applications?

I have occasionally seen CRCs in encoding formats, like ZIP, gzip, binhex,
etc.  I've seen the code, and all I saw a bunch of similar funky loops with
bit operations and/or giant hexadecimal constant tables.  Worse, it was hard
figuring out which parts of the algorithm were general and which were
related to the parameters of the particular implementation (and how the
numbers related).  I was wondering if there was a way to express CRC
computation that:

1. has all the parameters easily factored out
2. can permit computers of differing parameters easily co-exist
3. has a (reasonably) compact code representation
4. is made from easy-to-understand code

I finally found some Internet documents that explained CRC stuff in
(somewhat) easy terms, and that's how I started.

-- 
Daryle Walker
Mac, Internet, and Video Game Junkie
darylew AT mac DOT com