Xref: utzoo comp.sys.mac.programmer:1924 comp.sys.mac:19010
Path: utzoo!utgpu!attcan!uunet!munnari!otc!metro!basser!usage!ccadfa!csadfa!lpb
From: lpb@csadfa.oz (Lawrie Brown)
Newsgroups: comp.sys.mac.programmer,comp.sys.mac
Subject: Wanted - CRC polynomial used in macbinary header
Keywords: macbinary crc polynomial code
Message-ID: <1553@csadfa.oz>
Date: 2 Aug 88 23:24:17 GMT
Organization: Dept. of Computer Science, University College, UNSW, ADFA, Canberra, Australia
Lines: 25


Can someone please tell which CRC polynomial is used in the MacBinary II
header, preferably with some sample code calculating it. The documentation
I have makes no mention of how the CRC is found.

I'm using the MacBinary format in my DES encryption program, to pack the
file into a single stream before encrypting on the fly. It works quite
nicely apart from the aforementioned CRC. I can encrypt on the Mac,
download to a Unix beasty, decrypt, and get a MacBinary file that is
byte for byte identical to the original which was downloaded directly 
using Freeterm's MacBinary mode (apart from the ***expletive deleted*** CRC).

So, any help would be much appreciated.

Thanks
Lawrie.

----
Mr. Lawrie Brown,		Phone ISD:   +61 62 688170   Fax: +61 62 688581
Dept. Computer Science,		Telex:	     ADFADM AA62030
University College, UNSW,	CSNET:	lpb@cs.adfa.oz.au
Aust. Defence Force Academy,	UUCP:	...!uunet!munnari!cs.adfa.oz.au!lpb
Canberra. ACT 2600.		ARPA:	lpb%cs.adfa.oz.au@uunet.uu.net
AUSTRALIA			JANET:	lpb@au.oz.adfa.cs
				Other Gateways:	see CACM 29(10) Oct. 1986