A83: Re: Ti uses MD5

To: <assembly-83@lists.ticalc.org>
Subject: A83: Re: Ti uses MD5
From: "David Phillips" <david@acz.org>
Date: Wed, 30 Aug 2000 16:29:18 -0600
References: <000101c012aa$2ca31740$3f08e4d5@cygnus-h1>
Reply-To: assembly-83@lists.ticalc.org


I'm not one to argue since I haven't spent hours dissassembling the rom, but
this doesn't mean that it necessarily uses MD5.  They could be using a
modified version of the algorithm, or a completely different algorithm
altogether.  MD5 is a bear, and I would hate to have to implement it in z80.
If you want to be certain that it uses MD5, I suggest comparing data and
generated hashes with a known MD5.  I wrote a script that might be useful
while testing, and if you want I can send you the C code for calculating
MD5.  It's the same as the reference implementation from the RFC, but I made
it much easier to use.

http://david.acz.org/md5.php

> I can't believe what I just found, in the previous RFC I referred to, it
is
> explained that four 32 bit registers are used to compute a MD5 fingerprint
> and that they are initialized to the following values:
>
>           word A: 01 23 45 67
>           word B: 89 AB CD ef
>           word C: fe dc ba 98
>           word D: 76 54 32 10
>
> I actually found those four values aligned at page 1F. Which means that
the
> certification process uses MD5 message digests.

References:

A83: Ti uses MD5

From: "Solignac Julien" <x1cygnus@online.fr>