john-users - Re: Using john des routines for 3des (or straight des) cracking

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Date: Thu, 1 Sep 2005 15:27:13 +0200
From: dvorak <dvorak@...all.nl>
To: john-users@...ts.openwall.com
Subject: Re: Using john des routines for 3des (or straight des) cracking

Some more questions:

- Is there a reason in the LM cracker for setting the plain text
  everytime again? I see that the storage space is re-used to safe
  temporary values for the calculations, is this for cache reasons or
  merily to prevent having to write rounds(8) number of different s1..s8
  blocks ? Or is the resetting an insignificant portion of the time.

- Is it correct that the key setup for the LM hashes is some kind of
  efficient implementations that just sets the correct bits in the
  DES_bs_all.K array?
  It seems to be based on only restting the bits that are changed
  between old and new + some quick fixes to make all the passwords
  uppercase.

- What is the significance of the DES_BS_VECTOR it seems one round
  uses the full mmx register width already, is this a cache optimazation?
  If so why is it always 2 for mmx? or is there some other reason
  entirely?

thanks, 
  dvorak