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Date: Thu, 15 Dec 2011 21:34:15 +0530
From: piyush mittal <piyush.cse29@...il.com>
To: john-dev@...ts.openwall.com
Subject: Re: Bit slice implementation of DES based hashes

>
> You need to introduce a fourth function.  I suggest that you take
> DES_bs_crypt_LM(), copy it to a new function, and remove the
> initialization of B from there (let the caller specify the initial B).
> This way, you get a function implementing one DES block encryption
> (for DES_BS_DEPTH different blocks and/or keys in parallel).  As to
> block cipher modes, you'll implement those externally to that function
> (at least initially).
>


So you mean to say I use same mode as of LM for Oracle i.e same function
DES_bs_crypt_LM() accept name change and should not initialise
DES_bs_set_block_8().

Thanks,
On Thu, Dec 15, 2011 at 8:36 PM, Solar Designer <solar@...nwall.com> wrote:

> Piyush -
>
> On Thu, Dec 15, 2011 at 05:51:14PM +0530, piyush mittal wrote:
> > In File DES_bs_b.c Three methods are given i.e
> > 1,DES_bs_crypt_LM()
> > 2.DES_bs_crypt_25
> > 3.DES_bs_crypt()
> >
> >
> >
> > The first two is specific to Lm and Traditional DES respectively.First
> one
> > calls the S-boxes in ECB mode and for second one I don't
> > know.Third one i hope don't use any mode.However in oracle_fmt_plug.c
> > conversion we need CBC mode so how to call S Boxes in this case?
>
> You need to introduce a fourth function.  I suggest that you take
> DES_bs_crypt_LM(), copy it to a new function, and remove the
> initialization of B from there (let the caller specify the initial B).
> This way, you get a function implementing one DES block encryption
> (for DES_BS_DEPTH different blocks and/or keys in parallel).  As to
> block cipher modes, you'll implement those externally to that function
> (at least initially).
>
> Another question I expected from you was how to set arbitrary DES keys
> when the current DES_bs_set_key*() functions accept ASCII strings only.
> I'll answer this one without waiting for you to ask it. ;-)  I suggest
> that you simply use DES_bs_set_key() for now, but set bit 8 in every
> char (OR it with 0x80) to ensure that all 8 chars (with 7 significant
> bits per char) are processed.  We may introduce a more efficient binary
> key setup function later.
>
> Thanks,
>
> Alexander
>



-- 
Piyush Mittal
Department of Computer Science and Engineering
National Institute of Technology,Rourkela
INDIA

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