Re: [PATCH] Delete cryptoloop

From: Fruhwirth Clemens
Date: Sun Jul 25 2004 - 08:27:04 EST


On Sun, 2004-07-25 at 13:42, Jari Ruusu wrote:
> Fruhwirth Clemens wrote:
> > Second, modern ciphers like Twofish || AES are designed to resist
> > known-plaintext attacks. This is basically the FUD spread by Jari Rusuu.
>
> Ciphers are good, but both cryptoloop and dm-crypt use ciphers in insecure
> and exploitable way.
>
> This is not FUD. Fruhwirth, did you even try run the exploit code?
>
> http://marc.theaimsgroup.com/?l=linux-kernel&m=107719798631935&w=2

There is no use in running your code. It does not decipher any block
without the proper key. Where is the exploit?

Further the link you provide in the posting above is broken (as you
already noticed). I tried at google cache, citeseer and the rest of
Saarien's homepage. No success.

If you have any idea where I can obtain the paper, I'd be interested in
seeing the references for your claims.. But guessing from the apparent
logic of your code, it seems to be identical to the weakness brought
forward in the following paragraph of my original posting, which you've
cut out of the quoting.

> > - There is no suitable user space tool ready to use it. util-linux has
> > been broken ever since. My patch key-trunc-fix patch has to be applied
> > to make any use of losetup.
>
> Can you name implementation that your "key-truncated" version is compatible
> with that existed _before_ your version appeared?. To my knowledge, that
> key-truncated version is only compatible with itself, and there is no other
> version that does the same.

Actually there is a version: util-linux 2.12 official. But
unfortunately, the official version truncates binary keys (at 0x00, 0x0a
values), that's what my patch is for. cryptsetup handles keys the same
way. So migration is easy, something which does not hold true for your
strange util-linux patches. But you already know my critiques..

--
Fruhwirth Clemens <clemens@xxxxxxxxxxxxx> http://clemens.endorphin.org

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