From: Eric Biggers <ebiggers@kernel.org>
To: Milan Broz <gmazyland@gmail.com>
Cc: Pascal Van Leeuwen <pvanleeuwen@verimatrix.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
"dm-devel@redhat.com" <dm-devel@redhat.com>,
"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
Horia Geanta <horia.geanta@nxp.com>
Subject: Re: [dm-devel] xts fuzz testing and lack of ciphertext stealing support
Date: Fri, 19 Jul 2019 23:58:07 -0700 [thread overview]
Message-ID: <20190720065807.GA711@sol.localdomain> (raw)
In-Reply-To: <b042649c-db98-9710-b063-242bdf520252@gmail.com>
On Thu, Jul 18, 2019 at 01:19:41PM +0200, Milan Broz wrote:
>
> > From that perspective - to prevent people from doing cryptographically stupid things -
> > IMHO it would be better to just pull the CTS into the XTS implementation i.e. make
> > xts natively support blocks that are not a multiple of (but >=) the cipher blocksize ...
>
> I would definitely prefer adding CTS directly to XTS (as it is in gcrypt or OpenSSL now)
> instead of some new compositions.
>
> Also, I would like to avoid another "just because it is nicer" module dependence (XTS->XEX->ECB).
> Last time (when XTS was reimplemented using ECB) we have many reports with initramfs
> missing ECB module preventing boot from AES-XTS encrypted root after kernel upgrade...
> Just saying. (Despite the last time it was keyring what broke encrypted boot ;-)
>
Can't the "missing modules in initramfs" issue be solved by using a
MODULE_SOFTDEP()? Actually, why isn't that being used for xts -> ecb already?
(There was also a bug where CONFIG_CRYPTO_XTS didn't select CONFIG_CRYPTO_ECB,
but that was simply a bug, which was fixed.)
Or "xts" and "xex" could go in the same kernel module xts.ko, which would make
this a non-issue.
Anyway, I agree that the partial block support, if added, should just be made
available under the name "xts", as people would expect. It doesn't need a new
name.
- Eric
next prev parent reply other threads:[~2019-07-20 6:58 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-16 17:46 xts fuzz testing and lack of ciphertext stealing support Horia Geanta
2019-07-16 22:16 ` Eric Biggers
2019-07-17 17:09 ` Horia Geanta
2019-07-17 17:28 ` Eric Biggers
2019-07-17 18:08 ` Ard Biesheuvel
2019-07-18 6:52 ` Herbert Xu
2019-07-18 7:15 ` Ard Biesheuvel
2019-07-18 7:21 ` Herbert Xu
2019-07-18 7:28 ` Ard Biesheuvel
2019-07-18 7:50 ` Herbert Xu
2019-07-18 7:40 ` Milan Broz
2019-07-18 10:40 ` Pascal Van Leeuwen
2019-07-18 11:19 ` Milan Broz
2019-07-18 15:27 ` Herbert Xu
2019-07-20 6:58 ` Eric Biggers [this message]
2019-07-20 7:35 ` [dm-devel] " Milan Broz
2019-07-21 9:50 ` Ard Biesheuvel
2019-07-22 9:44 ` Pascal Van Leeuwen
2019-07-22 16:43 ` Ard Biesheuvel
2019-07-22 22:46 ` Pascal Van Leeuwen
2019-07-24 12:23 ` Pascal Van Leeuwen
2019-07-24 12:50 ` Pascal Van Leeuwen
2019-07-24 16:10 ` Pascal Van Leeuwen
2019-07-25 6:22 ` Ard Biesheuvel
2019-07-25 7:49 ` Pascal Van Leeuwen
2019-07-25 8:01 ` Ard Biesheuvel
2019-07-26 10:31 ` Pascal Van Leeuwen
2019-07-26 19:59 ` Horia Geanta
2019-07-26 21:43 ` Pascal Van Leeuwen
2019-07-27 5:39 ` Ard Biesheuvel
2019-07-27 12:56 ` Pascal Van Leeuwen
2019-07-27 16:04 ` Milan Broz
2019-08-04 8:36 ` Ard Biesheuvel
[not found] ` <20f4832e-e3af-e3c2-d946-13bf8c367a60@nxp.com>
2019-08-07 15:51 ` Horia Geanta
2019-08-07 20:57 ` Pascal Van Leeuwen
2019-08-08 14:50 ` Horia Geanta
2019-08-09 8:35 ` Pascal Van Leeuwen
2019-08-08 13:43 ` Pascal Van Leeuwen
2019-08-08 18:01 ` Horia Geanta
2019-08-09 2:48 ` Herbert Xu
2019-08-09 6:45 ` Ard Biesheuvel
2019-08-09 7:44 ` Horia Geanta
2019-08-09 17:49 ` Ard Biesheuvel
2019-08-09 20:57 ` Pascal Van Leeuwen
2019-08-10 4:39 ` Ard Biesheuvel
2019-08-11 11:12 ` Milan Broz
2019-08-11 20:34 ` Eric Biggers
2019-08-11 21:39 ` Pascal Van Leeuwen
2019-08-11 21:29 ` Pascal Van Leeuwen
2019-08-12 4:51 ` Herbert Xu
2019-08-11 21:15 ` Pascal Van Leeuwen
2019-08-11 22:24 ` Ard Biesheuvel
2019-08-12 1:04 ` Pascal Van Leeuwen
2019-07-18 15:29 ` Herbert Xu
2019-07-18 15:43 ` Pascal Van Leeuwen
2019-07-18 15:51 ` Herbert Xu
2019-07-18 16:19 ` Ard Biesheuvel
2019-07-18 16:22 ` Herbert Xu
2019-07-18 17:03 ` Pascal Van Leeuwen
2019-07-19 5:34 ` Ard Biesheuvel
2019-07-19 7:29 ` Pascal Van Leeuwen
2019-07-19 17:14 ` Ard Biesheuvel
2019-07-19 20:07 ` Pascal Van Leeuwen
2019-07-18 16:35 ` Pascal Van Leeuwen
2019-07-19 1:47 ` Herbert Xu
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