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From:   Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date:   Fri, 21 Jun 2019 07:39:21 +0200
Message-ID: <CAKv+Gu9DuYvMA7yOTT3p75hvNHY_LOaDBE_oCdxB=SRFZ7U-kA@mail.gmail.com>
Subject: Re: [PATCH v3 1/6] crypto: essiv - create wrapper template for ESSIV generation
To:     Herbert Xu <herbert@gondor.apana.org.au>
Cc:     Eric Biggers <ebiggers@kernel.org>,
        "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" 
        <linux-crypto@vger.kernel.org>,
        device-mapper development <dm-devel@redhat.com>,
        linux-fscrypt@vger.kernel.org,
        Gilad Ben-Yossef <gilad@benyossef.com>,
        Milan Broz <gmazyland@gmail.com>
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On Fri, 21 Jun 2019 at 03:07, Herbert Xu <herbert@gondor.apana.org.au> wrote:
>
> On Thu, Jun 20, 2019 at 03:53:45PM +0200, Ard Biesheuvel wrote:
> >
> > We'd need at least 512 and 4k for dm-crypt, but I don't think the
> > sector size is limited at all tbh
>
> In that case my preference would be to encode this into the key
> and hardware that encounters unsupported sector sizes can use a
> fallback.
>

OTOH, it also depends on what makes sense to implement in practice.

Gilad, I suppose sector size 512 is an obvious win, since the OS
always fetches at least 8 consective ones at a time. Do you see a
benefit for other sector sizes as well?