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From:   Nathan Huckleberry <nhuck@google.com>
Date:   Fri, 11 Feb 2022 14:30:24 -0600
Message-ID: <CAJkfWY7bet2V-w7NwMxqAsiwUqF5q7-FmFsgKJaMOBYSuY9M2g@mail.gmail.com>
Subject: Re: [RFC PATCH v2 5/7] crypto: arm64/aes-xctr: Add accelerated
 implementation of XCTR
To:     Ard Biesheuvel <ardb@kernel.org>
Cc:     Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Paul Crowley <paulcrowley@google.com>,
        Eric Biggers <ebiggers@kernel.org>,
        Sami Tolvanen <samitolvanen@google.com>
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On Fri, Feb 11, 2022 at 5:48 AM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Fri, 11 Feb 2022 at 00:28, Nathan Huckleberry <nhuck@google.com> wrote:
> >
> > Add hardware accelerated version of XCTR for ARM64 CPUs with ARMv8
> > Crypto Extension support.  This XCTR implementation is based on the CTR
> > implementation in aes-modes.S.
> >
> > More information on XCTR can be found in
> > the HCTR2 paper: Length-preserving encryption with HCTR2:
> > https://eprint.iacr.org/2021/1441.pdf
> >
> > Signed-off-by: Nathan Huckleberry <nhuck@google.com>
> > ---
> >
> > Changes since v1:
> >  * Added STRIDE back to aes-glue.c
> >
>
> NAK. Feel free to respond to my comments/questions against v1 if you
> want to discuss this.

 Oops, I misunderstood the tail block behavior of the CTR implementation and
 thought it wouldn't work with XCTR mode.  I have XCTR mirroring the tail
 behavior of CTR now. I'll submit it with the v3.