linux-kernel - Re: [PATCH v5 0/4] Implement GCM ghash using Zbc and Zbkb extensions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230613030216.GC883@sol.localdomain>
Date:   Mon, 12 Jun 2023 20:02:16 -0700
From:   Eric Biggers <ebiggers@...nel.org>
To:     Heiko Stuebner <heiko@...ech.de>
Cc:     palmer@...belt.com, paul.walmsley@...ive.com,
        aou@...s.berkeley.edu, herbert@...dor.apana.org.au,
        davem@...emloft.net, conor.dooley@...rochip.com,
        linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-crypto@...r.kernel.org, christoph.muellner@...ll.eu,
        Heiko Stuebner <heiko.stuebner@...ll.eu>
Subject: Re: [PATCH v5 0/4] Implement GCM ghash using Zbc and Zbkb extensions

Hi Heiko,

On Mon, Jun 12, 2023 at 11:04:38PM +0200, Heiko Stuebner wrote:
> From: Heiko Stuebner <heiko.stuebner@...ll.eu>
> 
> This was originally part of my vector crypto series, but was part
> of a separate openssl merge request implementing GCM ghash as using
> non-vector extensions.
> 
> As that pull-request
>     https://github.com/openssl/openssl/pull/20078
> got merged recently into openssl, we could also check if this could
> go into the kernel as well and provide a base for further accelerated
> cryptographic support.

I'm still a bit skeptical of the usefulness of a standalone "ghash"
implementation, when in practice it will only be used as part of "gcm(aes)".
Directly implementing "gcm(aes)" (instead of relying on crypto/gcm.c to compose
"ghash" and "ctr(aes)") also allows some performance optimizations.

I asked about this on v4
(https://lore.kernel.org/linux-crypto/ZCSG71bRuTzVutdm@gmail.com/),
but I didn't receive a response.

Any thoughts on this?

- Eric