linux-kernel - Re: [RFC V1 3/7] crypto: ghash - Optimized GHASH computations

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]

Date:   Fri, 15 Jan 2021 18:04:11 -0800
From:   Eric Biggers <ebiggers@...nel.org>
To:     Dave Hansen <dave.hansen@...el.com>
Cc:     "Dey, Megha" <megha.dey@...el.com>,
        Ard Biesheuvel <ardb@...nel.org>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S. Miller" <davem@...emloft.net>,
        Linux Crypto Mailing List <linux-crypto@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        ravi.v.shankar@...el.com, tim.c.chen@...el.com,
        andi.kleen@...el.com, wajdi.k.feghali@...el.com,
        greg.b.tucker@...el.com, robert.a.kasten@...el.com,
        rajendrakumar.chinnaiyan@...el.com, tomasz.kantecki@...el.com,
        ryan.d.saffores@...el.com, ilya.albrekht@...el.com,
        kyung.min.park@...el.com, Tony Luck <tony.luck@...el.com>,
        ira.weiny@...el.com
Subject: Re: [RFC V1 3/7] crypto: ghash - Optimized GHASH computations

On Fri, Jan 15, 2021 at 04:20:44PM -0800, Dave Hansen wrote:
> On 1/15/21 4:14 PM, Dey, Megha wrote:
> > Also, I do not know of any cores that implement PCLMULQDQ and not AES-NI.
> 
> That's true, bit it's also possible that a hypervisor could enumerate
> support for PCLMULQDQ and not AES-NI.  In general, we've tried to
> implement x86 CPU features independently, even if they never show up in
> a real CPU independently.

We only add optimized implementations of crypto algorithms if they are actually
useful, though.  If they would never be used in practice, that's not useful.

- Eric