Date: Tue, 20 Nov 2018 14:02:17 +0800
From: Herbert Xu <herbert@gondor.apana.org.au>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Eric Biggers <ebiggers@kernel.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        linux-fscrypt@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        LKML <linux-kernel@vger.kernel.org>,
        Paul Crowley <paulcrowley@google.com>,
        Greg Kaiser <gkaiser@google.com>,
        Samuel Neves <samuel.c.p.neves@gmail.com>,
        Tomer Ashur <tomer.ashur@esat.kuleuven.be>,
        Martin Willi <martin@strongswan.org>
Subject: [RFC PATCH v2 0/4] Exporting existing crypto API code through zinc
Message-ID: <20181120060217.t4nccaqpwnxkl4tx@gondor.apana.org.au>
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 <20181117001718.GA175522@gmail.com>
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On Mon, Nov 19, 2018 at 01:24:51PM +0800, Herbert Xu wrote:
>
> In response to Martin's patch-set which I merged last week, I think
> here is quick way out for the zinc interface.
> 
> Going through the past zinc discussions it would appear that
> everybody is quite happy with the zinc interface per se.  The
> most contentious areas are in fact the algorithm implementations
> under zinc, as well as the conversion of the crypto API algorithms
> over to using the zinc interface (e.g., you can no longer access
> specific implementations).
> 
> My proposal is to merge the zinc interface as is, but to invert
> how we place the algorithm implementations.  IOW the implementations
> should stay where they are now, with in the crypto API.  However,
> we will provide direct access to them for zinc without going through
> the crypto API.  IOW we'll just export the functions directly.
> 
> Here is a proof of concept patch to do it for chacha20-generic.
> It basically replaces patch 3 in the October zinc patch series.
> Actually this patch also exports the arm/x86 chacha20 functions
> too so they are ready for use by zinc.
> 
> If everyone is happy with this then we can immediately add the
> zinc interface and expose the existing crypto API algorithms
> through it.  This would allow wireguard to be merged right away.
> 
> In parallel, the discussions over replacing the implementations
> underneath can carry on without stalling the whole project.
> 
> PS This patch is totally untested :)

Here is an updated version demonstrating how we could access the
accelerated versions of chacha20.  It also includes a final patch
to deposit the new zinc version of x86-64 chacha20 into
arch/x86/crypto where it can be used by both the crypto API as well
as zinc.

The key differences between this and the last zinc patch series:

1. The crypto API algorithms remain individually accessible, this
is crucial as these algorithm names are exported to user-space so
changing the names to foo-zinc is not going to work.

2. The arch-specific algorithm code lives in their own module rather
than in a monolithic module.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt