Re: [PATCH v3 2/3] crypto: lib - move __crypto_xor into utils

[Ard Biesheuvel]

On Mon, 25 Jul 2022 at 15:09, Jason A. Donenfeld <Jason@xxxxxxxxx> wrote:
>
> On Mon, Jul 25, 2022 at 11:36:35AM -0700, Eric Biggers wrote:
> > From: Eric Biggers <ebiggers@xxxxxxxxxx>
> >
> > CRYPTO_LIB_CHACHA depends on CRYPTO for __crypto_xor, defined in
> > crypto/algapi.c.  This is a layering violation because the dependencies
> > should only go in the other direction (crypto/ => lib/crypto/).  Also
> > the correct dependency would be CRYPTO_ALGAPI, not CRYPTO.  Fix this by
> > moving __crypto_xor into the utils module in lib/crypto/.
> >
> > Note that CRYPTO_LIB_CHACHA_GENERIC selected XOR_BLOCKS, which is
> > unrelated and unnecessary.  It was perhaps thought that XOR_BLOCKS was
> > needed for __crypto_xor, but that's not the case.
> >
> > Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> Reviewed-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
>
> With one small question:
>
> > --- /dev/null
> > +++ b/lib/crypto/utils.c
> > @@ -0,0 +1,88 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Crypto library utility functions
> > + *
> > + * Copyright (c) 2006 Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
>
> Didn't Ard basically write the crypto_xor function in its current form?
> I seem to remember some pretty hardcore refactoring he did a while back.
>

Hi Jason,

Thanks for pointing this out. When I made those changes, I don't think
an authorship assertion for copyright purposes was appropriate for the
entire .c file (the FSF have some guidelines for this IIRC). It would
also be strange for me or Eric to suddenly introduce a (c) Linaro (or
ARM, not sure who my employer was at the time) at this point, so I
think we can just leave this as proposed by Eric.