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

From: Jason A. Donenfeld
Date: Mon Jul 25 2022 - 18:09:47 EST


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.

Jason