Re: [PATCH] crypto: keywrap - remove unused keywrap algorithm

[Geert Uytterhoeven]

On Fri, Dec 27, 2024 at 11:10 PM Eric Biggers <ebiggers@xxxxxxxxxx> wrote:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> The keywrap (kw) algorithm has no in-tree user.  It has never had an
> in-tree user, and the patch that added it provided no justification for
> its inclusion.  Even use of it via AF_ALG is impossible, as it uses a
> weird calling convention where part of the ciphertext is returned via
> the IV buffer, which is not returned to userspace in AF_ALG.
>
> It's also unclear whether any new code in the kernel that does key
> wrapping would actually use this algorithm.  It is controversial in the
> cryptographic community due to having no clearly stated security goal,
> no security proof, poor performance, and only a 64-bit auth tag.  Later
> work (https://eprint.iacr.org/2006/221) suggested that the goal is
> deterministic authenticated encryption.  But there are now more modern
> algorithms for this, and this is not the same as key wrapping, for which
> a regular AEAD such as AES-GCM usually can be (and is) used instead.
>
> Therefore, remove this unused code.
>
> There were several special cases for this algorithm in the self-tests,
> due to its weird calling convention.  Remove those too.
>
> Cc: Stephan Mueller <smueller@xxxxxxxxxx>
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>

>  arch/m68k/configs/amiga_defconfig          |   1 -
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>  arch/m68k/configs/atari_defconfig          |   1 -
>  arch/m68k/configs/bvme6000_defconfig       |   1 -
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>  arch/m68k/configs/mac_defconfig            |   1 -
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>  arch/m68k/configs/mvme147_defconfig        |   1 -
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>  arch/m68k/configs/sun3_defconfig           |   1 -
>  arch/m68k/configs/sun3x_defconfig          |   1 -

Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> # m68k

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds