[PATCH v5 03/12] libbpf: Implement SHA256 internal helper

[Alexei Starovoitov]

On Sat, Sep 27, 2025 at 10:03 PM Eric Biggers <ebiggers at kernel.org> wrote:
>
> On Sun, Sep 21, 2025 at 03:31:24PM +0200, KP Singh wrote:
> > Use AF_ALG sockets to not have libbpf depend on OpenSSL. The helper is
> > used for the loader generation code to embed the metadata hash in the
> > loader program and also by the bpf_map__make_exclusive API to calculate
> > the hash of the program the map is exclusive to.
> >
> > Acked-by: Andrii Nakryiko <andrii at kernel.org>
> > Signed-off-by: KP Singh <kpsingh at kernel.org>
>
> Nacked-by: Eric Biggers <ebiggers at kernel.org>
>
> No more users of AF_ALG, please.  It's a huge mistake and has been
> incredibly problematic over the years.

Lol. True, but good luck with that. AF_ALG is uapi and it will be removed
only when the last user retires many years from now.

> If you don't want to depend on a library, then just include some basic
> SHA-256 code, similar to what I'm doing for iproute2 and SHA-1 at
> https://lore.kernel.org/netdev/20250925225322.13013-1-ebiggers@kernel.org/.
> I'd even be glad to write the patch for you, if you want.

Yes. Please. If you can craft sha256 without external dependencies
we can certainly use it.
Certainly agree that it would be better than AF_ALG.