Re: [PATCH RFC v1 1/3] bpf: move from sha1 to blake2s in tag calculation

From: Geert Uytterhoeven
Date: Fri Jan 14 2022 - 10:36:40 EST


Hi Jason,

On Fri, Jan 14, 2022 at 4:20 PM Jason A. Donenfeld <Jason@xxxxxxxxx> wrote:
> I think the reason that Alexei doesn't think that the SHA-1 choice
> really matters is because the result is being truncated to 64-bits, so
> collisions are easy anyway, regardless of which hash function is
> chosen (birthday bound and all). But from Geert's perspective, that
> SHA-1 is still taking up precious bytes in m68k builds. And from my
> perspective, it's poor form and clutters vmlinux, and plus, now I'm
> curious about why this isn't using a more appropriately sized tag in
> the first place.

Not just on m68k. Same on other architectures.
Yes, people do make products with SoCs with 8 MiB of builtin SRAM,
running Linux. They might stay away from BPF, though ;-)

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