Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5)

[Hannes Frederic Sowa]

On 22.12.2016 20:56, Andy Lutomirski wrote:
> It's also not quite clear to me why userspace needs to be able to
> calculate the digest on its own.  A bpf(BPF_CALC_PROGRAM_DIGEST)
> command that takes a BPF program as input and hashes it would seem to
> serve the same purpose, and that would allow the kernel to key the
> digest and change the algorithm down the road without breaking things.

I think that people expect digests of BPF programs to be stable over
time and reboots.