Re: [PATCH v3 1/3] siphash: add cryptographically secure hashtable function

Jason A. Donenfeld
2016-12-14T23:17:25Z

Hey Tom,

On Thu, Dec 15, 2016 at 12:14 AM, Tom Herbert <tom@herbertland.com> wrote:
> I'm confused, doesn't 2dword == 1qword? Anyway, I think the qword
> functions are good enough. If someone needs to hash over some odd
> length they can either put them in a structure padded to 64 bits or
> call the hash function that takes a byte length.

Yes. Here's an example:

static inline u64 siphash24_2dwords(const u32 a, const u32 b, const u8
key[SIPHASH24_KEY_LEN])
{
return siphash24_1qword(((u64)b << 32) | a, key);
}

This winds up being extremely useful and syntactically convenient in a
few places. Check out my git branch in about 10 minutes or wait for v4
to be posted tomorrow; these are nice helpers.

> I'd still drop the "24" unless you really think we're going to have
> multiple variants coming into the kernel.

Okay. I don't have a problem with this, unless anybody has some reason
to the contrary.

Jason