Re: [PATCH] argon2 key generation method for cgdconfig(8)

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

On 2021/11/06 18:42, Taylor R Campbell wrote:
> > --- /dev/null	1 Jan 1970 00:00:00 -0000
> > +++ sbin/cgdconfig/argon2_utils.c	6 Nov 2021 00:17:48 -0000
> > [...]
> > +	mem = usermem / 100000;
>
> What units are these in?  Maybe add a comment explaining so the number
> 100000 is a little more obvious?

We have a similar code in libcrypt:

https://nxr.netbsd.org/xref/src/lib/libcrypt/crypt-argon2.c#180

But denominator is 10^5 here, and 10^6 there. Can you add a comment
also for libcrypt?

> +static uint64_t
> +get_usermem(void)
> +{
> (snip)
> +	if (sysctl(mib, __arraycount(mib),
> +	    &usermem64, &usermem64_len, NULL, 0) < 0) {
> +		return 1;
> +	}

I think this 1 is misleading. 0 is better?

> +void
> +argon2id_calibrate(size_t keylen, size_t saltlen,
> +    size_t *iterations, size_t *memory, size_t *parallelism)
> (snip)
> +	if (mem < ARGON2_MIN_MEMORY)
> +		mem = 256;

What is relation b/w ARGON2_MIN_MEMORY and magic number 256?

Thanks,
rin