Re: [SECURITY] [DSA 4187-1] linux security update
On Fri, 04 May 2018, Davide Prina wrote:
> On 04/05/2018 04:06, Paul Wise wrote:
> > On Thu, May 3, 2018 at 4:53 PM, richard lucassen wrote:
> >
> > > There is also an big increase in time before random is initialized:
> > ...
> > > One of the consequences is that openntpd (or a program like
> > > rdate) hangs until the crng is initialized.
> >
> > What do these two programs require entropy for?
>
> security:
>
> Integrates the latest secure API advances from OpenBSD such as
> getentropy(2), arc4random(3) (a fail-safe CSRNG that works in chroot
> environments), and reallocarray(3) (an integer overflow-checking
> malloc/calloc/realloc replacement).[1]
>
> you can read more detail on NTP RFC[2]
Well, it is false security if it depends on a RNG with too little
entropy, and unless you have hardware assistance, that also means you
need to delay their start until the RNG is properly seeded.
Maybe we should have a systemd target/sysvinit facility that can be used
properly for "crng available" (and use the !@#$ one for clock sync'd as
well, related to ntp... dnssec *really* depends on never enabling its
secure mode before you sync'd the clock, for example. But lots of other
stuff would like to start providing service only after the local clock
has been made realtively accurate by ntp/sntp/whatever).
--
Henrique Holschuh
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