libsodium mess

[Gary E. Miller]

Yo Eric!

On Thu, 19 Jan 2017 14:30:35 -0500
"Eric S. Raymond" <esr at thyrsus.com> wrote:

> Gary E. Miller <gem at rellim.com>:
> > > - to fuzz the low-order bits of the clock.  
> > 
> > Hmm, can you expand on this a bit?  Which clock?  How much fuzz?
> > Does this degrade anything?  
> 
> Whenever ntpd polls the system clock, it fuzzes the lowest-order
> digits of the result. The amount of fuzz to apply is bounded by half
> the measured interval between system clock ticks.

Hmm, and how much would that typically be?

> That shouldn't degrade anything. I presume it's a measure to foil
> timing attacks of some sort.  Daniel might be able to say more.

At first glance this seems reasonable, but my experience with the
GR-601W suggests otherwise.  My experience with the GR-601W shows that
ntpd can find a timing edge and hold onto it very well.

Whe ends up is there will be an offset of up to 1/1024 sec from the
correct time, but the jitter is much less.

Can you point me to this code?  I want to rip it out and do a test.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
	gem at rellim.com  Tel:+1 541 382 8588

	    Veritas liberabit vos. -- Quid est veritas?
    "If you can’t measure it, you can’t improve it." - Lord Kelvin
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