On 08/25/16 16:35, Sandy Harris wrote: > On Thu, Aug 25, 2016 at 5:30 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote: > >> The network stack is a good source of entropy, *once it is online*. >> However, the most serious case is while the machine is still booting, >> when the network will not have enabled yet. >> >> -hpa > > One possible solution is at: > https://github.com/sandy-harris/maxwell > > A small (< 700 lines) daemon that gets entropy from timer imprecision > and variations in time for arithmetic (cache misses, interrupts, etc.) > and pumps it into /dev/random. Make it the first userspace program > started and all should be covered. Directory above includes a PDF doc > with detailed rationale and some discussion of alternate solutions. > > Of course if you are dealing with a system-on-a-chip or low-end > embedded CPU & the timer is really inadequate, this will not work > well. Conceivably well enough, but we could not know that without > detailed analysis for each chip in question. > A lot of this is exactly the same thing /dev/random already does in kernel space. I have already in the past expressed skepticism toward this approach, because a lot of the analysis done has simply been bogus. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
