faster /dev/random

[Bill Davidsen]

Wolfgang S. Rupprecht wrote:
> Bill Davidsen <davidsen at tmr.com> writes:
>> Wolfgang S. Rupprecht wrote:
>>> Is there an approved way to increase the speed at which the random pool
>>> for /dev/random fills up?  I'm playig with dnssec and getnerating 2k rsa
>>> keys is taking up to 3 hours.  I've been googling a bit and Intel x86_64
>>> machines seem to have random number hardware built in (perhaps also
>>> AMD???)  Is there a way to funnel this into the entropy pool?
>>>
>> To be honest, I thought the data from the TCO random generator was funneled in 
>> already. That's what the "intel-rng" module does.
>>
>> Current kernel built with:
>> CONFIG_HW_RANDOM=y
>> CONFIG_HW_RANDOM_TIMERIOMEM=m
>> CONFIG_HW_RANDOM_INTEL=m
>> CONFIG_HW_RANDOM_AMD=m
>> CONFIG_HW_RANDOM_GEODE=m
>> CONFIG_HW_RANDOM_VIA=m
>> CONFIG_HW_RANDOM_VIRTIO=m
> 
> Thanks.  That gave me a few good strings to google for.
> 
>> If your CPU has the hardware the module should be loaded, but you can
>> check with "lsmod | grep rng" to be sure, or load manually to
>> test. Also virtio_rng might be useful. You might have to load by hand
>> to test, then config to load by default if you want.
> 
> It turns out my (2 year old) AMD Phenom 9350e Quad-Core doesn't seem to
> have that module loaded.  In fact, googling for "AMD hardware random
> number generator" got me a few hits of folks running an ms-windows tool
> on similar processors and one of the flags checked was for the hardware
> rng, which always seemed to be "not supported".  I guess the modern CPU
> really don't have that hardware any more.  How strange (and sad!).
> 
I haven't looked into what virtio-rng does, but it does load on anything I can 
quickly test, and I doubt it will make your number any worse.

There are number of cheap USB rng units around which are supported, I just read 
about one in Rich Jones' fine blog,
  http://rwmj.wordpress.com/2010/08/04/usb-hardware-random-number-generator/
which will probably get you started. His analysis is worth reading if only to 
see that some people still have pride in their product.

-- 
Bill Davidsen <davidsen at tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot