Re: [PATCH] API for true Random Number Generators to add entropy (2.6.11)

Bill Davidsen
2005-03-29T21:57:32Z

Herbert Xu wrote:

> You missed the point. This has nothing to do with the crypto API.
> Jeff is saying that if this is disabled by default, then only a few
> users will enable it and therefore use this API.
>
> Since we can't afford to enable it by default as hardware RNG may
> fail which can lead to catastrophic consequences, there is no point
> for this API at all.

Wait a minute, if it fails the system drops back to software, which is
not as good in a pedantic analysis, but perhaps falls a good bit short
of "catastrophic consequences" as most people would characterize that
phrase. And more to the point, now that many CPUs and chipsets are the
RNG of choice, what is the actual probability of a failure of the RNG
leaving a functional system (that's a real question seeking response
from someone who has some actual data).

It would be desirable for the kernel to detect a failure and do
something appropriate, but I have to feel that if an RNG is in the CPU
or chipset, it would serve users better to use it. By default. People
who need quality entropy would be better served by a hardware source,
and people who don't (or fail to realize they do) would not be hurt by
use of better numbers.

I'm not sure you would get people to agree what should be done if a
hardware RNG fails, other than make the failure information available to
user space.

--
-bill davidsen (davidsen@tmr.com)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me