Re: [PATCH] Re: [PATCH] drivers/net: remove network drivers' lastfew uses of IRQF_SAMPLE_RANDOM

From: Adrian Bunk
Date: Fri May 16 2008 - 09:22:50 EST

On Fri, May 16, 2008 at 12:19:49PM +0200, Andi Kleen wrote:
> The only problem you got from possible bogus input is that the entropy
> counts will be wrong, but in my experience nearly all programs
> use /dev/urandom anyways because /dev/random is just a DoS waiting
> to happen and user space programmers know that.

If programs just need some random data without relying on the fact that
it's cryptographically strong /dev/urandom is the right choice.

But some programs need entropy for doing crypto stuff, and a local DoS
is harmless compared to the consequences of bad /dev/random data.

Consider as a worst case the just discovered OpenSSL bug in Debian where
all accounts with public key authentification and keys created on a
Debian/Ubuntu system during the last 20 months [1] can be taken over by
an attacker within less than 20 minutes with a simple brute force
attack. [2]

> -Andi


[1] 13 months for Debian stable users


"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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