On Wed, 2 Feb 2000, Theo de Raadt wrote:
> I suppose then that anyone who attacks a machine which relies on
> /dev/random -- a world readable device -- should do the following:
>
> cat /dev/random > /dev/null &
Yep.
> Crypto software which uses those devices should be doing some kind of
> checking to make sure that they are getting at least good entropy. I
The good thing is that /dev/random blocks until there is enough entropy
available. /dev/urandom does not block but continues to return random
bytes by using a PRNG.
> suppose I could even argue that the random devices should make it easy
> for customer software to determine that entropy is low.
There is also an ioctl() to query some statistics. OpenBSD has some
more kinds of random devices but I don't know much about them.
I have not checked the latest Linux kernels but rumors are that this
device has been enhanced.
--
Werner Koch at guug.de www.gnupg.org keyid 621CC013
