Problem with /dev/random?

[Kent Borg]

On Thu, May 13, 2004 at 02:26:08PM -0700, Vladimir G. Ivanovic wrote:
> I am not logged in remotely but locally. I've had a "cat /dev/random"
> running in a GNOME Terminal tab (window) now for several hours while I
> read mail & surfed.

Eeek!

One of the problems with /dev/random (as opposed to /dev/urandom) is
that any user can read it, drain all the entropy, and prevent others
from getting any.  As a test it can be interesting, but don't do that
otherwise.  (Don't forget an extra cat left running on a different
console.)

Kill the cat.  cd to /proc/sys/kernel/random and look around.
Specifically, cat entropy_avail.  I am guessing you will see nothing.
Now cat a few bytes into /dev/random and cat entropy_avail again.  Did
any show up?  If so, then things are as I expect, you need to tell
your mouse and keyboard and other devices to contribute entropy.  I
would have to start searching through kernel sources and googling to
find out how.

-kb, the Kent who has run off the end of his immediate knowledge.


P.S.  Did you do a standard install?  What strange things have you
done?  (Compile your own kernel?  Mess with boot initializations?)