The general wisdom these days - in particular as given by the Linux
urandom(4) man page - seems to be that there's no need to use the
blocking /dev/random any more unless you're running at very early boot
time when the system random pool is at serious risk of not having any
entropy in it at all.
In case of non-Linux systems that don't think /dev/urandom is a
standard name, I fall back to /dev/random if /dev/urandom can't be
found.
E.g. you might pass '--random-device=/dev/urandom'.
Mostly because I got sick of waiting for /dev/random to finish
blocking while I was trying to generate throwaway keys for testing bug
fixes in cmdgen itself. But it might also be useful on systems that
call their random device by a different name that we haven't
encountered.
(Since cmdgen also reads the saved PuTTY random seed file, setting
this option to /dev/zero will not render key generation deterministic.
It's tempting to provide _some_ way to do that, for testing purposes
and clearly marked as dangerous of course, but I think it would take
more faff than this.)
on Linux, but the (very few) platform-specific bits are already
abstracted out of the main code, so it should port to other
platforms with a minimum of fuss.
[originally from svn r3762]
