Some random links. Needs research.
It is like haveged but for earlier boot. Here;s the author’s description:
haveged tries to use CPU jitter, in a way similar to jytter but
on a much more massive scale, to gather entropy-ish and writes
that to the kernel RNG. It, however, does that all the time, and
not just a little bit. Basically, it’s an attempt to gather entropy,
while early-rng-init-tools just takes what’s there during normal
system runtime (which you have to provide yourself, at the very
least before installing it, but sensibly also normally) and makes
it available to the kernel earlier (this really ought to be done
in the bootloader, even, but this at least improves on what we
currently have).
This needs a through review. There is some criticism on the Debian mailing list that I might share. Qutoe the authors original post, for example:
‣ uses that and a number of other things (to make it differ)…
← md5sum of dmesg
← the current time
This might be completely predictable. And why md5sum if there is sha512sum.
If that speculation of mine is true, it might be dangerous if it does credit entropy.
Yet, early-rng-init-tools is very interesting as a concept and something useful might come out of it.
The way md5sum is being used is not vulnerable to collision attacks. However it is a shitty source of entropy. Easily accounted for without salting.
True. Perhaps the Twuerand rewrite can make use of some ideas it has.