Re: [PATCH v4 0/5] /dev/random - a new approach

Stephan Mueller
2016-06-18T08:22:32Z

Am Freitag, 17. Juni 2016, 11:26:23 schrieb Sandy Harris:

Hi Sandy,

> David Jaša <djasa@redhat.com> wrote:
> > BTW when looking at an old BSI's issue with Linux urandom that Jarod
> > Wilson tried to solve with this series:
> > https://www.spinics.net/lists/linux-crypto/msg06113.html
> > I was thinking:
> > 1) wouldn't it help for large urandom consumers if kernel created a DRBG
> > instance for each of them? It would likely enhance performance and solve
> > BSI's concern of predicting what numbers could other urandom consumers
> > obtain at cost of memory footprint
> > and then, after reading paper associated with this series:
> > 2) did you evaluate use of intermediate DRBG fed by primary generator to
> > instantiate per-node DRBG's? It would allow initialization of all
> > secondary DRBGs right after primary generator initialization.
>
> Theodore Ts'o, the random maintainer, already has a patch that
> seems to deal with this issue. He has posted more than one
> version & I'm not sure this is the best or latest, but ...
> https://lkml.org/lkml/2016/5/30/22

His latest patch set that he mentioned to appear in 4.8 covers a per-NUMA DRNG
where there is a "primary" /dev/urandom DRNG where secondary DRNGs for the
NUMA nodes are spawned from.

Ciao
Stephan