Re: [PATCH v43 01/15] Linux Random Number Generator

From: Stephan Mueller
Date: Mon Nov 22 2021 - 01:43:38 EST


Am Montag, 22. November 2021, 07:02:14 CET schrieb Greg Kroah-Hartman:

Hi Greg,

> On Mon, Nov 22, 2021 at 06:34:43AM +0100, Stephan Mueller wrote:
> > Am Sonntag, 21. November 2021, 23:42:33 CET schrieb Jason A. Donenfeld:
> >
> > Hi Jason,
> >
> > > Hi Stephan,
> > >
> > > You've posted it again, and yet I still believe this is not the
> > > correct design or direction. I do not think the explicit goal of
> > > extended configurability ("flexibility") or the explicit goal of being
> > > FIPS compatible represent good directions, and I think this introduces
> > > new problems rather than solving any existing ones.
> >
> > The members from the Linux distributions that are on copy on this may tell
> > you a different story. They all developed their own downstream patches to
> > somehow add the flexibility that is needed for them. So, we have a great
> > deal of fragmentation at the resting-foundation of Linux cryptography.
>
> What distros specifically have patches in their kernels that do
> different things to the random code path? Do you have pointers to those
> patches anywhere? Why have the distros not submitted their changes
> upstream?

I will leave the representatives from the distros to chime in and point to
these patches.

Yet, these changes are commonly a band-aid only that have some additional
drawbacks. Bottom line, there is no appropriate way with the current code to
allow vendors what they want to achieve. One hint to what changes vendors are
attempting can be found in [1] slide 20.

[1] https://www.chronox.de/lrng/doc/lrng_presentation_v43.pdf
>
> thanks,
>
> greg k-h


Ciao
Stephan