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

From: Jeffrey Walton <noloader@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Stephan Mueller <smueller@chronox.de>,
	Simo Sorce <simo@redhat.com>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>, Tso Ted <tytso@mit.edu>,
	Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
	Willy Tarreau <w@1wt.eu>, Nicolai Stange <nstange@suse.de>,
	LKML <linux-kernel@vger.kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	"Alexander E. Patrakov" <patrakov@gmail.com>,
	"Ahmed S. Darwish" <darwish.07@gmail.com>,
	Matthew Garrett <mjg59@srcf.ucam.org>,
	Vito Caputo <vcaputo@pengaru.com>,
	Andreas Dilger <adilger.kernel@dilger.ca>,
	Jan Kara <jack@suse.cz>, Ray Strode <rstrode@redhat.com>,
	William Jon McCann <mccann@jhu.edu>,
	zhangjs <zachary@baishancloud.com>,
	Andy Lutomirski <luto@kernel.org>,
	Florian Weimer <fweimer@redhat.com>,
	Lennart Poettering <mzxreary@0pointer.de>,
	Peter Matthias <matthias.peter@bsi.bund.de>,
	Marcelo Henrique Cerri <marcelo.cerri@canonical.com>,
	Neil Horman <nhorman@redhat.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	Julia Lawall <julia.lawall@inria.fr>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Andy Lavr <andy.lavr@gmail.com>,
	Eric Biggers <ebiggers@kernel.org>,
	Petr Tesarik <ptesarik@suse.cz>,
	John Haxby <john.haxby@oracle.com>,
	Alexander Lobakin <alobakin@mailbox.org>,
	Jirka Hladky <jhladky@redhat.com>
Subject: Re: [PATCH v43 01/15] Linux Random Number Generator
Date: Tue, 30 Nov 2021 10:13:26 -0500	[thread overview]
Message-ID: <CAH8yC8nWLk9vhV1iACE+vmtby2rRN8RDqeuS54qZahE-xH2X_w@mail.gmail.com> (raw)
In-Reply-To: <YaYvYdnSaAvS8MAk@kroah.com>

On Tue, Nov 30, 2021 at 9:04 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Tue, Nov 30, 2021 at 07:24:15AM -0500, Jeffrey Walton wrote:
> > On Mon, Nov 29, 2021 at 6:07 PM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > > ...
> > > Sometimes, yes, it is valid to have different implementations for things
> > > that do different things in the same area (like filesystems), but for a
> > > core function of the kernel, so far the existing random maintainer has
> > > not wanted to have multiple implementations.  Same goes for other parts
> > > of the kernel, it's not specific only to this one very tiny driver.
> > >
> > > As a counterpoint, we do not allow duplicate drivers that control the
> > > same hardware types in the tree.  We have tried that in the past and it
> > > was a nightmare to support and maintain and just caused massive user
> > > confusion as well.  One can argue that the random driver is in this same
> > > category.
> >
> > I think an argument could be made that they are different drivers
> > since they have different requirements and security goals. I don't
> > think it matters where the requirements came from, whether it was ad
> > hoc from the developer, NIST, KISA, CRYPTREC, NESSIE, or another
> > organization.
> >
> > Maybe the problem is with the name of the driver? Perhaps the current
> > driver should be named random-linux, Stephan's driver should be named
> > random-nist, and the driver should be wired up based on a user's
> > selection. That should sidestep the problems associated with the
> > "duplicate drivers" policy.
>
> The "problem" here is that the drivers/char/random.c file has three users,
> the userspace /dev/random and syscall api, the in-kernel "here's some
> entropy for the random core to use" api, and the in-kernel "give me some
> random data" api.
>
> Odds are, you REALLY do not want the in-kernel calls to be pulling from
> the "random-government-crippled-specification" implementation, right?

It's not a question of whether some folks want it or not. They have to
accept it due to policy. They have no choice in the matter.

I hope I don't sound argumentative. It's not my intention. But I know
what it's like to have to comply with policies, even ones I don't
like.

Jeff