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

From: John Haxby <john.haxby@oracle.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Stephan Mueller <smueller@chronox.de>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>, Tso Ted <tytso@mit.edu>,
	"linux-crypto@vger.kernel.org" <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>,
	Alexander Lobakin <alobakin@mailbox.org>,
	Jirka Hladky <jhladky@redhat.com>
Subject: Re: [PATCH v43 01/15] Linux Random Number Generator
Date: Mon, 22 Nov 2021 16:56:24 +0000	[thread overview]
Message-ID: <DBF8E8A8-9968-4E81-8C6E-7BAD0C3F39FA@oracle.com> (raw)
In-Reply-To: <YZsyZua9T8DD6JF5@kroah.com>

[-- Attachment #1: Type: text/plain, Size: 2333 bytes --]

> On 22 Nov 2021, at 06:02, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> 
> 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?
> 

We (Oracle) are carrying such a patch at the moment.  We want this patch to be a temporary workaround simply to get FIPS certification in the current kernel.

We're carrying this patch simply because the certification requirements changed and this was the quickest and easiest way to workaround today's problem.  It won't fix tomorrow's problem and next time we, and others, attempt FIPS certification then we, and others, will need a different /dev/random because neither the old one nor our quick and dirty workaround will actually be acceptable.

The commit we're carrying at the moment is here: https://github.com/oracle/linux-uek/commit/5ebe83413c7573d566e581461bc95f9f139c5d4d -- you'll notice that we have a different RNG in fips mode compared to normal mode.

We really don't want to have to work out a new hack for future FIPS certifications and I'm sure no other distros want to do that either.

Personally, I'd far rather have any fips-certifiable /dev/random drivers be in mainline where everyone gets the same thing.  I don't like carrying out-of-tree patches like this, it's not healthy.

jch

> thanks,
> 
> greg k-h

[-- Attachment #2: Message signed with OpenPGP --]
[-- Type: application/pgp-signature, Size: 228 bytes --]