linux-kernel - RE: [PATCH] random: allow writes to /dev/urandom to influence fast init

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Date:   Wed, 23 Mar 2022 14:01:34 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     "'Jason A. Donenfeld'" <Jason@...c4.com>,
        "Alex Xu (Hello71)" <alex_y_xu@...oo.ca>
CC:     Linux Crypto Mailing List <linux-crypto@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Jann Horn <jannh@...gle.com>,
        "Dominik Brodowski" <linux@...inikbrodowski.net>,
        Guenter Roeck <linux@...ck-us.net>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Theodore Ts'o <tytso@....edu>,
        Sandy Harris <sandyinchina@...il.com>
Subject: RE: [PATCH] random: allow writes to /dev/urandom to influence fast
 init

From: Jason A. Donenfeld
> Sent: 23 March 2022 04:48
...
> - Plenty of things are seeding the RNG correctly, and buildroot's
> shell script is just "doing it wrong".
> 
> On that last point, I should reiterate that buildroot's shell script
> still isn't actually initializing the RNG, despite what it says in its
> echo; there's never been a way to initialize the RNG from a shell
> script, without calling out to various special purpose ioctl-aware
> binaries.

Perhaps the very first write after boot could be assumed to
be valid initialisation data?
(On top of a few other tests.)

Then I need a patch against 5.10 :-)

	David

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