From: David Jander <david@protonic.nl>
To: Clemens Gruber <clemens.gruber@pqgruber.com>
Cc: ptxdist@pengutronix.de
Subject: Re: [ptxdist] Python 3.5 and the use of getrandom() system call
Date: Mon, 21 Nov 2016 08:24:12 +0100 [thread overview]
Message-ID: <20161121082412.04f5d7c9@erd980> (raw)
In-Reply-To: <20161118171557.GA2369@archie.localdomain>
On Fri, 18 Nov 2016 18:15:58 +0100
Clemens Gruber <clemens.gruber@pqgruber.com> wrote:
> Hi,
>
> On Fri, Nov 18, 2016 at 02:21:36PM +0100, David Jander wrote:
> > Or is there a way (that I ignore) to speed-up the generation of entropy in the
> > Linux kernel?
>
> Did you build your kernel with CONFIG_CRYPTO_JITTERENTROPY=y and
> CONFIG_CRYPTO_DRBG_HASH=y ?
Yes I had those.
> Also, depending on your platform, there might be hardware support.
> We use an i.MX6 which also includes a hardware RNG in its Cryptographic
> Acceleration And Assurance Module (CAAM).
> So we enabled CONFIG_CRYPTO_DEV_FSL_CAAM and use rngd to feed /dev/hwrng
> into the kernel's entropy pool.
Ah. There it is. I was already wondering if there wasn't any CAAM support. I
expected it under drivers/char/hwrng. Instead it is hidden under /crypto/.
> Could you try with above options and rngd started early? There should be
> much more entropy available in a short time.
Will try that out.
> It's probably a bad idea to just patch python for every PTXdist user.
Yes, I was thinking about making that patch configurable somehow.
> Not everybody is willing to trade security for faster start times.
I agree.
> Besides, not having enough entropy will lead to other problems as well.
>
> If you are using systemd, verify that
> PTXCONF_SYSTEMD_DISABLE_RANDOM_SEED is not set.
> systemd-random-seed restores the random seed of the system at early boot
> and saves it at shutdown. So only the first boot would take longer.
Thanks a lot.
Best regards,
--
David Jander
Protonic Holland.
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next prev parent reply other threads:[~2016-11-21 7:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-18 13:21 David Jander
2016-11-18 17:15 ` Clemens Gruber
2016-11-19 1:23 ` Roland Hieber
2016-11-21 7:24 ` David Jander [this message]
2016-11-29 8:56 ` Alexander Dahl
2016-11-29 9:33 ` Michael Olbrich
2016-11-29 13:14 ` Clemens Gruber
2016-11-29 13:41 ` Alexander Dahl
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