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From: krzk@kernel.org (Krzysztof Kozlowski)
To: linux-arm-kernel@lists.infradead.org
Subject: Question - seeding the hw pseudo random number generator
Date: Mon, 20 Mar 2017 20:24:01 +0200	[thread overview]
Message-ID: <20170320182401.x2yhl5pcpqihcvj3@kozik-lap> (raw)
In-Reply-To: <20170320132858.GA27044@gondor.apana.org.au>

On Mon, Mar 20, 2017 at 09:28:58PM +0800, Herbert Xu wrote:
> On Mon, Mar 20, 2017 at 12:19:32PM +0530, PrasannaKumar Muralidharan wrote:
> >
> > AF_ALG interface for rng does have seeding support. I think hw_random
> > does not provide seeding support intentionally as I understand that
> > True RNG need not require seeding (please correct me if I am wrong).
> 
> Yes.  We should be converting PRNGs in hwrng over to algif_rng.

The actual hardware block can be seeded from true RNG (taking data
from thermal noise) so the solutions (if I understand correctly) for
exynos-rng might be:
1. Seed from internal TRNG making it a proper hwrandom device,
2. Convert to AF_ALG and seed with data from user-space through that
   interface.

Thanks for explanation, I'll queue it to my tasks list.

Best regards,
Krzysztof

  parent reply	other threads:[~2017-03-20 18:24 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-18  9:25 Question - seeding the hw pseudo random number generator Krzysztof Kozlowski
2017-03-20  6:49 ` PrasannaKumar Muralidharan
2017-03-20 13:28   ` Herbert Xu
2017-03-20 13:39     ` Stephan Müller
2017-03-23  8:03       ` Harald Freudenberger
2017-03-23 11:35         ` Stephan Müller
2017-03-20 18:24     ` Krzysztof Kozlowski [this message]
2017-03-23  8:23     ` Corentin Labbe
2017-03-23  9:44       ` Herbert Xu
2017-03-23 11:44         ` Stephan Müller
2017-03-23 13:06         ` Stephan Müller
2017-03-26  4:10         ` Stephan Müller

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