From: Herbert Xu Subject: Re: [PATCH] crypto: sun4i-ss: support the Security System PRNG Date: Thu, 22 Jun 2017 07:47:10 +0800 Message-ID: <20170621234710.GA22306@gondor.apana.org.au> References: <20170620085819.20114-1-clabbe.montjoie@gmail.com> <20170620095947.i3r3iym2cxz5jciw@flea.lan> <20170620114536.GA4766@Red> <20170621064855.z5mu4f3r3dt4kotc@flea.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Corentin Labbe , davem@davemloft.net, wens@csie.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org To: Maxime Ripard Return-path: Received: from orcrist.hmeau.com ([104.223.48.154]:33632 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751689AbdFUXrk (ORCPT ); Wed, 21 Jun 2017 19:47:40 -0400 Content-Disposition: inline In-Reply-To: <20170621064855.z5mu4f3r3dt4kotc@flea.lan> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Wed, Jun 21, 2017 at 08:48:55AM +0200, Maxime Ripard wrote: > On Tue, Jun 20, 2017 at 01:45:36PM +0200, Corentin Labbe wrote: > > On Tue, Jun 20, 2017 at 11:59:47AM +0200, Maxime Ripard wrote: > > > Hi, > > > > > > On Tue, Jun 20, 2017 at 10:58:19AM +0200, Corentin Labbe wrote: > > > > The Security System have a PRNG, this patch add support for it via > > > > crypto_rng. > > > > > > This might be a dumb question, but is the CRYPTO_RNG code really > > > supposed to be used with PRNG? > > > > > > > Yes, see recently added drivers/crypto/exynos-rng.c > > It's still not really clear from the commit log (if you're talking > about c46ea13f55b6) why and if using the RNG code for a PRNG is a good > idea. The hwrng interface is meant for true hardware RNGs. The crypto API rng interface is primarily intended for PRNGs. Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt