From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0241CC38A2A for ; Fri, 8 May 2020 12:17:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D297E208D6 for ; Fri, 8 May 2020 12:17:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726636AbgEHMRf (ORCPT ); Fri, 8 May 2020 08:17:35 -0400 Received: from mail.thorsis.com ([92.198.35.195]:60190 "EHLO mail.thorsis.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726627AbgEHMRf (ORCPT ); Fri, 8 May 2020 08:17:35 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.thorsis.com (Postfix) with ESMTP id 125A71FC7 for ; Fri, 8 May 2020 14:17:33 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mail.thorsis.com Received: from mail.thorsis.com ([127.0.0.1]) by localhost (mail.thorsis.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 7o0xgFGndeQp for ; Fri, 8 May 2020 14:17:28 +0200 (CEST) Received: by mail.thorsis.com (Postfix, from userid 109) id D2DFD2A4F; Fri, 8 May 2020 14:17:28 +0200 (CEST) From: Alexander Dahl To: linux-crypto@vger.kernel.org Cc: Stephan Mueller Subject: Re: jitterentropy_rng on armv5 embedded target Date: Fri, 08 May 2020 14:17:25 +0200 Message-ID: <2049720.SxWqT2AVQ6@ada> In-Reply-To: <6309135.Bj5FvMsAKG@tauon.chronox.de> References: <2567555.LKkejuagh6@ada> <6309135.Bj5FvMsAKG@tauon.chronox.de> Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Hello, Stephan, Am Freitag, 8. Mai 2020, 13:58:14 CEST schrieb Stephan Mueller: > > (Although those daemons would solve my problem, I currently try > > to avoid them, because memory on my platform is very restricted and every > > additional running userspace process costs at least around 1 MB.) > > If you compile it and you also have AF_ALG for RNGs compiled, you can use it > through the AF_ALG interface (see [1] for a library). But IMHO if you are > space-constrained, you do not want that code. > > Rather use the jitterentropy-library from [2] and link it straight from your > application. That would be dropbear or openssl (and applications using libssl). While that would certainly be nice, I fear it's out of my scope. ;-) > > If so, then how is it supposed to be set up? > > It is intended for in-kernel purposes (namely to seed its DRBG). Okay and DRBG has nothing to do with /dev/random ? Then where do the random numbers for that come from (in the current or previous kernels without your new lrng)? Curious Alex