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 CA951C43331 for ; Tue, 12 Nov 2019 13:23:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A6D08214E0 for ; Tue, 12 Nov 2019 13:23:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727392AbfKLNXX convert rfc822-to-8bit (ORCPT ); Tue, 12 Nov 2019 08:23:23 -0500 Received: from albireo.enyo.de ([37.24.231.21]:42750 "EHLO albireo.enyo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726188AbfKLNXW (ORCPT ); Tue, 12 Nov 2019 08:23:22 -0500 Received: from [172.17.203.2] (helo=deneb.enyo.de) by albireo.enyo.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) id 1iUW8U-0005If-Jp; Tue, 12 Nov 2019 13:23:10 +0000 Received: from fw by deneb.enyo.de with local (Exim 4.92) (envelope-from ) id 1iUW8U-0002Cz-BA; Tue, 12 Nov 2019 14:23:10 +0100 From: Florian Weimer To: Stephan =?iso-8859-1?Q?M=FCller?= Cc: Arnd Bergmann , Greg Kroah-Hartman , linux-crypto@vger.kernel.org, LKML , linux-api@vger.kernel.org, "Eric W. Biederman" , "Alexander E. Patrakov" , "Ahmed S. Darwish" , "Theodore Y. Ts'o" , Willy Tarreau , Matthew Garrett , Vito Caputo , Andreas Dilger , Jan Kara , Ray Strode , William Jon McCann , zhangjs , Andy Lutomirski , Florian Weimer , Lennart Poettering , Nicolai Stange , "Peter\, Matthias" , Marcelo Henrique Cerri , Roman Drahtmueller , Neil Horman Subject: Re: [PATCH v24 00/12] /dev/random - a new approach with full SP800-90B compliance References: <6157374.ptSnyUpaCn@positron.chronox.de> Date: Tue, 12 Nov 2019 14:23:10 +0100 In-Reply-To: <6157374.ptSnyUpaCn@positron.chronox.de> ("Stephan \=\?iso-8859-1\?Q\?M\=FCller\=22's\?\= message of "Mon, 11 Nov 2019 19:17:30 +0100") Message-ID: <875zjpfcu9.fsf@mid.deneb.enyo.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Stephan Müller: > * support deactivation of TRNG (i.e. blocking behavior of /dev/random) > at compile time. If deactivated, /dev/random behaves like > getrandom(2). I don't quite understand this comment. Doesn't getrandom with the GRND_RANDOM always behave like /dev/random? Presumably, without the TRNG tap, the GRND_RANDOM flag for getrandom is ignored, and reading from /dev/random behaves like reading from /dev/urandom. Anyway, reading the accompanying PDF, this looks rather impressive: the userspace bootstrapping problem is gone (the issue where waiting for more entropy prevents the collection of more entropy), *and* we can still make the standards people happy. (Replying from my other account due to mail issues, sorry.)