From owner-freebsd-rc@FreeBSD.ORG Tue Sep 11 23:01:19 2012 Return-Path: Delivered-To: freebsd-rc@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 20E08106566B; Tue, 11 Sep 2012 23:01:19 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from anubis.delphij.net (anubis.delphij.net [IPv6:2001:470:1:117::25]) by mx1.freebsd.org (Postfix) with ESMTP id EDBA28FC08; Tue, 11 Sep 2012 23:01:18 +0000 (UTC) Received: from epsilon.delphij.net (drawbridge.ixsystems.com [206.40.55.65]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by anubis.delphij.net (Postfix) with ESMTPSA id 5E48D1E127; Tue, 11 Sep 2012 16:01:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=delphij.net; s=anubis; t=1347404478; bh=EHfBL39JkbGdRPWINbuX1xpfNBO+MGgoBt+KbVi06NQ=; h=Date:From:Reply-To:To:CC:Subject:References:In-Reply-To; b=37P7b4iE8opeZbjFV+QqIRo0eYdIN2BB8G3UbP3q806U7vF3h/rgVERrJn3BBBC/E ScZRwZArs+hBidS4x8DlsbqMPKuFIqwyl4lxS7cqN96e+qgt/2o/YDKE+09mpcRb9N A2Q+qq6zhs3UW+dylPZYmzns2WSKWst0uUrpRQvE= Message-ID: <504FC2BD.6070402@delphij.net> Date: Tue, 11 Sep 2012 16:01:17 -0700 From: Xin Li Organization: The freeBSD Project User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:10.0.7) Gecko/20120830 Thunderbird/10.0.7 MIME-Version: 1.0 To: Arthur Mesh References: <20120911061530.GA77399@dragon.NUXI.org> <504EDC67.9070700@FreeBSD.org> <86sjao7q8c.fsf@ds4.des.no> <20120911205302.27484fd6@gumby.homeunix.com> <20120911200925.GA88456@dragon.NUXI.org> <504FA76A.5000209@delphij.net> <20120911211730.GB89188@dragon.NUXI.org> <504FAB87.3020701@delphij.net> <20120911215212.GA89515@dragon.NUXI.org> <504FBD15.8040907@delphij.net> <20120911224855.GE14077@x96.org> In-Reply-To: <20120911224855.GE14077@x96.org> X-Enigmail-Version: 1.4.3 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Doug Barton , freebsd-rc@freebsd.org, obrien@freebsd.org, freebsd-security@freebsd.org, RW , Dag-Erling ??? , d@delphij.net Subject: Re: svn commit: r239569 - head/etc/rc.d X-BeenThere: freebsd-rc@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: d@delphij.net List-Id: "Discussion related to /etc/rc.d design and implementation." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Sep 2012 23:01:19 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 09/11/12 15:48, Arthur Mesh wrote: > On Tue, Sep 11, 2012 at 03:37:09PM -0700, Xin Li wrote: >> Using gzip is better than not using it though, since 4k worth of >> compressed data is better than 4k worth of plain text because of >> higher entropy destiny (note that the FreeBSD gzip uses 64K of >> input/output buffer for compression by the way so maybe only the >> first 64K is meaningful if we take only 4k of output). > > Since there is 1:1 correspondence between compressed and > uncompressed data, entropy should be the same in both. I am not > sure it's better to use compression than not -- you do end up > seeding fewer bytes to yarrow, but you spend more CPU cycles > compressing it... Well, 1:1 correspondence is when we fed full text to /dev/random, which we don't, right? Only the first 4K gets consumed. So: Situation 1: we have 45K of plain text, and only first 4k is fed to /dev/random at about 5 bits of entropy per byte; Situation 2: we have 45K of plain text, compress to e.g. 25K and only first 4k is fed to /dev/random at more than 7.6 bits of entropy per byte; Therefore I think Situation 2 is better than situation 1. Cheers, - -- Xin LI https://www.delphij.net/ FreeBSD - The Power to Serve! Live free or die -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBCAAGBQJQT8K9AAoJEG80Jeu8UPuzdpAH/0yoP6LUeBTufuRG21olIWf0 Z8fAaJHPOplhNsiD8SCvZn2nep/FvUH4MARqVWeZ0GqcM9Yqz669WMEyDohWvufo TxjSDw+CmAZie+7IpBsyWmOWzqiaOG4RhCRed4KlKnJYWaBfxUDIQMOhpNANKVJY kL1TwI5dhz8twCMQiGLq/y975Sn7MegdoNTTCjLWBDJN9bCrH/8PnqJoXtd4KClP Jzu+ywbM1CwF+TV+g1QnfhFqZp8Gke0CSpZTNko0Vsk9XGJvHe0XmVxvlg7YYwJm zoXixJSbpdQsBuwUkzsrYK0nDIRLEbEIdh20Vi5aW1a9MBNsVSP/3lguuyz0Ntc= =o47Q -----END PGP SIGNATURE-----