From owner-freebsd-questions@FreeBSD.ORG Mon Feb 28 20:13:10 2005 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D4FE716A4CE for ; Mon, 28 Feb 2005 20:13:10 +0000 (GMT) Received: from obsecurity.dyndns.org (CPE0050040655c8-CM00111ae02aac.cpe.net.cable.rogers.com [69.199.47.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id 82DD743D39 for ; Mon, 28 Feb 2005 20:13:10 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: by obsecurity.dyndns.org (Postfix, from userid 1000) id 5BEE753483; Mon, 28 Feb 2005 12:13:08 -0800 (PST) Date: Mon, 28 Feb 2005 12:13:08 -0800 From: Kris Kennaway To: Ted Mittelstaedt Message-ID: <20050228201308.GC70059@xor.obsecurity.org> References: <20050228124023.GH1672@alzatex.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="0lnxQi9hkpPO77W3" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i cc: FreeBSD questions cc: "Loren M. Lang" cc: Rob cc: Kris Kennaway Subject: Re: /dev/io , /dev/mem : only used by Xorg? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Feb 2005 20:13:11 -0000 --0lnxQi9hkpPO77W3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 28, 2005 at 04:58:02AM -0800, Ted Mittelstaedt wrote: > Yes - there's some random testing suites on the Internet, find a > few and compile them. (ENT for example) Run them repeatedly and see what > happens. >=20 > Part of the problem is that BY DEFAULT the random device DOES NOT > look at interrupts. See the man page for rndcontrol. Presumably > the system admin of the system knows this and looks at his dmesg > output to see which irq's are assigned to network cards and hard > disks (which are fairly good sources of randomness) and sets the > random device to use these. In practice this isn't something mentioned > in the install docs so it is very unlikely many people know. >=20 > Another strange thing is that /dev/random should block when it > runs out of entropy - it doesen't seem to do so, however. And the > device doesen't seem to gain entropy that quickly. No, it should not block because it's not defined to block and that would be a bad interface anyway. It does return as many bytes as it can, and if the application wants more entropy than given then it can either poll, or fall back to alternative mechanisms as it sees fit (blocking would prevent this). Anyway, all your concerns are moot for 5.x. Kris --0lnxQi9hkpPO77W3 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (FreeBSD) iD8DBQFCI3tUWry0BWjoQKURAhMzAKDn6orujolRb5uFecKzDRGsuErjNgCfYpaw XvpBZRYuyBks/MD0vP1KTM8= =W9oP -----END PGP SIGNATURE----- --0lnxQi9hkpPO77W3--