From owner-freebsd-stable@FreeBSD.ORG Thu Apr 3 11:50:07 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 73642106566B for ; Thu, 3 Apr 2008 11:50:07 +0000 (UTC) (envelope-from freebsd-stable@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id EFE8F8FC0A for ; Thu, 3 Apr 2008 11:50:06 +0000 (UTC) (envelope-from freebsd-stable@m.gmane.org) Received: from root by ciao.gmane.org with local (Exim 4.43) id 1JhNxC-0006yQ-V5 for freebsd-stable@freebsd.org; Thu, 03 Apr 2008 11:50:02 +0000 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 03 Apr 2008 11:50:02 +0000 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 03 Apr 2008 11:50:02 +0000 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-stable@freebsd.org From: Ivan Voras Date: Thu, 03 Apr 2008 13:46:39 +0200 Lines: 47 Message-ID: References: <47F3DA07.4020209@forrie.com> <20080402203859.GB80314@slackbox.xs4all.nl> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigBB26BF08CA10B130C23DE644" X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Thunderbird 2.0.0.6 (X11/20071022) In-Reply-To: <20080402203859.GB80314@slackbox.xs4all.nl> X-Enigmail-Version: 0.95.0 Sender: news Subject: Re: Digitally Signed Binaries w/ Kernel support, etc. X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Apr 2008 11:50:07 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigBB26BF08CA10B130C23DE644 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Roland Smith wrote: > On Wed, Apr 02, 2008 at 03:09:59PM -0400, Forrest Aldrich wrote: >> Does FreeBSD have support for digitally signed binary checking, simila= r to=20 >> what Linux has with bsign and DigSig, where system binaries are signed= and=20 >> this signature is verified before being run in the kernel? >=20 > If an attacker can modify binaries, he already has root privileges. In > that case, what will stop him from creating a new pgp key and re-sign > his doctered binaries? >=20 >> This would be very useful to have to further tighen-down the system. >=20 > As an alternative, on FreeBSD you can set the system immutable flag on > binaries (see chflags(1)), and set the securelevel > 0. See > init(8). Once this is set, not even root can undo this. You have to > reboot to reset the securelevel to -1. Signing binaries could be naturally tied in with securelevel, where some securelevel (1?) would mean kernel no longer accepts new keys. > The only weakness is that the securelevel is set quite late in the boot= > process. An attacker could compromise the system if he gets access > before the securelevel is set. --------------enigBB26BF08CA10B130C23DE644 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFH9MOfldnAQVacBcgRAqTaAJ9ipONFQIGOYxYKpbiByRCdEyLQvwCfTCd6 BVj7lJYaNjUWDjFXmO8cuP8= =RAbH -----END PGP SIGNATURE----- --------------enigBB26BF08CA10B130C23DE644--