From owner-freebsd-stable@FreeBSD.ORG Fri Apr 4 16:55:43 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 CA50E1065673; Fri, 4 Apr 2008 16:55:43 +0000 (UTC) (envelope-from rsmith@xs4all.nl) Received: from smtp-vbr2.xs4all.nl (smtp-vbr2.xs4all.nl [194.109.24.22]) by mx1.freebsd.org (Postfix) with ESMTP id 5D3858FC25; Fri, 4 Apr 2008 16:55:43 +0000 (UTC) (envelope-from rsmith@xs4all.nl) Received: from slackbox.xs4all.nl (slackbox.xs4all.nl [213.84.242.160]) by smtp-vbr2.xs4all.nl (8.13.8/8.13.8) with ESMTP id m34Gtfpw085390; Fri, 4 Apr 2008 18:55:41 +0200 (CEST) (envelope-from rsmith@xs4all.nl) Received: by slackbox.xs4all.nl (Postfix, from userid 1001) id 1FDE1B82D; Fri, 4 Apr 2008 18:55:41 +0200 (CEST) Date: Fri, 4 Apr 2008 18:55:41 +0200 From: Roland Smith To: Ivan Voras Message-ID: <20080404165541.GA675@slackbox.xs4all.nl> Mail-Followup-To: Ivan Voras , freebsd-stable@freebsd.org References: <47F3DA07.4020209@forrie.com> <20080402203859.GB80314@slackbox.xs4all.nl> <20080403164108.GA12190@slackbox.xs4all.nl> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="yrj/dFKFPuw6o+aM" Content-Disposition: inline In-Reply-To: X-GPG-Fingerprint: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 X-GPG-Key: http://www.xs4all.nl/~rsmith/pubkey.txt X-GPG-Notice: If this message is not signed, don't assume I sent it! User-Agent: Mutt/1.5.17 (2007-11-01) X-Virus-Scanned: by XS4ALL Virus Scanner Cc: freebsd-stable@freebsd.org 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: Fri, 04 Apr 2008 16:55:43 -0000 --yrj/dFKFPuw6o+aM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Apr 04, 2008 at 10:58:40AM +0200, Ivan Voras wrote: > >> Signing binaries could be naturally tied in with securelevel, where so= me > >> securelevel (1?) would mean kernel no longer accepts new keys. > >=20 > > If you set the system immutable flag on the binaries, you cannot modify= them at > > all at securelevel >0. Signing the binaries would be pointless in that = case. >=20 > I think these are separate things. Modifying binaries is separate from > introducing new binaries. SCHG would prevent the former, but not the latt= er. If you set the SCHG flag on the directories in $PATH, you can't put anything new there as well. > Of course, with the popularity of various scripting languages it's not > as useful as it could be on the first thought. If an intruder want to do real damage with a script, he pretty much has to = be root. In which case you're already fscked. Or the script must contain a viable local root exploit, which amounts to the same thing. As usual, there is a balance between security and usability. Where that balance lies depends on the situation. Roland --=20 R.F.Smith http://www.xs4all.nl/~rsmith/ [plain text _non-HTML_ PGP/GnuPG encrypted/signed email much appreciated] pgp: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 (KeyID: C321A725) --yrj/dFKFPuw6o+aM Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.8 (FreeBSD) iEYEARECAAYFAkf2XY0ACgkQEnfvsMMhpyWjBgCgoMQMR+Np01KYLsU3SX+AuEgC Sq8AoI5dLg7xkJB1t8yKW1eMkGzjHGSl =9BP7 -----END PGP SIGNATURE----- --yrj/dFKFPuw6o+aM--