From owner-freebsd-security Thu Nov 18 9: 0:52 1999 Delivered-To: freebsd-security@freebsd.org Received: from newsfeed.win.net (newsfeed.win.net [216.24.27.8]) by hub.freebsd.org (Postfix) with ESMTP id 081F31547F; Thu, 18 Nov 1999 09:00:36 -0800 (PST) (envelope-from barrett@phoenix.aye.net) Received: from phoenix.aye.net (phoenix.aye.net [198.7.192.5]) by newsfeed.win.net (8.8.8/8.6.9) with SMTP id MAA07917; Thu, 18 Nov 1999 12:00:27 -0500 (EST) Date: Thu, 18 Nov 1999 12:00:47 -0500 (EST) From: Barrett Richardson To: Kris Kennaway Cc: TrouBle , David G Andersen , freebsd-security@FreeBSD.ORG Subject: Re: secure filesystem wiping In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Wed, 17 Nov 1999, Kris Kennaway wrote: > On Thu, 18 Nov 1999, TrouBle wrote: > > > obliterate only wipes the one file you specify.. i want to wipe all the > > free space on the disk, without damaging good intact files on it, linux > > has a progrtam called wipe that does this, now ill ask again is there > > something similiar for freebsd > > dd if=/dev/zero of=/usr/bigfile || rm -f /usr/bigfile > > Replace /dev/zero with /dev/urandom according to taste. > > Kris > Excellant idea, and simple. The problem with modern encoding formats is that the previous layer is still somewhat recoverable, and sometimes layers before that. The obliterate program overwrites with carefully chosen patterns intended to obscure the residual stray magnetic fields left by previously written data. A file that big will be a problem for obliterate though, it'll have to be done in strips. - Barrett To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message