From owner-freebsd-security Fri May 21 12:35:43 1999 Delivered-To: freebsd-security@freebsd.org Received: from andrew.cmu.edu (ANDREW.CMU.EDU [128.2.10.101]) by hub.freebsd.org (Postfix) with ESMTP id 169311502C; Fri, 21 May 1999 12:35:09 -0700 (PDT) (envelope-from tcrimi+@andrew.cmu.edu) Received: (from postman@localhost) by andrew.cmu.edu (8.8.5/8.8.2) id PAA20959; Fri, 21 May 1999 15:35:06 -0400 (EDT) Received: via switchmail; Fri, 21 May 1999 15:35:05 -0400 (EDT) Received: from unix6.andrew.cmu.edu via qmail ID ; Fri, 21 May 1999 15:34:57 -0400 (EDT) Received: from unix6.andrew.cmu.edu via qmail ID ; Fri, 21 May 1999 15:34:57 -0400 (EDT) Received: from mms.4.60.Jun.27.1996.03.02.53.sun4.51.EzMail.2.0.CUILIB.3.45.SNAP.NOT.LINKED.unix6.andrew.cmu.edu.sun4m.54 via MS.5.6.unix6.andrew.cmu.edu.sun4_51; Fri, 21 May 1999 15:34:56 -0400 (EDT) Message-ID: Date: Fri, 21 May 1999 15:34:56 -0400 (EDT) From: Thomas Valentino Crimi To: brooks@one-eyed-alien.net, Eivind Eklund Subject: Re: secure deletion Cc: Dag-Erling Smorgrav , "Ilmar S. Habibulin" , posix1e@cyrus.watson.org, freebsd-security@FreeBSD.ORG In-Reply-To: <19990521201043.I85583@bitbox.follo.net> References: <19990521201043.I85583@bitbox.follo.net> Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Excerpts from mail: 21-May-99 Re: secure deletion by Eivind Eklund@FreeBSD.OR > Either tunefs or chflags - it would be relatively expensive, so if you > only need it for some data, it is probably better to have more > fine-grained control than per-FS. Might I also suggest a 'normal' user option for one particular file to be securely wiped? Myself I usea simple replacement for rm I call wipe. It overwrites, fsyncs, overwrites again with the 10101, 01010 pattern, zero's out the file, renames it to a random direntry and then unlinks (whoa.. talk about what would happen to hardlinks :). As an extra opton to rm, for a user to be able to tell the kernel to securely delet a file even though it isn't routinely flagged for it (having to chflags then rm for each case is rather silly, although rm -w or something should do it for you). BTW, might I taek it thatwith the kernel deletion method, a warning should occur if you attemp to delete a secure file which still has a hardlink to it. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message