From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Michael Albinus Newsgroups: gmane.emacs.devel,gmane.emacs.pretest.bugs Subject: Re: 22.1.50; insert-file-contents is slow under tramp Date: Mon, 27 Aug 2007 16:53:23 +0200 Message-ID: References: <87veb6l9b0.fsf@escher.local.home> <46CD98DC.1050701@gmx.at> <87r6lul2fc.fsf@escher.local.home> <46CDC8B3.7000301@gmx.at> <46CDED2B.3080904@gmx.at> <87k5rmkmu0.fsf@escher.local.home> <46CDF5B7.2030201@gmx.at> <87fy2akjzt.fsf@escher.local.home> <87bqcxzeat.fsf@gmx.de> <871wdqlgzz.fsf@gmx.de> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1188226409 14792 80.91.229.12 (27 Aug 2007 14:53:29 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Mon, 27 Aug 2007 14:53:29 +0000 (UTC) Cc: emacs-pretest-bug@gnu.org, Stephen Berman , emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Aug 27 16:53:28 2007 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1IPfy1-0002c8-GY for ged-emacs-devel@m.gmane.org; Mon, 27 Aug 2007 16:53:26 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IPfxz-00074R-46 for ged-emacs-devel@m.gmane.org; Mon, 27 Aug 2007 10:53:23 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IPfxv-00070f-1f for emacs-devel@gnu.org; Mon, 27 Aug 2007 10:53:19 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IPfxs-0006xI-Cd for emacs-devel@gnu.org; Mon, 27 Aug 2007 10:53:18 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IPfxs-0006wu-2G for emacs-devel@gnu.org; Mon, 27 Aug 2007 10:53:16 -0400 Original-Received: from mailrelay2.alcatel.de ([194.113.59.96]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1IPfxn-0001or-2D; Mon, 27 Aug 2007 10:53:11 -0400 Original-Received: from slbhab.alcatel.de (slbhab.bln.sel.alcatel.de [149.204.63.218]) by mailrelay2.alcatel.de (8.13.4/8.13.4/ICT) with ESMTP id l7REr7lK027678; Mon, 27 Aug 2007 16:53:07 +0200 In-Reply-To: (Stefan Monnier's message of "Mon, 27 Aug 2007 09:58:32 -0400") User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (hpux) X-Scanned-By: MIMEDefang 2.51 on 149.204.45.73 X-Detected-Kernel: Linux 2.4-2.6 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:77292 gmane.emacs.pretest.bugs:19646 Archived-At: Stefan Monnier writes: > How can you do that? Let's say I access a file of user BAR from user FOO, > how would you go about doing it in such a way that user TOTO can never see > the content of the file? BAR can't use `chown' (unless it's root). BAR must give away the ownership of the temporary file to FOO. See this test (BAR is albinus, FOO is hostmann). Any TOTO cannot see the contents of the file, despite she is root - in this case we can forget security at all. # whoami albinus # touch stefan # chmod 0400 stefan # ll stefan -r-------- 1 albinus smc3 0 Aug 27 16:36 stefan # chown hostmann stefan # ll stefan -r-------- 1 hostmann smc3 0 Aug 27 16:36 stefan # cat stefan cat: stefan: Permission denied Note that we are speaking about temporary files. Either FOO or BAR is always me (locally), for the other user I have a Tramp connection capable to send UNIX commands. I can send commands under both user permissions in the order I do need. It's a kind of puzzling who must give ownership to whom (it depends on the copying direction), but it's a finite number of cases only. > Stefan Best regards, Michael.