From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Stephen J. Turnbull" Newsgroups: gmane.emacs.devel Subject: Re: [PATCH RFC] GnuTLS: Support TOFU certificate checking. Date: Thu, 09 Oct 2014 11:43:49 +0900 Message-ID: <878ukqq7x6.fsf@uwakimon.sk.tsukuba.ac.jp> References: <1412716565-7786-1-git-send-email-toke@toke.dk> <87a957o87z.fsf@alrua-karlstad.karlstad.toke.dk> <87bnpm2249.fsf@toke.dk> <83eguik9ip.fsf@gnu.org> <83d2a2k91n.fsf@gnu.org> <83bnpmk8fd.fsf@gnu.org> <838ukqk7gd.fsf@gnu.org> <834mvek6dq.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 X-Trace: ger.gmane.org 1412822676 24551 80.91.229.3 (9 Oct 2014 02:44:36 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 9 Oct 2014 02:44:36 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Oct 09 04:44:29 2014 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Xc3iP-0005qQ-BB for ged-emacs-devel@m.gmane.org; Thu, 09 Oct 2014 04:44:29 +0200 Original-Received: from localhost ([::1]:39530 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xc3iO-0005dX-W9 for ged-emacs-devel@m.gmane.org; Wed, 08 Oct 2014 22:44:29 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:36732) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xc3i5-0005dD-4B for emacs-devel@gnu.org; Wed, 08 Oct 2014 22:44:15 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xc3ht-00065P-PD for emacs-devel@gnu.org; Wed, 08 Oct 2014 22:44:09 -0400 Original-Received: from shako.sk.tsukuba.ac.jp ([130.158.97.161]:39923) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xc3ht-00063c-FJ for emacs-devel@gnu.org; Wed, 08 Oct 2014 22:43:57 -0400 Original-Received: from uwakimon.sk.tsukuba.ac.jp (uwakimon.sk.tsukuba.ac.jp [130.158.99.156]) by shako.sk.tsukuba.ac.jp (Postfix) with ESMTP id 344B01C3A17 for ; Thu, 9 Oct 2014 11:43:49 +0900 (JST) Original-Received: by uwakimon.sk.tsukuba.ac.jp (Postfix, from userid 1000) id 2611E1A2888; Thu, 9 Oct 2014 11:43:49 +0900 (JST) In-Reply-To: X-Mailer: VM undefined under 21.5 (beta34) "kale" acf1c26e3019 XEmacs Lucid (x86_64-unknown-linux) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 130.158.97.161 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:175156 Archived-At: Ted Zlatanov writes: > On Wed, 08 Oct 2014 17:31:33 +0200 Lars Magne Ingebrigtsen wrote: > LMI> If the user can't answer questions, the default would be to reject > LMI> invalid certificates. > > They are not necessarily invalid. Youngsters these days have trouble with precise use of English, and the usage "invalid" for "unable to establish a chain of trust to a trusted root"" is common. Get used to it, old man. :-) FWIW, I think I'm one of the more paranoid folks around Emacs development, and I don't see a problem with completing whatever operations are necessary to get safely back to Lisp to query the user, as long as (1) No data is transmitted from Emacs to the remote, except that needed by the protocol to establish the connection (transmitting credentials should be avoided if possible, but that may not be possible in some protocols). (2) All data received is squirreled away in a buffer inaccessible to Emacs (except for the code that will eventually move it to Lisp, of course), and this buffer is "read-locked" until permission is received from the user. (3) The amount of data accepted is effectively limited (to avoid DoS attacks -- this is probably gilding a lily, but I am paranoid). Regards,