From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/84218 Path: news.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.gnus.general Subject: Re: Emacs Cloud Date: Tue, 11 Feb 2014 04:14:40 -0800 Message-ID: <87a9dxkfrj.fsf@building.gnus.org> References: <877g9fxwih.fsf@building.gnus.org> <87d2j140t1.fsf@building.gnus.org> <87lhxnaw6g.fsf@lifelogs.com> <877g966y3u.fsf@building.gnus.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1392121052 17141 80.91.229.3 (11 Feb 2014 12:17:32 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 11 Feb 2014 12:17:32 +0000 (UTC) Cc: ding@gnus.org To: Daiki Ueno Original-X-From: ding-owner+M32470@lists.math.uh.edu Tue Feb 11 13:17:40 2014 Return-path: Envelope-to: ding-account@gmane.org Original-Received: from util0.math.uh.edu ([129.7.128.18]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WDCHR-0007Xe-9C for ding-account@gmane.org; Tue, 11 Feb 2014 13:17:37 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.math.uh.edu) by util0.math.uh.edu with smtp (Exim 4.63) (envelope-from ) id 1WDCGE-0007cJ-1N; Tue, 11 Feb 2014 06:16:22 -0600 Original-Received: from mx2.math.uh.edu ([129.7.128.33]) by util0.math.uh.edu with esmtps (TLSv1:AES256-SHA:256) (Exim 4.63) (envelope-from ) id 1WDCGC-0007c3-4L for ding@lists.math.uh.edu; Tue, 11 Feb 2014 06:16:20 -0600 Original-Received: from quimby.gnus.org ([80.91.231.51]) by mx2.math.uh.edu with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) (envelope-from ) id 1WDCG6-0000Ew-Ah for ding@lists.math.uh.edu; Tue, 11 Feb 2014 06:16:15 -0600 Original-Received: from hermes.netfonds.no ([80.91.224.195]) by quimby.gnus.org with esmtp (Exim 4.80) (envelope-from ) id 1WDCG4-00038I-S2 for ding@gnus.org; Tue, 11 Feb 2014 13:16:12 +0100 Original-Received: from [204.14.154.233] (helo=building.gnus.org) by hermes.netfonds.no with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.72) (envelope-from ) id 1WDCFq-0007KZ-UM; Tue, 11 Feb 2014 13:15:59 +0100 In-Reply-To: (Daiki Ueno's message of "Mon, 10 Feb 2014 17:43:11 +0900") User-Agent: Gnus/5.13001 (Ma Gnus v0.10) Emacs/24.3.50 (gnu/linux) X-MailScanner-ID: 1WDCFq-0007KZ-UM MailScanner-NULL-Check: 1392725759.62953@igVFRBV5JudaGJKSGx1rJg X-Spam-Status: No X-Spam-Score: -1.9 (-) List-ID: Precedence: bulk Xref: news.gmane.org gmane.emacs.gnus.general:84218 Archived-At: Daiki Ueno writes: > I wasn't really following the discussion, but I now suspect the use of > symmetric encryption here might be irrelevant in the first place. Do > you plan to use untrusted (even authenticated, e.g. Gmail) IMAP servers > for file sharing, right? > > If so, those symmetrically encrypted data can be a target of dictionary > attacks. You will be giving unlimited time to attackers (or server > admins) cracking your encrypted data. That's why people normally don't > want to upload their secret keys in ~/.ssh or ~/.gnupg (even if they are > password-protected by default). We're talking about storing the data at a host you trust enough that you let them store your unencrypted mail, which probably reveals more about you than any .newsrc data would ever do. However, that doesn't mean that Gnus shouldn't try to make things safer for you if you want. Somebody that runs an IMAP server for you already has some of your credentials on hand, as well as the data from a thousand password resets emails. Storing the .newsrc data with symmetric encryption helps against 1) accidental data leakage (when somebody is watching the output of tcpdump) or 2) idle curiosity (when somebody has too much time on their hands and are grubbing through data). If it's a directed attack by the owners of the IMAP server, you're probably screwed, anyway. In addition to storing the newsrc data, I also want to store the relevant bits from your .authinfo. That's the really ticklish bits. If you're connecting to a couple of news servers that require NNTP passwords, those would also be stored in the encrypted chunks. However, those aren't the most secret secrets in the universe, anyway. Most NNTP servers don't even support TLS, so you're sending those credentials using plain text. So to sum up: 1) Carthage should be destroyed. 2) Symmetric encryption is good enough for this use case. -- (domestic pets only, the antidote for overdose, milk.) bloggy blog http://lars.ingebrigtsen.no/