From paul at cypherpunks.ca Mon Apr 2 02:04:07 2007 From: paul at cypherpunks.ca (Paul Wouters) Date: Mon, 2 Apr 2007 08:04:07 +0200 (CEST) Subject: [OTR-dev] mod_otr: man in the middle implementation for ejabberd In-Reply-To: <44acbb800703311644u6addd811n7924e8e22fa62432@mail.gmail.com> References: <200703301528.54920.ogoffart@kde.org> <44acbb800703311644u6addd811n7924e8e22fa62432@mail.gmail.com> Message-ID: On Sat, 31 Mar 2007, Donny Viszneki wrote: > However, I do acknowledge that the idea of the fingerprint is not one > that has experienced a great deal of penetration into the collective > of mainstream computer users. Using the "session id" is easier for "non computer experts". I have been thinking how to make it more friendly towards "non computer experts". Perhaps we could permanently display the session-id somewhere. Another issue is that no non-expert will even realise to right-click the OTR button. The alternative via pop-ups though is also not a good way, and annoys the heck out of the more expert users. > I have been rolling around an idea in my mind for a long time to > improve the utility of fingerprint/checksum mechanisms by making > fingerprints more memorable. What if the output of a hash weren't such > tightly packed, seemingly random data? What if you plugged > fingerprints into a dictionary file and got out a couple of words > instead? What if you plugged it into a clipart library? Or the library > of congress? Similar things have been done before, such as bubble-babble. > As mentioned earlier, I'm sure a lot of research could be invested in > determining which techniques produce the most effective output. I'm not sure how that all fits into the fingerprint of the *other* user.... Paul From paul at xelerance.com Mon Apr 16 23:52:16 2007 From: paul at xelerance.com (Paul Wouters) Date: Tue, 17 Apr 2007 05:52:16 +0200 (CEST) Subject: [OTR-dev] Re: IMPORTANT: gaim renamed to pidgin In-Reply-To: <462442AC.9070204@redhat.com> References: <462442AC.9070204@redhat.com> Message-ID: On Mon, 16 Apr 2007, Warren Togami wrote: > I have e-mailed you because you are listed as owners of gaim-* plugin packages > in Extras. Your action is now required to fix your plugins and rename them so Upstream for gaim-otr will not rename, at least not at this point. Is it okay to just fix the plugin's dependancies? I don't think I would like to see a "pidgin-otr" package rename where the original upstream package is still called "gaim-otr". > that deps will resolve and upgrade automatically. Please file an Extras > package review ticket with your new package, and assign it to me so that I may > expedite replacement of these packages. In which case this all does not apply to gaim-otr (apart from just fixing my package tomorrow when pidgin is available in the repository) Paul -- Building and integrating Virtual Private Networks with Openswan: http://www.amazon.com/gp/product/1904811256/104-3099591-2946327?n=283155 From mail at scottellis.com.au Sun Apr 29 01:47:46 2007 From: mail at scottellis.com.au (Scott Ellis) Date: Sun, 29 Apr 2007 15:47:46 +1000 Subject: [OTR-dev] session termination Message-ID: <96e269140704282247j28650c70tdbebc99d8fb49eba@mail.gmail.com> Hi All, Had the following bug report from a miranda user talking to a gaim user (thx Zeffel): "Scenario: Chat "blabla". Miranda user goes offline. Gaim OTR doesn't seem to notice this. Gaim user sends Miranda user offline message. When Miranda user goes back online, he receives: '[OTR Message] The encrypted message received from Gaim user is unreadable, as you are not currently communicating privately.' So Gaim OTR still sends an encrypted message, though Miranda user went offline. Miranda user can't decrypt the message any more." From ian at cypherpunks.ca Sun Apr 29 15:43:43 2007 From: ian at cypherpunks.ca (Ian Goldberg) Date: Sun, 29 Apr 2007 15:43:43 -0400 Subject: [OTR-dev] session termination In-Reply-To: <96e269140704282247j28650c70tdbebc99d8fb49eba@mail.gmail.com> References: <96e269140704282247j28650c70tdbebc99d8fb49eba@mail.gmail.com> Message-ID: <20070429194343.GJ10564@yoink.cs.uwaterloo.ca> One problem with dropping to FINISHED when you notice the other side goes offline is that that notification is unauthenticated. An adversary can trivially spoof a "Bob went offline" message, and it would be unfortunate if that caused Alice to forget her session keys. I also note that most IM networks, I'm pretty sure, don't tell Alice when Bob goes offline if Bob isn't Alice's buddy, but I don't know how often people chat with non-buddies in practice. - Ian From bfordham at socialistsushi.com Sun Apr 29 17:33:26 2007 From: bfordham at socialistsushi.com (Bryan L. Fordham) Date: Sun, 29 Apr 2007 17:33:26 -0400 Subject: [OTR-dev] session termination In-Reply-To: <20070429194343.GJ10564@yoink.cs.uwaterloo.ca> References: <96e269140704282247j28650c70tdbebc99d8fb49eba@mail.gmail.com> <20070429194343.GJ10564@yoink.cs.uwaterloo.ca> Message-ID: <46350F26.2090001@socialistsushi.com> > I also note that most IM networks, I'm pretty sure, don't tell Alice > when Bob goes offline if Bob isn't Alice's buddy, but I don't know how > often people chat with non-buddies in practice. > Another scenario: my brother uses an IM service that allows him to appear offline. We chat all the time, but to me he's always offline. I'm not sure how you'd handle a situation like that. From marti at juffo.org Sun Apr 29 20:46:08 2007 From: marti at juffo.org (Marti Raudsepp) Date: Mon, 30 Apr 2007 03:46:08 +0300 Subject: [OTR-dev] session termination In-Reply-To: <20070429194343.GJ10564@yoink.cs.uwaterloo.ca> References: <96e269140704282247j28650c70tdbebc99d8fb49eba@mail.gmail.com> <20070429194343.GJ10564@yoink.cs.uwaterloo.ca> Message-ID: <2a12af650704291746p5e27b5f5m5ed0928fe5c172ee@mail.gmail.com> On 4/29/07, Ian Goldberg wrote: > One problem with dropping to FINISHED when you notice the other side > goes offline is that that notification is unauthenticated. An adversary > can trivially spoof a "Bob went offline" message, and it would be > unfortunate if that caused Alice to forget her session keys. But does it really matter? When the attacker already has the capability of spoofing messages on behalf of the IM network, then surely they could also just disrupt (deny) communication between the parties -- which is effectively the same as far as I can tell. Marti From mail at scottellis.com.au Sun Apr 29 20:53:01 2007 From: mail at scottellis.com.au (Scott Ellis) Date: Mon, 30 Apr 2007 10:53:01 +1000 Subject: Fwd: [OTR-dev] session termination In-Reply-To: <96e269140704291638s2bb04186w2b8ba5279ed5a3f4@mail.gmail.com> References: <96e269140704282247j28650c70tdbebc99d8fb49eba@mail.gmail.com> <20070429194343.GJ10564@yoink.cs.uwaterloo.ca> <46350F26.2090001@socialistsushi.com> <96e269140704291638s2bb04186w2b8ba5279ed5a3f4@mail.gmail.com> Message-ID: <96e269140704291753j45da4caelaeba6b0cc8414639@mail.gmail.com> It seems to me that the 'proper' way to handle this would be to do what a lot of protocols do, and have a periodic 'continue session' message, ending the session when nothing is received after a certain amount of time...? -------------- next part -------------- An HTML attachment was scrubbed... URL: From ian at cypherpunks.ca Sun Apr 29 21:24:47 2007 From: ian at cypherpunks.ca (Ian Goldberg) Date: Sun, 29 Apr 2007 21:24:47 -0400 Subject: Fwd: [OTR-dev] session termination In-Reply-To: <96e269140704291753j45da4caelaeba6b0cc8414639@mail.gmail.com> References: <96e269140704282247j28650c70tdbebc99d8fb49eba@mail.gmail.com> <20070429194343.GJ10564@yoink.cs.uwaterloo.ca> <46350F26.2090001@socialistsushi.com> <96e269140704291638s2bb04186w2b8ba5279ed5a3f4@mail.gmail.com> <96e269140704291753j45da4caelaeba6b0cc8414639@mail.gmail.com> Message-ID: <20070430012447.GL10564@yoink.cs.uwaterloo.ca> On Mon, Apr 30, 2007 at 10:53:01AM +1000, Scott Ellis wrote: > It seems to me that the 'proper' way to handle this would be to do what a > lot of protocols do, and have a periodic 'continue session' message, ending > the session when nothing is received after a certain amount of time...? OTR does in fact support such a "heartbeat" message, but for the most part, the underlying IM networks don't. For example, if you try to send a "heartbeat" message to someone who's just logged off AIM, the user will get an annoying popup error message (with gaim), which is Bad. - Ian From ian at cypherpunks.ca Sun Apr 29 21:26:22 2007 From: ian at cypherpunks.ca (Ian Goldberg) Date: Sun, 29 Apr 2007 21:26:22 -0400 Subject: [OTR-dev] session termination In-Reply-To: <2a12af650704291746p5e27b5f5m5ed0928fe5c172ee@mail.gmail.com> References: <96e269140704282247j28650c70tdbebc99d8fb49eba@mail.gmail.com> <20070429194343.GJ10564@yoink.cs.uwaterloo.ca> <2a12af650704291746p5e27b5f5m5ed0928fe5c172ee@mail.gmail.com> Message-ID: <20070430012622.GM10564@yoink.cs.uwaterloo.ca> On Mon, Apr 30, 2007 at 03:46:08AM +0300, Marti Raudsepp wrote: > On 4/29/07, Ian Goldberg wrote: > >One problem with dropping to FINISHED when you notice the other side > >goes offline is that that notification is unauthenticated. An adversary > >can trivially spoof a "Bob went offline" message, and it would be > >unfortunate if that caused Alice to forget her session keys. > > But does it really matter? When the attacker already has the > capability of spoofing messages on behalf of the IM network, then > surely they could also just disrupt (deny) communication between the > parties -- which is effectively the same as far as I can tell. Yes, an attacker can always cause a DoS by making the network stop working. But allowing him to easily force Alice to forget her session keys seems worse to me. - Ian