- tor-dev - lists.torproject.org

GSoC Stegotorus update 1
by Noah Rahman 07 Jun '14

07 Jun '14

- Progress so far 1) Fixed segfaulting refactored SWF steganographic code. Code now fails on decompression but at least it's not segfaulting anymore. Suspected it was due to how trace payload server is integrated and rest of problems should be fixed by reimplementing pre decompression logic that was lost in refactored-away SWF_receive code. Can then move on to JS 2) Added config file for options using inih library, still testing locally. 3) With Yawning' s help, began to replace Moeller handshake with libelligator implementation. (#8089) Goals for next update 1) Finish SWF refactoring and associated unit test, start on JS 2) Finish elligator handshake and write unit test for config file. Test with ctgrind when I figure out how to patch valgrind properly. 3) Meet with Vinod at SRI and determine most expedient way of merging SRI changes into Stegotorus build (meeting scheduled for next Friday the 13th) Best Noah R.

1 0

Orbot & Orfox - Bi-weekly report
by Amogh Pradeep 06 Jun '14

06 Jun '14

Hey all, Attached to this email is my bi-weekly report on the project Orbot and Orfox.

1 0

[GSoC 2014] Revamp GetTor status report #1
by Israel Leiva 06 Jun '14

06 Jun '14

Hi all! This is the first status report for the Revamp GetTor GSoC project. I'll try to summarize what has been done. For more details feel free to ask. If you have comments, please tell me. Achievments: * Decided to rewrite the code. Made a proposal for a new GetTor's design. Available at [0]. * Discussed this new design with my mentors. Several changes has been made since its original version, including the use of ConfigParser for reading the links files. * Improved Python knowledge. Read PEP8 and PEP-0257 to (try to) create standard code. * Created the basis of the Core module, including a dummy script to test it. It can successfully read links from files and display them on screen. Available at [1]. Goal(s) until next report: * Have the Core module working with _at least_ one provider (Dropbox). This means adapt the current dropbox script to the new design. All of this properly documented and as standard as possible. That's all for now. Have a nice weekend! [0] https://github.com/ileiva/gettor/tree/master/spec [1] https://github.com/ileiva/gettor/tree/master/src -- israel

1 0

Get the latest TBB
by Israel Leiva 06 Jun '14

06 Jun '14

Hi all! Is there a better way to get a link for the latest TBB rather than looking at https://www.torproject.org/dist/torbrowser/? I'm thinking on something easy to automate (for the Revamp GetTor project). Thanks! -- israel

3 4

Proposal 236, Single-guard designs, and directory guards
by Nick Mathewson 06 Jun '14

06 Jun '14

Hi, all! I noticed that proposal 236 doesn't mention directory guards. (See proposal 207, implemented in Tor 0.2.4.) I think that we should consider retaining multiple directory guards while going to a single guard for multi-hop circuits. My rationale here is that when we have only a single directory guard, it can more easily perform hard-to-detect route biasing attacks by pretending not to have descriptors for nodes it doesn't like. Its ability to do this is limited by fact that we won't build circuits unless 95% of all paths are buildable (see get_frac_paths_needed_for_circuits() and its users). But still, trusting a single source for the completeness and freshness of your directory info is suboptimal. I also think that most of the arguments for single-guard apply to circuit guards more than to directory guards. But there could be some left, and we should figure those out. peace, -- Nick

5 6

Pluggable transports meeting today (Friday 6th of June 2014)
by George Kadianakis 06 Jun '14

06 Jun '14

Hello friends, just wanted to remind you that the regular biweekly pluggable transports meeting is going to occur today at 16:00 UTC. Place is the #tor-dev IRC channel in the OFTC network. Please note that we recently *changed* the time from 17:00 to 16:00 UTC. Thanks!

1 0

[Patch] test/test.c. TEMP-dir
by Gisle Vanem 05 Jun '14

05 Jun '14

Hello list. I don't get any FAILED tests running on Win32 (MSVC), but IMHO the use of '\\' in the TEMP-directory doesn't look quite kosher (looks a bit like a "\\server\share\path" UNC-syntax). >From test_crypto_pk() running 'test.exe --warn': Jun 05 10:13:05.046 [warn] Could not open "F:\TEMP\\tor_test_3992_vv7drny6/xyzzy": No such file or directory Jun 05 10:13:05.046 [warn] Error reading private key from "F:\TEMP\\tor_test_3992_vv7drny6/xyzzy" So can you accept this small change: diff --git a/src/test/test.c b/src/test/test.c index 8bce9c9..98620e5 100644 --- a/src/test/test.c +++ b/src/test/test.c @@ -108,9 +108,9 @@ setup_directory(void) const char *tmp = buf; /* If this fails, we're probably screwed anyway */ if (!GetTempPathA(sizeof(buf),buf)) - tmp = "c:\\windows\\temp"; + tmp = "c:\\windows\\temp\\"; tor_snprintf(temp_dir, sizeof(temp_dir), - "%s\\tor_test_%d_%s", tmp, (int)getpid(), rnd32); + "%stor_test_%d_%s", tmp, (int)getpid(), rnd32); r = mkdir(temp_dir); } #else ------------------ Ref: http://msdn.microsoft.com/en-us/library/windows/desktop/aa364992(v=vs.85).a… lpBuffer [out] A pointer to a string buffer that receives the null-terminated string specifying the temporary file path. The returned string ends with a backslash, for example, "C:\TEMP\". ---------- I also tested 'test.exe --warn' without any TMP or TEMP. Thus my USERPROFILE is used: Jun 05 10:46:47.984 [warn] Could not open "f:\Documents and Settings\Gisle Vanem\tor_test_6368_s62ks2fe/xyzzy": No such file or directory Jun 05 10:46:47.984 [warn] Error reading private key from "f:\Documents and Settings\Gisle Vanem\tor_test_6368_s62ks2fe/xyzzy" --gv

1 0

Reminder: tor development meetings this (and every) Wednesday, 19:00 UTC
by Nick Mathewson 04 Jun '14

04 Jun '14

Hi, all! Here's your regular reminder for the weekly IRC meeting for people working on the program "tor". (This won't cover all the other programs developed under the Tor umbrella.) The next meeting time will be: Wednesday June 28, 19:00 UTC. (That's 3pm EDT and 12:00 noon PDT.) As usual, we'll do it on the #tor-dev IRC channel. I've seen a drop-off in the number of people coming since I stopped sending these out weekly, so I'm sending them again for a while. Among other stuff, I expect we'll be figuring out the rest of the 0.2.5 series, planning an 0.2.5.5 release maybe trying to chase some bugs, and figuring out how to open development on 0.2.6.x. cheers, -- Nick

3 3

tor-weather meeting Wed, 1800UTC
by meejah 03 Jun '14

03 Jun '14

Wednesday, 1800UTC, #tor-dev I will run the meeting. I haven't made MeetBot run anywhere; if someone has an instnace we can try out tomorrow, please mail me or follow-up here. If you have something to add to the agenda, either mail me directly or just show up at the meeting (we will figure out the agenda as the first thing). thanks, meejah

1 0

obfs4 and ntor (question wrt node_id)
by George Kadianakis 02 Jun '14

02 Jun '14

Hello Ian, hope you are well :) I have a question wrt a new PT and ntor. Yawning Angel has been developing a new PT called obfs4 (temp name), which is basically scramblesuit using ntor and elligator2. This results in better performance than UniformDH. You can find the spec of obfs4 here: https://github.com/Yawning/obfs4/blob/master/doc/obfs4-spec.txt You can read a description of the ntor handshake here: https://github.com/Yawning/obfs4/blob/master/doc/obfs4-spec.txt#L149 The protocol works fine, but it requires two shared-secrets between the client and the server. The first is the long-term public key of obfs4, and the other is the "node id" of the server (defined as fingerprint of the bridge's identity key). My question has to do with the "node id" (denoted as 'capped B' in the ntor paper) . The problem is that it complicates the deployment of obfs4, since the bridge operator has to find her bridge's fingerprint (by looking at $DataDirectory/fingerprint) and add it to her torrc (as part of the ServerTransportOptions line). Also, the bridge operator needs to give a similar Bridge line to her clients. I was trying to understand if it's possible to simplify this, by not requiring the bridge operator to make the effort of finding her bridge's fingerprint. There are at least two possible ways to do this: a) Instead of using the bridge's identity key as the node id (which provides some kind of (unneeded?) channel binding), just generate a random string to serve as the node id of the bridge. As I understand it, node id is just a 1-1 map to a specific public key, so a big random string should be able to do the trick, right? b) Just discard the node id, and use the public key in its place. So wherever 'capped B' is used, just use 'B' instead. Intuitively this seems OK to me, but I admit I couldn't follow the whole security proof on Appendix B, to verify that it doesn't make any difference. Do you think any of the above approaches is correct, without bludgeoning ntor's security? Thanks!

3 3