- tor-dev - lists.torproject.org

Txtorcon/Stem Integration : GSoC 2013
by Akshit Khurana 23 Apr '13

23 Apr '13

Hi, I'm Akshit, a 4th year Computer Science student at IIT Roorkee. I'm a part of Information Management Group(IMG) here, which is a student body responsible for developing and managing all Internet and Intranet applications in IIT Roorkee, including the institute website and registration & placement portals. I would like to work on Txtorcon/Stem Integration. I have some experience working with Python and web frameworks Django and Flask contributing to IMG's projects and to openSUSE's popcorn project[1]. I don't have much experience with Twisted except for a few tutorials but I'm sure I'll pick it up. To get acquainted with Tor and Stem, I'm working on a patch[2] for stem with Damian's help. I'm going though txtorcon's code as well. Thanks, Akshit http://github.com/axitkhurana [1] https://github.com/openSUSE/popcorn/commits/master?page=2 (username axitkhurana) [2] https://trac.torproject.org/projects/tor/ticket/8607

2 1

Stem GSoC 2013
by Tomasz Kunikowski 23 Apr '13

23 Apr '13

Hey, My name is Tomasz Kunikowski, I'm a production engineering student at Wroclaw University of Economics branching heavily into IT. My handle on IRC and trac is ragwater. I'm mainly interested in expanding stem's tutorial base as it could really use some more real-world applications and examples, but I'd be fine with extending the tests, too. I started with some minor bugfixes to stem to get a better hang of the library and the inner workings of tor in general, and if time permits I'll contribute some more besides the code sample required in application. Regards, Tom

2 1

Removing Onion Skins
by Frank Young 22 Apr '13

22 Apr '13

After circuit extension to the second Node, I realized that the OR at the second node can decrypt my cells and successfully process my circuit extension request to increase my circuit length to three but i can't decrypt the response from the same OR. At first I thought maybe I was messing up the key for backward encryption (should be decryption but it is counter mode crypto) but i realized it wasn't true. I extracted both the KF and KB at the same time and the crypto scheme is also the same for encryption and decryption since it is a counter mode AES operation. From the tor protocol specification, I will have to remove all skins starting with the immediate OR towards the exit Node. When the application of the above specification failed to decrypt the cell successfully, i decided to remove the skins in reverse order but this also failed. I'm really confused at the moment. Aren't each successive AES counter operation independent of the previous?

2 2

Remote access to TOR through web server
by Mahesh Baheti 22 Apr '13

22 Apr '13

I've discussed this idea before here. Few people asked me how to implement it? I can discuss it if someone gives me any idea about gsoc applications. Mentors please reply.

1 0

Behavior of pluggable transport proxies on SIGINT
by David Fifield 20 Apr '13

20 Apr '13

This is what 180-pluggable-transport.txt says about proxies and SIGINT: > Proxies should respond to a single INT signal by closing their listener > ports and not accepting any new connections, but keeping all connections > open, then terminating when connections are all closed. Proxies should > respond to a second INT signal by shutting down cleanly. I implemented the websocket-server transport to do this. https://gitweb.torproject.org/flashproxy.git/blob/c23caf1f71f8281319cadf550… I noticed unexpected behavior when the proxy receives a SIGINT, and doesn't have any open connection, and so exits immediately without waiting for a second SIGINT. The parent tor process tries to kill a nonexistent PID: > ^CApr 19 17:58:59.000 [notice] Interrupt: we have stopped accepting new connections, and will shut down in 30 seconds. Interrupt again to exit now. > ^CApr 19 17:59:05.000 [notice] SIGINT received a second time; exiting now. > Apr 19 17:59:05.000 [notice] Failed to terminate process with PID '18277' ('No such process'). Is this intended? It seems the PID might have been reclaimed in the meantime, and tor could be killing an unrelated process. I can think of two changes that would make it seem to me to work more naturally. The first is for tor to poll the child PID to see if it has exited before killing it; this reduces the race window. The other is to require proxies always to wait until their second SIGINT before quitting. (Concretely in the websocket-server example, remove the"numHandlers != 0" condition from the second sigint loop.) David Fifield

2 1

Scholar user questions
by Noel David Torres Taño 19 Apr '13

19 Apr '13

Hi all I need some help answering these questions from a scholar, for RT ticket #9112 El vie 19 de abr de 2013 07:12:45, leejunsik486(a)gmail.com escribió: > Hello~! > Thanks for your kind response. > Now I can use pop3 mail client using Tor network due to your help > > I am reading the thesis "Tor:The Second-Generation Onion Router" > There are some explains about Tor directory server. > > I have another Question about Tor Directory server. > > > 1. User's local SW(ex) Vidalia) already know directory server's IP or > URL? > Is it pre-loaded at SW? > (This Question means "how to access to directory server?") > > 2. How to user's local SW( ex) Vidalia) receive directory information? > Directory server send this information directly or other ORs > transfer > this information? > ( In vidalia control panel- relay setup, there are "Mirror the > relay > directory" option) > If other OR's transfer this infomation, Why directory server > doesn't > send directly? > > 3. In this thesis, "there are 3 directory server, but we expect as > many as > 9 as the network scale" > Now, How many directory server exist?(still 3 servers or increase) > > 4. All directory server have same directory information? > > 5. Is there any links or files about directory server's work(detailed > explanation)? > > > Always thanks your kind response > Best regards > > Leejiunsik > > > 2013/4/15 Noel David Torres Taño via RT <help(a)rt.torproject.org> > > > El lun 15 de abr de 2013 10:58:35, leejunsik486(a)gmail.com escribió: > > > Hi > > > > Dear user: > > > > > This is leejunsik in Korea. I'm studying computer network in > college. > > > I have some Question about Tor. > > > > We are happy you use Tor and try to understand it. > > > > > > In "Vidalia control panel- Setup Relay-Sharing" > > > I can select Exit Policies. > > > => It's mean I can use other services(POP3,IMAP,chat) using TOR > > > > > > I know that I can use web-browsing using Tor browser. > > > But I'dont know How can I use POP3, IMAP, chat etc. . > > > > > > 1) Is there any other Tor application for using POP3, IMAP, etc. > ?? > > > > You should either > > > > a) use a Tor-aware mail application. We do not know any of these > reliable > > at > > the moment. > > b) Torify an existing mail application. You should be very careful > and read > > this: > https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO/EMail > > c) Use Tor as a SOCKS proxy and route your standard e-mail > applications > > through > > it. You should read this: > > https://trac.torproject.org/projects/tor/wiki/doc/SupportPrograms > > > > > 2) When I send ping or nmap or nslookup message In console > terminal, Is > > > there any way to use Tor?? > > > > ICMP PING is in the same layer as IP, while SOCKS provides TCP > proxying > > (one > > layer above), so no, there is currently no way to use Tor for that. > > > > > > Please let me know about it. > > > > > > I'll wait your response. > > > > Regards > > > > Noel Torres > > Tor Project Help Team > > > > Hope you can help! Regards Noel Torres er Envite ------------------------- A: Because it breaks the logical flow of discussion. Q: Why is top posting bad?

2 1

Re: [tor-dev] Embedding tor in an application and using tor without opening a port
by Navin Francis 17 Apr '13

17 Apr '13

On Sat, Apr 13, 2013 at 10:42 AM, wac <waldoalvarez00(a)yahoo.com> wrote: > > Hi Navis: > > Good to hear you built it. I have a working library with a defined API but > is not re-entrant. It can connect with a server over Tor circuits and > transmit/receive data but nothing is re-entrant at all. So the same Tor > thread must be used for all of that ATM. > > I can fetch webpages like that however and can also do some limited > chit-chat over IRC. > > I didn't realize that you already had it working :) I guess I will wait untill you post the code. > I attempted to add some locking to some of the data structures but that is > insufficient. For instance lists and buffers. Hash tables are complex. They > are defined with some macros in order to make them generic overcoming some > limitations of C language but they are less than maintainable IMHO. So I > was thinking to replace them with another one already built with a similar > license but re-entrant. Found a very good one. > I thought Tor already had some level of locking since multiple applications can connect to it at the same time via SOCKS. I completely agree about replacing the macros though.

2 2

Re: [tor-dev] Interested in getting involved with pyDoctor
by Karsten Loesing 17 Apr '13

17 Apr '13

(Adding tor-dev back to the cc.) On 4/16/13 9:31 PM, Miłosz Gaczkowski wrote: > On 16/04/2013 07:28, Karsten Loesing wrote: >> Sounds great! Welcome to Tor! > Thanks for the warm welcome :) > >> In theory, you can start working on this project right now. The first >> step is probably to understand what the current DocTor code (Java) >> does and what capabilities the stem library (Python) may still be >> missing to rewrite DocTor in Python. See the links in the project >> idea, and ask for more pointers if you're missing something. > All right, I've started my research on DocTor earlier today. I'll start > looking at Stem when I have a decent understanding of the design choices > and approaches in DocTor. Sounds good. >> For the GSoC project, you should come up with a project plan >> explaining what parts need to be implemented, and you should suggest a >> schedule that fits the GSoC timeline. See the GSoC FAQ for details. >> Bonus points if you already have some code for PyDocTor in your GSoC >> application. Or you could write a patch for #8164 [0], which still >> means writing Java code not Python, but which would show you're >> familiar with the code base you're planning to rewrite. Another >> alternative would be to write a stem patch that adds part of the >> missing features to write PyDocTor. Lots of options there. > I think the best approach (in the long term, at least) would be to start > with extending Stem, then building pyDoctor on that, and only focusing > on extra functionality once we have the new product. Probably better > than doing #8164 now and then re-inventing it a few months later in > Python anyway. What do you think? I agree that doing #8164 now and rewriting it a few months later means duplicating some effort. But it's not that complicated, and we'll want to have that feature in the next few months anyway. But don't worry too much about it, I can write the #8164 patch myself. If you want to focus on the rewrite instead, please do so! >> Does that answer the who/what/where/when? If not, just ask! > It does, thanks a lot. I'll carry on reading through the code and > working out how things work for a while, but I should be able to start > work on my project plan and code in a week or so. > > If you have any ideas and suggestions, those are always welcome. If not, > I'll be in touch soon! Great! Looking forward to commenting on your project plan or code! :) Best, Karsten

1 0

More-static throttling parameters
by Roger Dingledine 17 Apr '13

17 Apr '13

Hi Rob, We spoke at the dev meeting about how throttling that's a function of number of clients introduces new anonymity vulnerabilities (for those following along at home, see the upcoming PETS paper "Balancing Performance with Anonymity in Tor"). It seems to me that we want to explore more static options. For example, we watch a rolling window of Y seconds and throttle you to 50KB/s for 2Y seconds if you send or receive more than X bytes in those Y seconds. Here are plausible values of X and Y: 12MB in 30 seconds ("400KB/s") 18MB in 60 seconds ("300KB/s") 27MB in 120 seconds ("225KB/s") 40.5MB in 240 seconds ("169KB/s") 60.75MB in 480 seconds ("126KB/s") 91.125MB in 960 seconds ("95KB/s") 136.6875MB in 1920 seconds ("71KB/s") The goal is that a client who wants to game the system could self-throttle to just under the limit, and then we don't trigger, but the user would have to self-throttle more and more over time as he continues to transfer many bytes. The smallest Y we consider is 12MB in 30 seconds, and from there when Y doubles we multiply X by 1.5. And then when X/Y reaches 50KB/s we don't throttle further. It's possible there are simple self-contained equations to describe the above curve; it's also possible there are better curves to explore. And I also confess that I didn't pick the above design with an eye towards easy implementation (somebody's going to have to get out their algorithms magic wand and rephrase it so it looks easier to implement). My goal was to pick parameters such that we don't impact normal users, but if we *do* trigger on a user then we sure are glad we did. And there are of course reduced returns here because the user can have multiple entry guards (and all the other cheating questions a la the LIRA design). --Roger

1 1

Remote anonymous browsing
by mahesh 17 Apr '13

17 Apr '13

Hi, I am a third year undergraduate student of Information Technology at PICT, Pune, India. I'm dying to contribute to tor community as I use it a lot. There's an opportunity for me in GSOC-2013. I read tor's idea page and came to know that would have to contribute to existing project. But, I would like to propose a new project. I came across this problem statement from a friend of mine who is journalist. He says, most of the times he don't have his laptop with him so he cant access tor from a CyberCafe as they won't let him download the bundle. So, I propose that there should be a web server to handle tor requests over http. I did my study and think its feasible but let me know everyone else's thought on it. Mahesh

5 7