- tor-relays - lists.torproject.org

Running a Relay behind a NAT (was Re: unflagged BAD EXIT nodes)
by teor 05 Jul '15

05 Jul '15

> Date: Sat, 4 Jul 2015 19:34:45 -0400 > From: Ben Serebin <ben(a)reefsolutions.com> > Subject: Re: [tor-relays] unflagged BAD EXIT nodes > > ?I'll hijack the response.... I'm a sysadmin, an unloved Windows one. My unwanted $0.02 are: > > - Windows installer (omg, Windows, the evil one which if you really want greater adoption is the answer! Oh smokes, someone said it! I agree that relay installers, particularly for non-Linux platforms, would help increase Tor's platform diversity. But platform diversity isn't a large part of Tor's threat model, as its impact is mainly felt through vulnerabilities shared by an entire platform. Currently, it looks like 90% of the Tor relays are Linux, by count of relays. (I believe the weighted bandwidth statistic is much higher than 90%.) https://metrics.torproject.org/platforms.html One suggestion I've heard, but that isn't ideal, is to download the Tor Browser Bundle, and modify the torrc in it to run a relay. That said, a relay operator really needs to know how to download, install, and configure a service on a secured server. So that's one reason a one-click installer is a bad idea. > - change the architecture so running behind nat works (this is probably the #1 limit factor for increasing relays). Every tom, dick, and harry could then add bandwidth via every internet circuit. It would be insane! Tor relays run quite fine behind a NAT, as long as the NAT box handles the number of connections which tor makes. There's even src/tools/tor-fw-helper, which supports NAT-PMP and UPnP. It can be configured via the torrc option: PortForwarding 1 Or, you can configure your NAT box to forward ports yourself. Tim Tim Wilson-Brown (teor) teor2345 at gmail dot com pgp ABFED1AC https://gist.github.com/teor2345/d033b8ce0a99adbc89c5 teor at blah dot im OTR D5BE4EC2 255D7585 F3874930 DB130265 7C9EBBC7

1 1

unflagged BAD EXIT nodes
by starlight.2015q2＠binnacle.cx 05 Jul '15

05 Jul '15

Could someone comment on why 15 exit nodes discovered to be sniffing and abusing login credentials have not been marked with the BAD EXIT flag? The research appears to be legitimate, involved a good deal of effort, and seems credible: https://chloe.re/2015/06/20/a-month-with-badonions/ was blogged by Sophos, also credible https://nakedsecurity.sophos.com/2015/06/25/can-you-trust-tors-exit-nodes/ Is there an issue of trust w/r/t this security researcher? An issue of methodology and/or reproducibility? A shortage of resources to follow up? An investigation attempting to identify the operators? The researcher writes that they received a polite reply from and was summarily ignored with no further comment. AND the exits continue to steal and abuse credentials. If true this would be contrary to the inclusiveness generally exhibited by the Tor Project. IMO a likely password-stealing exit should be marked-first, questions asked later. If some kind of mix-up or mistake has occurred, a good operator should readily be able to defend themselves and not feel ruffled for it.

7 11

Re: [tor-relays] unflagged BAD EXIT nodes
by starlight.2015q2＠binnacle.cx 05 Jul '15

05 Jul '15

At 10:04 7/4/2015 +0200, nusenu wrote: >I find it more worrying that we do not "hear" >about the 'more serious attacks' that keep >them busy and don't allow them to look into >i.e. 'AviatoChortler' (even after a few >weeks). That might mean that there is a >constant stream of 'more serious attacks' >(without information I can only guess). Here is one where 70 bad exits were rewriting an .onion address on a clearnet portal and sending a Tor email service's users to an evil onion clone: https://lists.torproject.org/pipermail/tor-talk/2015-April/037549.html I can see the argument for ignoring the near-zero-ranked exits (as they will virtually never be used) and the massive BW password stealer (due to the value of the bandwidth and the fact that HTTPS is immune to passive sniffing). But am concerned Chloe apparently received mute indifference as her contribution to the project is significant.

1 0

Re: [tor-relays] Simplifying ExoneraTor
by Magnus Hedemark 05 Jul '15

05 Jul '15

tor(a)dserrano5.es thus spoke: > Results: do we really need the "Exit: yes" column? Seems pretty redundant to > me. How so? All exits are relays, but not all relays are exits. And if a relay is only configured as an exit for part of the time, that's a potentially important part of the historic record. Sent from [ProtonMail](https://protonmail.ch), encrypted email based in Switzerland

2 1

de-centralised bad exit list files - a bad and/or naive idea ?
by Toralf Förster 04 Jul '15

04 Jul '15

Reading "[tor-relays] unflagged BAD EXIT nodes" /me wonders, such a feature would makes sense. Technically this could yield to a ./torrc.d config directory, where tor users could store the (regular updated) list/s they do trusts. -- Toralf, pgp key: 872AE508 0076E94E

3 2

turned on statistics
by starlight.2015q2＠binnacle.cx 02 Jul '15

02 Jul '15

It looked interesting so I turned on EntryStatistics 1 ConnDirectionStatistics 1 HiddenServiceStatistics 1 in addition to the default DirReqStatistics 1 and the output is indeed interesting. Also have CellStatistics 1 though this information does not seem to be published in the ExtraInfo digest. Any reason why having any of these enabled might be a bad idea? Running 0.2.6.9.

1 0

How to create HSDir on a private network
by Ceysun Sucu 02 Jul '15

02 Jul '15

Hi, I'm currently trying to simulate a tor network on shadow to test out some properties of hidden service's, i was wondering how could i create a hidden service directory or if someone could point towards an example configuration. Thanks, C,Sucu

3 2

Tor handshaking
by Adrian Soh 30 Jun '15

30 Jun '15

My ISP slows handshaking (circuit initialization) severely. Are there Torrc settings or changes to Orbot (Android) that I could use?

2 1

Re: [tor-relays] A bridge too far
by jchase 30 Jun '15

30 Jun '15

Thanks, isis, for your answer. I restarted my bridge without the flags and it's been running 7 days and still no stable flag back. Any experiments you can suggest? -J Chase > jchase transcribed 0.8K bytes: >> Hello, >> Can anybody help me figure out why my bridge has stopped showing the >> flags fast, running and stable? Especially stable, I would love to get >> that flag back. I run two bridges, on two different Rasp Pi's, the one >> with a globe fingerprint of B08284109C72C81ACF5866A17A4CC64CE3E16499 . >> The other with a globe fingerprint of >> 1BCD3EBEFE17EEB86EEDE21D5E2DB8468E2864CF . The first bridge runs with >> obfs 3 & 4 on a Pi 2. It seems I lost the stable flag around the time I >> got obfs 4 up and running. The second bridge runs only with obfs 3 on an >> older Pi. >> I've read that the stable flag is quite handy. Any ideas about how I can >> get it back? >> Greetings, >> J Chase > > Hi J, > > Your bridge B08284109C72C81ACF5866A17A4CC64CE3E16499 appears to have a current > uptime of about 50 hours, and to have the Stable flag, according to > dir-spec.txt, [0] it must have: > > "Stable" -- A router is 'Stable' if it is active, and either its Weighted > MTBF is at least the median for known active routers or its Weighted MTBF > corresponds to at least 7 days. > > Meaning that you probably just need to let the bridge run for a few more days, > and it'll get its Stable flag back. > > Also, for what it's worth, BridgeDB will still distribute your bridge, even if > it doesn't have the Stable flag. The only required flag for your bridge to > get distributed is the Running flag. However, you are correct that having the > Stable flag is useful, because BridgeDB, when distributing some bridges to a > user, will try pretty hard to make sure that at least one of the bridges has > the Stable flag. So, with the Stable flag, you've got a better chance of > being distributed to clients more often, but it's not strictly necessary to > have it, especially for a bridge like yours with small bandwidth and CPU. > > [0]: https://gitweb.torproject.org/torspec.git/tree/dir-spec.txt?id=26929b8c5554… >

1 0

Re: [tor-relays] More consensus weight problems
by Aaron Gibson 30 Jun '15

30 Jun '15

On 2015-06-29 17:51, Speak Freely wrote: > Hello, > > First of all, I love Tor. I love Tor Browser, and I love running > relays. > > When the problems are solved, I will most likely spin up more relays. > > I'm leaving my fastest relay running, as a method of checking the > status > for myself. The rest have already started to expire, and within the > next > week or so most of the other ones will have expired as well. > > I'm going to try tor-dev-alpha 2.7.1 and change fingerprints, as per a > suggestion from s7r, seeing as how I have nothing to lose. > > I just wish the bwauths could scan relays based off previous relative > consensus weights... If this particular relay was at 27000, it should > be > higher on the list to check compared to another one I have that is at > 487. My one relay was blazing fast with thousands of connections, my Well, relays are ranked by capacity, and split over several scanner processes - they do get measured against their relative peers. But it seems that, when they fall out of the measurement process ('Unmeasured') they must start again at the beginning. This is expected because all relays start Unmeasured, and gradually increase their position in the consensus (per relative capacity), in order to dampen sudden changes and limit sybil attacks by requiring relays to stick around for a while, increasing the cost to an adversary. It likely should not be the case that historically long running relays should start at the bottom if they are unmeasured for a short period of time. We are in the process of testing increasing the number of scanner and accompanying tor instances from 4 to 9 (double, plus one for currently unmeasured relays) in order to decrease the amount of time each fraction of the network takes to measure and ensure that new relays or unmeasured relays are measured often. There are additional patches that introduce extra exits into the slice of relays, if there are no suitable exits to measure with. This likely won't address the above behavior, but we hope it will reduce the number of relays that go missing. Currently we seem to have mixed results, with one Bandwidth Authority operator claiming minimal (50) unmeasured relays, and another claiming ~600 mixed relays. These numbers are not directly comparable because they were not sampled at the same time, and may not be representative of typical behavior - it's a little too soon to tell. It's a bit tricky to both test these changes, on the live tor network, demonstrate that they produce sane results, and convince the directory authority operators and partner bandwidth authority operators to upgrade - nor do we want to do that all at once - gradual change is better. So, the goal is to produce results that will convince operators they should update, improve the situation for relay operators, and then start looking at longer term solutions for the measurement problem that are more maintainable and scalable in the long run. > other is painfully useless with dozens, but my fastest one lost its > consensus while the slowest one kept it's consensus. It just seems > silly. That being said, I don't know how/if the bwauths scan in any > order or just willy-nilly, (that's not entirely true, I know it's > segmented to some degree as I recall reading a blog post about how it's > chopped up) but... I'd be much less upset if my best relays worked and > my worst relays didn't. More complaining... bleh. > I hope to have a testable hypothesis as to why your faster relays suffer(ed) more than the slower relays - it could be that the fraction of network by capacity allocated to a particular scanner is not well balanced, and that fraction is taking significantly longer to measure. In order to evaluate that statement I need to understand the common characteristics of relays that become unmeasured/lose rank and see if they are from a similar segment of the network, and whether or not that segment of the network takes longer to measure than other segments. Another hypothesis is that your relays are on the boundary between two segments, and that a transition between scanner instances causes enough missed measurements to drop your relays. It would be helpful to know what rank the last good measurement your or other relays had before becoming unmeasured. It will require some cooperation with the existing deployed Bandwidth Authorities, in order to learn what their current scan times are - I will be writing some simple scripts to scrape these results so that we can collect and publish some useful heuristics about the scanner processes to better try and debug this problem. > > One thing I would like to point out though... it appears... These > problems have at least a casual relationship with MyFamily. > > One group of MyFamily is completely done - all of them stuck at 20. > Another group of MyFamily is working happily. > I've been doing some tests over the past few months trying to > understand > why I keep having problems, and one thing has consistently popped up... > MyFamily. That is very interesting, because MyFamily should have nothing to do with the scanner process at all - I'll need to think about this some more. > > As one of MyFamily lost consensus, another family gained consensus back > on or around the same time. > > Yes, especially nusenu, I know I'm supposed to have it all configured > to > be under 1 MyFamily... But in a way I'm glad I didn't, as the casual > relationship I see really could only be seen having done what I did. > > I say casual because I have no proof of causation. But... it is > interesting. If no one else has experienced similar problems, then I'd > chock it up to a completely unexpected unrelated set of mysterious > circumstances that should not have happened for which there is no > explanation. > > Aaron, if there is anything I can do to help you please let me know. If anything that I said above sparks a thought, please let me know :) > > > So in conclusion, I'm not done, I'm just not happy. > > This was supposed to be a short email, oops. > > > Matt > Speak Freely

1 0