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3594 discussions

making sure I configure OutboundBindAddressExit correctly
by nusenu 05 May '17

05 May '17

Hi, since I really like this new feature I added [1] initial autoconfiguration support for it to ansible-relayor (user can opt-in via a single boolean and we automate the rest). I want to make sure I do this correctly and would like your feedback on the following questions: a) Is 'OutboundBindAddressOR' in the following context optional (in the sense that it does not change tor's behavior)? ExitRelay 1 ExitPolicy reject *:25,accept *:* ORPort 1.2.3.4:9001 OutboundBindAddress 1.2.3.4 OutboundBindAddressOR 1.2.3.4 OutboundBindAddressExit 7.7.7.7 is identical to: ExitRelay 1 ExitPolicy reject *:25,accept *:* ORPort 1.2.3.4:9001 OutboundBindAddress 1.2.3.4 OutboundBindAddressExit 7.7.7.7 (since according to the manual page OutboundBindAddress*OR* would just override OutboundBindAddress, which is not needed in the above example since they match) b) Is it ok to set OutboundBindAddressExit for IPv4 only, even if we set 'IPv6Exit 1' or is setting an IPv6 OutboundBindAddressExit address required after setting OutboundBindAddressExit for IPv4? Since this question might be a bit confusing I'll give an example in form of torrc lines: ORPort 1.2.3.4:9001 OutboundBindAddress 1.2.3.4 OutboundBindAddressExit 7.7.7.7 IPv6Exit 1 ExitRelay 1 ExitPolicy reject *:25,accept *:* (this config has an IPv4 OutboundBindAddressExit entry but no IPv6 OutboundBindAddressExit entry) c) Similar to (b) is it ok to enable OutboundBindAddressExit for IPv6 only? d) Is it ok if multiple tor instances on the same host use the same OutboundBindAddressExit address? (ignoring the fact that big exits might run out of source ports?) thanks, nusenu [1] https://github.com/nusenu/ansible-relayor/commit/00fa7c571e8b6f6256092d9928… -- https://mastodon.social/@nusenu https://twitter.com/nusenu_

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Leekspin and Stem descriptor creation
by Damian Johnson 02 May '17

02 May '17

Hi Isis. For kicks and giggles this weekend I added the ability for Stem to create descriptors... https://stem.torproject.org/tutorials/mirror_mirror_on_the_wall.html#can-i-… https://gitweb.torproject.org/stem.git/commit/?id=b2a54ad This is something Stem has always been able to do but it was buried in our testing helpers. Now descriptor subclasses have a static create() and content() method. This *doesn't* yet support signing descriptors. I'm looking into that next. To that end I took a peek today at leekspin (https://pypi.python.org/pypi/leekspin) and... damn. Beautiful work! Besides the crypto are there any other aspects of your library you think we should incorporate? Cheers! -Damian

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Prop279 and DNS
by Jeremy Rand 29 Apr '17

29 Apr '17

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello! Maybe this topic has already been brought up, but in case it hasn't, I'll do so. I notice that Prop279 (onion naming API) defines its own API rather than using DNS. I guess that this is because of security concerns about the centralization of the DNS. However, in case you're unaware, Namecoin is designed to interoperate with DNS. Let's say that, hypothetically, Tor defined a DNS-based naming system for onion services, where "_tor.example.com" had a TXT record that was verified with DNSSEC in order to make Tor direct "example.com" to whatever that TXT record had. If this were done, Namecoin would be able to produce the necessary TXT record and DNSSEC signatures, via the standard DNS protocol, using an authoritative nameserver that runs on localhost. (The DNSSEC keys used would be unique per user, generated on installation.) Indeed, this is how we're planning to interoperate with non-proxy-based Internet applications. My guess is that it would be a lot less work on Namecoin's end if such a system were used with Tor rather than a separate naming API. It's unclear to me how this would affect other naming systems such as GNS (does GNS interoperate with clients that use DNS?), and it's also unclear to me whether this would produce extra work for the Tor developers (maybe DNS adds extra attack surface that would need to be mitigated somehow, or maybe there would be complexity in implementing stream isolation?). Anyway, just figured I'd bring up the topic so that everyone's on the same page regarding figuring out whether it's a good idea. Cheers, - -- - -Jeremy Rand Lead Application Engineer at Namecoin Mobile email: jeremyrandmobile(a)airmail.cc Mobile PGP: 2158 0643 C13B B40F B0FD 5854 B007 A32D AB44 3D9C Send non-security-critical things to my Mobile with PGP. Please don't send me unencrypted messages. My business email jeremy(a)veclabs.net is having technical issues at the moment. -----BEGIN PGP SIGNATURE----- iQIcBAEBCgAGBQJY4rf2AAoJELPy0WV4bWVwviQP+wSz9/L8czef+L+viSIIrrtv BOp32fysFWw1HijQ/42IoELPhkkzsHjek4IuW6Hn3VHGYs9vJ+rQ9aOcCMGNGD/f f7ktcw3upH/UHiFPp2S0LeNqaoup8qvUQxG/AeP5R20gD/660ZXuIVl4uOaOu5HJ IaghO9ZpzSF695H97hf7bz3H3Wrmch8tjC+FZ+SwWdgqGa4ijjZbTvkypcPEZ6YI YQ22PmoQQWQBbe9JLujLa46PwRWU+UKsppmQYi7dY9K7aO7/J9eKQnOLkUWtdKrN WjtJMV+V4oL/g4IiJrPs5n82pGSvpFi/dMrakoGq2w+v1dJolz/lSGUj7+sWVQZl iqoq6c+l7MjKNynmj/Yn8IquhhwRmVAj4sjV+2jUeVmAf/tHDCBsDYvIDcDeIblu j6y9e7ePTlMTpuxbZ7OKJjsWgGF5+yumWHPtJYs9uBoATeYDM6+Gxm73rDZxRVCl +KGN1jMuREA9N1ZiWuK/ueeeZWGHii4L4UWvdK0qriSvc0HxaQeCGlovEDfO8btO ZDfq9P6USEZywqFyzjzvOUwxnhihwNMdFiSt0RfxLuX34H6POvFYHhw85ESlliY8 0RPjHW6GZywNuOgpYDu9kPS6HPFhXUtok708Jmc926ctX2TT0CJlK6Fl3R2kZGCa nOLHLSYVmkehj6u3RdBf =Hz3g -----END PGP SIGNATURE-----

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Tor Tech Report 2017-04-001 available
by iwakeh 28 Apr '17

28 Apr '17

Hi there! A new Tor Tech Report is available [0]: "Privacy analysis of Tor's in-memory statistics." Abstract: "This report analyzes which possibly sensitive, potentially personally identifying data is stored in memory of Tor relays and bridges or reported to the directory authorities and makes suggestions to reduce the collection and temporary storage of such data." The report addresses concerns regarding metrics collection about the Tor network that were often raised and discussed in the community. Many topics can only be briefly touched in the scope of such a report. Thus, there is quite some work in thinking, writing, and coding open to be done. Based on the report's suggestions the Metrics Team plans the following steps (mainly in May and June 2017): * Distill a change proposal for Tor server changes that address the most pressing of the identified issues. * Code the Tor server patches according to the proposal. * And, provide necessary patches for Tor Metrics products concerned by the changes for Tor servers. Future plans for the months after that are to assess privacy questions as raised in this report more in-depth and describe statistical accuracy throughout the data-verse of Tor Metrics. Many thanks to Aaron Johnson, Paul Syverson, Rob Jansen, and Tim Wilson-Brown, who gave very valuable feedback to ideas and questions we asked during the Amsterdam meeting! Also many thanks to Karsten Loesing, who collected the feedback in Amsterdam, patiently answered all questions about the details of Tor and Tor Metrics, and reviewed the report! Cheers! iwakeh [0] https://research.torproject.org/techreports/privacy-in-memory-2017-04-28.pdf

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txtorcon 0.19.0
by meejah 26 Apr '17

26 Apr '17

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I'm very happy to release txtorcon 0.19.0. This merges most of the development that happened over the last several months on the release-1.x branch. Featuring: * Full Python3 support (and universal wheels) * Drop txsocksx and use a custom implementation (this also implements the custom Tor SOCKS5 methods RESOLVE and RESOLVE_PTR). Uses Automat for the state-machine. * Drop support for older Twisted releases (12, 13 and 14 are no longer supported). * Add a top-level API object (txtorcon.Tor) that abstracts a running Tor. Instances of this class are created with txtorcon.connect or txtorcon.launch. These instances are intended to be "the" high-level API and most users shouldn't need anything else. * Integrated support for twisted.web.client.Agent, baked into txtorcon.Tor. This allows simple, straightforward use of treq or "raw" twisted.web.client for making client-type Web requests via Tor. Automatically handles configuration of SOCKS ports. * new high-level API for putting streams on specific Circuits. This adds txtorcon.Circuit.stream_via and txtorcon.Circuit.web_agent methods that work the same as the "Tor" equivalent methods except they use a specific circuit. This makes txtorcon.TorState.set_attacher the "low-level" / "expert" interface. Most users should only need the new API. * big revamp / re-write of the documentation, including the new Programming Guide: https://txtorcon.readthedocs.io/en/latest/guide.html * Issue 203: https://github.com/meejah/txtorcon/issues/203 * new helper: txtorcon.Router.get_onionoo_details which downloads JSON for a particular relay from OnionOO * new helper: txtorcon.util.create_tbb_web_headers which returns headers resembling a recent Tor Browser suitable for use with Twisted or treq web agents. * Issue 72: https://github.com/meejah/txtorcon/issues/72 * Specific SocksError subclasses for all the available SOCKS5 errors added by https://github.com/felipedau * (more) Python3 fixes from https://github.com/rodrigc You can download the release from PyPI or GitHub (or of course "pip install txtorcon"): https://pypi.python.org/pypi/txtorcon/0.19.0 https://github.com/meejah/txtorcon/releases/tag/v0.19.0 Releases are also available from the hidden service: http://timaq4ygg2iegci7.onion/txtorcon-0.19.0.tar.gz http://timaq4ygg2iegci7.onion/txtorcon-0.19.0.tar.gz.asc You can verify the sha256sum of both by running the following 4 lines in a shell wherever you have the files downloaded: cat <<EOF | sha256sum --check 09d56fbd6e33eef7405c8ca354bbba06da2cefa02763d15c4bc9ac274c5daeeb dist/txtorcon-0.19.0.tar.gz cc51b4249ad126c31ea2746ec5ef1bcb7f6b0c34ced070913ed7772c0e48edf5 dist/txtorcon-0.19.0-py2.py3-none-any.whl EOF thanks, meejah -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJY+ZjOAAoJEMJgKAMSgGmnadEH/R0YCoID3xTkbFL7mVhtqY2e p7sPcFT50jUGDASaER2YoQ4syzptnQcLid5/pCf+F2xMwCVgayqaipNXtugNHZIl 9cCOnI09+IntCFLkVXQqMGnEzSSzcM0Ln87Qa9MMjNNZM+aj2WshmFnObdqsWNRo tIhnuKgMDgqoO9OgiXCsUXFQeooDDidnrnJgl5U7AA0+13nIar+/q9vCxMtDqSV9 kfh5IkB4RaeJTzDtTMYQKKHTIltdn7o0LrCyp1QsMhX+iHU4xZVOi7etgFnACqsP S1u2LMT1FggvyEAzIwn45ADhKpuPBrR35N5C21vQklHVEb9nQxI9LXTHCi0Fv5g= =mGZj -----END PGP SIGNATURE-----

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Tor 0.3.1 ticket triage: please do this today if you hack on Tor.
by Nick Mathewson 26 Apr '17

26 Apr '17

Hi! We've got 3 weeks left in the 0.3.1 merge window (which closes on May 15) so let's try to triage the tickets. Here's what to do if you are going to develop anything for Tor 0.3.1: - Make sure that everything you are going to do for 031 is assigned to you, in the 0.3.1 milestone, and has a points estimate. ("Points" is a rough "how many days will this take me?" guess.) - If there is anything assigned to you for 031 that you _won't_ be doing for May 15, or that you won't be doing at all, please unassign it and/or defer it from the 031-milestone. - If your total points estimate is over 12 or so (or whatever number of programming days you think you will have, please defer the less important things, or tag them with 031-stretch. Then, in 24 hours or so, for all the tickets that don't get an owner, I will either defer them or mark them "too important to defer" and look for somebody else to do them. Let's see how this works! -- Nick

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Action items wrt ed25519 onion address verification in prop224 (was Re: [tor-project] Network team meetings notes from 17 April 2017)
by George Kadianakis 25 Apr '17

25 Apr '17

Ian Goldberg <tor(a)cypherpunks.ca> writes: > On Thu, Apr 20, 2017 at 03:40:58PM +0300, George Kadianakis wrote: >> Hey Ian, >> >> so the current problem with ed25519-donna is that when I'm doing the >> above, I'm getting the following 32-byte key after ge25519_pack(). Here >> it is hexed up: >> >> 0x0100000000000000000000000000000000000000000000000000000000000000 >> >> I don't see any methods in ed25519-donna for checking a point or a >> packed point to see if it's the point at infinity (identity element). > > There actually is such a function, but it's buried in a weird place. > ge25519_is_neutral_vartime in ed25519-donna-batchverify.h does what you > want, but it's static, so you would need to copy it (and remove the line > involving batch_point_buffer). Probably not worthwhile. > > I can easily believe the representation of the identity (neutral) > element in ed25519 is the hex value above. (And it is; see below.) > >> I've been assuming that the point at infinity would be an all-zeroes >> 32-byte array, because that's what we are doing in curve25519, but I >> actually have no idea how the array representation of ge25519_pack() >> works. Here is our process for curve25519: >> https://gitweb.torproject.org/tor.git/tree/src/common/crypto_curve25519.c#n… > > Curve25519 only outputs the x coordinate, which is indeed 0, so you get > the all-zero value. ed25519 outputs the y coordinate (which is the > 255-bit value 0x000...0001 in little-endian format) and the single-bit > parity of the x coordinate (which is 0), so you do get the hex you give > above. (The identity element is the point (0,1) in Edwards curves, not > actually the point at infinity.) > >> The above packed point is an all zeroes 32-byte string, apart from the >> very first bit which is set. Could it be that the first bit is the >> compressed sign of the 'x' coordinate or something, and that's actually >> the point at infinity? >> >> But then what's the right way to check for the point at infinity? Check >> that everything is 0 apart from the first sign bit? > > Yes, pack the point, and compare it to the above 32-byte value. > >> And after I figure this out, I need to do the same for the reference >> implementation of ed25519, because as it seems Tor uses two simultaneous >> implementations of ed25519: >> https://gitweb.torproject.org/tor.git/tree/src/ext/ed25519 > > Yes, hopefully that implementation packs points in the same way! > >> Thanks for the help Ian :) Very much appreciated! > > No worries. > [CCing tor-dev since people might find it interesting] Thanks for the advice Ian :) With your help, I have now implemented the validation check. Check out the ticket #22006 and the branch `bug22006` here: https://gitweb.torproject.org/user/asn/tor.git/commit/?h=bug22006&id=628dd1… One last thing I'd like to do here is test our validation function against a pubkey with torsion component to make sure that it gets rejected. How would you go about generating such a pubkey? I was thinking of using the CRT to find an integer a \in Z, s.t a == 0 (mod l) && a == 1 (mod 8) but then I didn't know how to go from that scalar with a torsion component to an ed25519 point... Cheers!

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Experimental Namecoin naming for Tor
by Jeremy Rand 23 Apr '17

23 Apr '17

Hi, I've pushed some experimental code for using Namecoin naming in Tor. The code is at https://github.com/JeremyRand/OnioNS-client , you want the "namecoin" branch. Rough instructions: 1. Install Namecoin Core and let it fully download the blockchain. (SPV support is in the works.) 2. Enable JSON-RPC with user/password authentication in Namecoin Core. (The procedure is identical as in Bitcoin Core.) 3. Set your Namecoin Core JSON-RPC login info in the init_namecoind function of src/assets/onions-stem.py. 4. Start Tor Browser Bundle. 5. Run src/assets/onions-stem.py. 6. The first time you run it, it will instruct you to add a line to one of the Tor config files; do this. Specifically, it will ask you to add the line "__LeaveStreamsUnattached 1" to torrc-defaults. 7. Start Tor Browser Bundle again. 8. Run src/assets/onions-stem.py again. 9. Try opening a Namecoin website in Tor Browser. Example websites that I've verified to work include: http://duckduckgo-onion.bit.onion http://bitcoinpl.bit http://federalistpapers.bit.onion http://botball.bit (gives a Dreamhost error) The .bit.onion sites should also work as plain .bit. Semantically, .bit.onion means that it will always resolve to a .onion address (meaning that .bit.onion names are encrypted and authenticated regardless of whether TLS is used); .bit means that it will resolve to any of .onion, IPv6, IPv4, or CNAME (prioritized in that order), meaning that .bit names are only encrypted and authenticated if TLS is used. These semantics are open to revision later, as the Tor community evolves its canonical naming semantics. This is all proof of concept for now; some or all of this code will be rewritten later (hopefully to use the pluggable naming API instead of the control port). It will probably not work with Whonix/Tails/Subgraph due to the control port filter. It will definitely make your Tor Browser instance stand out, since most users can't resolve Namecoin domain names. And since it accesses the control port, it could presumably do lots of horrible things to your Tor instance (and I make no guarantees that it's properly sanitizing the input that's passed to Tor's control port). Huge thanks to Jesse for OnioNS (on which this code is based), and also thanks to Nick for sharing helpful info on this mailing list. Let me know how it works for you. Cheers, -- -Jeremy Rand Lead Application Engineer at Namecoin Mobile email: jeremyrandmobile(a)airmail.cc Mobile OpenPGP: 2158 0643 C13B B40F B0FD 5854 B007 A32D AB44 3D9C Send non-security-critical things to my Mobile with OpenPGP. Please don't send me unencrypted messages. My business email jeremy(a)veclabs.net is having technical issues at the moment.

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Provisional Draft of Hyphae
by isis agora lovecruft 21 Apr '17

21 Apr '17

Hello! Henry and I have written up a provisional draft design for a social bridge distribution scheme, modelled after rBridge, which we're calling Hyphae. For those further interested, here is a draft PDF. [0] Included within is: - A technical history, with primary sources, of censorship of the Tor network, as well as remediations for those censorship attempts; - A description of the bridge distribution problem, including orthogonal problems and solutions, and prior proposals specific to the bridge distribution; - A description of an algebraic-MAC attribute-based credential scheme, requisite non-interactive zero-knowledge proofs, and sub-credentials and tokens, which we use to build our bridge distribution protocol; - A centralised, anonymous micropayments scheme, which we hope is of interest to other projects (such as Brave); - A description of our Hyphae protocol; - An high-level, cryptographic and protocol design comparison to the rBridge protocol; and - Draft notes on our implementation. Please note that this is a provisional draft paper, containing the design but not yet containing results specific to our implementation. We expect some things to change in minor ways during further refinement and implementation. That said, we welcome all feedback and appreciate review. [0]: https://patternsinthevoid.net/hyphae/hyphae.pdf Best regards, -- ♥Ⓐ isis agora lovecruft _________________________________________________________ OpenPGP: 4096R/0A6A58A14B5946ABDE18E207A3ADB67A2CDB8B35 Current Keys: https://fyb.patternsinthevoid.net/isis.txt

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maatuska's bwscanner down since 2017-04-14 -> significant drop in relay traffic
by relayoperator＠openmailboxbeta.com 20 Apr '17

20 Apr '17

Hi Tom! since maatuska's bwscanner is down [1] I see a significant drop of traffic on many of my relays, and I believe this is related. Do you have any update to [2] on when maatuska will report bwscan results again? thanks, a concerned relayoperator [1] https://lists.torproject.org/pipermail/tor-consensus-health/2017-April/0078… https://consensus-health.torproject.org/graphs.html#bwauthgraphs [2] https://lists.torproject.org/pipermail/tor-consensus-health/2017-April/0078…

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