Re: [tor-relays] Why MyFamily?
Am So., 23. Feb. 2020 um 01:55 Uhr schrieb teor : > Hi, > > I've gone a few emails back up the thread, because the risk > analysis is missing some really important factors. > > And just some reminders: > > Some users depend on the tor network for their safety. > > Relay operators take some risks, but we do our best to > reduce those risks. > > MyFamily is about user and operator safety. We pay more > attention to arguments based on safety. > > On 22 Feb 2020, at 23:02, Michael Gerstacker < > michael.gerstac...@googlemail.com> wrote: > > > So for what reason do i set the MyFamily option beside making a Hidden >> > Service Guard discovery attack more easy? >> >> - risk reduction for tor users >> MyFamily declarations allow the tor client software to automatically >> detect relay families when creating circuits to >> avoid using multiple relays from the same operator in a single circuit. >> > > This should not matter if the operator is not malicious and like i already > said an malicious operator will not use the same contact info or relay name. > > - reducing the risk for tor users that might become victims if some >> operator gets compromized (with all its relays) >> > > This is a reason i can understand. > Not sure how much that would really help in practice but i can understand > it. > > > In practice, relay operators become targets for compromise > when they don't set MyFamily. Because those relays can be > used to attack a Tor users. > > If relay operators correctly set MyFamily, then an attacker > needs to compromise multiple operators to see a single > user's traffic. > > In this case, it doesn't matter if the operator is malicious. > Understood. So for example if someone compromise multiple of my relays without me noticing it and installs software on them (or the providers network) to do a traffic correlations attack i am a less interesting target when i have set MyFamily. Another benefit of a proper MyFamily setting in this case would be that he first would need to remove the MyFamily to see any interesting traffic which i would most likely realize faster than without a proper MyFamily setting. This is indeed something what makes me very uncomfortable because it would be my fault if someones privacy would get affected by this. > - transparency >> Every relay operator should declare their relay group to allow everybody >> to measure their network fraction (Sybil detection). >> > > Should... > But i understand this one too. > But as long as my family is still a small one with only one exit compared > to others i am not a Sybil attack risk and even if i would would i get any > special treatment then? > > > It doesn't matter how small your relays are. Some clients > will choose your relays as guards. You're putting those > users in danger. > I understand this one as related to the first one. > - risk reduction for relay operators >> MyFamily also provides risk reduction for operators since they are less >> valuable as an attack target >> if they can not technically be used for e2e correlation attacks >> > > I think this is similar to your first point but i think that should be the > operators choice if he want to take steps against this case. > > > There's also a network effect here. If almost all operators > set MyFamily, then the Tor Network becomes a less > valuable target for attacks. So attackers use other > methods, like attacking Tor Browser, or offline attacks. > > But if a lot of operators don't set MyFamily, then attackers > develop tools and techniques to attack the network. Then > they can repeat these attacks easily whenever they get a > new target. I guess you could call that a market effect. > Understood. > So if you're not going to set MyFamily for yourself, do it for > Tor users, and do it for Luther relay operators. > Will try to do it tomorrow. > We prioritise the safety of users and relay operators here. > > T > ___ > tor-relays mailing list > tor-relays@lists.torproject.org > https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays > ___ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
Re: [tor-relays] Why MyFamily?
Hi, I've gone a few emails back up the thread, because the risk analysis is missing some really important factors. And just some reminders: Some users depend on the tor network for their safety. Relay operators take some risks, but we do our best to reduce those risks. MyFamily is about user and operator safety. We pay more attention to arguments based on safety. >> On 22 Feb 2020, at 23:02, Michael Gerstacker >> wrote: >>> > So for what reason do i set the MyFamily option beside making a Hidden >>> > Service Guard discovery attack more easy? >>> >>> - risk reduction for tor users >>> MyFamily declarations allow the tor client software to automatically detect >>> relay families when creating circuits to >>> avoid using multiple relays from the same operator in a single circuit. >> >> This should not matter if the operator is not malicious and like i already >> said an malicious operator will not use the same contact info or relay name. >> >> - reducing the risk for tor users that might become victims if some operator >> gets compromized (with all its relays) > > This is a reason i can understand. > Not sure how much that would really help in practice but i can understand it. In practice, relay operators become targets for compromise when they don't set MyFamily. Because those relays can be used to attack a Tor users. If relay operators correctly set MyFamily, then an attacker needs to compromise multiple operators to see a single user's traffic. In this case, it doesn't matter if the operator is malicious. >> - transparency >> Every relay operator should declare their relay group to allow everybody to >> measure their network fraction (Sybil detection). > > Should... > But i understand this one too. > But as long as my family is still a small one with only one exit compared to > others i am not a Sybil attack risk and even if i would would i get any > special treatment then? It doesn't matter how small your relays are. Some clients will choose your relays as guards. You're putting those users in danger. >> - risk reduction for relay operators >> MyFamily also provides risk reduction for operators since they are less >> valuable as an attack target >> if they can not technically be used for e2e correlation attacks > > I think this is similar to your first point but i think that should be the > operators choice if he want to take steps against this case. There's also a network effect here. If almost all operators set MyFamily, then the Tor Network becomes a less valuable target for attacks. So attackers use other methods, like attacking Tor Browser, or offline attacks. But if a lot of operators don't set MyFamily, then attackers develop tools and techniques to attack the network. Then they can repeat these attacks easily whenever they get a new target. I guess you could call that a market effect. So if you're not going to set MyFamily for yourself, do it for Tor users, and do it for Luther relay operators. We prioritise the safety of users and relay operators here. T___ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
Re: [tor-relays] Why MyFamily?
Am Sa., 22. Feb. 2020 um 17:11 Uhr schrieb nusenu : > Michael Gerstacker: > >>> But as long as my family is still a small > >> It is rather hard, time consuming and error prone > >> to asses group sizes without proper MyFamily declarations. > >> > > I am the operator of my relays so if i for whatever reason decide to not > > publish that i run a bigger family then this should be my own decision. > > There are two notions to this, depending on what you mean by 'publish'. > > 'publish' in the sense of linkability relays <-> operator identity: > Correct there is no need for that. > > 'publish' in the sense of declaring a proper MyFamily set: > > from the tor manual page: > "If you run more than one relay, the MyFamily option on each relay > **must** list all other relays" > I will list them or shut them down. Just not right now. I thought about why i do not want to list them right now and this reason might sound stupid to others but for me including a new relay into MyFamily is some sort of "celebration". When i include a new relay i commit myself to care for it for the next time period (no matter how long that means). For me that means checking nyx and the logfile everyday and taking a quick look into nmon. So as an operator who paies the bills for my new children i expect the torproject and all affected people to wait till i did my "celebration" or take the necessary steps and reject them so that i understand this as a message that the celebration took too long and that these relays are not wanted anymore. I think i do not want to automate this because it would destroy my celebration. I already automated upgrades because i see a purpose in this but from my point of view i can not see any porpose to automate MyFamily. I also thought about why i include them in MyFamily at all and i think the reason is because i want that others have the possibility to exclude my relays if they see a need to do so. > > If the torproject needs these information urgently they need to force it > > The Torproject Inc does not run the Tor network, nor the majority of Tor > directory authorities, > but yes, some Torproject employees play a key role on what gets actually > enforced on the network and what not > and The Torproject produces the software that dir auths run so they have > at least partial/indirect control over the imposed rules > and the network. > As far as I know there is no formal or informal written agreement between > Tor directory authorities as to how they run the network. > Past attempts by a Torproject employee an me, to establish something like > that unfortunately failed [1]. > I think i remember something where nick explained that he (or any other torproject member listed on the torprojects peoples page) can not directly tell the authorities operators what they should do. This made me think about for the first time what the torproject actually is. And i think that the way it is right now is actually a good thing. Maybe it even must be like that to ensure free speech as good as possible and to not make some people a big target. Bu its funny to hear from one of the main designers of Tor that he can actually not really decide what happens. I think there is the difference between a normal company and Tor and thats the reason why i am okay paying bills without getting something countable back (beside the fact that i learned a lot in many ways since i started my first relay). I think it is impressive how good this project works and i think you would put that at risk if you try to force standards too easily and telling directory authorities operators how to run them is one of these examples. Of course i only see what i can see and i see that you are more involved than i am but i think as long as its not broken dont try to fix it. > > > Not proposing relays of honest operators for removal should be in the > > interest of all to help protect tor users > > It is hard to tell honest operators from others if the relay has no > ContactInfo > or does not reply to emails. Even if they reply it can be non-trivial. So > if there were actual technical rules > they should apply to all relays equally and not just to dishonest operators > because how do you define and measure "honest" operator? > Should an operator who confirms to bad-relays@ that he setup modified > relays to collect onion addresses > be allowed on the network because he is at least honest about it? > (Just for the record i had contact info on all my relays and check that email address weekly. Since my first exit even daily.) Yes of course this is a problem and the only "solution" is to raise the bar for all. But this is not what MyFamily is doing. It is raising the bar for the honest ones but not for the dishonest ones. If this problem need to get fixed i propose using a contact email address as a replacement of MyFamily and sending a validation email. Maybe even send another validation email after some randomized timeframe from time to time
Re: [tor-relays] Why MyFamily?
Michael Gerstacker: >>> But as long as my family is still a small >> It is rather hard, time consuming and error prone >> to asses group sizes without proper MyFamily declarations. >> > I am the operator of my relays so if i for whatever reason decide to not > publish that i run a bigger family then this should be my own decision. There are two notions to this, depending on what you mean by 'publish'. 'publish' in the sense of linkability relays <-> operator identity: Correct there is no need for that. 'publish' in the sense of declaring a proper MyFamily set: from the tor manual page: "If you run more than one relay, the MyFamily option on each relay **must** list all other relays" > If the torproject needs these information urgently they need to force it The Torproject Inc does not run the Tor network, nor the majority of Tor directory authorities, but yes, some Torproject employees play a key role on what gets actually enforced on the network and what not and The Torproject produces the software that dir auths run so they have at least partial/indirect control over the imposed rules and the network. As far as I know there is no formal or informal written agreement between Tor directory authorities as to how they run the network. Past attempts by a Torproject employee an me, to establish something like that unfortunately failed [1]. > Not proposing relays of honest operators for removal should be in the > interest of all to help protect tor users It is hard to tell honest operators from others if the relay has no ContactInfo or does not reply to emails. Even if they reply it can be non-trivial. So if there were actual technical rules they should apply to all relays equally and not just to dishonest operators because how do you define and measure "honest" operator? Should an operator who confirms to bad-relays@ that he setup modified relays to collect onion addresses be allowed on the network because he is at least honest about it? > but an opt-in solution for > MyFamily which gets forced by random people on a public [tor-]bad-relays > mailinglist bad-relays@ is not public in the sense that everyone can read it, but everyone can send to it, which is its main purpose. [1] https://medium.com/@nusenu/the-growing-problem-of-malicious-relays-on-the-tor-network-2f14198af548 signature.asc Description: OpenPGP digital signature ___ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
Re: [tor-relays] Why MyFamily?
Am Sa., 22. Feb. 2020 um 15:17 Uhr schrieb nusenu : > >> - risk reduction for tor users > >> MyFamily declarations allow the tor client software to automatically > >> detect relay families when creating circuits to > >> avoid using multiple relays from the same operator in a single circuit. > >> > > > > This should not matter if the operator is not malicious > > That is a big if and impossible to detect automatically. > If we accept operators to run end-to-end correlation relay groups by > receiving "you can trust me" emails > you can guess what malicious actors will do next. > Of course would they do. > The only way the tor client software can detect relay groups across > multiple /16 blocks automatically and at scale > is currently by MyFamily declaration. > There is no "dude don't worry, you can trust me" flag. > And if there would be then this would be the worst possible solution. > > and like i already > > said an malicious operator will not use the same contact info or relay > name. > > We've had that already. > I know. Thats why i point that out again because now i am somehow affected too and can better understand what they mean with that sentence. > > But as long as my family is still a small > > It is rather hard, time consuming and error prone > to asses group sizes without proper MyFamily declarations. > I am the operator of my relays so if i for whatever reason decide to not publish that i run a bigger family then this should be my own decision. If the torproject needs these information urgently they need to force it for example with a relay registration or should find a better soultion which is not depending on a trust level. > > > I think MyFamily greatly fails in trying to solve a problem > > I agree, but it is currently the only option how operators can tell tor > clients > about their relay group in an automated way. > > To summarize: > > Multiple recommendations (with and without configuration management) > have been pointed out to practically solve the hassle of MyFamily across > multiple relays with a growing group of relays > without requiring to mess with all torrc files manually whenever a new > relay gets added to a group. > Understood. > Using one of them should be in the interest of relay operators to help > protect tor users > (and indirectly help with malicious relay detection). > Not proposing relays of honest operators for removal should be in the interest of all to help protect tor users but an opt-in solution for MyFamily which gets forced by random people on a public tor-bad-relays mailinglist is not the right way in my opinion because obviously at least in my case these people might lack information. I understand that this is only obvious for me but then these people should think twice before they propose relays for removal. > ___ > tor-relays mailing list > tor-relays@lists.torproject.org > https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays > ___ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
Re: [tor-relays] Why MyFamily?
>> - risk reduction for tor users >> MyFamily declarations allow the tor client software to automatically >> detect relay families when creating circuits to >> avoid using multiple relays from the same operator in a single circuit. >> > > This should not matter if the operator is not malicious That is a big if and impossible to detect automatically. If we accept operators to run end-to-end correlation relay groups by receiving "you can trust me" emails you can guess what malicious actors will do next. The only way the tor client software can detect relay groups across multiple /16 blocks automatically and at scale is currently by MyFamily declaration. There is no "dude don't worry, you can trust me" flag. > and like i already > said an malicious operator will not use the same contact info or relay name. We've had that already. > But as long as my family is still a small It is rather hard, time consuming and error prone to asses group sizes without proper MyFamily declarations. > I think MyFamily greatly fails in trying to solve a problem I agree, but it is currently the only option how operators can tell tor clients about their relay group in an automated way. To summarize: Multiple recommendations (with and without configuration management) have been pointed out to practically solve the hassle of MyFamily across multiple relays with a growing group of relays without requiring to mess with all torrc files manually whenever a new relay gets added to a group. Using one of them should be in the interest of relay operators to help protect tor users (and indirectly help with malicious relay detection). signature.asc Description: OpenPGP digital signature ___ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
Re: [tor-relays] Why MyFamily?
Hi nusenu Am Fr., 21. Feb. 2020 um 22:24 Uhr schrieb nusenu : > Hi Michael, > > > Last week i got an email with a warning that some of my relays are > > missing the correct MyFamily setup and that i am a risk to do > > end-to-end correlation attacks together with a list of all relays i > > operate plus one relay which uses the same name than i use but is not > > operated by me. > > the email Michael is referring to for the interested readers: [1] > > > I already knew that not all of my relays have a correct MyFamily setup > > because as long as i am not sure if they will stay i usually dont > > include them in MyFamily because it is a pain to edit every torrc > > Yes, manually managing MyFamily is a pain with that many relays. > It is best to automate it so you don't have to worry about it > no matter how long your relays might run. > > It is also relevant to note that we are not talking about fresh relays > (born days or weeks ago) but >6 months. > I think the relay you are talking about is the relay in Yekaterinburg. This relay is not listed as with no MyFamily in the first email but after receiving the first email i decided that i am okay with the newer hoster more than the older hoster so i included the newer one in MyFamily and excluded the older one and will probably let it expire so the relays mentioned with no MyFamily setup in the first and the ones in the second email should be slightly different. But thats not important anyway. I usually wait at least one billing period. Some of my relays are paid for three years in advance which means there might be cases where a relay will be in a state of unknown for three years till i know if they will stay. > > A few days later i got a message that some of my relays will soon get > > rejected because i did not responded to the previous email. > > A more correct version is: some relays were proposed for removal on the > bad-relays@ list > should there not be any reaction by the operator [2]. > > That is something different than informing an operator about an upcoming > removal since > everybody can propose removals and only dir auths can actually vote for > the removal. > Understood. > [2] > For the readers on this list, this is the second mentioned email: > > I'm proposing the removal of the first 5 entries in the following table > (end-to-end correlation risk) > > should there not be any reaction to this email from the operator. > > > > A previous email from 2020-02-15 did not result in a reply so far. > > > > > +-++--+--+---+-+---+--+ > > | first_seen | member | contact | nickname > | tor_version | IP | as_name >| fingerprint | > > > +-++--+--+---+-+---+--+ > > | 2020-02-01 18:00:00 | 1 | NULL | angeltest33 > | 0.4.2.6 | 139.99.238.17 | OVH SAS >| 4BF3D299BC500C350868F078749291C766C7AA6F | > > | 2020-01-11 16:00:00 | 1 | NULL | angeltest5test > | 0.4.2.6 | 51.38.147.96| OVH SAS >| 951307BA74E44A9C9C208B2F134CDA2409944075 | > > | 2019-08-06 11:00:00 | 1 | NULL | angeltest27 > | 0.4.2.6 | 185.173.177.153 | GalaxyStar LLC > | 95C8B9418E74F3FF80E5C3D3AF7F03156FFBBFBE | > > | 2019-08-31 09:00:00 | 1 | NULL | angeltest9 > | 0.2.9.14 | 104.244.76.190 | FranTech Solutions > | F1D5C0F5157D9B24014BE8C7A1D878AEA6843B42 | > > | 2019-11-21 12:00:00 | 1 | NULL | angeltest26test > | 0.4.2.6 | 91.243.50.239 | Petersburg Internet Network ltd. > | F51A927E34662D6005393F2327C870FB0D0D7FE0 | > > > > > - The bad-relays team expect an answer to their emails even if they do > > not tell you that in the first email and rather send you a second > > email that they will soon reject your relays if you dont answer them. > > I think you are confusing the "bad-relays team" with subscribers or people > sending emails to the bad-relays@ list. > If in doubt require the sender to have a @torproject.org address > (unfortunately there is no actual sender address for the bad-relays team > since it is just a mailing list) > The senders name was "tor-bad-rel...@riseup.net" which looked official to me. Then Georg Koppen "validated" the second email. For the next time i know that i only need to respond to valid emails. > > So for what reason do i set the MyFamily option beside making a Hidden > > Service Guard discovery attack more easy? > > > - risk reduction for tor users > MyFamily
Re: [tor-relays] Why MyFamily?
Toralf Förster: > On 2/22/20 10:55 AM, nusenu wrote: >> You can preemptively generate as many relay keys as you want and >> use their fingerprints in MyFamily so you don't have to bother about >> changing old >> configs when you add new relays as long as you use these preemptively >> generated keys. >> > And if you're already there then you can then deal with offline keys too ;-) I believe that is a different matter. If you run >2 relays without configuration management and don't want to update torrc file, you probably don't want to run in OfflineMasterKey mode either. So this is another reason to seriously consider configuration management if you run > 1Gbit/s of tor bandwidth. If you want to consider a state of the art relay > setup. signature.asc Description: OpenPGP digital signature ___ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
Re: [tor-relays] Why MyFamily?
On 2/22/20 10:55 AM, nusenu wrote: > You can preemptively generate as many relay keys as you want and > use their fingerprints in MyFamily so you don't have to bother about changing > old > configs when you add new relays as long as you use these preemptively > generated keys. > And if you're already there then you can then deal with offline keys too ;-) -- Toralf signature.asc Description: OpenPGP digital signature ___ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
Re: [tor-relays] Why MyFamily?
> Secondly, even though not recommended at all, MyFamily accepts nicknames; > If there's no practical way for you to automate it (such as to set up a > centralized system to manage torrcs and push them to hosts), you can make a > MyFamily like this: > > MyFamily MyNode1,MyNode2,MyNode3,...,MyNodeN Don't use nicknames in MyFamily. You can preemptively generate as many relay keys as you want and use their fingerprints in MyFamily so you don't have to bother about changing old configs when you add new relays as long as you use these preemptively generated keys. -- https://mastodon.social/@nusenu signature.asc Description: OpenPGP digital signature ___ tor-relays mailing list tor-relays@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
