[tor-talk] V3 censorship ?

[George Kadianakis]

hikki at Safe-mail.net writes:

> I run both a V2 and V3 service on my Linux server. I'm using the same Tor
> process with both. The torrc file is fairly standard, except I'm forcing 
> some custom entry nodes, and I compile Tor from source on Debian Stretch.
>
> The V2 service has worked flawlessly, more or less, for the last 5 years or 
> so. It has about 98% uptime 365 days a year, according to my server stats. 
> The server and Internet connection has always been fast and reliable.
>
> When I add a V3 address to my server, it works pretty much flawlessly as 
> well, but *only* until I make the address public. Non-public V3 addresses 
> have about 98-99% uptime per week/month. But after the address has been 
> made public, and people have learned about it, its uptime is suddenly 
> reduced to about 60%. It will be completely inaccessible for hours at a 
> time. *While* on the same Tor process, the V2 address works without issues.
>
> By inaccessible I mean the same as having turned the service off.
>
> Later I create a new V3 address, which is non-public. Only I know about it. 
> It has about 98% uptime and works fine. I leave it there for a while, and 
> it still works fine. I then make it public on my website, and the next day 
> it is inaccessible when trying it. Uptime drops from 98% to 60-70%, and 
> from there on it becomes randomly inaccessible, 4-8 hours at a time.
>
> I tried for a third time, then fourth, and finally a fifth time, and the 
> same pattern repeat itself, even with different and random timings.
> On the forth attempt I released the V3 address in public at the same moment 
> it was created, and it never achieved anything above 60% uptime per week 
> from the very beginning.
>
> I know the V3 system is new, and could have some undiscovered bugs, but my 
> gut feeling tells me that someone, or something, is capable of censoring 
> all my V3 addresses, while the old V2's are completely unaffected.
>

Thanks for the report, Hikki! It's really valuable for us to receive
such reports from HSv3 operators given that the system is so new and
there are undiscovered bugs we should fix.

Personally, I doubt this is a censorship attack by an adversary since
it's even harder to censor v3 onions than v2 onions. Of course, we can
never be sure.

If I were to bet, I would bet that it's some sort of bug on the v3
codebase, that perhaps could be triggering when it's getting used by
many people (hence why it appears when you make it
public). Unfortunately, there is no way to really know what's going on
except if we see some tor logs.

Please let us know if you'd be willing to send us some (sanitized) logs
of your tor process. If you don't want to do that, perhaps you could
check your log files to see if there are any really obvious log lines
there that could point out the problem, and let us know about them.

Thanks for the report again! v3 onions are still early in their
lifetime, so there will be various bugs to fix until they can reach the
stability of the older v2 onions!

Cheers! :)