[tor-project] September 2019 report for the Network Team

Alexander Færøy ahf at torproject.org
Mon Oct 14 16:01:54 UTC 2019

Hello Tor Project people,

In September, the Network Team have worked on the following items:

- Work on various new policy proposals in the network team:
    1. PR policy.
    2. Merge policy.
    3. Commit policy.

- Retirement of EOL relays.
- release
- 0.4.2 release prep.
     We froze the 0.4.2.x series to new series, identified all the
     issues we want to fix on the 042Status page, put out an alpha, and
     started working on the pending issues.

- C code style discussion
     Nick started working on a survey to figure out where we stand on issues of
     consistent code style.

# Project to improve Onion Service [0]

We started work on adopting OnionBalance features into onion services v3. We
kicked off this activity by working on stem support for v3 descriptors. There
is currently no support in stem to get descriptor information for v3 onion
services (HSv3) and we have been tackling this issue by:

1. Implementing HSv3 descriptor encoding in stem,
2. Adding code to stem to calculate the Hidden Service Directories (HSDirs)
   that are responsible for these v3 descriptors, and
3. Investigating the best way to implement key blinding for HSv3 in stem.

Additionally, we have been working on enhancing onion services overall
by working on a number of bugfixes and improvements. We are very excited to
announce that we now have complete support for IPv6 in v3 onion services. We
have also been working on identifying bugs related to HSv3 timeouts[8] through
the use of a health monitoring tool. As a result of this work we have now
identified four new bugs and are in the process of writing fixes for them. We
have also been making progress investigating an issue with missing HSv3
descriptors when setting up an intro circuit. All of these help to make v3
Onion services more scalable and stable which we hope will help with their

We have also been busy working with the SecureDrop team over the past few
months and are happy to share that the latest SecureDrop v1.0.0 release has
added support for enabling v3 onion services.

Other than that, work has continued on the Denial of Service (DoS) defenses
with the implementation and merge of proposal 305 which allows HSv3 operators
to send a number of DoS defense parameters to their introduction. We are also
still in discussions regarding whether our proposed fix for an attack that
forces rotation of the intro point for an onion service is good enough or
whether we need to go back to the drawing board to find a better solution. Once
the outstanding issues on these items are resolved, these features should be
available from the first tor v0.4.2 stable release.

# Project on Modularization of Key Aspects of the Tor Network [1]

We have been working on refactoring our code to make the modules more
resilient, segregated, and automatically testable. We started setting up a
system to change how Tor modules should communicate, designed to reduce module
complexity and maintenance burden. For that we created a generic
publish/subscribe system for cross-module communications.  We worked on
rearranging files for the module dirauth so that more directory authority code
can be compiled out when unneeded and spent time fixing bugs related the
refactoring of key modules. We also refactored crypto_digest.c to have fewer

We are working on distributing the config.c module across several modules
[5][39][46]. It initializes many other modules, and provides the proper amounts
to a set of global variables for the configuration settings. Similar to
config.c, we are working to distribute the functionality of control.c across
several modules [29] [47]. control.c queries and manipulates the internal
states of many different subsystems, so it currently needs to know about all
those internals.

[0] https://trac.torproject.org/projects/tor/wiki/org/sponsors/Sponsor27
[1] https://trac.torproject.org/projects/tor/wiki/org/sponsors/Sponsor31

All the best,

Alexander Færøy

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