Proposal 279

StemNS is an implementation of the "Tor side" of Proposal 279 ("naming layer API") so that actual naming plugins can be tested/prototyped "now" without changing Tor.

StemNS is a fork of the original TorNS by meejah, which is modified to use Stem instead of txtorcon, with some additional security features added.

Dependencies

• Tor v0.4.5.1 Alpha or higher is preferred; older versions should still work.
• Stem v1.9.0 or higher is preferred; older versions should still work.

Configuration and usage

StemNS loads configuration from the config directory. Example configurations are included; you can use them verbatim by renaming their extension from .py.example to .py. You can also use them as a guide to make your own configurations. You should include:

• Any number of bootstrap configs.
  • These are callbacks that run when Tor finishes bootstrap.
• Any number of exit configs.
  • These are callbacks that run when Tor disconnects its control port.
• Exactly one port config.
  • This is the Tor control port on localhost where StemNS connects to.
  • Example configs are provided for system-wide Tor, Tor Browser, and ControlPort auto.
• Any number of service configs.
  • These are mappings between eTLD's and Prop279 providers.
  • See "Name Resolution Services" below.

Tor must be configured with the following option before launching StemNS:

__LeaveStreamsUnattached 1

In a typical Tor Browser installation, torrc-defaults is the correct place to add this option. For Tor daemon installed in the system, the option can be added to /etc/tor/torrc.

If the flag is not enabled, StemNS will exit with an error.

Once the flag is enabled, the StemNS daemon must be running for Tor to work. The reason is that by default, with the flag disabled, Tor automatically attaches streams to circuits, but with the flag enabled, Tor instead waits for the controller (StemNS in this case) to attach them. StemNS does a REDIRECTSTREAM command on each .bit stream prior to attaching it to a circuit; this command is how it redirects .bit to .onion.

The choice to not make StemNS configure this option itself is deliberate; making StemNS configure the option itself would leave a short window during initial connect where name resolution is incorrectly forwarded to the exit relay, which would be a security issue.

Name resolution services

StemNS comes with two example name resolution services, invoked for resolving <something>.<service>.onion:

• .pet.onion implemented in ns_petname.py resolves a predefined set of names (try, e.g., "http://txtorcon.pet.onion" in Tor Browser).
• .demo.onion always remap to txtorcon's documentation hidden-service. So <anything>.demo.onion will redirect you to txtorcon's documentation.

You can implement custom services and add them via your own config files.

Naming Implementations

• "banana" does naming based on /etc/hosts: https://github.com/pickfire/banana
• "dns-prop279" does naming based on DNS TXT records: https://github.com/namecoin/dns-prop279
• "ncprop279" does naming based on Namecoin: https://github.com/namecoin/ncprop279

License

Code specific to StemNS, and the code StemNS inherits from TorNS, is licensed under the Unlicense (see LICENSE). StemNS inherits some code from OnioNS-client, which is licensed under the Modified/New BSD License (see LICENSE.OnioNS).

StemNS is produced independently from the Tor® anonymity software and carries no guarantee from The Tor Project about quality, suitability or anything else.