[tor-relays] A call to arms for obfuscated bridges

[George Kadianakis]

Greetings,

A year ago we asked you to run obfuscated bridges to help people in
Iran [0]. Many people answered our call and we ended up having a big
pool of obfuscated bridges to give to our users.

Unfortunately, today, most of those bridges are down, and fresh ones
are needed more than ever, since obfuscated bridges are the only way
for people to access Tor in some areas of the world (like China, Iran
and Syria).

On the bright side, Tor's anti-censorship infrastructure has improved,
and now you don't have to send the bridge addresses to us; if you run
an obfuscated bridge with Tor 0.2.4.x, Tor will send its own address
to BridgeDB [1] like normal bridges do.

Also, obfsproxy was rewritten in Python and it now supports a new
pluggable transport called 'obfs3' which works even in China [2]. We
have dropped support for the C-version of Obfsproxy, and the new
Pluggable Transport Bundles contain the Python version [3]. Finally,
future pluggable transports will be developed for the Python version.

Looking into BridgeDB, we have 200 obfs2 bridges, but only 40 obfs3
bridges: this means that we need more people running the new Python
obfsproxy! Upgrading obfsproxy should be easy now, since we prepared
new instructions and Debian/Ubuntu packages. If you run Debian or
Ubuntu check out these instructiosn:
https://www.torproject.org/projects/obfsproxy-debian-instructions.html.en
otherwise use these:
https://www.torproject.org/projects/obfsproxy-instructions.html.en
(and make sure your pip is upgraded so that it uses HTTPS [4])

Furthermore, Tor's support assistants need some _unpublished_ bridges to
give to censored users who ask for help via email. To configure an
unpublished bridge you add
"PublishServerDescriptor 0"
to its torrc. After you do so, fire up Tor, and check its logs to find
the ports that 'obfs2' and 'obfs3' are using. Send your IP and ports
to tor-assistants at torproject.org. 

Finally, if in the future we need you to do something extra (for example to
upgrade obfsproxy to support a new pluggable transport) we will send
another mail to tor-relays.

Thanks for the help!

[0]: https://lists.torproject.org/pipermail/tor-talk/2012-February/023070.html
[1]: https://bridges.torproject.org
[2]: In China obfs2 is blocked using active probes: https://trac.torproject.org/projects/tor/ticket/8591
[3]: https://blog.torproject.org/blog/new-name-obfsproxy-tor-browser-bundles
[4]: https://groups.google.com/forum/#!msg/python-virtualenv/foXxh-NpdGg/uT0NPc9mFQ8J