[ooni-dev] Egypt Blocking with Tor 0.2.8

teor teor2345 at gmail.com
Tue Nov 1 16:24:11 UTC 2016


Hi,

I was reading about blocking in Egypt:
https://ooni.torproject.org/post/egypt-network-interference/

And noticed that you were still using Tor 0.2.7:
https://explorer.ooni.torproject.org/measurement/20161026T162218Z_AS36935_kTY80ArJx4baKS9FIss3oPEYfqpzEp0bubESO1T0aEc3Njl3QU
which Egypt blocks by blocking connections to the directory authorities.

You say:
"In our testing we found 7 out of 9 directory authority consensus file
requests to be blocked:"

Tor Browser uses Tor 0.2.8, which:
* bootstraps using Fallback Directory mirrors as well as Authorities
https://trac.torproject.org/projects/tor/wiki/doc/FallbackDirectoryMirrors
* tries 5 fallbacks and 2 authorities before giving up
https://trac.torproject.org/projects/tor/ticket/4483
* only bootstraps over the ORPort
https://trac.torproject.org/projects/tor/ticket/18483

I think these changes make Tor harder to block, except perhaps for the
ORPort bootstrap change, which means tor can be blocked using only the
SSL handshake. (But it secures the HTTP headers from interference.)

Can you repeat the Egypt tests with Tor 0.2.8?
We've heard from users in Mexico that it evades some of their ISP blocks.

T

-- 
Tim Wilson-Brown (teor)

teor2345 at gmail dot com
PGP C855 6CED 5D90 A0C5 29F6 4D43 450C BA7F 968F 094B
ricochet:ekmygaiu4rzgsk6n
xmpp: teor at torproject dot org
------------------------------------------------------------------------------





More information about the ooni-dev mailing list