[tor-dev] SkypeMorph

[Hooman]

Greetings,

A while ago the Tor project rolled out Obfsproxy as a Browser Bundle 
[1], for users behind firewalls filtering SSL or detecting other 
characteristics of a Tor connection, to help them access bridges.

In our recent work, SkypeMorph [2], we have tried to use Skype video 
communications as our target protocol for protocol obfuscation. 
SkypeMorph functionality is similar to Obfsproxy, but the connection 
between the bridge and the client looks like a Skype video call (the 
details of how we do this is discussed in the technical report).

We also have an open-source proof-of-concept impelmenation of the 
SkypeMorph available at: [3]


Notes:
1- At the moment our code relies on SkypeKit SDK [4] (a paid Skype SDK 
which you can get for around US$ 5) for Skype functionalities (the 
README file in the package explains how one can obtain SkypeKit). 
However, it can be easily ported to Skype public API [5], so users would 
not have to pay for it.

2- SkypeMorph and pluggable transports: Although our code can 
potentially be used as a pluggable transport, there is a minor 
difficulty with the pluggable transport framework that needs to be 
addressed before it can host our code. As mentioned above, our code uses 
Skype network for basic login stuff, so it takes a little bit more time 
than what Tor expect from a typical transport (like Obfsproxy), so the 
Tor client gives up building circuits after a while. We are aware of 
ORControllers tricks to solve the problem, but it does not seem to be 
the right way to do it and it would be awesome if the pluggable 
transport were able to tell Tor that it's working on setting up the 
connection, and that Tor
shouldn't give up on it until it says it's ready. I am sure other 
transports could also benefit from this.

Hooman



[1]:https://blog.torproject.org/blog/obfsproxy-next-step-censorship-arms-race
[2]:http://cacr.uwaterloo.ca/techreports/2012/cacr2012-08.pdf
[3]:http://crysp.uwaterloo.ca/software/
[4]:http://developer.skype.com/public/skypekit
[5]:http://developer.skype.com/public-api-reference

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