How to anonymize Skype on Linux / Use anonymous
skype through tor
I've recently worked on anonymizing as many of my applications as I
could in that spirit.
I looked for a practical way to anonymize my Skype. Skype
communication is so essential this days,
it's very likely that a huge part of skype communication is being
monitored by skype corp, it's not impossible that some malicious
installed trojan in skype would report about which IP address
you're using to connect to Skype.
Therefore proxifying skype could be a step further to at least
prevent for following your skype traffic route.
Of course passing
Skype traffic via tor is not a guarantee
for anonimity since it's probably very easy for Skype owner company
to keep record of Skype users, where do they people originate from,
full log of people comminication via skype based on their user
login.
As skype is a closed software and we have no access neither to the
protocol specs neither to program source code, it's almost
impossible to know if communication via skype is secure in sense of
privacy.
It appeared that proxifying skype is a piece of cake and comes just
to a proper instalating of
Tor + polipo caching proxy and
further installing
proxychains
Proxychains is a rather interesting software, it's able to carry
any application TCP and DNS traffic through a proxy server (http
and socks).
Therefore
proxychains is able to run any program through
proxy server and hence hide your real IP.
Interesting fact is that proxychains is the Unix equivalent for
Window's
Freecap -
"Program based on universal DLL injection in alien
process (works on all Windows from Win95 to Longhorn), which hooks
Winsock API, redirecting connect requests to the SOCKS
server.
So if you intend to proxify your Skype application on a Windows
host you will have to use Wincap.
Back to the main topic of "what is the way to proxify" skype on
Linux, so here is how I did it:
1. Install proxychains (available on a Debian host directly as a
deb package)
debian:~# apt-get install proxychains
2. Install skype from source on Debian Testing/Unstable (Lenny /
Squeeze / Sid). I personally use
skype_static-2.0.0.72.tar.bz2
debian:~# cd /root
debian:/root# wget
http://pc-freak.net/files/skype_static-2.0.0.72.tar.bz2
debian:/root# tar -jxvf skype_static-2.0.0.72.tar.bz2
debian:/root# mkdir /opt/Skype/
debian:/root# mv skype_static-2.0.0.72 /opt/Skype/
Also place a skype startup script to instruct skype that it will
have to use the pulseaudio for a sound server.
Crete the /usr/local/bin/skype file.
It should contain the following
#!/bin/sh export SDL_AUDIODRIVER=pulse; /usr/bin/proxychains
/usr/bin/linux32 /opt/Skype/skype_static-2.0.0.72/skype
#/usr/bin/torify /usr/bin/linux32
/opt/Skype/skype_static-2.0.0.72/skype
Now simply startup skype by either typing
/usr/local/bin/skype from a terminal or either create a
shortcut towards skype or edit the existing shortcut added in
either GNOME or KDE menus and set it to use /usr/local/bin/skype as
a skype starter.
Even better proxychains can be used to proxify via a tsocks proxy
any other application on your BSD or Linux.
I've also noticed that tor deb is also equipped with a program
called torify - torify - wrapper for tsocks and
tor
I'm not quite sure if torify is also able to torify skype along
with the other applications for which it can be used to torify
traffic, so if any of the readers of this article can give some
feedback if they have tried that would be really nice :)