How the Chinese internet is tapped.

[Jun-ichiro itojun Hagino]

	on a similar topic as Greek.

	i was in Shinsen and DongAng, mainland china (right next to HongKong).
	i was able to experience GSM/GPRS Internet as well as hotel wired
	Internet (both are IPv4, sigh).

	in both cases, TCP port 80 (http) was sucked into transparent web proxy
	(squid).  i was careful enough not to type offensive words, but
	zh.wikipedia.org was invisible (squid raises some kind of connection
	error, always).  ja.wikipedia.org and en.wikipedia.org were visible.
	luckily TCP port 22 was open.  the hotel net was behind NAT so i could
	not use IPsec VPN.  i did not have enough time to configure NAT
	traversal stuff.

	from my past experience with chinese academic network operated in
	some university in Beijing (i forgot the name of the network/
	university), i know that every connectivity from china goes out of
	Beijing.  at least in year 2000-2002 timeframe.
	so if it is still true (inject me some clue if you know about the
	current situation), all the traffic that go out of china are tapped
	in Beijing.  i'm wondering what kind of server farm they are
	operating which are able to suck all TCP port 80 traffic from the
	entire china...  i forgot to run nmap OS fingerprint :-(

	also, my friend in china was using Skype from Tom Online on top of
	Windows.  i did not believe it until i see it, but ContentFilter.exe
	was really there.  it is the backdoor process for Tom Online Skype
	which transmits cleartext content to somewhere, which is likely to be
	some law enforcement or government organization.  otherwise, Skype
	traffic is totally encrypted - see "silver needle in skype" paper.

	i was informed that it is a common practice for south east asian
	nations to run censorship on the internet.  for instance, in thai
	www.youtube.com is not accessible.  they have never seen dodolook,
	very cute taiwanese girl from canada (IIRC) i guess.

	for more info, the following URL would be useful.  Japanese content
	and English content are a bit different so if possible be sure to
	check both of them (and other languages if possible).  the email is
	encoded in iso-2022-jp (Japanese standard encoding for email) but when
	you click it please click it Japanese URL in utf-8.

	http://en.wikipedia.org/wiki/Golden_Shield_Project
	http://ja.wikipedia.org/wiki/金盾
	http://en.wikipedia.org/wiki/Internet_censorship_in_the_People%27s_Republic_of_China#International_corporations
	http://ja.wikipedia.org/wiki/中国のネット検閲
	http://ice.citizenlab.org/?p=219

itojun

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