Testing Wikileaks DNS mirrors
First publication of this article on 10 December 2010
Among the efforts to prevent censorship to take down WikiLeaks, several persons have set up DNS mirrors. They are names that point, not to one Web server but to a list of IP addresses which host a Web mirror. These lists can be quite long and it is better to have an automatic tool to test them.
There is a technical reason why you cannot put the IP address of any WikiLeaks Web mirror in a DNS record for
wikileaks.anything.example: the
HTTP protocol expects a
Host: header in the query and dispatches the
request to the proper virtual host, depending on this header. If the
header is missing or wrong, you are sent to the "default" virtual
host, which may be quite different from what you expect. So, you
cannot just take a list of Web mirrors and add their IP addresses, you
need to test.
The program test-wikileaks.py, written in
Python, does exactly that: it takes the IP
addresses from a name, and performs a HTTP connection to this address,
retrieves a page and searches if it looks like a correct Wikileaks
page. If not, it complains:
% test-wikileaks.py wikileaks.jmp.net Wrong data in http://88.80.13.160/cablegate.html, not a Wikileaks mirror?
Note well that it does not mean that
wikileaks.jmp.net is wrong, just that it is not a
DNS mirror, you cannot copy its addresses blindly.
If you want more details, you can use the -v
option:
% test-wikileaks.py -v wikileaks.jmp.net Testing http://46.59.1.2/cablegate.html... 1269 cables Testing http://88.80.13.160/cablegate.html... Wrong data in http://88.80.13.160/cablegate.html, not a Wikileaks mirror? Testing http://213.251.145.96/cablegate.html... 1269 cables
It shows also the current number of diplomatic cables uploaded on this
mirror. This is important because some mirrors are really behind. Here
is a test on a large mirror, wklk.eu.org:
wklk.eu.org-test-2010-12-10.txt. Thanks to Pierre Beyssac for his
contributions to this program.
Oh, by the way, my DNS mirrors are
wikileaks.bortzmeyer.fr (a small subset) and
all-wikileaks.bortzmeyer.fr (a larger set, which
may create problems with some DNS resolvers).
Version PDF de cette page (mais vous pouvez aussi imprimer depuis votre navigateur, il y a une feuille de style prévue pour cela)
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