  Since 2006, Turkmenistan has been listed as one of the few Internet enemies
by Reporters without Borders due to its extensively censored Internet and
strictly regulated information control policies. Existing reports of filtering
in Turkmenistan rely on a small number of vantage points or test a small number
of websites. Yet, the country's poor Internet adoption rates and small
population can make more comprehensive measurement challenging. With a
population of only six million people and an Internet penetration rate of only
38%, it is challenging to either recruit in-country volunteers or obtain
vantage points to conduct remote network measurements at scale.
  We present the largest measurement study to date of Turkmenistan's Web
censorship. To do so, we developed TMC, which tests the blocking status of
millions of domains across the three foundational protocols of the Web (DNS,
HTTP, and HTTPS). Importantly, TMC does not require access to vantage points in
the country. We apply TMC to 15.5M domains, our results reveal that
Turkmenistan censors more than 122K domains, using different blocklists for
each protocol. We also reverse-engineer these censored domains, identifying 6K
over-blocking rules causing incidental filtering of more than 5.4M domains.
Finally, we use Geneva, an open-source censorship evasion tool, to discover
five new censorship evasion strategies that can defeat Turkmenistan's
censorship at both transport and application layers. We will publicly release
both the data collected by TMC and the code for censorship evasion.
