Skip to content
Simulates the initiation of a Tor connection.
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.
COPYING initial commit Mar 19, 2012
README reformat Mar 19, 2012
tcis.c initial commit Mar 19, 2012


tcis is short for ``Tor Connection Initiation Simulator''. The tool
partially simulates the initiation of a Tor connection to a given IP
address by sending a TLS client hello containing the Tor cipher list
(see [1]). After that, the program terminates. The TLS client hello is
hardcoded into the program and in order to make the client hello
appear like a real Tor connection, dynamic fields such as the
timestamp, the random value and the host name are initialized when the
program is started.

The tool is useful for analyzing the Great Firewall of China which is
known to search for the Tor cipher list and launches active scanning
after a cipher list was detected in a connection.

To run the program, you need to specify an IP address and a port where
a TCP daemon is listening. It does not have to be a Tor process. A
simple ``nc -l -p 1234'' is enough.

$ make
$ ./tcis <IP> <port>

You can’t perform that action at this time.