[tor-commits] [stem/master] Tutorial section for determining the exit you're using

Mon Feb 24 17:39:55 UTC 2014

commit a6f0255673a949ca9950007aa07f2c35359e79ca
Author: Damian Johnson <atagar at torproject.org>
Date:   Sat Feb 22 07:42:44 2014 -0800

    Tutorial section for determining the exit you're using
    
    Neat idea from Arturo for a tutorial section showing users how to determine the
    exit node they're using at a given time.
---
 docs/tutorials/to_russia_with_love.rst |   74 +++++++++++++++++++++++++++++++-
 1 file changed, 73 insertions(+), 1 deletion(-)

diff --git a/docs/tutorials/to_russia_with_love.rst b/docs/tutorials/to_russia_with_love.rst
index 4124a08..8e75e80 100644
--- a/docs/tutorials/to_russia_with_love.rst
+++ b/docs/tutorials/to_russia_with_love.rst
@@ -4,6 +4,7 @@ To Russia With Love
 * :ref:`using-socksipy`
 * :ref:`using-pycurl`
 * :ref:`reading-twitter`
+* :ref:`determine-the-exit-you-re-using`
 
 .. _using-socksipy:
 
@@ -97,7 +98,7 @@ Besides SocksiPy, you can also use `PycURL <http://pycurl.sourceforge.net/>`_ to
   import pycurl
 
   def query(url):
-    """ 
+    """
     Uses pycurl to fetch a site using the proxy on the SOCKS_PORT.
     """
 
@@ -172,3 +173,74 @@ Now lets do somthing a little more interesting, and read a Twitter feed over Tor
 
 .. image:: /_static/twitter_output.png
 
+.. _determine-the-exit-you-re-using:
+
+Determine The Exit You're Using
+---------------------------------
+
+Finally, lets say you're using Tor and one day you run into something odd. Maybe a misconfigured relay, or maybe one that's being malicious. How can you figure out what exit you're using?
+
+Here's a simple script that prints information about the exits used to service the requests going through Tor...
+
+::
+
+  import functools
+
+  from stem import StreamStatus
+  from stem.control import EventType, Controller
+
+  def main():
+    print "Tracking requests for tor exits. Press 'enter' to end."
+    print
+
+    with Controller.from_port() as controller:
+      controller.authenticate()
+
+      stream_listener = functools.partial(stream_event, controller)
+      controller.add_event_listener(stream_listener, EventType.STREAM)
+
+      raw_input()  # wait for user to press enter
+
+
+  def stream_event(controller, event):
+    if event.status == StreamStatus.SUCCEEDED:
+      circ = controller.get_circuit(event.circ_id)
+
+      exit_fingerprint = circ.path[-1][0]
+      exit_relay = controller.get_network_status(exit_fingerprint)
+
+      print "Exit relay for our connection to %s" % (event.target)
+      print "  address: %s:%i" % (exit_relay.address, exit_relay.or_port)
+      print "  fingerprint: %s" % exit_relay.fingerprint
+      print "  nickname: %s" % exit_relay.nickname
+      print "  locale: %s" % controller.get_info("ip-to-country/%s" % exit_relay.address, 'unknown')
+      print
+
+
+  if __name__ == '__main__':
+    main()
+
+Now if you make a request over tor...
+
+::
+
+  % curl --socks4a 127.0.0.1:9050 google.com
+  <HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
+  <TITLE>301 Moved</TITLE></HEAD><BODY>
+  <H1>301 Moved</H1>
+  The document has moved
+  <A HREF="http://www.google.com/">here</A>.
+  </BODY></HTML>
+
+... this script will tell you about the exit...
+
+::
+
+  % python example.py
+  Tracking requests for tor exits. Press 'enter' to end.
+
+  Exit relay for our connection to 64.15.112.44:80
+    address: 31.172.30.2:443
+    fingerprint: A59E1E7C7EAEE083D756EE1FF6EC31CA3D8651D7
+    nickname: chaoscomputerclub19
+    locale: unknown



