commit 6d588153f83b43fd1ca4b592816f37abc5f8bea8 Author: Arturo Filastò hellais@torproject.org Date: Thu Jul 12 18:30:18 2012 +0200

Refactor code and write minimal client implementation --- ooni/protocols/b0wser.py | 84 ++++++++++++++++++++++++++++++++++++++++++++++ oonib/b0wser.py | 81 +------------------------------------------- 2 files changed, 85 insertions(+), 80 deletions(-)

diff --git a/ooni/protocols/b0wser.py b/ooni/protocols/b0wser.py index ae6b002..e0a3a56 100644 --- a/ooni/protocols/b0wser.py +++ b/ooni/protocols/b0wser.py @@ -102,3 +102,87 @@ class Mutator: print "Mutating %s with idx %s" % (data, self.idx) return self._mutate(data, self.idx)

+class B0wserProtocol(protocol.Protocol): + """ + This implements the B0wser protocol for the server side. + It gets instanced once for every client that connects to the oonib. + For every instance of protocol there is only 1 mutation. + Once the last step is reached the connection is closed on the serverside. + """ + steps = [{'data': "STEP1", 'wait': 4}, + {'data': "STEP2", 'wait': 4}, + {'data': "STEP3", 'wait': 4}] + mutator = None + + state = 0 + total_states = len(steps) - 1 + received_data = 0 + report = reports.Report('b0wser', 'b0wser.yamlooni') + + def next_state(self): + """ + This is called once I have completed one step of the protocol and need + to proceed to the next step. + """ + data = self.mutator.get_mutation(self.state) + self.transport.write(data) + self.state += 1 + self.received_data = 0 + + def dataReceived(self, data): + """ + This is called every time some data is received. I transition to the + next step once the amount of data that I expect to receive is received. + + @param data: the data that has been sent by the client. + """ + if len(self.steps) <= self.state: + print "I have reached the end of the state machine" + print "Censorship fingerprint bruteforced!" + report = {'mutator_state': self.mutator.state()} + self.report(report) + self.transport.loseConnection() + return + self.received_data += len(data) + if self.received_data >= self.steps[self.state]['wait']: + print "Moving to next state %s" % self.state + self.next_state() + + def censorship_detected(self, report): + """ + I have detected the possible presence of censorship we need to write a + report on it. + + @param report: a dict containing the report to be written. Must contain + the keys 'reason', 'proto_state' and 'mutator_state'. + The reason is the reason for which the connection was + closed. The proto_state is the current state of the + protocol instance and mutator_state is what was being + mutated. + """ + print "The connection was closed because of %s" % report['reason'] + print "State %s, Mutator %s" % (report['proto_state'], + report['mutator_state']) + self.mutator.next_mutation() + + + + def connectionLost(self, reason): + """ + The connection was closed. This may be because of a legittimate reason + or it may be because of a censorship event. + """ + report = {'reason': reason, 'proto_state': self.state, + 'mutator_state': self.mutator.state(), 'trigger': None} + + if self.state < self.total_states: + report['trigger'] = 'did not finish state walk' + self.censorship_detected(report) + + if reason.check(ConnectionDone): + print "Connection closed cleanly" + else: + report['trigger'] = 'unclean connection closure' + self.censorship_detected(report) + + diff --git a/oonib/b0wser.py b/oonib/b0wser.py index 4b01cc7..33501de 100644 --- a/oonib/b0wser.py +++ b/oonib/b0wser.py @@ -2,86 +2,7 @@ from twisted.internet import protocol from twisted.internet.error import ConnectionDone

from ooni.plugoo import reports -from ooni.protocols.b0wser import Mutator - -class B0wserProtocol(protocol.Protocol): - """ - This implements the B0wser protocol for the server side. - It gets instanced once for every client that connects to the oonib. - For every instance of protocol there is only 1 mutation. - Once the last step is reached the connection is closed on the serverside. - """ - steps = [{'data': "STEP1", 'wait': 4}, - {'data': "STEP2", 'wait': 4}, - {'data': "STEP3", 'wait': 4}] - mutator = None - - state = 0 - total_states = len(steps) - 1 - received_data = 0 - report = reports.Report('b0wser', 'b0wser.yamlooni') - - def next_state(self): - """ - This is called once I have completed one step of the protocol and need - to proceed to the next step. - """ - data = self.mutator.get_mutation(self.state) - self.transport.write(data) - self.state += 1 - self.received_data = 0 - - def dataReceived(self, data): - """ - This is called every time some data is received. I transition to the - next step once the amount of data that I expect to receive is received. - - @param data: the data that has been sent by the client. - """ - if len(self.steps) <= self.state: - self.transport.loseConnection() - return - self.received_data += len(data) - if self.received_data >= self.steps[self.state]['wait']: - print "Moving to next state %s" % self.state - self.next_state() - - def censorship_detected(self, report): - """ - I have detected the possible presence of censorship we need to write a - report on it. - - @param report: a dict containing the report to be written. Must contain - the keys 'reason', 'proto_state' and 'mutator_state'. - The reason is the reason for which the connection was - closed. The proto_state is the current state of the - protocol instance and mutator_state is what was being - mutated. - """ - print "The connection was closed because of %s" % report['reason'] - print "I may have matched the censorship fingerprint" - print "State %s, Mutator %s" % (report['proto_state'], - report['mutator_state']) - self.report(report) - - - def connectionLost(self, reason): - """ - The connection was closed. This may be because of a legittimate reason - or it may be because of a censorship event. - """ - report = {'reason': reason, 'proto_state': self.state, - 'mutator_state': self.mutator.state(), 'trigger': None} - - if self.state < self.total_states: - report['trigger'] = 'did not finish state walk' - self.censorship_detected(report) - - if reason.check(ConnectionDone): - print "Connection closed cleanly" - else: - report['trigger'] = 'unclean connection closure' - self.censorship_detected(report) +from ooni.protocols.b0wser import Mutator, B0wserProtocol

class B0wserServer(protocol.ServerFactory): """