commit 30ba1019fcbeca9220e85fa5216b6bac1b5db16f Author: Sathyanarayanan Gunasekaran gsathya.ceg@gmail.com Date: Tue Jul 3 02:03:12 2012 +0530

Add microdescriptor exit policy

The microdescriptor policy class can now parse exit policy summaries. Add tests for this --- stem/exit_policy.py | 73 ++++++++++++++++++++++++++++++++++++++++++++++ test/unit/exit_policy.py | 54 +++++++++++++++++++++++++++++++++- 2 files changed, 126 insertions(+), 1 deletions(-)

diff --git a/stem/exit_policy.py b/stem/exit_policy.py index 314110c..33f5cc1 100644 --- a/stem/exit_policy.py +++ b/stem/exit_policy.py @@ -10,6 +10,16 @@ easily parsed and compared, for instance... accept *:80 , accept *:443, reject *:*

...

...

print exit_policies.get_summary()

accept 80, 443 +>>> exit_policies.check("www.google.com", 80) +True + +>>> microdesc_exit_policy = stem.exit_policy.MicrodescriptorExitPolicy("accept 80,443") +>>> print microdesc_exit_policy +accept 80,443 +>>> microdesc_exit_policy.check("www.google.com", 80) +True +>>> microdesc_exit_policy.check(80) +True

ExitPolicyLine - Single rule from the exit policy |- __str__ - string representation @@ -23,6 +33,11 @@ ExitPolicy - List of ExitPolicyLine objects |- get_summary - provides a summary description of the policy chain +- is_exiting_allowed - check if exit node

+MicrodescriptorExitPolicy - Microdescriptor exit policy + |- check - check if exiting to this port is allowed + |- ports - returns a list of ports + |- is_accept - check if it's a list of accepted/rejected ports + +- __str__ - return the summary """

import stem.util.connection @@ -271,6 +286,64 @@ class ExitPolicy: """ return ', '.join([str(policy) for policy in self._policies])

+class MicrodescriptorExitPolicy: + """ + Microdescriptor exit policy - 'accept 53,80,443' + """ + + def __init__(self, summary): + self.ports = [] + self.is_accept = None + self.summary = summary + + # sanitize the input a bit, cleaning up tabs and stripping quotes + summary = self.summary.replace("\t", " ").replace(""", "") + + self.is_accept = summary.startswith("accept") + + # strips off "accept " or "reject " and extra spaces + summary = summary[7:].replace(" ", "") + + for ports in summary.split(','): + if '-' in ports: + port_range = ports.split("-", 1) + if not stem.util.connection.is_valid_port(port_range): + raise ExitPolicyError + self.ports.append(range(int(port_range[2])), int(port_range[1])) + if not stem.util.connection.is_valid_port(ports): + raise ExitPolicyError + self.ports.append(int(ports)) + + def check(self, ip_address=None, port=None): + # stem is intelligent about the arguments + if not port: + if not '.' in str(ip_address): + port = ip_address + + port = int(port) + + if port in self.ports: + # its a list of accepted ports + if self.is_accept: + return True + else: + return False + else: + # its a list of rejected ports + if not self.is_accept: + return True + else: + return False + + def __str__(self): + return self.summary + + def ports(self): + return self.ports + + def is_accept(self): + return self.is_accept + class ExitPolicyError(Exception): """ Base error for exit policy issues. diff --git a/test/unit/exit_policy.py b/test/unit/exit_policy.py index d4fd7e0..b12cd9a 100644 --- a/test/unit/exit_policy.py +++ b/test/unit/exit_policy.py @@ -55,4 +55,56 @@ class TestExitPolicy(unittest.TestCase): """ Tests if exiting to this ip is allowed. """ - pass + + exit_policies = stem.exit_policy.ExitPolicy() + exit_policies = stem.exit_policy.ExitPolicy() + exit_policies.add("accept *:80") + exit_policies.add("accept *:443") + exit_policies.add("reject *:*") + + self.assertTrue(exit_policies.check("www.google.com", 80)) + self.assertTrue(exit_policies.check("www.atagar.com", 443)) + + self.assertFalse(exit_policies.check("www.atagar.com", 22)) + self.assertFalse(exit_policies.check("www.atagar.com", 8118)) + + def test_is_exiting_allowed(self): + """ + Tests if this is an exit node + """ + + exit_policies = stem.exit_policy.ExitPolicy() + exit_policies = stem.exit_policy.ExitPolicy() + exit_policies.add("accept *:80") + exit_policies.add("accept *:443") + exit_policies.add("reject *:*") + + self.assertTrue(exit_policies.is_exiting_allowed()) + + exit_policies = stem.exit_policy.ExitPolicy() + exit_policies = stem.exit_policy.ExitPolicy() + exit_policies.add("reject *:*") + + self.assertFalse(exit_policies.is_exiting_allowed()) + + def test_microdesc_exit_parsing(self): + microdesc_exit_policy = stem.exit_policy.MicrodescriptorExitPolicy("accept 80,443") + + self.assertEqual(str(microdesc_exit_policy),"accept 80,443") + + self.assertRaises(stem.exit_policy.ExitPolicyError, stem.exit_policy.MicrodescriptorExitPolicy, "accept 80,-443") + self.assertRaises(stem.exit_policy.ExitPolicyError, stem.exit_policy.MicrodescriptorExitPolicy, "accept 80,+443") + self.assertRaises(stem.exit_policy.ExitPolicyError, stem.exit_policy.MicrodescriptorExitPolicy, "accept 80,66666") + self.assertRaises(stem.exit_policy.ExitPolicyError, stem.exit_policy.MicrodescriptorExitPolicy, "reject 80,foo") + self.assertRaises(stem.exit_policy.ExitPolicyError, stem.exit_policy.MicrodescriptorExitPolicy, "bar 80,foo") + self.assertRaises(stem.exit_policy.ExitPolicyError, stem.exit_policy.MicrodescriptorExitPolicy, "foo") + self.assertRaises(stem.exit_policy.ExitPolicyError, stem.exit_policy.MicrodescriptorExitPolicy, "bar 80-foo") + + def test_micodesc_exit_check(self): + microdesc_exit_policy = stem.exit_policy.MicrodescriptorExitPolicy("accept 80,443") + + self.assertTrue(microdesc_exit_policy.check(80)) + self.assertTrue(microdesc_exit_policy.check("www.atagar.com", 443)) + + self.assertFalse(microdesc_exit_policy.check(22)) + self.assertFalse(microdesc_exit_policy.check("www.atagar.com", 8118))