onionshare/lib/stem/descriptor/tordnsel.py
2014-05-21 14:09:41 -04:00

116 lines
3.8 KiB
Python

# Copyright 2013, Damian Johnson and The Tor Project
# See LICENSE for licensing information
"""
Parsing for `TorDNSEL <https://www.torproject.org/projects/tordnsel.html.en>`_
exit list files.
"""
import datetime
import stem.util.connection
import stem.util.str_tools
import stem.util.tor_tools
from stem.descriptor import (
Descriptor,
_read_until_keywords,
_get_descriptor_components,
)
def _parse_file(tordnsel_file, validate = True, **kwargs):
"""
Iterates over a tordnsel file.
:returns: iterator for :class:`~stem.descriptor.tordnsel.TorDNSEL`
instances in the file
:raises:
* **ValueError** if the contents is malformed and validate is **True**
* **IOError** if the file can't be read
"""
# skip content prior to the first ExitNode
_read_until_keywords("ExitNode", tordnsel_file, skip = True)
while True:
contents = _read_until_keywords("ExitAddress", tordnsel_file)
contents += _read_until_keywords("ExitNode", tordnsel_file)
if contents:
yield TorDNSEL(bytes.join(b"", contents), validate, **kwargs)
else:
break # done parsing file
class TorDNSEL(Descriptor):
"""
TorDNSEL descriptor (`exitlist specification
<https://www.torproject.org/tordnsel/exitlist-spec.txt>`_)
:var str fingerprint: **\*** authority's fingerprint
:var datetime published: **\*** time in UTC when this descriptor was made
:var datetime last_status: **\*** time in UTC when the relay was seen in a v2 network status
:var list exit_addresses: **\*** list of (str address, datetime date) tuples consisting of the found IPv4 exit address and the time
**\*** attribute is either required when we're parsed with validation or has
a default value, others are left as **None** if undefined
"""
def __init__(self, raw_contents, validate):
super(TorDNSEL, self).__init__(raw_contents)
raw_contents = stem.util.str_tools._to_unicode(raw_contents)
entries = _get_descriptor_components(raw_contents, validate)
self.fingerprint = None
self.published = None
self.last_status = None
self.exit_addresses = []
self._parse(entries, validate)
def _parse(self, entries, validate):
for keyword, values in entries.items():
value, block_content = values[0]
if validate and block_content:
raise ValueError("Unexpected block content: %s" % block_content)
if keyword == "ExitNode":
if validate and not stem.util.tor_tools.is_valid_fingerprint(value):
raise ValueError("Tor relay fingerprints consist of forty hex digits: %s" % value)
self.fingerprint = value
elif keyword == "Published":
try:
self.published = datetime.datetime.strptime(value, "%Y-%m-%d %H:%M:%S")
except ValueError:
if validate:
raise ValueError("Published time wasn't parsable: %s" % value)
elif keyword == "LastStatus":
try:
self.last_status = datetime.datetime.strptime(value, "%Y-%m-%d %H:%M:%S")
except ValueError:
if validate:
raise ValueError("LastStatus time wasn't parsable: %s" % value)
elif keyword == "ExitAddress":
for value, block_content in values:
address, date = value.split(" ", 1)
if validate:
if not stem.util.connection.is_valid_ipv4_address(address):
raise ValueError("ExitAddress isn't a valid IPv4 address: %s" % address)
elif block_content:
raise ValueError("Unexpected block content: %s" % block_content)
try:
date = datetime.datetime.strptime(date, "%Y-%m-%d %H:%M:%S")
self.exit_addresses.append((address, date))
except ValueError:
if validate:
raise ValueError("ExitAddress found time wasn't parsable: %s" % value)
elif validate:
raise ValueError("Unrecognized keyword: %s" % keyword)