February 2015 - tor-commits - lists.torproject.org

[bridgedb/develop] Fix a bug in bridgedb.schedule which caused months >= 13.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit d2f9498e6d0cfda6a9452ebe1efcf8b6b8eeb606 Author: Isis Lovecruft <isis(a)torproject.org> Date: Fri Dec 5 23:48:51 2014 +0000 Fix a bug in bridgedb.schedule which caused months >= 13. --- lib/bridgedb/schedule.py | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/bridgedb/schedule.py b/lib/bridgedb/schedule.py index 930f2e7..71b4254 100644 --- a/lib/bridgedb/schedule.py +++ b/lib/bridgedb/schedule.py @@ -260,8 +260,12 @@ class ScheduledInterval(Unscheduled): if self.intervalPeriod == 'month': date = fromUnixSeconds(seconds) + year = date.year months = date.month + self.intervalCount - return toUnixSeconds((date.year, months, 1, 0, 0, 0)) + if months > 12: + year = date.year + 1 + months = months - 12 + return toUnixSeconds((year, months, 1, 0, 0, 0)) elif self.intervalPeriod == 'day': return seconds + (86400 * self.intervalCount) elif self.intervalPeriod == 'hour':

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[bridgedb/develop] Add a bridgedb.bridges.Bridge.__str__ method.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit fe405ac660ad1258fbc31d32f80aae550c31099b Author: Isis Lovecruft <isis(a)torproject.org> Date: Sat Dec 6 01:10:10 2014 +0000 Add a bridgedb.bridges.Bridge.__str__ method. --- lib/bridgedb/bridges.py | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py index 100dd12..cb81dff 100644 --- a/lib/bridgedb/bridges.py +++ b/lib/bridgedb/bridges.py @@ -11,6 +11,7 @@ from __future__ import print_function +import hashlib import ipaddr import logging import os @@ -465,6 +466,36 @@ class Bridge(object): idDigest=id_digest, orAddresses=or_addresses) + def __str__(self): + """Return a pretty string representation that identifies this Bridge. + + .. warning:: With safelogging disabled, the returned string contains + the bridge's fingerprint, which should be handled with care. + + If safelogging is enabled, the returned string will have the SHA-1 + hash of the bridge's fingerprint (a.k.a. a hashed fingerprint). + + Hashed fingerprints will be prefixed with ``'$$'``, and the real + fingerprints are prefixed with ``'$'``. + + :rtype: str + :returns: A string in the form: + :data:`nickname```.$``:data:`fingerprint`. + """ + nickname = self.nickname if self.nickname else 'Unnamed' + separator = '.$' + fingerprint = self.fingerprint + + if safelog.safe_logging: + separator = '.$$' + if fingerprint: + fingerprint = hashlib.sha1(fingerprint).hexdigest() + + if not fingerprint: + fingerprint = '0' * 40 + + return nickname + separator + fingerprint + def _backwardsCompatible(self, nickname=None, address=None, orPort=None, fingerprint=None, idDigest=None, orAddresses=None):

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[bridgedb/develop] Add `client` attribute and `getHashringPlacement()` to IRequestBridges.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit ef1e219f715e09d525561b0a90cfbf00df45d9f5 Author: Isis Lovecruft <isis(a)torproject.org> Date: Fri Dec 5 23:56:11 2014 +0000 Add `client` attribute and `getHashringPlacement()` to IRequestBridges. * ADD interface definitions for IRequestBridges.client and IRequestBridges.getHashringPlacement(). --- lib/bridgedb/bridgerequest.py | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/lib/bridgedb/bridgerequest.py b/lib/bridgedb/bridgerequest.py index 3ef0dc7..840b2fc 100644 --- a/lib/bridgedb/bridgerequest.py +++ b/lib/bridgedb/bridgerequest.py @@ -36,6 +36,12 @@ class IRequestBridges(Interface): "not be blocked in these countries.") valid = Attribute( "A boolean. Should be ``True`` if the client's request was valid.") + client = Attribute( + "This should be some information unique to the client making the " + "request for bridges, such that we are able to HMAC this unique " + "data, via getHashringPlacement(), in order to place the client " + "into a hashring (determining which bridge addresses they get in " + "the request response).") def addFilter(): """Add a filter to the list of ``filters``.""" @@ -49,6 +55,13 @@ class IRequestBridges(Interface): ``addressClass``. """ + def getHashringPlacement(): + """Use some unique parameters of the client making this request to + obtain a value which we can use to place them into one of the hashrings + with :class:`~bridgedb.bridges.Bridge`s in it, in order to give that + client different bridges than other clients. + """ + def isValid(): """Determine if the request is ``valid`` according to some parameters."""

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[bridgedb/develop] Implement bridgedb.bridges.Flags for storing/parsing flags.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit 62f6039b435058c711a6918fd153f85d9889012b Author: Isis Lovecruft <isis(a)torproject.org> Date: Sat Dec 6 00:04:52 2014 +0000 Implement bridgedb.bridges.Flags for storing/parsing flags. * ADD bridgedb.bridges.Flags class. * CHANGE bridgedb.bridges.Bridge.flags attribute to be an instance of bridgedb.bridges.Flags. --- lib/bridgedb/bridges.py | 49 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py index 1ab88f1..21d9257 100644 --- a/lib/bridgedb/bridges.py +++ b/lib/bridgedb/bridges.py @@ -42,6 +42,53 @@ class ServerDescriptorWithoutNetworkstatus(MalformedBridgeInfo): mentioned in the latest ``@type bridge-networkstatus`` document. """ +class Flags(object): + """All the flags which a :class:`Bridge` may have.""" + + fast = False + guard = False + running = False + stable = False + valid = False + + def update(self, flags): + """Update with **flags** taken from an ``@type networkstatus-bridge`` + 's'-line. + + From `dir-spec.txt`_: + | + | "s" SP Flags NL + | + | [Exactly once.] + | + | A series of space-separated status flags, in lexical order (as ASCII + | byte strings). Currently documented flags are: + | + | [...] + | "Fast" if the router is suitable for high-bandwidth circuits. + | "Guard" if the router is suitable for use as an entry guard. + | [...] + | "Stable" if the router is suitable for long-lived circuits. + | "Running" if the router is currently usable. + | [...] + | "Valid" if the router has been 'validated'. + + .. _dir-spec.txt: + https://gitweb.torproject.org/torspec.git/blob/7647f6d4d:/dir-spec.txt#l1603 + + :param list flags: A list of strings containing each of the flags + parsed from the 's'-line. + """ + self.fast = 'Fast' in flags + self.guard = 'Guard' in flags + self.running = 'Running' in flags + self.stable = 'Stable' in flags + self.valid = 'Valid' in flags + + if self.fast or self.guard or self.running or self.stable or self.valid: + logging.debug("Parsed Flags: %s" % ' '.join(flags)) + + class PluggableTransport(object): """A single instance of a Pluggable Transport (PT) offered by a :class:`Bridge`. @@ -357,7 +404,7 @@ class Bridge(object): self.dirPort = 0 # ``DirPort`` set to ``0`` self.orAddresses = [] self.transports = [] - self.flags = BridgeFlags() + self.flags = Flags() self.hibernating = False self.bandwidth = None

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[bridgedb/develop] Add methods to bridgedb.bridges.Bridge for determining block status.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit 444722265ad42617a051c8dd015aabb93a78a2cb Author: Isis Lovecruft <isis(a)torproject.org> Date: Sat Dec 6 01:48:43 2014 +0000 Add methods to bridgedb.bridges.Bridge for determining block status. * ADD new methods: addressIsBlockedIn() transportIsBlockedIn() isBlockedIn() for determining which (if any) of a Bridge's pluggable transports and addresses is blocked in a particular country. --- lib/bridgedb/bridges.py | 158 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py index 640008f..17486e2 100644 --- a/lib/bridgedb/bridges.py +++ b/lib/bridgedb/bridges.py @@ -177,6 +177,7 @@ class PluggableTransport(object): self.port = port self.methodname = methodname self.arguments = arguments + self._blockedIn = {} # Because we can intitialise this class with the __init__() # parameters, or use the ``updateFromStemTransport()`` method, we'll @@ -432,6 +433,7 @@ class Bridge(object): self.transports = [] self.flags = Flags() self.hibernating = False + self._blockedIn = {} self.bandwidth = None self.bandwidthAverage = None @@ -699,6 +701,25 @@ class Bridge(object): return ' '.join(bridgeLine) + @classmethod + def _getBlockKey(cls, address, port): + """Format an **address**:**port** pair appropriately for use as a key + in the :data:`_blockedIn` dictionary. + + :param address: An IP address of this :class:`Bridge` or one of its + :data:`transports`. + :param port: A port. + :rtype: str + :returns: A string in the form ``"ADDRESS:PORT"`` for IPv4 addresses, + and ``"[ADDRESS]:PORT`` for IPv6. + """ + if isIPv6(str(address)): + key = "[%s]:%s" % (address, port) + else: + key = "%s:%s" % (address, port) + + return key + def _getTransportForRequest(self, bridgeRequest): """If a transport was requested, return the correlated :term:`Bridge Line` based upon the client identifier in the @@ -891,6 +912,143 @@ class Bridge(object): bridgePrefix) return bridgeLine + def _addBlockByKey(self, key, countryCode): + """Create or append to the list of blocked countries for a **key**. + + :param str key: The key to lookup in the :data:`Bridge._blockedIn` + dictionary. This should be in the form returned by + :classmethod:`_getBlockKey`. + :param str countryCode: A two-character country code specifier. + """ + if self._blockedIn.has_key(key): + self._blockedIn[key].append(countryCode.lower()) + else: + self._blockedIn[key] = [countryCode.lower(),] + + def addressIsBlockedIn(self, countryCode, address, port): + """Determine if a specific (address, port) tuple is blocked in + **countryCode**. + + :param str countryCode: A two-character country code specifier. + :param str address: An IP address (presumedly one used by this + bridge). + :param int port: A port. + :rtype: bool + :returns: ``True`` if the **address**:**port** pair is blocked in + **countryCode**, ``False`` otherwise. + """ + key = self._getBlockKey(address, port) + + try: + if countryCode.lower() in self._blockedIn[key]: + logging.info("Vanilla address %s of bridge %s blocked in %s." + % (key, self, countryCode.lower())) + return True + except KeyError: + return False # That address:port pair isn't blocked anywhere + + return False + + def transportIsBlockedIn(self, countryCode, methodname): + """Determine if any of a specific type of pluggable transport which + this bridge might be running is blocked in a specific country. + + :param str countryCode: A two-character country code specifier. + :param str methodname: The type of pluggable transport to check, + i.e. ``'obfs3'``. + :rtype: bool + :returns: ``True`` if any address:port pair which this bridge is + running a :class:`PluggableTransport` on is blocked in + **countryCode**, ``False`` otherwise. + """ + for pt in self.transports: + if pt.methodname.lower() == methodname.lower(): + if self.addressIsBlockedIn(countryCode, pt.address, pt.port): + logging.info("Transport %s of bridge %s is blocked in %s." + % (pt.methodname, self, countryCode)) + return True + return False + + def isBlockedIn(self, countryCode): + """Determine, according to our stored bridge reachability reports, if + any of the address:port pairs used by this :class:`Bridge` or it's + :data:`transports` are blocked in **countryCode**. + + :param str countryCode: A two-character country code specifier. + :rtype: bool + :returns: ``True`` if at least one address:port pair used by this + bridge is blocked in **countryCode**; ``False`` otherwise. + """ + # Check all supported pluggable tranport types: + for methodname in self.supportedTransportTypes: + if self.transportIsBlockedIn(countryCode.lower(), methodname): + return True + + for address, port, version in self.allVanillaAddresses: + if self.addressIsBlockedIn(countryCode.lower(), address, port): + return True + + return False + + def setBlockedIn(self, countryCode, address=None, port=None, methodname=None): + """Mark this :class:`Bridge` as being blocked in **countryCode**. + + By default, if called with no parameters other than a **countryCode**, + we'll mark all this :class:`Bridge`'s :data:`allVanillaAddresses` and + :data:`transports` as being blocked. + + Otherwise, we'll filter on any and all parameters given. + + If only a **methodname** is given, then we assume that all + :data:`transports` with that **methodname** are blocked in + **countryCode**. If the methodname is ``"vanilla"``, then we assume + each address in data:`allVanillaAddresses` is blocked. + + :param str countryCode: A two-character country code specifier. + :param address: An IP address of this Bridge or one of its + :data:`transports`. + :param port: A specific port that is blocked, if available. If the + **port** is ``None``, then any address this :class:`Bridge` or its + :class:`PluggableTransport`s has that matches the given **address** + will be marked as block, regardless of its port. This parameter + is ignored unless an **address** is given. + :param str methodname: A :data:`PluggableTransport.methodname` to + match. Any remaining :class:`PluggableTransport`s from + :data:`transports` which matched the other parameters and now also + match this **methodname** will be marked as being blocked in + **countryCode**. + """ + vanillas = self.allVanillaAddresses + transports = self.transports + + if methodname: + # Don't process the vanilla if we weren't told to do so: + if not (methodname == 'vanilla') and not (address or port): + vanillas = [] + + transports = filter(lambda pt: methodname == pt.methodname, transports) + + if address: + vanillas = filter(lambda ip: str(address) == str(ip[0]), vanillas) + transports = filter(lambda pt: str(address) == str(pt.address), transports) + + if port: + vanillas = filter(lambda ip: int(port) == int(ip[1]), vanillas) + transports = filter(lambda pt: int(port) == int(pt.port), transports) + + for addr, port, _ in vanillas: + key = self._getBlockKey(addr, port) + logging.info("Vanilla address %s for bridge %s is now blocked in %s." + % (key, self, countryCode)) + self._addBlockByKey(key, countryCode) + + for transport in transports: + key = self._getBlockKey(transport.address, transport.port) + logging.info("Transport %s %s for bridge %s is now blocked in %s." + % (transport.methodname, key, self, countryCode)) + self._addBlockByKey(key, countryCode) + transport._blockedIn[key] = self._blockedIn[key] + def getDescriptorLastPublished(self): """Get the timestamp for when this bridge's last known server descriptor was published.

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[bridgedb/develop] Add methods to bridgedb.bridges.Bridge for constructing bridge lines.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit 50a01e2d6fc22603f305f3c44acda67b259f5ced Author: Isis Lovecruft <isis(a)torproject.org> Date: Sat Dec 6 01:42:02 2014 +0000 Add methods to bridgedb.bridges.Bridge for constructing bridge lines. * ADD new methods and properties: _constructBridgeLine() _getTransportForRequest() _getVanillaForRequest() allVanillaAddresses() getBridgeLine() supportedTransportTypes() * CHANGE _updateORAddresses() to take a three-tuple. * ADD new PluggableTransportUnavailable exception class for when a pluggable transport has been requested which the Bridge doesn't know about. --- lib/bridgedb/bridges.py | 218 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 212 insertions(+), 6 deletions(-) diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py index cb81dff..640008f 100644 --- a/lib/bridgedb/bridges.py +++ b/lib/bridgedb/bridges.py @@ -27,11 +27,14 @@ from bridgedb.parse.fingerprint import toHex from bridgedb.parse.fingerprint import fromHex +class PluggableTransportUnavailable(Exception): + """Raised when a :class:`Bridge` doesn't have the requested + :class:`PluggableTransport`. + """ class MalformedBridgeInfo(ValueError): """Raised when some information about a bridge appears malformed.""" - class MalformedPluggableTransport(MalformedBridgeInfo): """Raised when information used to initialise a :class:`PluggableTransport` appears malformed. @@ -653,14 +656,170 @@ class Bridge(object): "Actual descriptor digest: %s\n") % (descriptor.fingerprint, self.descriptorDigest, digested)) + def _constructBridgeLine(self, addrport, includeFingerprint=True, + bridgePrefix=False): + """Construct a :term:`Bridge Line` from an (address, port) tuple. + + :param tuple addrport: A 3-tuple of ``(address, port, ipversion)`` + where ``address`` is a string, ``port`` is an integer, and + ``ipversion`` is a integer (``4`` or ``6``). + :param bool includeFingerprint: If ``True``, include the + ``fingerprint`` of this :class:`Bridge` in the returned bridge + line. + :param bool bridgePrefix: if ``True``, prefix the :term:`Bridge Line` + with ``'Bridge '``. + :raises MalformedBridgeInfo: if the **addrport** didn't turn out to be + a 2-tuple containing ``(ipaddress, port)``. + :rtype: string + :returns: A bridge line suitable for adding into a ``torrc`` file or + Tor Launcher. + """ + if not addrport: + return + + try: + address, port, version = addrport + except (TypeError, ValueError): + raise MalformedBridgeInfo("Can't process addrport: %r" % addrport) + + bridgeLine = [] + + if bridgePrefix: + bridgeLine.append('Bridge') + + if version == 4: + bridgeLine.append("%s:%d" % (str(address), port)) + elif version == 6: + bridgeLine.append("[%s]:%d" % (str(address), port)) + else: + raise MalformedBridgeInfo("IP version must be 4 or 6") + + if includeFingerprint: + bridgeLine.append("%s" % self.fingerprint) + + return ' '.join(bridgeLine) + + def _getTransportForRequest(self, bridgeRequest): + """If a transport was requested, return the correlated + :term:`Bridge Line` based upon the client identifier in the + **bridgeRequest**. + + :type bridgeRequest: :class:`bridgedb.bridgerequest.BridgeRequestBase` + :param bridgeRequest: A ``BridgeRequest`` which stores all of the + client-specified options for which type of bridge they want to + receive. + :raises PluggableTransportUnavailable: if this bridge doesn't have any + of the requested pluggable transport type. This shouldn't happen + because the bridges are filtered into the client's hashring based + on the **bridgeRequest** options, however, this is useful in the + unlikely event that it does happen, so that the calling function + can fetch an additional bridge from the hashring as recompense for + what would've otherwise been a missing :term:`Bridge Line`. + :rtype: str or ``None`` + :returns: If no transports were requested, return ``None``, otherwise + return a :term:`Bridge Line` for the requested pluggable transport + type. + """ + addressClass = bridgeRequest.addressClass + desiredTransport = bridgeRequest.justOnePTType() + hashringPosition = bridgeRequest.getHashringPlacement(bridgeRequest.client, + 'Order-Or-Addresses') + + logging.info("Bridge %s answering request for %s transport..." % + (safelog.logSafely(self.fingerprint), desiredTransport)) + # Filter all this Bridge's ``transports`` according to whether or not + # their ``methodname`` matches the requested transport, i.e. only + # 'obfs3' transports, or only 'scramblesuit' transports: + transports = filter(lambda pt: desiredTransport == pt.methodname, + self.transports) + # Filter again for whichever of IPv4 or IPv6 was requested: + transports = filter(lambda pt: isinstance(pt.address, addressClass), + transports) + + if transports: + return transports[hashringPosition % len(transports)] + else: + raise PluggableTransportUnavailable( + ("Client requested transport %s from bridge %s, but this " + "bridge doesn't have any of that transport!") % + (desiredTransport, self.fingerprint)) + + def _getVanillaForRequest(self, bridgeRequest): + """If vanilla bridges were requested, return the assigned + :term:`Bridge Line` based upon the client identifier in the + **bridgeRequest**. + + :type bridgeRequest: :class:`bridgedb.bridgerequest.BridgeRequestBase` + :param bridgeRequest: A ``BridgeRequest`` which stores all of the + client-specified options for which type of bridge they want to + receive. + :rtype: str or ``None`` + :returns: If no transports were requested, return ``None``, otherwise + return a :term:`Bridge Line` for the requested pluggable transport + type. + """ + logging.info("Bridge %s answering request for vanilla address..." % self) + + if not bridgeRequest.filters: + logging.debug(("Request %s didn't have any filters; " + "generating them now...") % bridgeRequest) + bridgeRequest.generateFilters() + + addresses = self.allVanillaAddresses + + # Filter ``allVanillaAddresses`` by whether IPv4 or IPv6 was requested: + addresses = filter( + # ``address`` here is a 3-tuple: + # ``(ipaddr.IPAddress, int(port), int(ipaddr.IPAddress.version))`` + lambda address: isinstance(address[0], bridgeRequest.addressClass), + self.allVanillaAddresses) + + if addresses: + # Use the client's unique data to HMAC them into their position in + # the hashring of filtered bridges addresses: + position = bridgeRequest.getHashringPlacement('Order-Or-Addresses', + bridgeRequest.client) + logging.debug("Client's hashring position is %r" % position) + vanilla = addresses[position % len(addresses)] + logging.info("Got vanilla bridge for client.") + + return vanilla + def _updateORAddresses(self, orAddresses): + """Update this :class:`Bridge`'s :data:`orAddresses` attribute from a + 3-tuple (i.e. as Stem creates when parsing descriptors). + + :param tuple orAddresses: A 3-tuple of: an IP address, a port number, + and a boolean (``False`` if IPv4, ``True`` if IPv6). + :raises FutureWarning: if any IPv4 addresses are found. As of + tor-0.2.5, only IPv6 addresses should be found in a descriptor's + `ORAddress` line. + """ for (address, port, ipVersion) in orAddresses: + version = 6 if not ipVersion: # `False` means IPv4; `True` means IPv6. # See https://bugs.torproject.org/9380#comment:27 - warnings.warn(FutureWarning( - ("Got IPv4 address in 'a'/'or-address' line! " - "Desriptor format may have changed!"))) - self.orAddresses.append(tuple([address, port])) + warnings.warn(FutureWarning(( + "Got IPv4 address in 'a'/'or-address' line! Descriptor " + "format may have changed!"))) + version = 4 + + validatedAddress = isIPAddress(address, compressed=False) + if validatedAddress: + self.orAddresses.append( (validatedAddress, port, version,) ) + + @property + def allVanillaAddresses(self): + """Get all valid, non-PT address:port pairs for this bridge. + + :rtype: list + :returns: All of this bridge's ORAddresses, as well as its ORPort IP + address and port. + """ + addresses = self.orAddresses + # Add the default ORPort address: + addresses.append((self.address, self.orPort,)) + return addresses def assertOK(self): """Perform some additional validation on this bridge's info. @@ -697,6 +856,41 @@ class Bridge(object): if malformed: raise MalformedBridgeInfo('\n'.join(malformed)) + def getBridgeLine(self, bridgeRequest, includeFingerprint=True, + bridgePrefix=False): + """Return a valid :term:`Bridge Line` for a client to give to Tor + Launcher or paste directly into their ``torrc``. + + This is a helper method to call either :meth:`_getTransportForRequest` + or :meth:`_getVanillaForRequest` depending on whether or not any + :class:`PluggableTransport`s were requested in the + :class:`bridgeRequest <bridgedb bridgerequest.BridgeRequestBase>`, and + then construct the :term:`Bridge Line` accordingly. + + :type bridgeRequest: :class:`bridgedb.bridgerequest.BridgeRequestBase` + :param bridgeRequest: A ``BridgeRequest`` which stores all of the + client-specified options for which type of bridge they want to + receive. + :param bool includeFingerprint: If ``True``, include the + ``fingerprint`` of this :class:`Bridge` in the returned bridge + line. + :param bool bridgePrefix: if ``True``, prefix the :term:`Bridge Line` + with ``'Bridge '``. + """ + if not bridgeRequest.isValid(): + logging.info("Bridge request was not valid. Dropping request.") + return # XXX raise error perhaps? + + if bridgeRequest.transports: + pt = self._getTransportForRequest(bridgeRequest) + bridgeLine = pt.getTransportLine(includeFingerprint, bridgePrefix) + else: + addrport = self._getVanillaForRequest(bridgeRequest) + bridgeLine = self._constructBridgeLine(addrport, + includeFingerprint, + bridgePrefix) + return bridgeLine + def getDescriptorLastPublished(self): """Get the timestamp for when this bridge's last known server descriptor was published. @@ -733,7 +927,19 @@ class Bridge(object): """ return getattr(self.descriptors['networkstatus'], 'published', None) - def updateFromNetworkstatus(self, descriptor): + @property + def supportedTransportTypes(self): + """A deduplicated list of all the :data:`PluggableTranport.methodname`s + which this bridge supports. + """ + supported = [] + + for transport in self.transports: + supported.append(transport.methodname) + + return list(set(supported)) + + def updateFromNetworkStatus(self, descriptor): """Update this bridge's attributes from a parsed networkstatus descriptor.

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[bridgedb/develop] Include bridge stability properties from #5482.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit 1fcb3c022ba05ba4830464af83e1e066ba55c41d Author: Isis Lovecruft <isis(a)torproject.org> Date: Fri Dec 5 18:55:59 2014 -0800 Include bridge stability properties from #5482. These have not been changed. --- lib/bridgedb/bridges.py | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py index fede979..dec5e16 100644 --- a/lib/bridgedb/bridges.py +++ b/lib/bridgedb/bridges.py @@ -22,6 +22,8 @@ from Crypto.Util import asn1 from Crypto.Util.number import bytes_to_long from Crypto.Util.number import long_to_bytes +import bridgedb.Storage + from bridgedb import safelog from bridgedb import bridgerequest from bridgedb.crypto import removePKCS1Padding @@ -1326,3 +1328,43 @@ class Bridge(object): % (self, ' '.join(dead))) for died in dead: self.transports.remove(died) + + # Bridge Stability (`#5482 <https://bugs.torproject.org>`_) properties. + @property + def familiar(self): + """A bridge is "familiar" if 1/8 of all active bridges have appeared + more recently than it, or if it has been around for a Weighted Time of + eight days. + """ + with bridgedb.Storage.getDB() as db: + return db.getBridgeHistory(self.fingerprint).familiar + + @property + def wfu(self): + """Weighted Fractional Uptime""" + with bridgedb.Storage.getDB() as db: + return db.getBridgeHistory(self.fingerprint).weightedFractionalUptime + + @property + def weightedTime(self): + """Weighted Time""" + with bridgedb.Storage.getDB() as db: + return db.getBridgeHistory(self.fingerprint).weightedTime + + @property + def wmtbac(self): + """Weighted Mean Time Between Address Change""" + with bridgedb.Storage.getDB() as db: + return db.getBridgeHistory(self.fingerprint).wmtbac + + @property + def tosa(self): + """The Time On Same Address (TOSA)""" + with bridgedb.Storage.getDB() as db: + return db.getBridgeHistory(self.fingerprint).tosa + + @property + def weightedUptime(self): + """Weighted Uptime""" + with bridgedb.Storage.getDB() as db: + return db.getBridgeHistory(self.fingerprint).weightedUptime

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[bridgedb/develop] Add method for verifying a Bridge's extrainfo router-signature.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit 6b4c3f08545009a68cb6b2a24c2357603e484609 Author: Isis Lovecruft <isis(a)torproject.org> Date: Fri Dec 5 18:43:49 2014 -0800 Add method for verifying a Bridge's extrainfo router-signature. * ADD new method bridgedb.bridges.Bridge._verifyExtraInfoSignature(). * ADD new function bridgedb.crypto.removePKCS1Padding(). --- lib/bridgedb/bridges.py | 109 ++++++++++++++++++++++++++++++++++++++++++++++- lib/bridgedb/crypto.py | 41 ++++++++++++++++++ 2 files changed, 149 insertions(+), 1 deletion(-) diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py index 17486e2..d2e528d 100644 --- a/lib/bridgedb/bridges.py +++ b/lib/bridgedb/bridges.py @@ -11,13 +11,20 @@ from __future__ import print_function +import base64 +import codecs import hashlib import ipaddr import logging import os +from Crypto.Util import asn1 +from Crypto.Util.number import bytes_to_long +from Crypto.Util.number import long_to_bytes + from bridgedb import safelog from bridgedb import bridgerequest +from bridgedb.crypto import removePKCS1Padding from bridgedb.parse.addr import isIPAddress from bridgedb.parse.addr import isIPv6 from bridgedb.parse.addr import isValidIP @@ -55,6 +62,10 @@ class ServerDescriptorWithoutNetworkstatus(MalformedBridgeInfo): mentioned in the latest ``@type bridge-networkstatus`` document. """ +class InvalidExtraInfoSignature(MalformedBridgeInfo): + """Raised if the signature on an ``@type bridge-extrainfo`` is invalid.""" + + class Flags(object): """All the flags which a :class:`Bridge` may have.""" @@ -1174,7 +1185,91 @@ class Bridge(object): self.extrainfoDigest = descriptor.extrainfoDigest - def updateFromExtraInfoDescriptor(self, descriptor): + def _verifyExtraInfoSignature(self, descriptor): + """Verify the signature on the contents of this :class:`Bridge`'s + ``@type bridge-extrainfo`` descriptor. + + :type descriptor: + :api:`stem.descriptor.extrainfo_descriptor.RelayExtraInfoDescriptor` + :param descriptor: An ``@type bridge-extrainfo`` descriptor for this + :class:`Bridge`, parsed with Stem. + :raises InvalidExtraInfoSignature: if the signature was invalid, + missing, malformed, or couldn't be verified successfully. + :returns: ``None`` if the signature was valid and verifiable. + """ + # The blocksize is always 128 bits for a 1024-bit key + BLOCKSIZE = 128 + + TOR_SIGNING_KEY_HEADER = u'-----BEGIN RSA PUBLIC KEY-----\n' + TOR_SIGNING_KEY_FOOTER = u'-----END RSA PUBLIC KEY-----' + TOR_BEGIN_SIGNATURE = u'-----BEGIN SIGNATURE-----\n' + TOR_END_SIGNATURE = u'-----END SIGNATURE-----\n' + + logging.info("Verifying extrainfo signature for %s..." % self) + + # Get the bytes of the descriptor signature without the headers: + document, signature = descriptor.get_bytes().split(TOR_BEGIN_SIGNATURE) + signature = signature.replace(TOR_END_SIGNATURE, '') + signature = signature.replace('\n', '') + signature = signature.strip() + + try: + # Get the ASN.1 sequence: + sequence = asn1.DerSequence() + + key = self.signingKey + key = key.strip(TOR_SIGNING_KEY_HEADER) + key = key.strip(TOR_SIGNING_KEY_FOOTER) + key = key.replace('\n', '') + key = base64.b64decode(key) + + sequence.decode(key) + + modulus = sequence[0] + publicExponent = sequence[1] + + # The public exponent of RSA signing-keys should always be 65537, + # but we're not going to turn them down if they want to use a + # potentially dangerous exponent. + if publicExponent != 65537: # pragma: no cover + logging.warn("Odd RSA exponent in signing-key for %s: %s" % + (self, publicExponent)) + + # Base64 decode the signature: + signatureDecoded = base64.b64decode(signature) + + # Convert the signature to a long: + signatureLong = bytes_to_long(signatureDecoded) + + # Decrypt the long signature with the modulus and public exponent: + decryptedInt = pow(signatureLong, publicExponent, modulus) + + # Then convert it back to a byte array: + decryptedBytes = long_to_bytes(decryptedInt, BLOCKSIZE) + + # Remove the PKCS#1 padding from the signature: + unpadded = removePKCS1Padding(decryptedBytes) + + # This is the hexadecimal SHA-1 hash digest of the descriptor document + # as it was signed: + signedDigest = codecs.encode(unpadded, 'hex_codec') + actualDigest = hashlib.sha1(document).hexdigest() + + except Exception as error: + logging.debug("Error verifying extrainfo signature: %s" % error) + raise InvalidExtraInfoSignature( + "Extrainfo signature for %s couldn't be decoded: %s" % + (self, signature)) + else: + if signedDigest != actualDigest: + raise InvalidExtraInfoSignature( + ("The extrainfo digest signed by bridge %s didn't match the " + "actual digest.\nSigned digest: %s\nActual digest: %s") % + (self, signedDigest, actualDigest)) + else: + logging.info("Extrainfo signature was verified successfully!") + + def updateFromExtraInfoDescriptor(self, descriptor, verify=True): """Update this bridge's information from an extrainfo descriptor. .. todo:: The ``transport`` attribute of Stem's @@ -1186,5 +1281,17 @@ class Bridge(object): :type descriptor: :api:`stem.descriptor.extrainfo_descriptor.BridgeExtraInfoDescriptor` :param descriptor: DOCDOC + :param bool verify: If ``True``, check that the ``router-signature`` + on the extrainfo **descriptor** is a valid signature from + :data:`signingkey`. """ + if verify: + try: + self._verifyExtraInfoSignature(descriptor) + except InvalidExtraInfoSignature as error: + logging.warn(error) + logging.info(("Tossing extrainfo descriptor due to an invalid " + "signature.")) + return + self.descriptors['extrainfo'] = descriptor diff --git a/lib/bridgedb/crypto.py b/lib/bridgedb/crypto.py index e8cf8fd..63e532b 100644 --- a/lib/bridgedb/crypto.py +++ b/lib/bridgedb/crypto.py @@ -87,6 +87,9 @@ GPGME_CONTEXT_HOMEDIR = '.gnupg' GPGME_CONTEXT_BINARY = which('gpg2') or which('gpg') # These will be lists +class PKCS1PaddingError(Exception): + """Raised when there is a problem adding or removing PKCS#1 padding.""" + class RSAKeyGenerationError(Exception): """Raised when there was an error creating an RSA keypair.""" @@ -273,6 +276,44 @@ def getHMACFunc(key, hex=True): return h_tmp.digest() return hmac_fn +def removePKCS1Padding(message): + """Remove PKCS#1 padding from a **message**. + + (PKCS#1 v1.0? see https://bugs.torproject.org/13042) + + Each block is 128 bytes total in size: + + * 2 bytes for the type info ('\x00\x01') + * 1 byte for the separator ('\x00') + * variable length padding ('\xFF') + * variable length for the **message** + + For more information on the structure of PKCS#1 padding, see :rfc:`2313`, + particularly the notes in §8.1. + + :param str message: A message which is PKCS#1 padded. + :raises PKCS1PaddingError: if there is an issue parsing the **message**. + :rtype: bytes + :returns: The message without the PKCS#1 padding. + """ + padding = b'\xFF' + typeinfo = b'\x00\x01' + separator = b'\x00' + + unpadded = None + + try: + if message.index(typeinfo) != 0: + raise PKCS1PaddingError("Couldn't find PKCS#1 identifier bytes!") + start = message.index(separator, 2) + 1 # 2 bytes for the typeinfo, + # and 1 byte for the separator. + except ValueError: + raise PKCS1PaddingError("Couldn't find PKCS#1 separator byte!") + else: + unpadded = message[start:] + + return unpadded + def _createGPGMEErrorInterpreters(): """Create a mapping of GPGME ERRNOs ←→ human-readable error names/causes.

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[bridgedb/develop] Update the Bridge's transports in updateFromExtraInfoDescriptor().
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit 122ad409aa0dd84563d580e5002cecb1cc20d25f Author: Isis Lovecruft <isis(a)torproject.org> Date: Fri Dec 5 18:55:14 2014 -0800 Update the Bridge's transports in updateFromExtraInfoDescriptor(). --- lib/bridgedb/bridges.py | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py index d2e528d..fede979 100644 --- a/lib/bridgedb/bridges.py +++ b/lib/bridgedb/bridges.py @@ -1295,3 +1295,34 @@ class Bridge(object): return self.descriptors['extrainfo'] = descriptor + + updatedTransports = [] + + for transport in self.transports: + for methodname, kitchenSink in descriptor.transport: + if transport.methodname == methodname: + if transport.address == kitchenSink[0]: + logging.info( + "Updating %s pluggable transport for bridge %s." % + (methodname, safelog.logSafely(self.fingerprint))) + updatedTransports.append(transport) + transport.updateFromStemTransport(self.fingerprint, + methodname, + kitchenSink) + else: + logging.info( + ("Received new %s pluggable transport for bridge " + "%s.") % + (methodname, safelog.logSafely(self.fingerprint))) + pt = PluggableTransport() + pt.updateFromStemTransport(self.fingerprint, + methodname, + kitchenSink) + updatedTransports.append(pt) + self.transports.append(pt) + + dead = set(self.transports).difference(set(updatedTransports)) + logging.info("The following transports for bridge %s died: %s" + % (self, ' '.join(dead))) + for died in dead: + self.transports.remove(died)

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[bridgedb/develop] PEP8 whitespace fix for bridgedb.bridges module.
by isis＠torproject.org 19 Feb '15

19 Feb '15

commit dd3192c2279c2e0226fa6c94e38cb90e72e1afa9 Author: Isis Lovecruft <isis(a)torproject.org> Date: Fri Dec 5 18:57:58 2014 -0800 PEP8 whitespace fix for bridgedb.bridges module. --- lib/bridgedb/bridges.py | 1 - 1 file changed, 1 deletion(-) diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py index dec5e16..6268f6d 100644 --- a/lib/bridgedb/bridges.py +++ b/lib/bridgedb/bridges.py @@ -52,7 +52,6 @@ class MalformedPluggableTransport(MalformedBridgeInfo): class InvalidPluggableTransportIP(MalformedBridgeInfo): """Raised when a :class:`PluggableTransport` has an invalid address.""" - class ServerDescriptorDigestMismatch(MalformedBridgeInfo): """Raised when the digest in an ``@type bridge-networkstatus`` document doesn't match the hash digest of the ``@type bridge-server-descriptor``'s

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