PyBitmessage-2021-04-27/src/network/bmproto.py
Peter Surda 5d4e1e2007
asyncore fixes
- bm headers and commands are only read up to expected length.
On a very fast connection (e.g. local VM), reading verack
also read a part of the TLS handshake
- some debugging info moved from print to logger.debug
- tls handshake cleanup
2017-05-27 22:30:30 +02:00

482 lines
21 KiB
Python

import base64
from binascii import hexlify
import hashlib
import math
import time
from pprint import pprint
import socket
import struct
import random
import traceback
from addresses import calculateInventoryHash
from debug import logger
from inventory import Inventory
import knownnodes
from network.advanceddispatcher import AdvancedDispatcher
from network.bmobject import BMObject, BMObjectInsufficientPOWError, BMObjectInvalidDataError, BMObjectExpiredError, BMObjectUnwantedStreamError, BMObjectInvalidError, BMObjectAlreadyHaveError
import network.connectionpool
from network.downloadqueue import DownloadQueue
from network.node import Node
import network.asyncore_pollchoose as asyncore
from network.objectracker import ObjectTracker
from network.proxy import Proxy, ProxyError, GeneralProxyError
from network.uploadqueue import UploadQueue, UploadElem, AddrUploadQueue, ObjUploadQueue
import addresses
from bmconfigparser import BMConfigParser
from queues import objectProcessorQueue, portCheckerQueue, UISignalQueue
import shared
import state
import protocol
class BMProtoError(ProxyError): pass
class BMProtoInsufficientDataError(BMProtoError): pass
class BMProtoExcessiveDataError(BMProtoError): pass
class BMProto(AdvancedDispatcher, ObjectTracker):
# ~1.6 MB which is the maximum possible size of an inv message.
maxMessageSize = 1600100
# 2**18 = 256kB is the maximum size of an object payload
maxObjectPayloadSize = 2**18
# protocol specification says max 1000 addresses in one addr command
maxAddrCount = 1000
# protocol specification says max 50000 objects in one inv command
maxObjectCount = 50000
# address is online if online less than this many seconds ago
addressAlive = 10800
# maximum time offset
maxTimeOffset = 3600
# def __init__(self, address=None, sock=None):
# AdvancedDispatcher.__init__(self, sock)
# self.verackReceived = False
# self.verackSent = False
# self.lastTx = time.time()
# self.streams = [0]
# self.fullyEstablished = False
# self.connectedAt = 0
# self.skipUntil = 0
# if address is None and sock is not None:
# self.destination = state.Peer(sock.getpeername()[0], sock.getpeername()[1])
# self.isOutbound = False
# TLSDispatcher.__init__(self, sock, server_side=True)
# self.connectedAt = time.time()
# #print "received connection in background from %s:%i" % (self.destination.host, self.destination.port)
# else:
# self.destination = address
# self.isOutbound = True
# if ":" in address.host:
# self.create_socket(socket.AF_INET6, socket.SOCK_STREAM)
# else:
# self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
# self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
# TLSDispatcher.__init__(self, sock, server_side=False)
# self.connect(self.destination)
# #print "connecting in background to %s:%i" % (self.destination.host, self.destination.port)
# shared.connectedHostsList[self.destination] = 0
# ObjectTracker.__init__(self)
# UISignalQueue.put(('updateNetworkStatusTab', 'no data'))
def bm_proto_reset(self):
self.magic = None
self.command = None
self.payloadLength = 0
self.checksum = None
self.payload = None
self.invalid = False
self.payloadOffset = 0
self.expectBytes = protocol.Header.size
self.object = None
def state_bm_header(self):
#print "%s:%i: header" % (self.destination.host, self.destination.port)
if len(self.read_buf) < protocol.Header.size:
#print "Length below header size"
return False
self.magic, self.command, self.payloadLength, self.checksum = protocol.Header.unpack(self.read_buf[:protocol.Header.size])
self.command = self.command.rstrip('\x00')
if self.magic != 0xE9BEB4D9:
# skip 1 byte in order to sync
self.bm_proto_reset()
self.set_state("bm_header", 1)
print "Bad magic"
self.close()
return False
if self.payloadLength > BMProto.maxMessageSize:
self.invalid = True
self.set_state("bm_command", protocol.Header.size, expectBytes=self.payloadLength)
return True
def state_bm_command(self):
if len(self.read_buf) < self.payloadLength:
#print "Length below announced object length"
return False
print "%s:%i: command %s (%ib)" % (self.destination.host, self.destination.port, self.command, self.payloadLength)
self.payload = self.read_buf[:self.payloadLength]
if self.checksum != hashlib.sha512(self.payload).digest()[0:4]:
print "Bad checksum, ignoring"
self.invalid = True
retval = True
if not self.fullyEstablished and self.command not in ("version", "verack"):
logger.error("Received command %s before connection was fully established, ignoring", self.command)
self.invalid = True
if not self.invalid:
try:
retval = getattr(self, "bm_command_" + str(self.command).lower())()
except AttributeError:
# unimplemented command
print "unimplemented command %s" % (self.command)
except BMProtoInsufficientDataError:
print "packet length too short, skipping"
except BMProtoExcessiveDataError:
print "too much data, skipping"
except BMObjectInsufficientPOWError:
print "insufficient PoW, skipping"
except BMObjectInvalidDataError:
print "object invalid data, skipping"
except BMObjectExpiredError:
print "object expired, skipping"
except BMObjectUnwantedStreamError:
print "object not in wanted stream, skipping"
except BMObjectInvalidError:
print "object invalid, skipping"
except BMObjectAlreadyHaveError:
print "already got object, skipping"
except struct.error:
print "decoding error, skipping"
else:
#print "Skipping command %s due to invalid data" % (self.command)
print "Closing due to invalid data" % (self.command)
self.close()
return False
if retval:
self.set_state("bm_header", self.payloadLength)
self.bm_proto_reset()
# else assume the command requires a different state to follow
return True
def decode_payload_string(self, length):
value = self.payload[self.payloadOffset:self.payloadOffset+length]
self.payloadOffset += length
return value
def decode_payload_varint(self):
value, offset = addresses.decodeVarint(self.payload[self.payloadOffset:])
self.payloadOffset += offset
return value
def decode_payload_node(self):
services, host, port = self.decode_payload_content("Q16sH")
if host[0:12] == '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xFF\xFF':
host = socket.inet_ntop(socket.AF_INET, host[12:])
elif host[0:6] == '\xfd\x87\xd8\x7e\xeb\x43':
# Onion, based on BMD/bitcoind
host = base64.b32encode(host[6:]).lower() + ".onion"
else:
host = socket.inet_ntop(socket.AF_INET6, host)
if host == "":
# This can happen on Windows systems which are not 64-bit compatible
# so let us drop the IPv6 address.
host = socket.inet_ntop(socket.AF_INET, host[12:])
return Node(services, host, port)
def decode_payload_content(self, pattern = "v"):
# l = varint indicating the length of the next array
# L = varint indicating the length of the next item
# v = varint (or array)
# H = uint16
# I = uint32
# Q = uint64
# i = net_addr (without time and stream number)
# s = string
# 0-9 = length of the next item
# , = end of array
retval = []
size = None
insideDigit = False
i = 0
while i < len(pattern):
if pattern[i] in "0123456789" and (i == 0 or pattern[i-1] not in "lL"):
if size is None:
size = 0
size = size * 10 + int(pattern[i])
i += 1
continue
elif pattern[i] == "l" and size is None:
size = self.decode_payload_varint()
i += 1
continue
elif pattern[i] == "L" and size is None:
size = self.decode_payload_varint()
i += 1
continue
if size is not None:
if pattern[i] == "s":
retval.append(self.payload[self.payloadOffset:self.payloadOffset + size])
self.payloadOffset += size
i += 1
else:
if "," in pattern[i:]:
subpattern = pattern[i:pattern.index(",")]
else:
subpattern = pattern[i:]
for j in range(size):
if pattern[i-1:i] == "L":
retval.extend(self.decode_payload_content(subpattern))
else:
retval.append(self.decode_payload_content(subpattern))
i += len(subpattern)
size = None
else:
if pattern[i] == "v":
retval.append(self.decode_payload_varint())
if pattern[i] == "i":
retval.append(self.decode_payload_node())
if pattern[i] == "H":
retval.append(struct.unpack(">H", self.payload[self.payloadOffset:self.payloadOffset+2])[0])
self.payloadOffset += 2
if pattern[i] == "I":
retval.append(struct.unpack(">I", self.payload[self.payloadOffset:self.payloadOffset+4])[0])
self.payloadOffset += 4
if pattern[i] == "Q":
retval.append(struct.unpack(">Q", self.payload[self.payloadOffset:self.payloadOffset+8])[0])
self.payloadOffset += 8
i += 1
if self.payloadOffset > self.payloadLength:
print "Insufficient data %i/%i" % (self.payloadOffset, self.payloadLength)
raise BMProtoInsufficientDataError()
return retval
def bm_command_error(self):
fatalStatus, banTime, inventoryVector, errorText = self.decode_payload_content("vvlsls")
print "%s:%i error: %i, %s" % (self.destination.host, self.destination.port, fatalStatus, errorText)
return True
def bm_command_getdata(self):
items = self.decode_payload_content("L32s")
# if time.time() < self.skipUntil:
# print "skipping getdata"
# return True
for i in items:
#print "received getdata request for item %s" % (hexlify(i))
#logger.debug('received getdata request for item:' + hexlify(i))
#if i in ObjUploadQueue.streamElems(1):
if False:
self.antiIntersectionDelay()
else:
self.receiveQueue.put(("object", i))
return True
def bm_command_inv(self):
items = self.decode_payload_content("L32s")
if len(items) >= BMProto.maxObjectCount:
logger.error("Too many items in inv message!")
raise BMProtoExcessiveDataError()
else:
pass
for i in items:
self.receiveQueue.put(("inv", i))
self.handleReceivedInventory(i)
payload = addresses.encodeVarint(len(self.objectsNewToMe)) + ''.join(self.objectsNewToMe.keys())
self.writeQueue.put(protocol.CreatePacket('getdata', payload))
return True
def bm_command_object(self):
objectOffset = self.payloadOffset
nonce, expiresTime, objectType, version, streamNumber = self.decode_payload_content("QQIvv")
self.object = BMObject(nonce, expiresTime, objectType, version, streamNumber, self.payload)
if len(self.payload) - self.payloadOffset > BMProto.maxObjectPayloadSize:
logger.info('The payload length of this object is too large (%s bytes). Ignoring it.' % len(self.payload) - self.payloadOffset)
raise BMProtoExcessiveDataError()
self.object.checkProofOfWorkSufficient()
self.object.checkEOLSanity()
self.object.checkStream()
try:
if self.object.objectType == protocol.OBJECT_GETPUBKEY:
self.object.checkGetpubkey()
elif self.object.objectType == protocol.OBJECT_PUBKEY:
self.object.checkPubkey(self.payload[self.payloadOffset:self.payloadOffset+32])
elif self.object.objectType == protocol.OBJECT_MSG:
self.object.checkMessage()
elif self.object.objectType == protocol.OBJECT_BROADCAST:
self.object.checkBroadcast(self.payload[self.payloadOffset:self.payloadOffset+32])
# other objects don't require other types of tests
except BMObjectAlreadyHaveError:
pass
else:
Inventory()[self.object.inventoryHash] = (
self.object.objectType, self.object.streamNumber, self.payload[objectOffset:], self.object.expiresTime, self.object.tag)
objectProcessorQueue.put((self.object.objectType,self.object.data))
#DownloadQueue().task_done(self.object.inventoryHash)
network.connectionpool.BMConnectionPool().handleReceivedObject(self, self.object.streamNumber, self.object.inventoryHash)
#ObjUploadQueue().put(UploadElem(self.object.streamNumber, self.object.inventoryHash))
#broadcastToSendDataQueues((streamNumber, 'advertiseobject', inventoryHash))
return True
def _decode_addr(self):
return self.decode_payload_content("lQIQ16sH")
def bm_command_addr(self):
addresses = self._decode_addr()
for i in addresses:
seenTime, stream, services, ip, port = i
decodedIP = protocol.checkIPAddress(ip)
if stream not in state.streamsInWhichIAmParticipating:
continue
#print "maybe adding %s in stream %i to knownnodes (%i)" % (decodedIP, stream, len(knownnodes.knownNodes[stream]))
if decodedIP is not False and seenTime > time.time() - BMProto.addressAlive:
peer = state.Peer(decodedIP, port)
if peer in knownnodes.knownNodes[stream] and knownnodes.knownNodes[stream][peer] > seenTime:
continue
knownnodes.knownNodes[stream][peer] = seenTime
AddrUploadQueue().put((stream, peer))
return True
def bm_command_portcheck(self):
portCheckerQueue.put(state.Peer(self.destination, self.peerNode.port))
return True
def bm_command_ping(self):
self.writeQueue.put(protocol.CreatePacket('pong'))
return True
def bm_command_pong(self):
# nothing really
return True
def bm_command_verack(self):
self.verackReceived = True
if self.verackSent:
if self.isSSL:
self.set_state("tls_init", self.payloadLength)
self.bm_proto_reset()
return False
else:
self.set_connection_fully_established()
return True
return True
def bm_command_version(self):
#self.remoteProtocolVersion, self.services, self.timestamp, padding1, self.myExternalIP, padding2, self.remoteNodeIncomingPort = protocol.VersionPacket.unpack(self.payload[:protocol.VersionPacket.size])
self.remoteProtocolVersion, self.services, self.timestamp, self.sockNode, self.peerNode, self.nonce, self.userAgent, self.streams = self.decode_payload_content("IQQiiQlslv")
self.nonce = struct.pack('>Q', self.nonce)
self.timeOffset = self.timestamp - int(time.time())
logger.debug("remoteProtocolVersion: %i", self.remoteProtocolVersion)
logger.debug("services: %08X", self.services)
logger.debug("time offset: %i", self.timestamp - int(time.time()))
logger.debug("my external IP: %s", self.sockNode.host)
logger.debug("remote node incoming port: %i", self.peerNode.port)
logger.debug("user agent: %s", self.userAgent)
logger.debug("streams: [%s]", ",".join(map(str,self.streams)))
if not self.peerValidityChecks():
# TODO ABORT
return True
#shared.connectedHostsList[self.destination] = self.streams[0]
self.writeQueue.put(protocol.CreatePacket('verack'))
self.verackSent = True
if not self.isOutbound:
self.writeQueue.put(protocol.assembleVersionMessage(self.destination.host, self.destination.port, network.connectionpool.BMConnectionPool().streams, True))
print "%s:%i: Sending version" % (self.destination.host, self.destination.port)
if ((self.services & protocol.NODE_SSL == protocol.NODE_SSL) and
protocol.haveSSL(not self.isOutbound)):
self.isSSL = True
if self.verackReceived:
if self.isSSL:
self.set_state("tls_init", self.payloadLength)
self.bm_proto_reset()
return False
else:
self.set_connection_fully_established()
return True
return True
def peerValidityChecks(self):
if self.remoteProtocolVersion < 3:
self.writeQueue.put(protocol.assembleErrorMessage(fatal=2,
errorText="Your is using an old protocol. Closing connection."))
logger.debug ('Closing connection to old protocol version %s, node: %s',
str(self.remoteProtocolVersion), str(self.destination))
return False
if self.timeOffset > BMProto.maxTimeOffset:
self.writeQueue.put(protocol.assembleErrorMessage(fatal=2,
errorText="Your time is too far in the future compared to mine. Closing connection."))
logger.info("%s's time is too far in the future (%s seconds). Closing connection to it.",
self.destination, self.timeOffset)
shared.timeOffsetWrongCount += 1
return False
elif self.timeOffset < -BMProto.maxTimeOffset:
self.writeQueue.put(protocol.assembleErrorMessage(fatal=2,
errorText="Your time is too far in the past compared to mine. Closing connection."))
logger.info("%s's time is too far in the past (timeOffset %s seconds). Closing connection to it.",
self.destination, self.timeOffset)
shared.timeOffsetWrongCount += 1
return False
else:
shared.timeOffsetWrongCount = 0
if len(self.streams) == 0:
self.writeQueue.put(protocol.assembleErrorMessage(fatal=2,
errorText="We don't have shared stream interests. Closing connection."))
logger.debug ('Closed connection to %s because there is no overlapping interest in streams.',
str(self.destination))
return False
if self.destination in network.connectionpool.BMConnectionPool().inboundConnections:
try:
if not protocol.checkSocksIP(self.destination.host):
self.writeQueue.put(protocol.assembleErrorMessage(fatal=2,
errorText="Too many connections from your IP. Closing connection."))
logger.debug ('Closed connection to %s because we are already connected to that IP.',
str(self.destination))
return False
except:
pass
if self.nonce == protocol.eightBytesOfRandomDataUsedToDetectConnectionsToSelf:
self.writeQueue.put(protocol.assembleErrorMessage(fatal=2,
errorText="I'm connected to myself. Closing connection."))
logger.debug ("Closed connection to %s because I'm connected to myself.",
str(self.destination))
return True
@staticmethod
def assembleAddr(peerList):
if type(peerList) is state.Peer:
peerList = (peerList)
# TODO handle max length, now it's done by upper layers
payload = addresses.encodeVarint(len(peerList))
for address in peerList:
stream, peer, timestamp = address
payload += struct.pack(
'>Q', timestamp) # 64-bit time
payload += struct.pack('>I', stream)
payload += struct.pack(
'>q', 1) # service bit flags offered by this node
payload += protocol.encodeHost(peer.host)
payload += struct.pack('>H', peer.port) # remote port
return protocol.CreatePacket('addr', payload)
def close(self, reason=None):
self.set_state("close")
# if reason is None:
# print "%s:%i: closing" % (self.destination.host, self.destination.port)
# #traceback.print_stack()
# else:
# print "%s:%i: closing, %s" % (self.destination.host, self.destination.port, reason)
network.connectionpool.BMConnectionPool().removeConnection(self)
AdvancedDispatcher.close(self)