#!/usr/bin/env python3
# Copyright (c) 2015-2021 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test node responses to invalid network messages."""
import random
import time
from test_framework.messages import (
CBlockHeader,
CInv,
MAX_HEADERS_RESULTS,
MAX_INV_SIZE,
MAX_PROTOCOL_MESSAGE_LENGTH,
MSG_TX,
from_hex,
msg_getdata,
msg_headers,
msg_inv,
msg_ping,
msg_version,
ser_string,
)
from test_framework.p2p import (
P2PDataStore,
P2PInterface,
)
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import (
assert_equal,
)
VALID_DATA_LIMIT = MAX_PROTOCOL_MESSAGE_LENGTH - 5 # Account for the 5-byte length prefix
class msg_unrecognized:
"""Nonsensical message. Modeled after similar types in test_framework.messages."""
msgtype = b'badmsg\x01'
def __init__(self, *, str_data):
self.str_data = str_data.encode() if not isinstance(str_data, bytes) else str_data
def serialize(self):
return ser_string(self.str_data)
def __repr__(self):
return "{}(data={})".format(self.msgtype, self.str_data)
class SenderOfAddrV2(P2PInterface):
def wait_for_sendaddrv2(self):
self.wait_until(lambda: 'sendaddrv2' in self.last_message)
class InvalidMessagesTest(BitcoinTestFramework):
def set_test_params(self):
self.num_nodes = 1
self.setup_clean_chain = True
self.extra_args = [["-whitelist=addr@127.0.0.1"]]
def run_test(self):
self.test_buffer()
self.test_duplicate_version_msg()
self.test_magic_bytes()
self.test_checksum()
self.test_size()
self.test_msgtype()
self.test_addrv2_empty()
self.test_addrv2_no_addresses()
self.test_addrv2_too_long_address()
self.test_addrv2_unrecognized_network()
self.test_oversized_inv_msg()
self.test_oversized_getdata_msg()
self.test_oversized_headers_msg()
self.test_invalid_pow_headers_msg()
self.test_noncontinuous_headers_msg()
self.test_resource_exhaustion()
def test_buffer(self):
self.log.info("Test message with header split across two buffers is received")
conn = self.nodes[0].add_p2p_connection(P2PDataStore())
# After add_p2p_connection both sides have the verack processed.
# However the pong from conn in reply to the ping from the node has not
# been processed and recorded in totalbytesrecv.
# Flush the pong from conn by sending a ping from conn.
conn.sync_with_ping(timeout=1)
# Create valid message
msg = conn.build_message(msg_ping(nonce=12345))
cut_pos = 12 # Chosen at an arbitrary position within the header
# Send message in two pieces
before = self.nodes[0].getnettotals()['totalbytesrecv']
conn.send_raw_message(msg[:cut_pos])
# Wait until node has processed the first half of the message
self.wait_until(lambda: self.nodes[0].getnettotals()['totalbytesrecv'] != before)
middle = self.nodes[0].getnettotals()['totalbytesrecv']
assert_equal(middle, before + cut_pos)
conn.send_raw_message(msg[cut_pos:])
conn.sync_with_ping(timeout=1)
self.nodes[0].disconnect_p2ps()
def test_duplicate_version_msg(self):
self.log.info("Test duplicate version message is ignored")
conn = self.nodes[0].add_p2p_connection(P2PDataStore())
with self.nodes[0].assert_debug_log(['redundant version message from peer']):
conn.send_and_ping(msg_version())
self.nodes[0].disconnect_p2ps()
def test_magic_bytes(self):
# Skip with v2, magic bytes are v1-specific
if self.options.v2transport:
return
self.log.info("Test message with invalid magic bytes disconnects peer")
conn = self.nodes[0].add_p2p_connection(P2PDataStore())
with self.nodes[0].assert_debug_log(['Header error: Wrong MessageStart ffffffff received']):
msg = conn.build_message(msg_unrecognized(str_data="d"))
# modify magic bytes
msg = b'\xff' * 4 + msg[4:]
conn.send_raw_message(msg)
conn.wait_for_disconnect(timeout=1)
self.nodes[0].disconnect_p2ps()
def test_checksum(self):
# Skip with v2, the checksum is v1-specific
if self.options.v2transport:
return
self.log.info("Test message with invalid checksum logs an error")
conn = self.nodes[0].add_p2p_connection(P2PDataStore())
with self.nodes[0].assert_debug_log(['Header error: Wrong checksum (badmsg, 2 bytes), expected 78df0a04 was ffffffff']):
msg = conn.build_message(msg_unrecognized(str_data="d"))
# Checksum is after start bytes (4B), message type (12B), len (4B)
cut_len = 4 + 12 + 4
# modify checksum
msg = msg[:cut_len] + b'\xff' * 4 + msg[cut_len + 4:]
conn.send_raw_message(msg)
conn.sync_with_ping(timeout=1)
# Check that traffic is accounted for (24 bytes header + 2 bytes payload)
assert_equal(self.nodes[0].getpeerinfo()[0]['bytesrecv_per_msg']['*other*'], 26)
self.nodes[0].disconnect_p2ps()
def test_size(self):
self.log.info("Test message with oversized payload disconnects peer")
conn = self.nodes[0].add_p2p_connection(P2PDataStore())
error_msg = (
['V2 transport error: packet too large (4000014 bytes)'] if self.options.v2transport
else ['Header error: Size too large (badmsg, 4000001 bytes)']
)
with self.nodes[0].assert_debug_log(error_msg):
msg = msg_unrecognized(str_data="d" * (VALID_DATA_LIMIT + 1))
msg = conn.build_message(msg)
conn.send_raw_message(msg)
conn.wait_for_disconnect(timeout=1)
self.nodes[0].disconnect_p2ps()
def test_msgtype(self):
self.log.info("Test message with invalid message type logs an error")
conn = self.nodes[0].add_p2p_connection(P2PDataStore())
if self.options.v2transport:
msgtype = 99 # not defined
msg = msg_unrecognized(str_data="d")
contents = msgtype.to_bytes(1, 'big') + msg.serialize()
tmsg = conn.v2_state.v2_enc_packet(contents, ignore=False)
with self.nodes[0].assert_debug_log(['V2 transport error: invalid message type']):
conn.send_raw_message(tmsg)
conn.sync_with_ping(timeout=1)
# Check that traffic is accounted for (20 bytes plus 3 bytes contents)
assert_equal(self.nodes[0].getpeerinfo()[0]['bytesrecv_per_msg']['*other*'], 23)
else:
with self.nodes[0].assert_debug_log(['Header error: Invalid message type']):
msg = msg_unrecognized(str_data="d")
msg = conn.build_message(msg)
# Modify msgtype
msg = msg[:7] + b'\x00' + msg[7 + 1:]
conn.send_raw_message(msg)
conn.sync_with_ping(timeout=1)
# Check that traffic is accounted for (24 bytes header + 2 bytes payload)
assert_equal(self.nodes[0].getpeerinfo()[0]['bytesrecv_per_msg']['*other*'], 26)
self.nodes[0].disconnect_p2ps()
def test_addrv2(self, label, required_log_messages, raw_addrv2):
node = self.nodes[0]
conn = node.add_p2p_connection(SenderOfAddrV2())
# Make sure bitcoind signals support for ADDRv2, otherwise this test
# will bombard an old node with messages it does not recognize which
# will produce unexpected results.
conn.wait_for_sendaddrv2()
self.log.info('Test addrv2: ' + label)
msg = msg_unrecognized(str_data=b'')
msg.msgtype = b'addrv2'
with node.assert_debug_log(required_log_messages):
# override serialize() which would include the length of the data
msg.serialize = lambda: raw_addrv2
conn.send_raw_message(conn.build_message(msg))
conn.sync_with_ping()
node.disconnect_p2ps()
def test_addrv2_empty(self):
self.test_addrv2('empty',
[
'received: addrv2 (0 bytes)',
'ProcessMessages(addrv2, 0 bytes): Exception',
'end of data',
],
b'')
def test_addrv2_no_addresses(self):
self.test_addrv2('no addresses',
[
'received: addrv2 (1 bytes)',
],
bytes.fromhex('00'))
def test_addrv2_too_long_address(self):
self.test_addrv2('too long address',
[
'received: addrv2 (525 bytes)',
'ProcessMessages(addrv2, 525 bytes): Exception',
'Address too long: 513 > 512',
],
bytes.fromhex(
'01' + # number of entries
'61bc6649' + # time, Fri Jan 9 02:54:25 UTC 2009
'00' + # service flags, COMPACTSIZE(NODE_NONE)
'01' + # network type (IPv4)
'fd0102' + # address length (COMPACTSIZE(513))
'ab' * 513 + # address
'208d')) # port
def test_addrv2_unrecognized_network(self):
now_hex = int(time.time()).to_bytes(4, "little").hex()
self.test_addrv2('unrecognized network',
[
'received: addrv2 (25 bytes)',
'9.9.9.9:8333',
'Added 1 addresses',
],
bytes.fromhex(
'02' + # number of entries
# this should be ignored without impeding acceptance of subsequent ones
now_hex + # time
'01' + # service flags, COMPACTSIZE(NODE_NETWORK)
'99' + # network type (unrecognized)
'02' + # address length (COMPACTSIZE(2))
'ab' * 2 + # address
'208d' + # port
# this should be added:
now_hex + # time
'01' + # service flags, COMPACTSIZE(NODE_NETWORK)
'01' + # network type (IPv4)
'04' + # address length (COMPACTSIZE(4))
'09' * 4 + # address
'208d')) # port
def test_oversized_msg(self, msg, size):
msg_type = msg.msgtype.decode('ascii')
self.log.info("Test {} message of size {} is logged as misbehaving".format(msg_type, size))
with self.nodes[0].assert_debug_log(['Misbehaving', '{} message size = {}'.format(msg_type, size)]):
conn = self.nodes[0].add_p2p_connection(P2PInterface())
conn.send_without_ping(msg)
conn.wait_for_disconnect()
self.nodes[0].disconnect_p2ps()
def test_oversized_inv_msg(self):
size = MAX_INV_SIZE + 1
self.test_oversized_msg(msg_inv([CInv(MSG_TX, 1)] * size), size)
def test_oversized_getdata_msg(self):
size = MAX_INV_SIZE + 1
self.test_oversized_msg(msg_getdata([CInv(MSG_TX, 1)] * size), size)
def test_oversized_headers_msg(self):
size = MAX_HEADERS_RESULTS + 1
self.test_oversized_msg(msg_headers([CBlockHeader()] * size), size)
def test_invalid_pow_headers_msg(self):
self.log.info("Test headers message with invalid proof-of-work is logged as misbehaving and disconnects peer")
blockheader_tip_hash = self.nodes[0].getbestblockhash()
blockheader_tip = from_hex(CBlockHeader(), self.nodes[0].getblockheader(blockheader_tip_hash, False))
# send valid headers message first
assert_equal(self.nodes[0].getblockchaininfo()['headers'], 0)
blockheader = CBlockHeader()
blockheader.hashPrevBlock = int(blockheader_tip_hash, 16)
blockheader.nTime = int(time.time())
blockheader.nBits = blockheader_tip.nBits
blockheader.rehash()
while not blockheader.hash.startswith('0'):
blockheader.nNonce += 1
blockheader.rehash()
peer = self.nodes[0].add_p2p_connection(P2PInterface())
peer.send_and_ping(msg_headers([blockheader]))
assert_equal(self.nodes[0].getblockchaininfo()['headers'], 1)
chaintips = self.nodes[0].getchaintips()
assert_equal(chaintips[0]['status'], 'headers-only')
assert_equal(chaintips[0]['hash'], blockheader.hash)
# invalidate PoW
while not blockheader.hash.startswith('f'):
blockheader.nNonce += 1
blockheader.rehash()
with self.nodes[0].assert_debug_log(['Misbehaving', 'header with invalid proof of work']):
peer.send_without_ping(msg_headers([blockheader]))
peer.wait_for_disconnect()
def test_noncontinuous_headers_msg(self):
self.log.info("Test headers message with non-continuous headers sequence is logged as misbehaving")
block_hashes = self.generate(self.nodes[0], 10)
block_headers = []
for block_hash in block_hashes:
block_headers.append(from_hex(CBlockHeader(), self.nodes[0].getblockheader(block_hash, False)))
# continuous headers sequence should be fine
MISBEHAVING_NONCONTINUOUS_HEADERS_MSGS = ['Misbehaving', 'non-continuous headers sequence']
peer = self.nodes[0].add_p2p_connection(P2PInterface())
with self.nodes[0].assert_debug_log([], unexpected_msgs=MISBEHAVING_NONCONTINUOUS_HEADERS_MSGS):
peer.send_and_ping(msg_headers(block_headers))
# delete arbitrary block header somewhere in the middle to break link
del block_headers[random.randrange(1, len(block_headers)-1)]
with self.nodes[0].assert_debug_log(expected_msgs=MISBEHAVING_NONCONTINUOUS_HEADERS_MSGS):
peer.send_without_ping(msg_headers(block_headers))
peer.wait_for_disconnect()
self.nodes[0].disconnect_p2ps()
def test_resource_exhaustion(self):
self.log.info("Test node stays up despite many large junk messages")
# Don't use v2 here - the non-optimised encryption would take too long to encrypt
# the large messages
conn = self.nodes[0].add_p2p_connection(P2PDataStore(), supports_v2_p2p=False)
conn2 = self.nodes[0].add_p2p_connection(P2PDataStore(), supports_v2_p2p=False)
msg_at_size = msg_unrecognized(str_data="b" * VALID_DATA_LIMIT)
assert len(msg_at_size.serialize()) == MAX_PROTOCOL_MESSAGE_LENGTH
self.log.info("(a) Send 80 messages, each of maximum valid data size (4MB)")
for _ in range(80):
conn.send_without_ping(msg_at_size)
# Check that, even though the node is being hammered by nonsense from one
# connection, it can still service other peers in a timely way.
self.log.info("(b) Check node still services peers in a timely way")
for _ in range(20):
conn2.sync_with_ping(timeout=2)
self.log.info("(c) Wait for node to drop junk messages, while remaining connected")
conn.sync_with_ping(timeout=400)
# Despite being served up a bunch of nonsense, the peers should still be connected.
assert conn.is_connected
assert conn2.is_connected
self.nodes[0].disconnect_p2ps()
if __name__ == '__main__':
InvalidMessagesTest(__file__).main()