#!/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_message(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_message(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_message(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_message(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().main()