/ test / functional / p2p_invalid_messages.py
p2p_invalid_messages.py
  1  #!/usr/bin/env python3
  2  # Copyright (c) 2015-present The Bitcoin Core developers
  3  # Distributed under the MIT software license, see the accompanying
  4  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  5  """Test node responses to invalid network messages."""
  6  
  7  import random
  8  import time
  9  
 10  from test_framework.messages import (
 11      CBlockHeader,
 12      CInv,
 13      MAX_HEADERS_RESULTS,
 14      MAX_INV_SIZE,
 15      MAX_PROTOCOL_MESSAGE_LENGTH,
 16      MSG_TX,
 17      from_hex,
 18      msg_getdata,
 19      msg_headers,
 20      msg_inv,
 21      msg_ping,
 22      msg_version,
 23      ser_string,
 24  )
 25  from test_framework.p2p import (
 26      P2PDataStore,
 27      P2PInterface,
 28  )
 29  from test_framework.test_framework import BitcoinTestFramework
 30  from test_framework.util import (
 31      assert_equal,
 32  )
 33  
 34  VALID_DATA_LIMIT = MAX_PROTOCOL_MESSAGE_LENGTH - 5  # Account for the 5-byte length prefix
 35  
 36  
 37  class msg_unrecognized:
 38      """Nonsensical message. Modeled after similar types in test_framework.messages."""
 39  
 40      msgtype = b'badmsg\x01'
 41  
 42      def __init__(self, *, str_data):
 43          self.str_data = str_data.encode() if not isinstance(str_data, bytes) else str_data
 44  
 45      def serialize(self):
 46          return ser_string(self.str_data)
 47  
 48      def __repr__(self):
 49          return "{}(data={})".format(self.msgtype, self.str_data)
 50  
 51  
 52  class SenderOfAddrV2(P2PInterface):
 53      def wait_for_sendaddrv2(self):
 54          self.wait_until(lambda: 'sendaddrv2' in self.last_message)
 55  
 56  
 57  class InvalidMessagesTest(BitcoinTestFramework):
 58      def set_test_params(self):
 59          self.num_nodes = 1
 60          self.setup_clean_chain = True
 61          self.extra_args = [["-whitelist=addr@127.0.0.1"]]
 62  
 63      def run_test(self):
 64          self.test_buffer()
 65          self.test_duplicate_version_msg()
 66          self.test_magic_bytes()
 67          self.test_checksum()
 68          self.test_size()
 69          self.test_msgtype()
 70          self.test_addrv2_empty()
 71          self.test_addrv2_no_addresses()
 72          self.test_addrv2_too_long_address()
 73          self.test_addrv2_unrecognized_network()
 74          self.test_oversized_inv_msg()
 75          self.test_oversized_getdata_msg()
 76          self.test_oversized_headers_msg()
 77          self.test_invalid_pow_headers_msg()
 78          self.test_noncontinuous_headers_msg()
 79          self.test_resource_exhaustion()
 80  
 81      def test_buffer(self):
 82          self.log.info("Test message with header split across two buffers is received")
 83          conn = self.nodes[0].add_p2p_connection(P2PDataStore())
 84          # After add_p2p_connection both sides have the verack processed.
 85          # However the pong from conn in reply to the ping from the node has not
 86          # been processed and recorded in totalbytesrecv.
 87          # Flush the pong from conn by sending a ping from conn.
 88          conn.sync_with_ping(timeout=1)
 89          # Create valid message
 90          msg = conn.build_message(msg_ping(nonce=12345))
 91          cut_pos = 12  # Chosen at an arbitrary position within the header
 92          # Send message in two pieces
 93          before = self.nodes[0].getnettotals()['totalbytesrecv']
 94          conn.send_raw_message(msg[:cut_pos])
 95          # Wait until node has processed the first half of the message
 96          self.wait_until(lambda: self.nodes[0].getnettotals()['totalbytesrecv'] != before)
 97          middle = self.nodes[0].getnettotals()['totalbytesrecv']
 98          assert_equal(middle, before + cut_pos)
 99          conn.send_raw_message(msg[cut_pos:])
100          conn.sync_with_ping(timeout=1)
101          self.nodes[0].disconnect_p2ps()
102  
103      def test_duplicate_version_msg(self):
104          self.log.info("Test duplicate version message is ignored")
105          conn = self.nodes[0].add_p2p_connection(P2PDataStore())
106          with self.nodes[0].assert_debug_log(['redundant version message from peer']):
107              conn.send_and_ping(msg_version())
108          self.nodes[0].disconnect_p2ps()
109  
110      def test_magic_bytes(self):
111          # Skip with v2, magic bytes are v1-specific
112          if self.options.v2transport:
113              return
114          self.log.info("Test message with invalid magic bytes disconnects peer")
115          conn = self.nodes[0].add_p2p_connection(P2PDataStore())
116          with self.nodes[0].assert_debug_log(['Header error: Wrong MessageStart ffffffff received']):
117              msg = conn.build_message(msg_unrecognized(str_data="d"))
118              # modify magic bytes
119              msg = b'\xff' * 4 + msg[4:]
120              conn.send_raw_message(msg)
121              conn.wait_for_disconnect(timeout=1)
122          self.nodes[0].disconnect_p2ps()
123  
124      def test_checksum(self):
125          # Skip with v2, the checksum is v1-specific
126          if self.options.v2transport:
127              return
128          self.log.info("Test message with invalid checksum logs an error")
129          conn = self.nodes[0].add_p2p_connection(P2PDataStore())
130          with self.nodes[0].assert_debug_log(['Header error: Wrong checksum (badmsg, 2 bytes), expected 78df0a04 was ffffffff']):
131              msg = conn.build_message(msg_unrecognized(str_data="d"))
132              # Checksum is after start bytes (4B), message type (12B), len (4B)
133              cut_len = 4 + 12 + 4
134              # modify checksum
135              msg = msg[:cut_len] + b'\xff' * 4 + msg[cut_len + 4:]
136              conn.send_raw_message(msg)
137              conn.sync_with_ping(timeout=1)
138          # Check that traffic is accounted for (24 bytes header + 2 bytes payload)
139          assert_equal(self.nodes[0].getpeerinfo()[0]['bytesrecv_per_msg']['*other*'], 26)
140          self.nodes[0].disconnect_p2ps()
141  
142      def test_size(self):
143          self.log.info("Test message with oversized payload disconnects peer")
144          conn = self.nodes[0].add_p2p_connection(P2PDataStore())
145          error_msg = (
146              ['V2 transport error: packet too large (4000014 bytes)'] if self.options.v2transport
147              else ['Header error: Size too large (badmsg, 4000001 bytes)']
148          )
149          with self.nodes[0].assert_debug_log(error_msg):
150              msg = msg_unrecognized(str_data="d" * (VALID_DATA_LIMIT + 1))
151              msg = conn.build_message(msg)
152              conn.send_raw_message(msg)
153              conn.wait_for_disconnect(timeout=1)
154          self.nodes[0].disconnect_p2ps()
155  
156      def test_msgtype(self):
157          self.log.info("Test message with invalid message type logs an error")
158          conn = self.nodes[0].add_p2p_connection(P2PDataStore())
159          if self.options.v2transport:
160              msgtype = 99 # not defined
161              msg = msg_unrecognized(str_data="d")
162              contents = msgtype.to_bytes(1, 'big') + msg.serialize()
163              tmsg = conn.v2_state.v2_enc_packet(contents, ignore=False)
164              with self.nodes[0].assert_debug_log(['V2 transport error: invalid message type']):
165                  conn.send_raw_message(tmsg)
166                  conn.sync_with_ping(timeout=1)
167              # Check that traffic is accounted for (20 bytes plus 3 bytes contents)
168              assert_equal(self.nodes[0].getpeerinfo()[0]['bytesrecv_per_msg']['*other*'], 23)
169          else:
170              with self.nodes[0].assert_debug_log(['Header error: Invalid message type']):
171                  msg = msg_unrecognized(str_data="d")
172                  msg = conn.build_message(msg)
173                  # Modify msgtype
174                  msg = msg[:7] + b'\x00' + msg[7 + 1:]
175                  conn.send_raw_message(msg)
176                  conn.sync_with_ping(timeout=1)
177                  # Check that traffic is accounted for (24 bytes header + 2 bytes payload)
178                  assert_equal(self.nodes[0].getpeerinfo()[0]['bytesrecv_per_msg']['*other*'], 26)
179          self.nodes[0].disconnect_p2ps()
180  
181      def test_addrv2(self, label, required_log_messages, raw_addrv2):
182          node = self.nodes[0]
183          conn = node.add_p2p_connection(SenderOfAddrV2())
184  
185          # Make sure bitcoind signals support for ADDRv2, otherwise this test
186          # will bombard an old node with messages it does not recognize which
187          # will produce unexpected results.
188          conn.wait_for_sendaddrv2()
189  
190          self.log.info('Test addrv2: ' + label)
191  
192          msg = msg_unrecognized(str_data=b'')
193          msg.msgtype = b'addrv2'
194          with node.assert_debug_log(required_log_messages):
195              # override serialize() which would include the length of the data
196              msg.serialize = lambda: raw_addrv2
197              conn.send_raw_message(conn.build_message(msg))
198              conn.sync_with_ping()
199  
200          node.disconnect_p2ps()
201  
202      def test_addrv2_empty(self):
203          self.test_addrv2('empty',
204              [
205                  'received: addrv2 (0 bytes)',
206                  'ProcessMessages(addrv2, 0 bytes): Exception',
207                  'end of data',
208              ],
209              b'')
210  
211      def test_addrv2_no_addresses(self):
212          self.test_addrv2('no addresses',
213              [
214                  'received: addrv2 (1 bytes)',
215              ],
216              bytes.fromhex('00'))
217  
218      def test_addrv2_too_long_address(self):
219          self.test_addrv2('too long address',
220              [
221                  'received: addrv2 (525 bytes)',
222                  'ProcessMessages(addrv2, 525 bytes): Exception',
223                  'Address too long: 513 > 512',
224              ],
225              bytes.fromhex(
226                  '01' +       # number of entries
227                  '61bc6649' + # time, Fri Jan  9 02:54:25 UTC 2009
228                  '00' +       # service flags, COMPACTSIZE(NODE_NONE)
229                  '01' +       # network type (IPv4)
230                  'fd0102' +   # address length (COMPACTSIZE(513))
231                  'ab' * 513 + # address
232                  '208d'))     # port
233  
234      def test_addrv2_unrecognized_network(self):
235          now_hex = int(time.time()).to_bytes(4, "little").hex()
236          self.test_addrv2('unrecognized network',
237              [
238                  'received: addrv2 (25 bytes)',
239                  '9.9.9.9:8333',
240                  'Added 1 addresses',
241              ],
242              bytes.fromhex(
243                  '02' +     # number of entries
244                  # this should be ignored without impeding acceptance of subsequent ones
245                  now_hex +  # time
246                  '01' +     # service flags, COMPACTSIZE(NODE_NETWORK)
247                  '99' +     # network type (unrecognized)
248                  '02' +     # address length (COMPACTSIZE(2))
249                  'ab' * 2 + # address
250                  '208d' +   # port
251                  # this should be added:
252                  now_hex +  # time
253                  '01' +     # service flags, COMPACTSIZE(NODE_NETWORK)
254                  '01' +     # network type (IPv4)
255                  '04' +     # address length (COMPACTSIZE(4))
256                  '09' * 4 + # address
257                  '208d'))   # port
258  
259      def test_oversized_msg(self, msg, size):
260          msg_type = msg.msgtype.decode('ascii')
261          self.log.info("Test {} message of size {} is logged as misbehaving".format(msg_type, size))
262          with self.nodes[0].assert_debug_log(['Misbehaving', '{} message size = {}'.format(msg_type, size)]):
263              conn = self.nodes[0].add_p2p_connection(P2PInterface())
264              conn.send_without_ping(msg)
265              conn.wait_for_disconnect()
266          self.nodes[0].disconnect_p2ps()
267  
268      def test_oversized_inv_msg(self):
269          size = MAX_INV_SIZE + 1
270          self.test_oversized_msg(msg_inv([CInv(MSG_TX, 1)] * size), size)
271  
272      def test_oversized_getdata_msg(self):
273          size = MAX_INV_SIZE + 1
274          self.test_oversized_msg(msg_getdata([CInv(MSG_TX, 1)] * size), size)
275  
276      def test_oversized_headers_msg(self):
277          size = MAX_HEADERS_RESULTS + 1
278          self.test_oversized_msg(msg_headers([CBlockHeader()] * size), size)
279  
280      def test_invalid_pow_headers_msg(self):
281          self.log.info("Test headers message with invalid proof-of-work is logged as misbehaving and disconnects peer")
282          blockheader_tip_hash = self.nodes[0].getbestblockhash()
283          blockheader_tip = from_hex(CBlockHeader(), self.nodes[0].getblockheader(blockheader_tip_hash, False))
284  
285          # send valid headers message first
286          assert_equal(self.nodes[0].getblockchaininfo()['headers'], 0)
287          blockheader = CBlockHeader()
288          blockheader.hashPrevBlock = int(blockheader_tip_hash, 16)
289          blockheader.nTime = int(time.time())
290          blockheader.nBits = blockheader_tip.nBits
291          while not blockheader.hash_hex.startswith('0'):
292              blockheader.nNonce += 1
293          peer = self.nodes[0].add_p2p_connection(P2PInterface())
294          peer.send_and_ping(msg_headers([blockheader]))
295          assert_equal(self.nodes[0].getblockchaininfo()['headers'], 1)
296          chaintips = self.nodes[0].getchaintips()
297          assert_equal(chaintips[0]['status'], 'headers-only')
298          assert_equal(chaintips[0]['hash'], blockheader.hash_hex)
299  
300          # invalidate PoW
301          while not blockheader.hash_hex.startswith('f'):
302              blockheader.nNonce += 1
303          with self.nodes[0].assert_debug_log(['Misbehaving', 'header with invalid proof of work']):
304              peer.send_without_ping(msg_headers([blockheader]))
305              peer.wait_for_disconnect()
306  
307      def test_noncontinuous_headers_msg(self):
308          self.log.info("Test headers message with non-continuous headers sequence is logged as misbehaving")
309          block_hashes = self.generate(self.nodes[0], 10)
310          block_headers = []
311          for block_hash in block_hashes:
312              block_headers.append(from_hex(CBlockHeader(), self.nodes[0].getblockheader(block_hash, False)))
313  
314          # continuous headers sequence should be fine
315          MISBEHAVING_NONCONTINUOUS_HEADERS_MSGS = ['Misbehaving', 'non-continuous headers sequence']
316          peer = self.nodes[0].add_p2p_connection(P2PInterface())
317          with self.nodes[0].assert_debug_log([], unexpected_msgs=MISBEHAVING_NONCONTINUOUS_HEADERS_MSGS):
318              peer.send_and_ping(msg_headers(block_headers))
319  
320          # delete arbitrary block header somewhere in the middle to break link
321          del block_headers[random.randrange(1, len(block_headers)-1)]
322          with self.nodes[0].assert_debug_log(expected_msgs=MISBEHAVING_NONCONTINUOUS_HEADERS_MSGS):
323              peer.send_without_ping(msg_headers(block_headers))
324              peer.wait_for_disconnect()
325          self.nodes[0].disconnect_p2ps()
326  
327      def test_resource_exhaustion(self):
328          self.log.info("Test node stays up despite many large junk messages")
329          # Don't use v2 here - the non-optimised encryption would take too long to encrypt
330          # the large messages
331          conn = self.nodes[0].add_p2p_connection(P2PDataStore(), supports_v2_p2p=False)
332          conn2 = self.nodes[0].add_p2p_connection(P2PDataStore(), supports_v2_p2p=False)
333          msg_at_size = msg_unrecognized(str_data="b" * VALID_DATA_LIMIT)
334          assert len(msg_at_size.serialize()) == MAX_PROTOCOL_MESSAGE_LENGTH
335  
336          self.log.info("(a) Send 80 messages, each of maximum valid data size (4MB)")
337          for _ in range(80):
338              conn.send_without_ping(msg_at_size)
339  
340          # Check that, even though the node is being hammered by nonsense from one
341          # connection, it can still service other peers in a timely way.
342          self.log.info("(b) Check node still services peers in a timely way")
343          for _ in range(20):
344              conn2.sync_with_ping(timeout=2)
345  
346          self.log.info("(c) Wait for node to drop junk messages, while remaining connected")
347          conn.sync_with_ping(timeout=400)
348  
349          # Despite being served up a bunch of nonsense, the peers should still be connected.
350          assert conn.is_connected
351          assert conn2.is_connected
352          self.nodes[0].disconnect_p2ps()
353  
354  
355  if __name__ == '__main__':
356      InvalidMessagesTest(__file__).main()