Merge #16021: p2p: Avoid logging transaction decode errors to stderr

fa2b52af32 Disallow extended encoding for non-witness transactions (take 3) (MarcoFalke)

Pull request description:

  (previous title "p2p: Disallow extended encoding for non-witness transactions (take 3)")

  Remote peers can send us illegally encoded txs and thus have us write to stderr. Fix that by not writing to stderr.

  This is a follow up to the previous (incomplete) attempts at this:

  *  Disallow extended encoding for non-witness transactions #14039
  *  Add test for superfluous witness record in deserialization #15893

ACKs for commit fa2b52:
  laanwj:
    utACK fa2b52af32
  ryanofsky:
    utACK fa2b52af32. Would change title to something like "Avoid logging transaction decode errors to stderr" instead of "Disallow extended encoding for non-witness transactions." The current title is confusing because this PR isn't really allowing or disallowing anything, just logging the condition differently. "Disallow" also seems to contradict the "Allow exceptions from..." comments in the actual code.

Tree-SHA512: c66990e69b432d00dc1c5510bf976a1188664d0890a32d1e5c6459094e7e27da82a5d227627afcbc203676f5540eec74b7d9b1d71d2c62d3b2069e1781824b4d
This commit is contained in:
Wladimir J. van der Laan 2019-05-20 17:27:56 +02:00
commit bb291b50f2
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GPG key ID: 1E4AED62986CD25D
2 changed files with 33 additions and 14 deletions

View file

@ -3288,23 +3288,22 @@ bool PeerLogicValidation::ProcessMessages(CNode* pfrom, std::atomic<bool>& inter
if (m_enable_bip61) { if (m_enable_bip61) {
connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_MALFORMED, std::string("error parsing message"))); connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_MALFORMED, std::string("error parsing message")));
} }
if (strstr(e.what(), "end of data")) if (strstr(e.what(), "end of data")) {
{
// Allow exceptions from under-length message on vRecv // Allow exceptions from under-length message on vRecv
LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught, normally caused by a message being shorter than its stated length\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught, normally caused by a message being shorter than its stated length\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
} } else if (strstr(e.what(), "size too large")) {
else if (strstr(e.what(), "size too large"))
{
// Allow exceptions from over-long size // Allow exceptions from over-long size
LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
} } else if (strstr(e.what(), "non-canonical ReadCompactSize()")) {
else if (strstr(e.what(), "non-canonical ReadCompactSize()"))
{
// Allow exceptions from non-canonical encoding // Allow exceptions from non-canonical encoding
LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
} } else if (strstr(e.what(), "Superfluous witness record")) {
else // Allow exceptions from illegal witness encoding
{ LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
} else if (strstr(e.what(), "Unknown transaction optional data")) {
// Allow exceptions from unknown witness encoding
LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
} else {
PrintExceptionContinue(&e, "ProcessMessages()"); PrintExceptionContinue(&e, "ProcessMessages()");
} }
} }

View file

@ -2038,9 +2038,9 @@ class SegWitTest(BitcoinTestFramework):
# TODO: test p2sh sigop counting # TODO: test p2sh sigop counting
def test_superfluous_witness(self): def test_superfluous_witness(self):
# Serialization of tx that puts witness flag to 1 always # Serialization of tx that puts witness flag to 3 always
def serialize_with_bogus_witness(tx): def serialize_with_bogus_witness(tx):
flags = 1 flags = 3
r = b"" r = b""
r += struct.pack("<i", tx.nVersion) r += struct.pack("<i", tx.nVersion)
if flags: if flags:
@ -2059,9 +2059,29 @@ class SegWitTest(BitcoinTestFramework):
r += struct.pack("<I", tx.nLockTime) r += struct.pack("<I", tx.nLockTime)
return r return r
raw = self.nodes[0].createrawtransaction([{"txid":"00"*32, "vout":0}], {self.nodes[0].getnewaddress():1}) class msg_bogus_tx(msg_tx):
def serialize(self):
return serialize_with_bogus_witness(self.tx)
self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(address_type='bech32'), 5)
self.nodes[0].generate(1)
unspent = next(u for u in self.nodes[0].listunspent() if u['spendable'] and u['address'].startswith('bcrt'))
raw = self.nodes[0].createrawtransaction([{"txid": unspent['txid'], "vout": unspent['vout']}], {self.nodes[0].getnewaddress(): 1})
tx = FromHex(CTransaction(), raw) tx = FromHex(CTransaction(), raw)
assert_raises_rpc_error(-22, "TX decode failed", self.nodes[0].decoderawtransaction, serialize_with_bogus_witness(tx).hex()) assert_raises_rpc_error(-22, "TX decode failed", self.nodes[0].decoderawtransaction, serialize_with_bogus_witness(tx).hex())
with self.nodes[0].assert_debug_log(['Superfluous witness record']):
self.nodes[0].p2p.send_message(msg_bogus_tx(tx))
self.nodes[0].p2p.sync_with_ping()
raw = self.nodes[0].signrawtransactionwithwallet(raw)
assert raw['complete']
raw = raw['hex']
tx = FromHex(CTransaction(), raw)
assert_raises_rpc_error(-22, "TX decode failed", self.nodes[0].decoderawtransaction, serialize_with_bogus_witness(tx).hex())
with self.nodes[0].assert_debug_log(['Unknown transaction optional data']):
self.nodes[0].p2p.send_message(msg_bogus_tx(tx))
self.nodes[0].p2p.sync_with_ping()
if __name__ == '__main__': if __name__ == '__main__':
SegWitTest().main() SegWitTest().main()