feature_versionbits_warning.py

#!/usr/bin/env python3
# Copyright (c) 2016-2020 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 version bits warning system.

Generate chains with block versions that appear to be signalling unknown
soft-forks, and test that warning alerts are generated.
"""
import os
import re

from test_framework.address import key_to_p2pkh
from test_framework.blocktools import create_block, create_coinbase, sign_block, NORMAL_GBT_REQUEST_PARAMS
from test_framework.messages import msg_block
from test_framework.p2p import P2PInterface
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import advance_time_for_pos

VB_PERIOD = 144           # versionbits period length for regtest
VB_THRESHOLD = 108        # versionbits activation threshold for regtest
VB_TOP_BITS = 0x20000000
VB_UNKNOWN_BIT = 27       # Choose a bit unassigned to any deployment
VB_UNKNOWN_VERSION = VB_TOP_BITS | (1 << VB_UNKNOWN_BIT)

WARN_UNKNOWN_RULES_ACTIVE = "Unknown new rules activated (versionbit {})".format(VB_UNKNOWN_BIT)
VB_PATTERN = re.compile("Unknown new rules activated.*versionbit")

class VersionBitsWarningTest(BitcoinTestFramework):
    def set_test_params(self):
        self.setup_clean_chain = True
        self.num_nodes = 1

    def skip_test_if_missing_module(self):
        self.skip_if_no_wallet()

    def setup_network(self):
        self.alert_filename = os.path.join(self.options.tmpdir, "alert.txt")
        # Open and close to create zero-length file
        with open(self.alert_filename, 'w', encoding='utf8'):
            pass
        self.extra_args = [["-alertnotify=echo %s >> \"" + self.alert_filename + "\"", "-whitelist=127.0.0.1"]]
        self.setup_nodes()

    def get_signing_key(self, node, block):
        """Extract the signing key for a PoS block from the coinstake transaction."""
        coinstake = block.vtx[1]
        coinstake_hex = coinstake.serialize().hex()
        decoded_tx = node.decoderawtransaction(coinstake_hex)

        signing_key = None
        try:
            script_pubkey = decoded_tx['vout'][1]['scriptPubKey']
            coinstake_address = script_pubkey.get('address')
            if not coinstake_address:
                addresses = script_pubkey.get('addresses', [])
                if addresses:
                    coinstake_address = addresses[0]

            if not coinstake_address and script_pubkey.get('type') == 'pubkey':
                asm = script_pubkey.get('asm', '')
                parts = asm.split()
                if len(parts) >= 1 and parts[0] != 'OP_CHECKSIG':
                    pubkey_hex = parts[0]
                    coinstake_address = key_to_p2pkh(pubkey_hex, main=False)

            if coinstake_address:
                signing_key = node.dumpprivkey(coinstake_address)
        except Exception as e:
            self.log.debug(f"Could not get signing key: {e}")

        if not signing_key:
            self.log.debug("No signing key found, using deterministic key")
            signing_key = node.get_deterministic_priv_key().key

        return signing_key

    def send_blocks_with_version(self, peer, numblocks, version):
        """Send numblocks blocks to peer with version set"""
        node = self.nodes[0]
        height = node.getblockcount()

        # PoW path for heights <= 89 (nLastPowHeight)
        if height < 89:
            tip = node.getbestblockhash()
            block_time = node.getblockheader(tip)["time"] + 1
            tip = int(tip, 16)

            pow_blocks = min(numblocks, 89 - height)
            for _ in range(pow_blocks):
                block = create_block(tip, create_coinbase(height + 1), block_time)
                block.nVersion = version
                block.solve()
                peer.send_message(msg_block(block))
                block_time += 1
                height += 1
                tip = block.sha256
            peer.sync_with_ping()
            numblocks -= pow_blocks

        # PoS path for heights >= 90
        for _ in range(numblocks):
            max_attempts = 10
            for attempt in range(max_attempts):
                try:
                    advance_time_for_pos(node, seconds=60)
                    tmpl = node.getblocktemplate(NORMAL_GBT_REQUEST_PARAMS)
                    block = create_block(tmpl=tmpl, version=version)
                    block.solve()

                    signing_key = self.get_signing_key(node, block)
                    sign_block(block, signing_key)

                    peer.send_message(msg_block(block))
                    peer.sync_with_ping()
                    break
                except Exception as e:
                    if "no valid coinstake found" in str(e) and attempt < max_attempts - 1:
                        advance_time_for_pos(node, seconds=120)
                        continue
                    raise

    def versionbits_in_alert_file(self):
        """Test that the versionbits warning has been written to the alert file."""
        alert_text = open(self.alert_filename, 'r', encoding='utf8').read()
        return VB_PATTERN.search(alert_text) is not None

    def run_test(self):
        node = self.nodes[0]
        peer = node.add_p2p_connection(P2PInterface())

        # Mine one period worth of blocks
        node.generate(VB_PERIOD)

        self.log.info("Check that there is no warning if previous VB_BLOCKS have <VB_THRESHOLD blocks with unknown versionbits version.")
        # Build one period of blocks with < VB_THRESHOLD blocks signaling some unknown bit
        self.send_blocks_with_version(peer, VB_THRESHOLD - 1, VB_UNKNOWN_VERSION)
        node.generate(VB_PERIOD - VB_THRESHOLD + 1)

        # Check that we're not getting any versionbit-related errors in get*info()
        assert not VB_PATTERN.match(node.getmininginfo()["warnings"])
        assert not VB_PATTERN.match(node.getnetworkinfo()["warnings"])

        # Build one period of blocks with VB_THRESHOLD blocks signaling some unknown bit
        self.send_blocks_with_version(peer, VB_THRESHOLD, VB_UNKNOWN_VERSION)
        node.generate(VB_PERIOD - VB_THRESHOLD)

        self.log.info("Check that there is a warning if previous VB_BLOCKS have >=VB_THRESHOLD blocks with unknown versionbits version.")
        # Mine a period worth of expected blocks so the generic block-version warning
        # is cleared. This will move the versionbit state to ACTIVE.
        node.generate(VB_PERIOD)

        # Stop-start the node. This is required because bitcoind will only warn once about unknown versions or unknown rules activating.
        self.restart_node(0)

        # Generating one block guarantees that we'll get out of IBD
        node.generate(1)
        self.wait_until(lambda: not node.getblockchaininfo()['initialblockdownload'])
        # Generating one more block will be enough to generate an error.
        node.generate(1)
        # Check that get*info() shows the versionbits unknown rules warning
        assert WARN_UNKNOWN_RULES_ACTIVE in node.getmininginfo()["warnings"]
        assert WARN_UNKNOWN_RULES_ACTIVE in node.getnetworkinfo()["warnings"]
        # Check that the alert file shows the versionbits unknown rules warning
        self.wait_until(lambda: self.versionbits_in_alert_file())

if __name__ == '__main__':
    VersionBitsWarningTest().main()