#!/usr/bin/env python3 # Copyright (c) 2014-2016 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 logic for skipping signature validation on old blocks. Test logic for skipping signature validation on blocks which we've assumed valid (https://github.com/bitcoin/bitcoin/pull/9484) We build a chain that includes and invalid signature for one of the transactions: 0: genesis block 1: block 1 with coinbase transaction output. 2-101: bury that block with 100 blocks so the coinbase transaction output can be spent 102: a block containing a transaction spending the coinbase transaction output. The transaction has an invalid signature. 103-2202: bury the bad block with just over two weeks' worth of blocks (2100 blocks) Start three nodes: - node0 has no -assumevalid parameter. Try to sync to block 2202. It will reject block 102 and only sync as far as block 101 - node1 has -assumevalid set to the hash of block 102. Try to sync to block 2202. node1 will sync all the way to block 2202. - node2 has -assumevalid set to the hash of block 102. Try to sync to block 200. node2 will reject block 102 since it's assumed valid, but it isn't buried by at least two weeks' work. """ import time from test_framework.blocktools import (create_block, create_coinbase) from test_framework.key import CECKey from test_framework.mininode import (CBlockHeader, COutPoint, CTransaction, CTxIn, CTxOut, network_thread_join, network_thread_start, P2PInterface, msg_block, msg_headers) from test_framework.script import (CScript, OP_TRUE) from test_framework.test_framework import BitcoinTestFramework from test_framework.util import (assert_equal, set_node_times) class BaseNode(P2PInterface): def send_header_for_blocks(self, new_blocks): headers_message = msg_headers() headers_message.headers = [CBlockHeader(b) for b in new_blocks] self.send_message(headers_message) class AssumeValidTest(BitcoinTestFramework): def set_test_params(self): self.setup_clean_chain = True self.num_nodes = 3 self.extra_args = ["-dip3params=9000:9000", "-checkblockindex=0"] def setup_network(self): self.add_nodes(3) # Start node0. We don't start the other nodes yet since # we need to pre-mine a block with an invalid transaction # signature so we can pass in the block hash as assumevalid. self.start_node(0, extra_args=self.extra_args) def send_blocks_until_disconnected(self, p2p_conn): """Keep sending blocks to the node until we're disconnected.""" for i in range(len(self.blocks)): if not p2p_conn.is_connected: break try: p2p_conn.send_message(msg_block(self.blocks[i])) # TODO There is a race condition between send_message and on_close which causes an AttributError on Travis # We can reenable the correct exception handling and the assert when Bitcoin 0.16 mininode.py changes have been # backported #except IOError as e: except: #assert not p2p_conn.is_connected break def assert_blockchain_height(self, node, height): """Wait until the blockchain is no longer advancing and verify it's reached the expected height.""" last_height = node.getblock(node.getbestblockhash())['height'] timeout = 10 while True: time.sleep(0.25) current_height = node.getblock(node.getbestblockhash())['height'] if current_height != last_height: last_height = current_height if timeout < 0: assert False, "blockchain too short after timeout: %d" % current_height timeout - 0.25 continue elif current_height > height: assert False, "blockchain too long: %d" % current_height elif current_height == height: break def run_test(self): # Connect to node0 p2p0 = self.nodes[0].add_p2p_connection(BaseNode()) network_thread_start() self.nodes[0].p2p.wait_for_verack() # Build the blockchain self.tip = int(self.nodes[0].getbestblockhash(), 16) self.block_time = self.nodes[0].getblock(self.nodes[0].getbestblockhash())['time'] + 1 self.blocks = [] # Get a pubkey for the coinbase TXO coinbase_key = CECKey() coinbase_key.set_secretbytes(b"horsebattery") coinbase_pubkey = coinbase_key.get_pubkey() # Create the first block with a coinbase output to our key height = 1 block = create_block(self.tip, create_coinbase(height, coinbase_pubkey), self.block_time) self.blocks.append(block) self.block_time += 1 block.solve() # Save the coinbase for later self.block1 = block self.tip = block.sha256 height += 1 # Bury the block 100 deep so the coinbase output is spendable for i in range(100): block = create_block(self.tip, create_coinbase(height), self.block_time) block.solve() self.blocks.append(block) self.tip = block.sha256 self.block_time += 1 height += 1 # Create a transaction spending the coinbase output with an invalid (null) signature tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.block1.vtx[0].sha256, 0), scriptSig=b"")) tx.vout.append(CTxOut(49 * 100000000, CScript([OP_TRUE]))) tx.calc_sha256() block102 = create_block(self.tip, create_coinbase(height), self.block_time) self.block_time += 1 block102.vtx.extend([tx]) block102.hashMerkleRoot = block102.calc_merkle_root() block102.rehash() block102.solve() self.blocks.append(block102) self.tip = block102.sha256 self.block_time += 1 height += 1 # Bury the assumed valid block 8400 deep (Dash needs 4x as much blocks to allow -assumevalid to work) for i in range(8400): block = create_block(self.tip, create_coinbase(height), self.block_time) block.nVersion = 4 block.solve() self.blocks.append(block) self.tip = block.sha256 self.block_time += 1 height += 1 # We're adding new connections so terminate the network thread self.nodes[0].disconnect_p2ps() network_thread_join() # Start node1 and node2 with assumevalid so they accept a block with a bad signature. self.start_node(1, extra_args=self.extra_args + ["-assumevalid=" + hex(block102.sha256)]) self.start_node(2, extra_args=self.extra_args + ["-assumevalid=" + hex(block102.sha256)]) p2p0 = self.nodes[0].add_p2p_connection(BaseNode()) p2p1 = self.nodes[1].add_p2p_connection(BaseNode()) p2p2 = self.nodes[2].add_p2p_connection(BaseNode()) network_thread_start() p2p0.wait_for_verack() p2p1.wait_for_verack() p2p2.wait_for_verack() # Make sure nodes actually accept the many headers self.mocktime = self.block_time set_node_times(self.nodes, self.mocktime) # send header lists to all three nodes. # node0 does not need to receive all headers # node1 must receive all headers as otherwise assumevalid is ignored in ConnectBlock # node2 should NOT receive all headers to force skipping of the assumevalid check in ConnectBlock p2p0.send_header_for_blocks(self.blocks[0:2000]) p2p1.send_header_for_blocks(self.blocks[0:2000]) p2p1.send_header_for_blocks(self.blocks[2000:4000]) p2p1.send_header_for_blocks(self.blocks[4000:6000]) p2p1.send_header_for_blocks(self.blocks[6000:8000]) p2p1.send_header_for_blocks(self.blocks[8000:]) p2p2.send_header_for_blocks(self.blocks[0:200]) # Send blocks to node0. Block 102 will be rejected. self.send_blocks_until_disconnected(p2p0) self.assert_blockchain_height(self.nodes[0], 101) # Send 200 blocks to node1. All blocks, including block 102, will be accepted. for i in range(200): p2p1.send_message(msg_block(self.blocks[i])) # Syncing so many blocks can take a while on slow systems. Give it plenty of time to sync. p2p1.sync_with_ping(300) assert_equal(self.nodes[1].getblock(self.nodes[1].getbestblockhash())['height'], 200) # Send blocks to node2. Block 102 will be rejected. self.send_blocks_until_disconnected(p2p2) self.assert_blockchain_height(self.nodes[2], 101) if __name__ == '__main__': AssumeValidTest().main()