test/functional/assumevalid.py

   1 #!/usr/bin/env python3
   2 # Copyright (c) 2014-2016 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 logic for skipping signature validation on old blocks.
   6
   7 Test logic for skipping signature validation on blocks which we've assumed
   8 valid (https://github.com/bitcoin/bitcoin/pull/9484)
   9
  10 We build a chain that includes and invalid signature for one of the
  11 transactions:
  12
  13     0:        genesis block
  14     1:        block 1 with coinbase transaction output.
  15     2-101:    bury that block with 100 blocks so the coinbase transaction
  16               output can be spent
  17     102:      a block containing a transaction spending the coinbase
  18               transaction output. The transaction has an invalid signature.
  19     103-2202: bury the bad block with just over two weeks' worth of blocks
  20               (2100 blocks)
  21
  22 Start three nodes:
  23
  24     - node0 has no -assumevalid parameter. Try to sync to block 2202. It will
  25       reject block 102 and only sync as far as block 101
  26     - node1 has -assumevalid set to the hash of block 102. Try to sync to
  27       block 2202. node1 will sync all the way to block 2202.
  28     - node2 has -assumevalid set to the hash of block 102. Try to sync to
  29       block 200. node2 will reject block 102 since it's assumed valid, but it
  30       isn't buried by at least two weeks' work.
  31 """
  32 import time
  33
  34 from test_framework.blocktools import (create_block, create_coinbase)
  35 from test_framework.key import CECKey
  36 from test_framework.mininode import (CBlockHeader,
  37                                      COutPoint,
  38                                      CTransaction,
  39                                      CTxIn,
  40                                      CTxOut,
  41                                      NetworkThread,
  42                                      NodeConn,
  43                                      NodeConnCB,
  44                                      msg_block,
  45                                      msg_headers)
  46 from test_framework.script import (CScript, OP_TRUE)
  47 from test_framework.test_framework import BitcoinTestFramework
  48 from test_framework.util import (p2p_port, assert_equal)
  49
  50 class BaseNode(NodeConnCB):
  51     def send_header_for_blocks(self, new_blocks):
  52         headers_message = msg_headers()
  53         headers_message.headers = [CBlockHeader(b) for b in new_blocks]
  54         self.send_message(headers_message)
  55
  56 class AssumeValidTest(BitcoinTestFramework):
  57     def __init__(self):
  58         super().__init__()
  59         self.setup_clean_chain = True
  60         self.num_nodes = 3
  61
  62     def setup_network(self):
  63         self.add_nodes(3)
  64         # Start node0. We don't start the other nodes yet since
  65         # we need to pre-mine a block with an invalid transaction
  66         # signature so we can pass in the block hash as assumevalid.
  67         self.start_node(0)
  68
  69     def send_blocks_until_disconnected(self, node):
  70         """Keep sending blocks to the node until we're disconnected."""
  71         for i in range(len(self.blocks)):
  72             try:
  73                 node.send_message(msg_block(self.blocks[i]))
  74             except IOError as e:
  75                 assert str(e) == 'Not connected, no pushbuf'
  76                 break
  77
  78     def assert_blockchain_height(self, node, height):
  79         """Wait until the blockchain is no longer advancing and verify it's reached the expected height."""
  80         last_height = node.getblock(node.getbestblockhash())['height']
  81         timeout = 10
  82         while True:
  83             time.sleep(0.25)
  84             current_height = node.getblock(node.getbestblockhash())['height']
  85             if current_height != last_height:
  86                 last_height = current_height
  87                 if timeout < 0:
  88                     assert False, "blockchain too short after timeout: %d" % current_height
  89                 timeout - 0.25
  90                 continue
  91             elif current_height > height:
  92                 assert False, "blockchain too long: %d" % current_height
  93             elif current_height == height:
  94                 break
  95
  96     def run_test(self):
  97
  98         # Connect to node0
  99         node0 = BaseNode()
 100         connections = []
 101         connections.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], node0))
 102         node0.add_connection(connections[0])
 103
 104         NetworkThread().start()  # Start up network handling in another thread
 105         node0.wait_for_verack()
 106
 107         # Build the blockchain
 108         self.tip = int(self.nodes[0].getbestblockhash(), 16)
 109         self.block_time = self.nodes[0].getblock(self.nodes[0].getbestblockhash())['time'] + 1
 110
 111         self.blocks = []
 112
 113         # Get a pubkey for the coinbase TXO
 114         coinbase_key = CECKey()
 115         coinbase_key.set_secretbytes(b"horsebattery")
 116         coinbase_pubkey = coinbase_key.get_pubkey()
 117
 118         # Create the first block with a coinbase output to our key
 119         height = 1
 120         block = create_block(self.tip, create_coinbase(height, coinbase_pubkey), self.block_time)
 121         self.blocks.append(block)
 122         self.block_time += 1
 123         block.solve()
 124         # Save the coinbase for later
 125         self.block1 = block
 126         self.tip = block.sha256
 127         height += 1
 128
 129         # Bury the block 100 deep so the coinbase output is spendable
 130         for i in range(100):
 131             block = create_block(self.tip, create_coinbase(height), self.block_time)
 132             block.solve()
 133             self.blocks.append(block)
 134             self.tip = block.sha256
 135             self.block_time += 1
 136             height += 1
 137
 138         # Create a transaction spending the coinbase output with an invalid (null) signature
 139         tx = CTransaction()
 140         tx.vin.append(CTxIn(COutPoint(self.block1.vtx[0].sha256, 0), scriptSig=b""))
 141         tx.vout.append(CTxOut(49 * 100000000, CScript([OP_TRUE])))
 142         tx.calc_sha256()
 143
 144         block102 = create_block(self.tip, create_coinbase(height), self.block_time)
 145         self.block_time += 1
 146         block102.vtx.extend([tx])
 147         block102.hashMerkleRoot = block102.calc_merkle_root()
 148         block102.rehash()
 149         block102.solve()
 150         self.blocks.append(block102)
 151         self.tip = block102.sha256
 152         self.block_time += 1
 153         height += 1
 154
 155         # Bury the assumed valid block 2100 deep
 156         for i in range(2100):
 157             block = create_block(self.tip, create_coinbase(height), self.block_time)
 158             block.nVersion = 4
 159             block.solve()
 160             self.blocks.append(block)
 161             self.tip = block.sha256
 162             self.block_time += 1
 163             height += 1
 164
 165         # Start node1 and node2 with assumevalid so they accept a block with a bad signature.
 166         self.start_node(1, extra_args=["-assumevalid=" + hex(block102.sha256)])
 167         node1 = BaseNode()  # connects to node1
 168         connections.append(NodeConn('127.0.0.1', p2p_port(1), self.nodes[1], node1))
 169         node1.add_connection(connections[1])
 170         node1.wait_for_verack()
 171
 172         self.start_node(2, extra_args=["-assumevalid=" + hex(block102.sha256)])
 173         node2 = BaseNode()  # connects to node2
 174         connections.append(NodeConn('127.0.0.1', p2p_port(2), self.nodes[2], node2))
 175         node2.add_connection(connections[2])
 176         node2.wait_for_verack()
 177
 178         # send header lists to all three nodes
 179         node0.send_header_for_blocks(self.blocks[0:2000])
 180         node0.send_header_for_blocks(self.blocks[2000:])
 181         node1.send_header_for_blocks(self.blocks[0:2000])
 182         node1.send_header_for_blocks(self.blocks[2000:])
 183         node2.send_header_for_blocks(self.blocks[0:200])
 184
 185         # Send blocks to node0. Block 102 will be rejected.
 186         self.send_blocks_until_disconnected(node0)
 187         self.assert_blockchain_height(self.nodes[0], 101)
 188
 189         # Send all blocks to node1. All blocks will be accepted.
 190         for i in range(2202):
 191             node1.send_message(msg_block(self.blocks[i]))
 192         # Syncing 2200 blocks can take a while on slow systems. Give it plenty of time to sync.
 193         node1.sync_with_ping(120)
 194         assert_equal(self.nodes[1].getblock(self.nodes[1].getbestblockhash())['height'], 2202)
 195
 196         # Send blocks to node2. Block 102 will be rejected.
 197         self.send_blocks_until_disconnected(node2)
 198         self.assert_blockchain_height(self.nodes[2], 101)
 199
 200 if __name__ == '__main__':
 201     AssumeValidTest().main()