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 set_test_params(self):
  58         self.setup_clean_chain = True
  59         self.num_nodes = 3
  60
  61     def setup_network(self):
  62         self.add_nodes(3)
  63         # Start node0. We don't start the other nodes yet since
  64         # we need to pre-mine a block with an invalid transaction
  65         # signature so we can pass in the block hash as assumevalid.
  66         self.start_node(0)
  67
  68     def send_blocks_until_disconnected(self, node):
  69         """Keep sending blocks to the node until we're disconnected."""
  70         for i in range(len(self.blocks)):
  71             try:
  72                 node.send_message(msg_block(self.blocks[i]))
  73             except IOError as e:
  74                 assert str(e) == 'Not connected, no pushbuf'
  75                 break
  76
  77     def assert_blockchain_height(self, node, height):
  78         """Wait until the blockchain is no longer advancing and verify it's reached the expected height."""
  79         last_height = node.getblock(node.getbestblockhash())['height']
  80         timeout = 10
  81         while True:
  82             time.sleep(0.25)
  83             current_height = node.getblock(node.getbestblockhash())['height']
  84             if current_height != last_height:
  85                 last_height = current_height
  86                 if timeout < 0:
  87                     assert False, "blockchain too short after timeout: %d" % current_height
  88                 timeout - 0.25
  89                 continue
  90             elif current_height > height:
  91                 assert False, "blockchain too long: %d" % current_height
  92             elif current_height == height:
  93                 break
  94
  95     def run_test(self):
  96
  97         # Connect to node0
  98         node0 = BaseNode()
  99         connections = []
 100         connections.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], node0))
 101         node0.add_connection(connections[0])
 102
 103         NetworkThread().start()  # Start up network handling in another thread
 104         node0.wait_for_verack()
 105
 106         # Build the blockchain
 107         self.tip = int(self.nodes[0].getbestblockhash(), 16)
 108         self.block_time = self.nodes[0].getblock(self.nodes[0].getbestblockhash())['time'] + 1
 109
 110         self.blocks = []
 111
 112         # Get a pubkey for the coinbase TXO
 113         coinbase_key = CECKey()
 114         coinbase_key.set_secretbytes(b"horsebattery")
 115         coinbase_pubkey = coinbase_key.get_pubkey()
 116
 117         # Create the first block with a coinbase output to our key
 118         height = 1
 119         block = create_block(self.tip, create_coinbase(height, coinbase_pubkey), self.block_time)
 120         self.blocks.append(block)
 121         self.block_time += 1
 122         block.solve()
 123         # Save the coinbase for later
 124         self.block1 = block
 125         self.tip = block.sha256
 126         height += 1
 127
 128         # Bury the block 100 deep so the coinbase output is spendable
 129         for i in range(100):
 130             block = create_block(self.tip, create_coinbase(height), self.block_time)
 131             block.solve()
 132             self.blocks.append(block)
 133             self.tip = block.sha256
 134             self.block_time += 1
 135             height += 1
 136
 137         # Create a transaction spending the coinbase output with an invalid (null) signature
 138         tx = CTransaction()
 139         tx.vin.append(CTxIn(COutPoint(self.block1.vtx[0].sha256, 0), scriptSig=b""))
 140         tx.vout.append(CTxOut(49 * 100000000, CScript([OP_TRUE])))
 141         tx.calc_sha256()
 142
 143         block102 = create_block(self.tip, create_coinbase(height), self.block_time)
 144         self.block_time += 1
 145         block102.vtx.extend([tx])
 146         block102.hashMerkleRoot = block102.calc_merkle_root()
 147         block102.rehash()
 148         block102.solve()
 149         self.blocks.append(block102)
 150         self.tip = block102.sha256
 151         self.block_time += 1
 152         height += 1
 153
 154         # Bury the assumed valid block 2100 deep
 155         for i in range(2100):
 156             block = create_block(self.tip, create_coinbase(height), self.block_time)
 157             block.nVersion = 4
 158             block.solve()
 159             self.blocks.append(block)
 160             self.tip = block.sha256
 161             self.block_time += 1
 162             height += 1
 163
 164         # Start node1 and node2 with assumevalid so they accept a block with a bad signature.
 165         self.start_node(1, extra_args=["-assumevalid=" + hex(block102.sha256)])
 166         node1 = BaseNode()  # connects to node1
 167         connections.append(NodeConn('127.0.0.1', p2p_port(1), self.nodes[1], node1))
 168         node1.add_connection(connections[1])
 169         node1.wait_for_verack()
 170
 171         self.start_node(2, extra_args=["-assumevalid=" + hex(block102.sha256)])
 172         node2 = BaseNode()  # connects to node2
 173         connections.append(NodeConn('127.0.0.1', p2p_port(2), self.nodes[2], node2))
 174         node2.add_connection(connections[2])
 175         node2.wait_for_verack()
 176
 177         # send header lists to all three nodes
 178         node0.send_header_for_blocks(self.blocks[0:2000])
 179         node0.send_header_for_blocks(self.blocks[2000:])
 180         node1.send_header_for_blocks(self.blocks[0:2000])
 181         node1.send_header_for_blocks(self.blocks[2000:])
 182         node2.send_header_for_blocks(self.blocks[0:200])
 183
 184         # Send blocks to node0. Block 102 will be rejected.
 185         self.send_blocks_until_disconnected(node0)
 186         self.assert_blockchain_height(self.nodes[0], 101)
 187
 188         # Send all blocks to node1. All blocks will be accepted.
 189         for i in range(2202):
 190             node1.send_message(msg_block(self.blocks[i]))
 191         # Syncing 2200 blocks can take a while on slow systems. Give it plenty of time to sync.
 192         node1.sync_with_ping(120)
 193         assert_equal(self.nodes[1].getblock(self.nodes[1].getbestblockhash())['height'], 2202)
 194
 195         # Send blocks to node2. Block 102 will be rejected.
 196         self.send_blocks_until_disconnected(node2)
 197         self.assert_blockchain_height(self.nodes[2], 101)
 198
 199 if __name__ == '__main__':
 200     AssumeValidTest().main()