text: #!/usr/bin/env python3
  # Copyright (c) 2015-2018 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 node responses to invalid blocks.
  
  In this test we connect to one node over p2p, and test block requests:
  1) Valid blocks should be requested and become chain tip.
  2) Invalid block with duplicated transaction should be re-requested.
  3) Invalid block with bad coinbase value should be rejected and not
  re-requested.
  """
  import copy
  
  from test_framework.blocktools import create_block, create_coinbase, create_tx_with_script
  from test_framework.messages import COIN
  from test_framework.mininode import P2PDataStore
  from test_framework.test_framework import BitcoinTestFramework
  from test_framework.util import assert_equal
  
  class InvalidBlockRequestTest(BitcoinTestFramework):
      def set_test_params(self):
          self.num_nodes = 1
          self.setup_clean_chain = True
          self.extra_args = [["-whitelist=127.0.0.1"]]
  
      def run_test(self):
          # Add p2p connection to node0
          node = self.nodes[0]  # convenience reference to the node
          node.add_p2p_connection(P2PDataStore())
  
          best_block = node.getblock(node.getbestblockhash())
          tip = int(node.getbestblockhash(), 16)
          height = best_block["height"] + 1
          block_time = best_block["time"] + 1
  
          self.log.info("Create a new block with an anyone-can-spend coinbase")
  
          height = 1
          block = create_block(self.nodes[0], tip, create_coinbase(height), block_time)
          block.solve()
          # Save the coinbase for later
          block1 = block
          tip = block.sha256
          node.p2p.send_blocks_and_test([block1], node, success=True)
  
          self.log.info("Mature the block.")
          node.generatetoaddress(100, node.get_deterministic_priv_key().address)
  
          best_block = node.getblock(node.getbestblockhash())
          tip = int(node.getbestblockhash(), 16)
          height = best_block["height"] + 1
          block_time = best_block["time"] + 1
  
          # Use merkle-root malleability to generate an invalid block with
          # same blockheader (CVE-2012-2459).
          # Manufacture a block with 3 transactions (coinbase, spend of prior
          # coinbase, spend of that spend).  Duplicate the 3rd transaction to
          # leave merkle root and blockheader unchanged but invalidate the block.
          # For more information on merkle-root malleability see src/consensus/merkle.cpp.
          self.log.info("Test merkle root malleability.")
  
          block2 = create_block(self.nodes[0], tip, create_coinbase(height), block_time)
          block_time += 1
  
          # b'0x51' is OP_TRUE
          tx1 = create_tx_with_script(block1.vtx[0], 0, script_sig=b'\x51', amount=50 * COIN)
          tx2 = create_tx_with_script(tx1, 0, script_sig=b'\x51', amount=50 * COIN)
  
          block2.vtx.extend([tx1, tx2])
          block2.hashMerkleRoot = block2.calc_merkle_root()
          block2.rehash()
          block2.solve()
          orig_hash = block2.sha256
          block2_orig = copy.deepcopy(block2)
  
          # Mutate block 2
          block2.vtx.append(tx2)
          assert_equal(block2.hashMerkleRoot, block2.calc_merkle_root())
          assert_equal(orig_hash, block2.rehash())
          assert block2_orig.vtx != block2.vtx
  
          node.p2p.send_blocks_and_test([block2], node, success=False, reject_reason='bad-txns-duplicate')
  
          # Check transactions for duplicate inputs (CVE-2018-17144)
          self.log.info("Test duplicate input block.")
  
          block2_dup = copy.deepcopy(block2_orig)
          block2_dup.vtx[2].vin.append(block2_dup.vtx[2].vin[0])
          block2_dup.vtx[2].rehash()
          block2_dup.hashMerkleRoot = block2_dup.calc_merkle_root()
          block2_dup.rehash()
          block2_dup.solve()
          node.p2p.send_blocks_and_test([block2_dup], node, success=False, reject_reason='bad-txns-inputs-duplicate')
  
          self.log.info("Test very broken block.")
  
          block3 = create_block(self.nodes[0], tip, create_coinbase(height), block_time)
          block_time += 1
          block3.vtx[0].vout[0].nValue = 100 * COIN  # Too high!
          block3.vtx[0].sha256 = None
          block3.vtx[0].calc_sha256()
          block3.hashMerkleRoot = block3.calc_merkle_root()
          block3.rehash()
          block3.solve()
  
          node.p2p.send_blocks_and_test([block3], node, success=False, reject_reason='bad-cb-amount')
  
  
          # Complete testing of CVE-2012-2459 by sending the original block.
          # It should be accepted even though it has the same hash as the mutated one.
  
          self.log.info("Test accepting original block after rejecting its mutated version.")
          node.p2p.send_blocks_and_test([block2_orig], node, success=True, timeout=5)
  
          # Update tip info
          height += 1
          block_time += 1
          tip = int(block2_orig.hash, 16)
  
          # Complete testing of CVE-2018-17144, by checking for the inflation bug.
          # Create a block that spends the output of a tx in a previous block.
          block4 = create_block(self.nodes[0], tip, create_coinbase(height), block_time)
          tx3 = create_tx_with_script(tx2, 0, script_sig=b'\x51', amount=50 * COIN)
  
          # Duplicates input
          tx3.vin.append(tx3.vin[0])
          tx3.rehash()
          block4.vtx.append(tx3)
          block4.hashMerkleRoot = block4.calc_merkle_root()
          block4.rehash()
          block4.solve()
          self.log.info("Test inflation by duplicating input")
          node.p2p.send_blocks_and_test([block4], node, success=False,  reject_reason='bad-txns-inputs-duplicate')
  
  if __name__ == '__main__':
      InvalidBlockRequestTest().main()
  