text: #!/usr/bin/env python3
  # Copyright (c) 2015-2016 The Lood Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Test BIP66 (DER SIG).
  
  Test that the DERSIG soft-fork activates at (regtest) height 1251.
  """
  
  from test_framework.test_framework import LoodTestFramework
  from test_framework.util import *
  from test_framework.mininode import *
  from test_framework.blocktools import create_coinbase, create_block
  from test_framework.script import CScript
  from io import BytesIO
  
  DERSIG_HEIGHT = 1251
  
  # Reject codes that we might receive in this test
  REJECT_INVALID = 16
  REJECT_OBSOLETE = 17
  REJECT_NONSTANDARD = 64
  VB_TOP_BITS = 0x20000000
  
  # A canonical signature consists of:
  # <30> <total len> <02> <len R> <R> <02> <len S> <S> <hashtype>
  def unDERify(tx):
      """
      Make the signature in vin 0 of a tx non-DER-compliant,
      by adding padding after the S-value.
      """
      scriptSig = CScript(tx.vin[0].scriptSig)
      newscript = []
      for i in scriptSig:
          if (len(newscript) == 0):
              newscript.append(i[0:-1] + b'\0' + i[-1:])
          else:
              newscript.append(i)
      tx.vin[0].scriptSig = CScript(newscript)
  
  def create_transaction(node, coinbase, to_address, amount):
      from_txid = node.getblock(coinbase)['tx'][0]
      inputs = [{ "txid" : from_txid, "vout" : 0}]
      outputs = { to_address : amount }
      rawtx = node.createrawtransaction(inputs, outputs)
      signresult = node.signrawtransaction(rawtx)
      tx = CTransaction()
      tx.deserialize(BytesIO(hex_str_to_bytes(signresult['hex'])))
      return tx
  
  class BIP66Test(LoodTestFramework):
      def set_test_params(self):
          self.num_nodes = 1
          self.extra_args = [['-promiscuousmempoolflags=1', '-whitelist=127.0.0.1']]
          self.setup_clean_chain = True
  
      def run_test(self):
          node0 = NodeConnCB()
          connections = []
          connections.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], node0))
          node0.add_connection(connections[0])
          NetworkThread().start() # Start up network handling in another thread
  
          # wait_for_verack ensures that the P2P connection is fully up.
          node0.wait_for_verack()
  
          self.log.info("Mining %d blocks", DERSIG_HEIGHT - 2)
          self.coinbase_blocks = self.nodes[0].generate(DERSIG_HEIGHT - 2)
          self.nodeaddress = self.nodes[0].getnewaddress()
  
          self.log.info("Test that a transaction with non-DER signature can still appear in a block")
  
          spendtx = create_transaction(self.nodes[0], self.coinbase_blocks[0],
                  self.nodeaddress, 1.0)
          unDERify(spendtx)
          spendtx.rehash()
  
          tip = self.nodes[0].getbestblockhash()
          block_time = self.nodes[0].getblockheader(tip)['mediantime'] + 1
          block = create_block(int(tip, 16), create_coinbase(DERSIG_HEIGHT - 1), block_time)
          block.nVersion = VB_TOP_BITS
          block.vtx.append(spendtx)
          block.hashMerkleRoot = block.calc_merkle_root()
          block.rehash()
          block.solve()
  
          node0.send_and_ping(msg_block(block))
          assert_equal(self.nodes[0].getbestblockhash(), block.hash)
  
          self.log.info("Test that blocks must now be at least version VB_TOP_BITS")
          tip = block.sha256
          block_time += 1
          block = create_block(tip, create_coinbase(DERSIG_HEIGHT), block_time)
          block.nVersion = 2
          block.rehash()
          block.solve()
          node0.send_and_ping(msg_block(block))
          assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
  
          wait_until(lambda: "reject" in node0.last_message.keys(), lock=mininode_lock)
          with mininode_lock:
              assert_equal(node0.last_message["reject"].code, REJECT_OBSOLETE)
              assert_equal(node0.last_message["reject"].reason, b'bad-version(0x00000002)')
              assert_equal(node0.last_message["reject"].data, block.sha256)
              del node0.last_message["reject"]
  
          self.log.info("Test that transactions with non-DER signatures cannot appear in a block")
          block.nVersion = VB_TOP_BITS
  
          spendtx = create_transaction(self.nodes[0], self.coinbase_blocks[1],
                  self.nodeaddress, 1.0)
          unDERify(spendtx)
          spendtx.rehash()
  
          # First we show that this tx is valid except for DERSIG by getting it
          # accepted to the mempool (which we can achieve with
          # -promiscuousmempoolflags).
          node0.send_and_ping(msg_tx(spendtx))
          assert spendtx.hash in self.nodes[0].getrawmempool()
  
          # Now we verify that a block with this transaction is invalid.
          block.vtx.append(spendtx)
          block.hashMerkleRoot = block.calc_merkle_root()
          block.rehash()
          block.solve()
  
          node0.send_and_ping(msg_block(block))
          assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
  
          wait_until(lambda: "reject" in node0.last_message.keys(), lock=mininode_lock)
          with mininode_lock:
              # We can receive different reject messages depending on whether
              # loodd is running with multiple script check threads. If script
              # check threads are not in use, then transaction script validation
              # happens sequentially, and loodd produces more specific reject
              # reasons.
              assert node0.last_message["reject"].code in [REJECT_INVALID, REJECT_NONSTANDARD]
              assert_equal(node0.last_message["reject"].data, block.sha256)
              if node0.last_message["reject"].code == REJECT_INVALID:
                  # Generic rejection when a block is invalid
                  assert_equal(node0.last_message["reject"].reason, b'block-validation-failed')
              else:
                  assert b'Non-canonical DER signature' in node0.last_message["reject"].reason
  
          self.log.info("Test that a version VB_TOP_BITS block with a DERSIG-compliant transaction is accepted")
          block.vtx[1] = create_transaction(self.nodes[0],
                  self.coinbase_blocks[1], self.nodeaddress, 1.0)
          block.hashMerkleRoot = block.calc_merkle_root()
          block.rehash()
          block.solve()
  
          node0.send_and_ping(msg_block(block))
          assert_equal(int(self.nodes[0].getbestblockhash(), 16), block.sha256)
  
  if __name__ == '__main__':
      BIP66Test().main()
  