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 BIP66 (DER SIG).
  
  Test that the DERSIG soft-fork activates at (regtest) height 1251.
  """
  
  from test_framework.blocktools import create_coinbase, create_block, create_transaction
  from test_framework.messages import msg_block
  from test_framework.mininode import mininode_lock, P2PInterface
  from test_framework.script import CScript
  from test_framework.test_framework import RingTestFramework
  from test_framework.util import (
      assert_equal,
      bytes_to_hex_str,
      wait_until,
  )
  
  DERSIG_HEIGHT = 1251
  
  # Reject codes that we might receive in this test
  REJECT_INVALID = 16
  REJECT_NONSTANDARD = 64
  
  # 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)
  
  
  
  class BIP66Test(RingTestFramework):
      def set_test_params(self):
          self.num_nodes = 1
          self.extra_args = [['-whitelist=127.0.0.1', '-par=1', '-enablebip61']]  # Use only one script thread to get the exact reject reason for testing
          self.setup_clean_chain = True
          self.rpc_timeout = 120
  
      def skip_test_if_missing_module(self):
          self.skip_if_no_wallet()
  
      def run_test(self):
          self.nodes[0].add_p2p_connection(P2PInterface())
  
          self.log.info("Mining %d blocks", DERSIG_HEIGHT - 2)
          self.coinbase_txids = [self.nodes[0].getblock(b)['tx'][0] for b in 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_txids[0],
                  self.nodeaddress, amount=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 = 2
          block.vtx.append(spendtx)
          block.hashMerkleRoot = block.calc_merkle_root()
          block.rehash()
          block.solve()
  
          self.nodes[0].p2p.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 3")
          tip = block.sha256
          block_time += 1
          block = create_block(tip, create_coinbase(DERSIG_HEIGHT), block_time)
          block.nVersion = 2
          block.rehash()
          block.solve()
  
          with self.nodes[0].assert_debug_log(expected_msgs=['{}, bad-version(0x00000002)'.format(block.hash)]):
              self.nodes[0].p2p.send_and_ping(msg_block(block))
              assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
              self.nodes[0].p2p.sync_with_ping()
  
          self.log.info("Test that transactions with non-DER signatures cannot appear in a block")
          block.nVersion = 3
  
          spendtx = create_transaction(self.nodes[0], self.coinbase_txids[1],
                  self.nodeaddress, amount=1.0)
          unDERify(spendtx)
          spendtx.rehash()
  
          # First we show that this tx is valid except for DERSIG by getting it
          # rejected from the mempool for exactly that reason.
          assert_equal(
              [{'txid': spendtx.hash, 'allowed': False, 'reject-reason': '64: non-mandatory-script-verify-flag (Non-canonical DER signature)'}],
              self.nodes[0].testmempoolaccept(rawtxs=[bytes_to_hex_str(spendtx.serialize())], allowhighfees=True)
          )
  
          # Now we verify that a block with this transaction is also invalid.
          block.vtx.append(spendtx)
          block.hashMerkleRoot = block.calc_merkle_root()
          block.rehash()
          block.solve()
  
          with self.nodes[0].assert_debug_log(expected_msgs=['CheckInputs on {} failed with non-mandatory-script-verify-flag (Non-canonical DER signature)'.format(block.vtx[-1].hash)]):
              self.nodes[0].p2p.send_and_ping(msg_block(block))
              assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
              self.nodes[0].p2p.sync_with_ping()
  
          wait_until(lambda: "reject" in self.nodes[0].p2p.last_message.keys(), lock=mininode_lock)
          with mininode_lock:
              assert self.nodes[0].p2p.last_message["reject"].code in [REJECT_INVALID, REJECT_NONSTANDARD]
              assert_equal(self.nodes[0].p2p.last_message["reject"].data, block.sha256)
              assert b'Non-canonical DER signature' in self.nodes[0].p2p.last_message["reject"].reason
  
          self.log.info("Test that a version 3 block with a DERSIG-compliant transaction is accepted")
          block.vtx[1] = create_transaction(self.nodes[0], self.coinbase_txids[1], self.nodeaddress, amount=1.0)
          block.hashMerkleRoot = block.calc_merkle_root()
          block.rehash()
          block.solve()
  
          self.nodes[0].p2p.send_and_ping(msg_block(block))
          assert_equal(int(self.nodes[0].getbestblockhash(), 16), block.sha256)
  
  if __name__ == '__main__':
      BIP66Test().main()
  