#!/usr/bin/env python3 # Copyright (c) 2016-2019 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 segwit transactions and blocks on P2P network.""" import math import random import struct import time from test_framework.blocktools import create_block, create_coinbase, add_witness_commitment, get_witness_script, WITNESS_COMMITMENT_HEADER from test_framework.key import ECKey from test_framework.messages import ( BIP125_SEQUENCE_NUMBER, CBlock, CBlockHeader, CInv, COutPoint, CTransaction, CTxIn, CTxInWitness, CTxOut, CTxWitness, MAX_BLOCK_BASE_SIZE, MSG_WITNESS_FLAG, NODE_NETWORK, NODE_WITNESS, msg_no_witness_block, msg_getdata, msg_headers, msg_inv, msg_tx, msg_block, msg_witness_tx, ser_uint256, ser_vector, sha256, uint256_from_str, FromHex, ) from test_framework.mininode import ( P2PInterface, mininode_lock, ) from test_framework.script import ( CScript, CScriptNum, CScriptOp, MAX_SCRIPT_ELEMENT_SIZE, OP_0, OP_1, OP_16, OP_2DROP, OP_CHECKMULTISIG, OP_CHECKSIG, OP_DROP, OP_DUP, OP_ELSE, OP_ENDIF, OP_EQUAL, OP_EQUALVERIFY, OP_HASH160, OP_IF, OP_RETURN, OP_TRUE, SIGHASH_ALL, SIGHASH_ANYONECANPAY, SIGHASH_NONE, SIGHASH_SINGLE, SegwitVersion1SignatureHash, SignatureHash, hash160, ) from test_framework.test_framework import BitcoinTestFramework from test_framework.util import ( assert_equal, connect_nodes, disconnect_nodes, softfork_active, hex_str_to_bytes, assert_raises_rpc_error, ) # The versionbit bit used to signal activation of SegWit VB_WITNESS_BIT = 1 VB_PERIOD = 144 VB_TOP_BITS = 0x20000000 MAX_SIGOP_COST = 80000 SEGWIT_HEIGHT = 120 class UTXO(): """Used to keep track of anyone-can-spend outputs that we can use in the tests.""" def __init__(self, sha256, n, value): self.sha256 = sha256 self.n = n self.nValue = value def get_p2pkh_script(pubkeyhash): """Get the script associated with a P2PKH.""" return CScript([CScriptOp(OP_DUP), CScriptOp(OP_HASH160), pubkeyhash, CScriptOp(OP_EQUALVERIFY), CScriptOp(OP_CHECKSIG)]) def sign_p2pk_witness_input(script, tx_to, in_idx, hashtype, value, key): """Add signature for a P2PK witness program.""" tx_hash = SegwitVersion1SignatureHash(script, tx_to, in_idx, hashtype, value) signature = key.sign_ecdsa(tx_hash) + chr(hashtype).encode('latin-1') tx_to.wit.vtxinwit[in_idx].scriptWitness.stack = [signature, script] tx_to.rehash() def get_virtual_size(witness_block): """Calculate the virtual size of a witness block. Virtual size is base + witness/4.""" base_size = len(witness_block.serialize(with_witness=False)) total_size = len(witness_block.serialize()) # the "+3" is so we round up vsize = int((3 * base_size + total_size + 3) / 4) return vsize def test_transaction_acceptance(node, p2p, tx, with_witness, accepted, reason=None): """Send a transaction to the node and check that it's accepted to the mempool - Submit the transaction over the p2p interface - use the getrawmempool rpc to check for acceptance.""" reason = [reason] if reason else [] with node.assert_debug_log(expected_msgs=reason): p2p.send_message(msg_witness_tx(tx) if with_witness else msg_tx(tx)) p2p.sync_with_ping() assert_equal(tx.hash in node.getrawmempool(), accepted) def test_witness_block(node, p2p, block, accepted, with_witness=True, reason=None): """Send a block to the node and check that it's accepted - Submit the block over the p2p interface - use the getbestblockhash rpc to check for acceptance.""" reason = [reason] if reason else [] with node.assert_debug_log(expected_msgs=reason): p2p.send_message(msg_block(block) if with_witness else msg_no_witness_block(block)) p2p.sync_with_ping() assert_equal(node.getbestblockhash() == block.hash, accepted) class TestP2PConn(P2PInterface): def __init__(self): super().__init__() self.getdataset = set() def on_getdata(self, message): for inv in message.inv: self.getdataset.add(inv.hash) def announce_tx_and_wait_for_getdata(self, tx, timeout=60, success=True): with mininode_lock: self.last_message.pop("getdata", None) self.send_message(msg_inv(inv=[CInv(1, tx.sha256)])) if success: self.wait_for_getdata(timeout) else: time.sleep(timeout) assert not self.last_message.get("getdata") def announce_block_and_wait_for_getdata(self, block, use_header, timeout=60): with mininode_lock: self.last_message.pop("getdata", None) self.last_message.pop("getheaders", None) msg = msg_headers() msg.headers = [CBlockHeader(block)] if use_header: self.send_message(msg) else: self.send_message(msg_inv(inv=[CInv(2, block.sha256)])) self.wait_for_getheaders() self.send_message(msg) self.wait_for_getdata() def request_block(self, blockhash, inv_type, timeout=60): with mininode_lock: self.last_message.pop("block", None) self.send_message(msg_getdata(inv=[CInv(inv_type, blockhash)])) self.wait_for_block(blockhash, timeout) return self.last_message["block"].block class SegWitTest(BitcoinTestFramework): def set_test_params(self): self.setup_clean_chain = True self.num_nodes = 3 # This test tests SegWit both pre and post-activation, so use the normal BIP9 activation. self.extra_args = [ ["-whitelist=127.0.0.1", "-acceptnonstdtxn=1", "-segwitheight={}".format(SEGWIT_HEIGHT)], ["-whitelist=127.0.0.1", "-acceptnonstdtxn=0", "-segwitheight={}".format(SEGWIT_HEIGHT)], ["-whitelist=127.0.0.1", "-acceptnonstdtxn=1", "-segwitheight=-1"] ] def skip_test_if_missing_module(self): self.skip_if_no_wallet() def skip_test_if_missing_module(self): self.skip_if_no_wallet() def setup_network(self): self.setup_nodes() connect_nodes(self.nodes[0], 1) connect_nodes(self.nodes[0], 2) self.sync_all() # Helper functions def build_next_block(self, version=4): """Build a block on top of node0's tip.""" tip = self.nodes[0].getbestblockhash() height = self.nodes[0].getblockcount() + 1 block_time = self.nodes[0].getblockheader(tip)["mediantime"] + 1 block = create_block(int(tip, 16), create_coinbase(height), block_time) block.nVersion = version block.rehash() return block def update_witness_block_with_transactions(self, block, tx_list, nonce=0): """Add list of transactions to block, adds witness commitment, then solves.""" block.vtx.extend(tx_list) add_witness_commitment(block, nonce) block.solve() def run_test(self): # Setup the p2p connections # self.test_node sets NODE_WITNESS|NODE_NETWORK self.test_node = self.nodes[0].add_p2p_connection(TestP2PConn(), services=NODE_NETWORK | NODE_WITNESS) # self.old_node sets only NODE_NETWORK self.old_node = self.nodes[0].add_p2p_connection(TestP2PConn(), services=NODE_NETWORK) # self.std_node is for testing node1 (fRequireStandard=true) self.std_node = self.nodes[1].add_p2p_connection(TestP2PConn(), services=NODE_NETWORK | NODE_WITNESS) assert self.test_node.nServices & NODE_WITNESS != 0 # Keep a place to store utxo's that can be used in later tests self.utxo = [] self.log.info("Starting tests before segwit activation") self.segwit_active = False self.test_non_witness_transaction() self.test_v0_outputs_arent_spendable() self.test_block_relay() self.test_getblocktemplate_before_lockin() self.test_unnecessary_witness_before_segwit_activation() self.test_witness_tx_relay_before_segwit_activation() self.test_standardness_v0() self.log.info("Advancing to segwit activation") self.advance_to_segwit_active() # Segwit status 'active' self.test_p2sh_witness() self.test_witness_commitments() self.test_block_malleability() self.test_witness_block_size() self.test_submit_block() self.test_extra_witness_data() self.test_max_witness_push_length() self.test_max_witness_program_length() self.test_witness_input_length() self.test_block_relay() self.test_tx_relay_after_segwit_activation() self.test_standardness_v0() self.test_segwit_versions() self.test_premature_coinbase_witness_spend() self.test_uncompressed_pubkey() self.test_signature_version_1() self.test_non_standard_witness_blinding() self.test_non_standard_witness() self.test_upgrade_after_activation() self.test_witness_sigops() self.test_superfluous_witness() # Individual tests def subtest(func): # noqa: N805 """Wraps the subtests for logging and state assertions.""" def func_wrapper(self, *args, **kwargs): self.log.info("Subtest: {} (Segwit active = {})".format(func.__name__, self.segwit_active)) # Assert segwit status is as expected assert_equal(softfork_active(self.nodes[0], 'segwit'), self.segwit_active) func(self, *args, **kwargs) # Each subtest should leave some utxos for the next subtest assert self.utxo self.sync_blocks() # Assert segwit status is as expected at end of subtest assert_equal(softfork_active(self.nodes[0], 'segwit'), self.segwit_active) return func_wrapper @subtest def test_non_witness_transaction(self): """See if sending a regular transaction works, and create a utxo to use in later tests.""" # Mine a block with an anyone-can-spend coinbase, # let it mature, then try to spend it. block = self.build_next_block(version=1) block.solve() self.test_node.send_message(msg_no_witness_block(block)) self.test_node.sync_with_ping() # make sure the block was processed txid = block.vtx[0].sha256 self.nodes[0].generate(99) # let the block mature # Create a transaction that spends the coinbase tx = CTransaction() tx.vin.append(CTxIn(COutPoint(txid, 0), b"")) tx.vout.append(CTxOut(49 * 100000000, CScript([OP_TRUE, OP_DROP] * 15 + [OP_TRUE]))) tx.calc_sha256() # Check that serializing it with or without witness is the same # This is a sanity check of our testing framework. assert_equal(msg_tx(tx).serialize(), msg_witness_tx(tx).serialize()) self.test_node.send_message(msg_witness_tx(tx)) self.test_node.sync_with_ping() # make sure the tx was processed assert tx.hash in self.nodes[0].getrawmempool() # Save this transaction for later self.utxo.append(UTXO(tx.sha256, 0, 49 * 100000000)) self.nodes[0].generate(1) @subtest def test_unnecessary_witness_before_segwit_activation(self): """Verify that blocks with witnesses are rejected before activation.""" tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) tx.vout.append(CTxOut(self.utxo[0].nValue - 1000, CScript([OP_TRUE]))) tx.wit.vtxinwit.append(CTxInWitness()) tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([CScriptNum(1)])] # Verify the hash with witness differs from the txid # (otherwise our testing framework must be broken!) tx.rehash() assert tx.sha256 != tx.calc_sha256(with_witness=True) # Construct a segwit-signaling block that includes the transaction. block = self.build_next_block(version=(VB_TOP_BITS | (1 << VB_WITNESS_BIT))) self.update_witness_block_with_transactions(block, [tx]) # Sending witness data before activation is not allowed (anti-spam # rule). test_witness_block(self.nodes[0], self.test_node, block, accepted=False, reason='unexpected-witness') # But it should not be permanently marked bad... # Resend without witness information. self.test_node.send_message(msg_no_witness_block(block)) self.test_node.sync_with_ping() assert_equal(self.nodes[0].getbestblockhash(), block.hash) # Update our utxo list; we spent the first entry. self.utxo.pop(0) self.utxo.append(UTXO(tx.sha256, 0, tx.vout[0].nValue)) @subtest def test_block_relay(self): """Test that block requests to NODE_WITNESS peer are with MSG_WITNESS_FLAG. This is true regardless of segwit activation. Also test that we don't ask for blocks from unupgraded peers.""" blocktype = 2 | MSG_WITNESS_FLAG # test_node has set NODE_WITNESS, so all getdata requests should be for # witness blocks. # Test announcing a block via inv results in a getdata, and that # announcing a version 4 or random VB block with a header results in a getdata block1 = self.build_next_block() block1.solve() self.test_node.announce_block_and_wait_for_getdata(block1, use_header=False) assert self.test_node.last_message["getdata"].inv[0].type == blocktype test_witness_block(self.nodes[0], self.test_node, block1, True) block2 = self.build_next_block(version=4) block2.solve() self.test_node.announce_block_and_wait_for_getdata(block2, use_header=True) assert self.test_node.last_message["getdata"].inv[0].type == blocktype test_witness_block(self.nodes[0], self.test_node, block2, True) block3 = self.build_next_block(version=(VB_TOP_BITS | (1 << 15))) block3.solve() self.test_node.announce_block_and_wait_for_getdata(block3, use_header=True) assert self.test_node.last_message["getdata"].inv[0].type == blocktype test_witness_block(self.nodes[0], self.test_node, block3, True) # Check that we can getdata for witness blocks or regular blocks, # and the right thing happens. if not self.segwit_active: # Before activation, we should be able to request old blocks with # or without witness, and they should be the same. chain_height = self.nodes[0].getblockcount() # Pick 10 random blocks on main chain, and verify that getdata's # for MSG_BLOCK, MSG_WITNESS_BLOCK, and rpc getblock() are equal. all_heights = list(range(chain_height + 1)) random.shuffle(all_heights) all_heights = all_heights[0:10] for height in all_heights: block_hash = self.nodes[0].getblockhash(height) rpc_block = self.nodes[0].getblock(block_hash, False) block_hash = int(block_hash, 16) block = self.test_node.request_block(block_hash, 2) wit_block = self.test_node.request_block(block_hash, 2 | MSG_WITNESS_FLAG) assert_equal(block.serialize(), wit_block.serialize()) assert_equal(block.serialize(), hex_str_to_bytes(rpc_block)) else: # After activation, witness blocks and non-witness blocks should # be different. Verify rpc getblock() returns witness blocks, while # getdata respects the requested type. block = self.build_next_block() self.update_witness_block_with_transactions(block, []) # This gives us a witness commitment. assert len(block.vtx[0].wit.vtxinwit) == 1 assert len(block.vtx[0].wit.vtxinwit[0].scriptWitness.stack) == 1 test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Now try to retrieve it... rpc_block = self.nodes[0].getblock(block.hash, False) non_wit_block = self.test_node.request_block(block.sha256, 2) wit_block = self.test_node.request_block(block.sha256, 2 | MSG_WITNESS_FLAG) assert_equal(wit_block.serialize(), hex_str_to_bytes(rpc_block)) assert_equal(wit_block.serialize(False), non_wit_block.serialize()) assert_equal(wit_block.serialize(), block.serialize()) # Test size, vsize, weight rpc_details = self.nodes[0].getblock(block.hash, True) assert_equal(rpc_details["size"], len(block.serialize())) assert_equal(rpc_details["strippedsize"], len(block.serialize(False))) weight = 3 * len(block.serialize(False)) + len(block.serialize()) assert_equal(rpc_details["weight"], weight) # Upgraded node should not ask for blocks from unupgraded block4 = self.build_next_block(version=4) block4.solve() self.old_node.getdataset = set() # Blocks can be requested via direct-fetch (immediately upon processing the announcement) # or via parallel download (with an indeterminate delay from processing the announcement) # so to test that a block is NOT requested, we could guess a time period to sleep for, # and then check. We can avoid the sleep() by taking advantage of transaction getdata's # being processed after block getdata's, and announce a transaction as well, # and then check to see if that particular getdata has been received. # Since 0.14, inv's will only be responded to with a getheaders, so send a header # to announce this block. msg = msg_headers() msg.headers = [CBlockHeader(block4)] self.old_node.send_message(msg) self.old_node.announce_tx_and_wait_for_getdata(block4.vtx[0]) assert block4.sha256 not in self.old_node.getdataset @subtest def test_v0_outputs_arent_spendable(self): """Test that v0 outputs aren't spendable before segwit activation. ~6 months after segwit activation, the SCRIPT_VERIFY_WITNESS flag was backdated so that it applies to all blocks, going back to the genesis block. Consequently, version 0 witness outputs are never spendable without witness, and so can't be spent before segwit activation (the point at which blocks are permitted to contain witnesses).""" # node2 doesn't need to be connected for this test. # (If it's connected, node0 may propagate an invalid block to it over # compact blocks and the nodes would have inconsistent tips.) disconnect_nodes(self.nodes[0], 2) # Create two outputs, a p2wsh and p2sh-p2wsh witness_program = CScript([OP_TRUE]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) p2sh_pubkey = hash160(script_pubkey) p2sh_script_pubkey = CScript([OP_HASH160, p2sh_pubkey, OP_EQUAL]) value = self.utxo[0].nValue // 3 tx = CTransaction() tx.vin = [CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b'')] tx.vout = [CTxOut(value, script_pubkey), CTxOut(value, p2sh_script_pubkey)] tx.vout.append(CTxOut(value, CScript([OP_TRUE]))) tx.rehash() txid = tx.sha256 # Add it to a block block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx]) # Verify that segwit isn't activated. A block serialized with witness # should be rejected prior to activation. test_witness_block(self.nodes[0], self.test_node, block, accepted=False, with_witness=True, reason='unexpected-witness') # Now send the block without witness. It should be accepted test_witness_block(self.nodes[0], self.test_node, block, accepted=True, with_witness=False) # Now try to spend the outputs. This should fail since SCRIPT_VERIFY_WITNESS is always enabled. p2wsh_tx = CTransaction() p2wsh_tx.vin = [CTxIn(COutPoint(txid, 0), b'')] p2wsh_tx.vout = [CTxOut(value, CScript([OP_TRUE]))] p2wsh_tx.wit.vtxinwit.append(CTxInWitness()) p2wsh_tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([OP_TRUE])] p2wsh_tx.rehash() p2sh_p2wsh_tx = CTransaction() p2sh_p2wsh_tx.vin = [CTxIn(COutPoint(txid, 1), CScript([script_pubkey]))] p2sh_p2wsh_tx.vout = [CTxOut(value, CScript([OP_TRUE]))] p2sh_p2wsh_tx.wit.vtxinwit.append(CTxInWitness()) p2sh_p2wsh_tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([OP_TRUE])] p2sh_p2wsh_tx.rehash() for tx in [p2wsh_tx, p2sh_p2wsh_tx]: block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx]) # When the block is serialized with a witness, the block will be rejected because witness # data isn't allowed in blocks that don't commit to witness data. test_witness_block(self.nodes[0], self.test_node, block, accepted=False, with_witness=True, reason='unexpected-witness') # When the block is serialized without witness, validation fails because the transaction is # invalid (transactions are always validated with SCRIPT_VERIFY_WITNESS so a segwit v0 transaction # without a witness is invalid). # Note: The reject reason for this failure could be # 'block-validation-failed' (if script check threads > 1) or # 'non-mandatory-script-verify-flag (Witness program was passed an # empty witness)' (otherwise). # TODO: support multiple acceptable reject reasons. test_witness_block(self.nodes[0], self.test_node, block, accepted=False, with_witness=False) connect_nodes(self.nodes[0], 2) self.utxo.pop(0) self.utxo.append(UTXO(txid, 2, value)) @subtest def test_getblocktemplate_before_lockin(self): txid = int(self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), 1), 16) for node in [self.nodes[0], self.nodes[2]]: gbt_results = node.getblocktemplate({"rules": ["segwit"]}) if node == self.nodes[2]: # If this is a non-segwit node, we should not get a witness # commitment. assert 'default_witness_commitment' not in gbt_results else: # For segwit-aware nodes, check the witness # commitment is correct. assert 'default_witness_commitment' in gbt_results witness_commitment = gbt_results['default_witness_commitment'] # Check that default_witness_commitment is present. witness_root = CBlock.get_merkle_root([ser_uint256(0), ser_uint256(txid)]) script = get_witness_script(witness_root, 0) assert_equal(witness_commitment, script.hex()) # Clear out the mempool self.nodes[0].generate(1) self.sync_blocks() @subtest def test_witness_tx_relay_before_segwit_activation(self): # Generate a transaction that doesn't require a witness, but send it # with a witness. Should be rejected for premature-witness, but should # not be added to recently rejected list. tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) tx.vout.append(CTxOut(self.utxo[0].nValue - 1000, CScript([OP_TRUE, OP_DROP] * 15 + [OP_TRUE]))) tx.wit.vtxinwit.append(CTxInWitness()) tx.wit.vtxinwit[0].scriptWitness.stack = [b'a'] tx.rehash() tx_hash = tx.sha256 tx_value = tx.vout[0].nValue # Verify that if a peer doesn't set nServices to include NODE_WITNESS, # the getdata is just for the non-witness portion. self.old_node.announce_tx_and_wait_for_getdata(tx) assert self.old_node.last_message["getdata"].inv[0].type == 1 # Since we haven't delivered the tx yet, inv'ing the same tx from # a witness transaction ought not result in a getdata. self.test_node.announce_tx_and_wait_for_getdata(tx, timeout=2, success=False) # Delivering this transaction with witness should fail (no matter who # its from) assert_equal(len(self.nodes[0].getrawmempool()), 0) assert_equal(len(self.nodes[1].getrawmempool()), 0) test_transaction_acceptance(self.nodes[0], self.old_node, tx, with_witness=True, accepted=False) test_transaction_acceptance(self.nodes[0], self.test_node, tx, with_witness=True, accepted=False) # But eliminating the witness should fix it test_transaction_acceptance(self.nodes[0], self.test_node, tx, with_witness=False, accepted=True) # Cleanup: mine the first transaction and update utxo self.nodes[0].generate(1) assert_equal(len(self.nodes[0].getrawmempool()), 0) self.utxo.pop(0) self.utxo.append(UTXO(tx_hash, 0, tx_value)) @subtest def test_standardness_v0(self): """Test V0 txout standardness. V0 segwit outputs and inputs are always standard. V0 segwit inputs may only be mined after activation, but not before.""" witness_program = CScript([OP_TRUE]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) p2sh_pubkey = hash160(witness_program) p2sh_script_pubkey = CScript([OP_HASH160, p2sh_pubkey, OP_EQUAL]) # First prepare a p2sh output (so that spending it will pass standardness) p2sh_tx = CTransaction() p2sh_tx.vin = [CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")] p2sh_tx.vout = [CTxOut(self.utxo[0].nValue - 1000, p2sh_script_pubkey)] p2sh_tx.rehash() # Mine it on test_node to create the confirmed output. test_transaction_acceptance(self.nodes[0], self.test_node, p2sh_tx, with_witness=True, accepted=True) self.nodes[0].generate(1) self.sync_blocks() # Now test standardness of v0 P2WSH outputs. # Start by creating a transaction with two outputs. tx = CTransaction() tx.vin = [CTxIn(COutPoint(p2sh_tx.sha256, 0), CScript([witness_program]))] tx.vout = [CTxOut(p2sh_tx.vout[0].nValue - 10000, script_pubkey)] tx.vout.append(CTxOut(8000, script_pubkey)) # Might burn this later tx.vin[0].nSequence = BIP125_SEQUENCE_NUMBER # Just to have the option to bump this tx from the mempool tx.rehash() # This is always accepted, since the mempool policy is to consider segwit as always active # and thus allow segwit outputs test_transaction_acceptance(self.nodes[1], self.std_node, tx, with_witness=True, accepted=True) # Now create something that looks like a P2PKH output. This won't be spendable. script_pubkey = CScript([OP_0, hash160(witness_hash)]) tx2 = CTransaction() # tx was accepted, so we spend the second output. tx2.vin = [CTxIn(COutPoint(tx.sha256, 1), b"")] tx2.vout = [CTxOut(7000, script_pubkey)] tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[0].scriptWitness.stack = [witness_program] tx2.rehash() test_transaction_acceptance(self.nodes[1], self.std_node, tx2, with_witness=True, accepted=True) # Now update self.utxo for later tests. tx3 = CTransaction() # tx and tx2 were both accepted. Don't bother trying to reclaim the # P2PKH output; just send tx's first output back to an anyone-can-spend. self.sync_mempools([self.nodes[0], self.nodes[1]]) tx3.vin = [CTxIn(COutPoint(tx.sha256, 0), b"")] tx3.vout = [CTxOut(tx.vout[0].nValue - 1000, CScript([OP_TRUE, OP_DROP] * 15 + [OP_TRUE]))] tx3.wit.vtxinwit.append(CTxInWitness()) tx3.wit.vtxinwit[0].scriptWitness.stack = [witness_program] tx3.rehash() if not self.segwit_active: # Just check mempool acceptance, but don't add the transaction to the mempool, since witness is disallowed # in blocks and the tx is impossible to mine right now. assert_equal(self.nodes[0].testmempoolaccept([tx3.serialize_with_witness().hex()]), [{'txid': tx3.hash, 'allowed': True}]) # Create the same output as tx3, but by replacing tx tx3_out = tx3.vout[0] tx3 = tx tx3.vout = [tx3_out] tx3.rehash() assert_equal(self.nodes[0].testmempoolaccept([tx3.serialize_with_witness().hex()]), [{'txid': tx3.hash, 'allowed': True}]) test_transaction_acceptance(self.nodes[0], self.test_node, tx3, with_witness=True, accepted=True) self.nodes[0].generate(1) self.sync_blocks() self.utxo.pop(0) self.utxo.append(UTXO(tx3.sha256, 0, tx3.vout[0].nValue)) assert_equal(len(self.nodes[1].getrawmempool()), 0) @subtest def advance_to_segwit_active(self): """Mine enough blocks to activate segwit.""" assert not softfork_active(self.nodes[0], 'segwit') height = self.nodes[0].getblockcount() self.nodes[0].generate(SEGWIT_HEIGHT - height - 2) assert not softfork_active(self.nodes[0], 'segwit') self.nodes[0].generate(1) assert softfork_active(self.nodes[0], 'segwit') self.segwit_active = True @subtest def test_p2sh_witness(self): """Test P2SH wrapped witness programs.""" # Prepare the p2sh-wrapped witness output witness_program = CScript([OP_DROP, OP_TRUE]) witness_hash = sha256(witness_program) p2wsh_pubkey = CScript([OP_0, witness_hash]) p2sh_witness_hash = hash160(p2wsh_pubkey) script_pubkey = CScript([OP_HASH160, p2sh_witness_hash, OP_EQUAL]) script_sig = CScript([p2wsh_pubkey]) # a push of the redeem script # Fund the P2SH output tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) tx.vout.append(CTxOut(self.utxo[0].nValue - 1000, script_pubkey)) tx.rehash() # Verify mempool acceptance and block validity test_transaction_acceptance(self.nodes[0], self.test_node, tx, with_witness=False, accepted=True) block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True, with_witness=True) self.sync_blocks() # Now test attempts to spend the output. spend_tx = CTransaction() spend_tx.vin.append(CTxIn(COutPoint(tx.sha256, 0), script_sig)) spend_tx.vout.append(CTxOut(tx.vout[0].nValue - 1000, CScript([OP_TRUE]))) spend_tx.rehash() # This transaction should not be accepted into the mempool pre- or # post-segwit. Mempool acceptance will use SCRIPT_VERIFY_WITNESS which # will require a witness to spend a witness program regardless of # segwit activation. Note that older bitcoind's that are not # segwit-aware would also reject this for failing CLEANSTACK. with self.nodes[0].assert_debug_log( expected_msgs=(spend_tx.hash, 'was not accepted: non-mandatory-script-verify-flag (Witness program was passed an empty witness)')): test_transaction_acceptance(self.nodes[0], self.test_node, spend_tx, with_witness=False, accepted=False) # Try to put the witness script in the scriptSig, should also fail. spend_tx.vin[0].scriptSig = CScript([p2wsh_pubkey, b'a']) spend_tx.rehash() with self.nodes[0].assert_debug_log( expected_msgs=(spend_tx.hash, 'was not accepted: mandatory-script-verify-flag-failed (Script evaluated without error but finished with a false/empty top stack element)')): test_transaction_acceptance(self.nodes[0], self.test_node, spend_tx, with_witness=False, accepted=False) # Now put the witness script in the witness, should succeed after # segwit activates. spend_tx.vin[0].scriptSig = script_sig spend_tx.rehash() spend_tx.wit.vtxinwit.append(CTxInWitness()) spend_tx.wit.vtxinwit[0].scriptWitness.stack = [b'a', witness_program] # Verify mempool acceptance test_transaction_acceptance(self.nodes[0], self.test_node, spend_tx, with_witness=True, accepted=True) block = self.build_next_block() self.update_witness_block_with_transactions(block, [spend_tx]) # If we're after activation, then sending this with witnesses should be valid. # This no longer works before activation, because SCRIPT_VERIFY_WITNESS # is always set. # TODO: rewrite this test to make clear that it only works after activation. test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Update self.utxo self.utxo.pop(0) self.utxo.append(UTXO(spend_tx.sha256, 0, spend_tx.vout[0].nValue)) @subtest def test_witness_commitments(self): """Test witness commitments. This test can only be run after segwit has activated.""" # First try a correct witness commitment. block = self.build_next_block() add_witness_commitment(block) block.solve() # Test the test -- witness serialization should be different assert msg_block(block).serialize() != msg_no_witness_block(block).serialize() # This empty block should be valid. test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Try to tweak the nonce block_2 = self.build_next_block() add_witness_commitment(block_2, nonce=28) block_2.solve() # The commitment should have changed! assert block_2.vtx[0].vout[-1] != block.vtx[0].vout[-1] # This should also be valid. test_witness_block(self.nodes[0], self.test_node, block_2, accepted=True) # Now test commitments with actual transactions tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) # Let's construct a witness program witness_program = CScript([OP_TRUE]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) tx.vout.append(CTxOut(self.utxo[0].nValue - 1000, script_pubkey)) tx.rehash() # tx2 will spend tx1, and send back to a regular anyone-can-spend address tx2 = CTransaction() tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b"")) tx2.vout.append(CTxOut(tx.vout[0].nValue - 1000, witness_program)) tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[0].scriptWitness.stack = [witness_program] tx2.rehash() block_3 = self.build_next_block() self.update_witness_block_with_transactions(block_3, [tx, tx2], nonce=1) # Add an extra OP_RETURN output that matches the witness commitment template, # even though it has extra data after the incorrect commitment. # This block should fail. block_3.vtx[0].vout.append(CTxOut(0, CScript([OP_RETURN, WITNESS_COMMITMENT_HEADER + ser_uint256(2), 10]))) block_3.vtx[0].rehash() block_3.hashMerkleRoot = block_3.calc_merkle_root() block_3.rehash() block_3.solve() test_witness_block(self.nodes[0], self.test_node, block_3, accepted=False) # Add a different commitment with different nonce, but in the # right location, and with some funds burned(!). # This should succeed (nValue shouldn't affect finding the # witness commitment). add_witness_commitment(block_3, nonce=0) block_3.vtx[0].vout[0].nValue -= 1 block_3.vtx[0].vout[-1].nValue += 1 block_3.vtx[0].rehash() block_3.hashMerkleRoot = block_3.calc_merkle_root() block_3.rehash() assert len(block_3.vtx[0].vout) == 4 # 3 OP_returns block_3.solve() test_witness_block(self.nodes[0], self.test_node, block_3, accepted=True) # Finally test that a block with no witness transactions can # omit the commitment. block_4 = self.build_next_block() tx3 = CTransaction() tx3.vin.append(CTxIn(COutPoint(tx2.sha256, 0), b"")) tx3.vout.append(CTxOut(tx.vout[0].nValue - 1000, witness_program)) tx3.rehash() block_4.vtx.append(tx3) block_4.hashMerkleRoot = block_4.calc_merkle_root() block_4.solve() test_witness_block(self.nodes[0], self.test_node, block_4, with_witness=False, accepted=True) # Update available utxo's for use in later test. self.utxo.pop(0) self.utxo.append(UTXO(tx3.sha256, 0, tx3.vout[0].nValue)) @subtest def test_block_malleability(self): # Make sure that a block that has too big a virtual size # because of a too-large coinbase witness is not permanently # marked bad. block = self.build_next_block() add_witness_commitment(block) block.solve() block.vtx[0].wit.vtxinwit[0].scriptWitness.stack.append(b'a' * 5000000) assert get_virtual_size(block) > MAX_BLOCK_BASE_SIZE # We can't send over the p2p network, because this is too big to relay # TODO: repeat this test with a block that can be relayed self.nodes[0].submitblock(block.serialize().hex()) assert self.nodes[0].getbestblockhash() != block.hash block.vtx[0].wit.vtxinwit[0].scriptWitness.stack.pop() assert get_virtual_size(block) < MAX_BLOCK_BASE_SIZE self.nodes[0].submitblock(block.serialize().hex()) assert self.nodes[0].getbestblockhash() == block.hash # Now make sure that malleating the witness reserved value doesn't # result in a block permanently marked bad. block = self.build_next_block() add_witness_commitment(block) block.solve() # Change the nonce -- should not cause the block to be permanently # failed block.vtx[0].wit.vtxinwit[0].scriptWitness.stack = [ser_uint256(1)] test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Changing the witness reserved value doesn't change the block hash block.vtx[0].wit.vtxinwit[0].scriptWitness.stack = [ser_uint256(0)] test_witness_block(self.nodes[0], self.test_node, block, accepted=True) @subtest def test_witness_block_size(self): # TODO: Test that non-witness carrying blocks can't exceed 1MB # Skipping this test for now; this is covered in p2p-fullblocktest.py # Test that witness-bearing blocks are limited at ceil(base + wit/4) <= 1MB. block = self.build_next_block() assert len(self.utxo) > 0 # Create a P2WSH transaction. # The witness program will be a bunch of OP_2DROP's, followed by OP_TRUE. # This should give us plenty of room to tweak the spending tx's # virtual size. NUM_DROPS = 200 # 201 max ops per script! NUM_OUTPUTS = 50 witness_program = CScript([OP_2DROP] * NUM_DROPS + [OP_TRUE]) witness_hash = uint256_from_str(sha256(witness_program)) script_pubkey = CScript([OP_0, ser_uint256(witness_hash)]) prevout = COutPoint(self.utxo[0].sha256, self.utxo[0].n) value = self.utxo[0].nValue parent_tx = CTransaction() parent_tx.vin.append(CTxIn(prevout, b"")) child_value = int(value / NUM_OUTPUTS) for i in range(NUM_OUTPUTS): parent_tx.vout.append(CTxOut(child_value, script_pubkey)) parent_tx.vout[0].nValue -= 50000 assert parent_tx.vout[0].nValue > 0 parent_tx.rehash() child_tx = CTransaction() for i in range(NUM_OUTPUTS): child_tx.vin.append(CTxIn(COutPoint(parent_tx.sha256, i), b"")) child_tx.vout = [CTxOut(value - 100000, CScript([OP_TRUE]))] for i in range(NUM_OUTPUTS): child_tx.wit.vtxinwit.append(CTxInWitness()) child_tx.wit.vtxinwit[-1].scriptWitness.stack = [b'a' * 195] * (2 * NUM_DROPS) + [witness_program] child_tx.rehash() self.update_witness_block_with_transactions(block, [parent_tx, child_tx]) vsize = get_virtual_size(block) additional_bytes = (MAX_BLOCK_BASE_SIZE - vsize) * 4 i = 0 while additional_bytes > 0: # Add some more bytes to each input until we hit MAX_BLOCK_BASE_SIZE+1 extra_bytes = min(additional_bytes + 1, 55) block.vtx[-1].wit.vtxinwit[int(i / (2 * NUM_DROPS))].scriptWitness.stack[i % (2 * NUM_DROPS)] = b'a' * (195 + extra_bytes) additional_bytes -= extra_bytes i += 1 block.vtx[0].vout.pop() # Remove old commitment add_witness_commitment(block) block.solve() vsize = get_virtual_size(block) assert_equal(vsize, MAX_BLOCK_BASE_SIZE + 1) # Make sure that our test case would exceed the old max-network-message # limit assert len(block.serialize()) > 2 * 1024 * 1024 test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Now resize the second transaction to make the block fit. cur_length = len(block.vtx[-1].wit.vtxinwit[0].scriptWitness.stack[0]) block.vtx[-1].wit.vtxinwit[0].scriptWitness.stack[0] = b'a' * (cur_length - 1) block.vtx[0].vout.pop() add_witness_commitment(block) block.solve() assert get_virtual_size(block) == MAX_BLOCK_BASE_SIZE test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Update available utxo's self.utxo.pop(0) self.utxo.append(UTXO(block.vtx[-1].sha256, 0, block.vtx[-1].vout[0].nValue)) @subtest def test_submit_block(self): """Test that submitblock adds the nonce automatically when possible.""" block = self.build_next_block() # Try using a custom nonce and then don't supply it. # This shouldn't possibly work. add_witness_commitment(block, nonce=1) block.vtx[0].wit = CTxWitness() # drop the nonce block.solve() self.nodes[0].submitblock(block.serialize().hex()) assert self.nodes[0].getbestblockhash() != block.hash # Now redo commitment with the standard nonce, but let bitcoind fill it in. add_witness_commitment(block, nonce=0) block.vtx[0].wit = CTxWitness() block.solve() self.nodes[0].submitblock(block.serialize().hex()) assert_equal(self.nodes[0].getbestblockhash(), block.hash) # This time, add a tx with non-empty witness, but don't supply # the commitment. block_2 = self.build_next_block() add_witness_commitment(block_2) block_2.solve() # Drop commitment and nonce -- submitblock should not fill in. block_2.vtx[0].vout.pop() block_2.vtx[0].wit = CTxWitness() self.nodes[0].submitblock(block_2.serialize().hex()) # Tip should not advance! assert self.nodes[0].getbestblockhash() != block_2.hash @subtest def test_extra_witness_data(self): """Test extra witness data in a transaction.""" block = self.build_next_block() witness_program = CScript([OP_DROP, OP_TRUE]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) # First try extra witness data on a tx that doesn't require a witness tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) tx.vout.append(CTxOut(self.utxo[0].nValue - 2000, script_pubkey)) tx.vout.append(CTxOut(1000, CScript([OP_TRUE]))) # non-witness output tx.wit.vtxinwit.append(CTxInWitness()) tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([])] tx.rehash() self.update_witness_block_with_transactions(block, [tx]) # Extra witness data should not be allowed. test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Try extra signature data. Ok if we're not spending a witness output. block.vtx[1].wit.vtxinwit = [] block.vtx[1].vin[0].scriptSig = CScript([OP_0]) block.vtx[1].rehash() add_witness_commitment(block) block.solve() test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Now try extra witness/signature data on an input that DOES require a # witness tx2 = CTransaction() tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b"")) # witness output tx2.vin.append(CTxIn(COutPoint(tx.sha256, 1), b"")) # non-witness tx2.vout.append(CTxOut(tx.vout[0].nValue, CScript([OP_TRUE]))) tx2.wit.vtxinwit.extend([CTxInWitness(), CTxInWitness()]) tx2.wit.vtxinwit[0].scriptWitness.stack = [CScript([CScriptNum(1)]), CScript([CScriptNum(1)]), witness_program] tx2.wit.vtxinwit[1].scriptWitness.stack = [CScript([OP_TRUE])] block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx2]) # This has extra witness data, so it should fail. test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Now get rid of the extra witness, but add extra scriptSig data tx2.vin[0].scriptSig = CScript([OP_TRUE]) tx2.vin[1].scriptSig = CScript([OP_TRUE]) tx2.wit.vtxinwit[0].scriptWitness.stack.pop(0) tx2.wit.vtxinwit[1].scriptWitness.stack = [] tx2.rehash() add_witness_commitment(block) block.solve() # This has extra signature data for a witness input, so it should fail. test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Now get rid of the extra scriptsig on the witness input, and verify # success (even with extra scriptsig data in the non-witness input) tx2.vin[0].scriptSig = b"" tx2.rehash() add_witness_commitment(block) block.solve() test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Update utxo for later tests self.utxo.pop(0) self.utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue)) @subtest def test_max_witness_push_length(self): """Test that witness stack can only allow up to 520 byte pushes.""" block = self.build_next_block() witness_program = CScript([OP_DROP, OP_TRUE]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) tx.vout.append(CTxOut(self.utxo[0].nValue - 1000, script_pubkey)) tx.rehash() tx2 = CTransaction() tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b"")) tx2.vout.append(CTxOut(tx.vout[0].nValue - 1000, CScript([OP_TRUE]))) tx2.wit.vtxinwit.append(CTxInWitness()) # First try a 521-byte stack element tx2.wit.vtxinwit[0].scriptWitness.stack = [b'a' * (MAX_SCRIPT_ELEMENT_SIZE + 1), witness_program] tx2.rehash() self.update_witness_block_with_transactions(block, [tx, tx2]) test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Now reduce the length of the stack element tx2.wit.vtxinwit[0].scriptWitness.stack[0] = b'a' * (MAX_SCRIPT_ELEMENT_SIZE) add_witness_commitment(block) block.solve() test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Update the utxo for later tests self.utxo.pop() self.utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue)) @subtest def test_max_witness_program_length(self): """Test that witness outputs greater than 10kB can't be spent.""" MAX_PROGRAM_LENGTH = 10000 # This program is 19 max pushes (9937 bytes), then 64 more opcode-bytes. long_witness_program = CScript([b'a' * 520] * 19 + [OP_DROP] * 63 + [OP_TRUE]) assert len(long_witness_program) == MAX_PROGRAM_LENGTH + 1 long_witness_hash = sha256(long_witness_program) long_script_pubkey = CScript([OP_0, long_witness_hash]) block = self.build_next_block() tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) tx.vout.append(CTxOut(self.utxo[0].nValue - 1000, long_script_pubkey)) tx.rehash() tx2 = CTransaction() tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b"")) tx2.vout.append(CTxOut(tx.vout[0].nValue - 1000, CScript([OP_TRUE]))) tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[0].scriptWitness.stack = [b'a'] * 44 + [long_witness_program] tx2.rehash() self.update_witness_block_with_transactions(block, [tx, tx2]) test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Try again with one less byte in the witness program witness_program = CScript([b'a' * 520] * 19 + [OP_DROP] * 62 + [OP_TRUE]) assert len(witness_program) == MAX_PROGRAM_LENGTH witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) tx.vout[0] = CTxOut(tx.vout[0].nValue, script_pubkey) tx.rehash() tx2.vin[0].prevout.hash = tx.sha256 tx2.wit.vtxinwit[0].scriptWitness.stack = [b'a'] * 43 + [witness_program] tx2.rehash() block.vtx = [block.vtx[0]] self.update_witness_block_with_transactions(block, [tx, tx2]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) self.utxo.pop() self.utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue)) @subtest def test_witness_input_length(self): """Test that vin length must match vtxinwit length.""" witness_program = CScript([OP_DROP, OP_TRUE]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) # Create a transaction that splits our utxo into many outputs tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) value = self.utxo[0].nValue for i in range(10): tx.vout.append(CTxOut(int(value / 10), script_pubkey)) tx.vout[0].nValue -= 1000 assert tx.vout[0].nValue >= 0 block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Try various ways to spend tx that should all break. # This "broken" transaction serializer will not normalize # the length of vtxinwit. class BrokenCTransaction(CTransaction): def serialize_with_witness(self): flags = 0 if not self.wit.is_null(): flags |= 1 r = b"" r += struct.pack(" version 1 transactions # are standard script_pubkey = CScript([CScriptOp(OP_1), witness_hash]) tx2 = CTransaction() tx2.vin = [CTxIn(COutPoint(tx.sha256, 0), b"")] tx2.vout = [CTxOut(tx.vout[0].nValue - 1000, script_pubkey)] tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[0].scriptWitness.stack = [witness_program] tx2.rehash() # Gets accepted to both policy-enforcing nodes and others. test_transaction_acceptance(self.nodes[0], self.test_node, tx2, with_witness=True, accepted=True) test_transaction_acceptance(self.nodes[1], self.std_node, tx2, with_witness=True, accepted=True) temp_utxo.pop() # last entry in temp_utxo was the output we just spent temp_utxo.append(UTXO(tx2.sha256, 0, tx2.vout[0].nValue)) # Spend everything in temp_utxo back to an OP_TRUE output. tx3 = CTransaction() total_value = 0 for i in temp_utxo: tx3.vin.append(CTxIn(COutPoint(i.sha256, i.n), b"")) tx3.wit.vtxinwit.append(CTxInWitness()) total_value += i.nValue tx3.wit.vtxinwit[-1].scriptWitness.stack = [witness_program] tx3.vout.append(CTxOut(total_value - 1000, CScript([OP_TRUE]))) tx3.rehash() # Spending a higher version witness output is not allowed by policy, # even with fRequireStandard=false. test_transaction_acceptance(self.nodes[0], self.test_node, tx3, with_witness=True, accepted=False, reason="reserved for soft-fork upgrades") # Building a block with the transaction must be valid, however. block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx2, tx3]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) self.sync_blocks() # Add utxo to our list self.utxo.append(UTXO(tx3.sha256, 0, tx3.vout[0].nValue)) @subtest def test_premature_coinbase_witness_spend(self): block = self.build_next_block() # Change the output of the block to be a witness output. witness_program = CScript([OP_TRUE]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) block.vtx[0].vout[0].scriptPubKey = script_pubkey # This next line will rehash the coinbase and update the merkle # root, and solve. self.update_witness_block_with_transactions(block, []) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) spend_tx = CTransaction() spend_tx.vin = [CTxIn(COutPoint(block.vtx[0].sha256, 0), b"")] spend_tx.vout = [CTxOut(block.vtx[0].vout[0].nValue, witness_program)] spend_tx.wit.vtxinwit.append(CTxInWitness()) spend_tx.wit.vtxinwit[0].scriptWitness.stack = [witness_program] spend_tx.rehash() # Now test a premature spend. self.nodes[0].generate(98) self.sync_blocks() block2 = self.build_next_block() self.update_witness_block_with_transactions(block2, [spend_tx]) test_witness_block(self.nodes[0], self.test_node, block2, accepted=False) # Advancing one more block should allow the spend. self.nodes[0].generate(1) block2 = self.build_next_block() self.update_witness_block_with_transactions(block2, [spend_tx]) test_witness_block(self.nodes[0], self.test_node, block2, accepted=True) self.sync_blocks() @subtest def test_uncompressed_pubkey(self): """Test uncompressed pubkey validity in segwit transactions. Uncompressed pubkeys are no longer supported in default relay policy, but (for now) are still valid in blocks.""" # Segwit transactions using uncompressed pubkeys are not accepted # under default policy, but should still pass consensus. key = ECKey() key.generate(False) pubkey = key.get_pubkey().get_bytes() assert_equal(len(pubkey), 65) # This should be an uncompressed pubkey utxo = self.utxo.pop(0) # Test 1: P2WPKH # First create a P2WPKH output that uses an uncompressed pubkey pubkeyhash = hash160(pubkey) script_pkh = CScript([OP_0, pubkeyhash]) tx = CTransaction() tx.vin.append(CTxIn(COutPoint(utxo.sha256, utxo.n), b"")) tx.vout.append(CTxOut(utxo.nValue - 1000, script_pkh)) tx.rehash() # Confirm it in a block. block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Now try to spend it. Send it to a P2WSH output, which we'll # use in the next test. witness_program = CScript([pubkey, CScriptOp(OP_CHECKSIG)]) witness_hash = sha256(witness_program) script_wsh = CScript([OP_0, witness_hash]) tx2 = CTransaction() tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b"")) tx2.vout.append(CTxOut(tx.vout[0].nValue - 1000, script_wsh)) script = get_p2pkh_script(pubkeyhash) sig_hash = SegwitVersion1SignatureHash(script, tx2, 0, SIGHASH_ALL, tx.vout[0].nValue) signature = key.sign_ecdsa(sig_hash) + b'\x01' # 0x1 is SIGHASH_ALL tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[0].scriptWitness.stack = [signature, pubkey] tx2.rehash() # Should fail policy test. test_transaction_acceptance(self.nodes[0], self.test_node, tx2, True, False, 'non-mandatory-script-verify-flag (Using non-compressed keys in segwit)') # But passes consensus. block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx2]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Test 2: P2WSH # Try to spend the P2WSH output created in last test. # Send it to a P2SH(P2WSH) output, which we'll use in the next test. p2sh_witness_hash = hash160(script_wsh) script_p2sh = CScript([OP_HASH160, p2sh_witness_hash, OP_EQUAL]) script_sig = CScript([script_wsh]) tx3 = CTransaction() tx3.vin.append(CTxIn(COutPoint(tx2.sha256, 0), b"")) tx3.vout.append(CTxOut(tx2.vout[0].nValue - 1000, script_p2sh)) tx3.wit.vtxinwit.append(CTxInWitness()) sign_p2pk_witness_input(witness_program, tx3, 0, SIGHASH_ALL, tx2.vout[0].nValue, key) # Should fail policy test. test_transaction_acceptance(self.nodes[0], self.test_node, tx3, True, False, 'non-mandatory-script-verify-flag (Using non-compressed keys in segwit)') # But passes consensus. block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx3]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Test 3: P2SH(P2WSH) # Try to spend the P2SH output created in the last test. # Send it to a P2PKH output, which we'll use in the next test. script_pubkey = get_p2pkh_script(pubkeyhash) tx4 = CTransaction() tx4.vin.append(CTxIn(COutPoint(tx3.sha256, 0), script_sig)) tx4.vout.append(CTxOut(tx3.vout[0].nValue - 1000, script_pubkey)) tx4.wit.vtxinwit.append(CTxInWitness()) sign_p2pk_witness_input(witness_program, tx4, 0, SIGHASH_ALL, tx3.vout[0].nValue, key) # Should fail policy test. test_transaction_acceptance(self.nodes[0], self.test_node, tx4, True, False, 'non-mandatory-script-verify-flag (Using non-compressed keys in segwit)') block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx4]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Test 4: Uncompressed pubkeys should still be valid in non-segwit # transactions. tx5 = CTransaction() tx5.vin.append(CTxIn(COutPoint(tx4.sha256, 0), b"")) tx5.vout.append(CTxOut(tx4.vout[0].nValue - 1000, CScript([OP_TRUE]))) (sig_hash, err) = SignatureHash(script_pubkey, tx5, 0, SIGHASH_ALL) signature = key.sign_ecdsa(sig_hash) + b'\x01' # 0x1 is SIGHASH_ALL tx5.vin[0].scriptSig = CScript([signature, pubkey]) tx5.rehash() # Should pass policy and consensus. test_transaction_acceptance(self.nodes[0], self.test_node, tx5, True, True) block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx5]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) self.utxo.append(UTXO(tx5.sha256, 0, tx5.vout[0].nValue)) @subtest def test_signature_version_1(self): key = ECKey() key.generate() pubkey = key.get_pubkey().get_bytes() witness_program = CScript([pubkey, CScriptOp(OP_CHECKSIG)]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) # First create a witness output for use in the tests. tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) tx.vout.append(CTxOut(self.utxo[0].nValue - 1000, script_pubkey)) tx.rehash() test_transaction_acceptance(self.nodes[0], self.test_node, tx, with_witness=True, accepted=True) # Mine this transaction in preparation for following tests. block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) self.sync_blocks() self.utxo.pop(0) # Test each hashtype prev_utxo = UTXO(tx.sha256, 0, tx.vout[0].nValue) for sigflag in [0, SIGHASH_ANYONECANPAY]: for hashtype in [SIGHASH_ALL, SIGHASH_NONE, SIGHASH_SINGLE]: hashtype |= sigflag block = self.build_next_block() tx = CTransaction() tx.vin.append(CTxIn(COutPoint(prev_utxo.sha256, prev_utxo.n), b"")) tx.vout.append(CTxOut(prev_utxo.nValue - 1000, script_pubkey)) tx.wit.vtxinwit.append(CTxInWitness()) # Too-large input value sign_p2pk_witness_input(witness_program, tx, 0, hashtype, prev_utxo.nValue + 1, key) self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Too-small input value sign_p2pk_witness_input(witness_program, tx, 0, hashtype, prev_utxo.nValue - 1, key) block.vtx.pop() # remove last tx self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Now try correct value sign_p2pk_witness_input(witness_program, tx, 0, hashtype, prev_utxo.nValue, key) block.vtx.pop() self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) prev_utxo = UTXO(tx.sha256, 0, tx.vout[0].nValue) # Test combinations of signature hashes. # Split the utxo into a lot of outputs. # Randomly choose up to 10 to spend, sign with different hashtypes, and # output to a random number of outputs. Repeat NUM_SIGHASH_TESTS times. # Ensure that we've tested a situation where we use SIGHASH_SINGLE with # an input index > number of outputs. NUM_SIGHASH_TESTS = 500 temp_utxos = [] tx = CTransaction() tx.vin.append(CTxIn(COutPoint(prev_utxo.sha256, prev_utxo.n), b"")) split_value = prev_utxo.nValue // NUM_SIGHASH_TESTS for i in range(NUM_SIGHASH_TESTS): tx.vout.append(CTxOut(split_value, script_pubkey)) tx.wit.vtxinwit.append(CTxInWitness()) sign_p2pk_witness_input(witness_program, tx, 0, SIGHASH_ALL, prev_utxo.nValue, key) for i in range(NUM_SIGHASH_TESTS): temp_utxos.append(UTXO(tx.sha256, i, split_value)) block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) block = self.build_next_block() used_sighash_single_out_of_bounds = False for i in range(NUM_SIGHASH_TESTS): # Ping regularly to keep the connection alive if (not i % 100): self.test_node.sync_with_ping() # Choose random number of inputs to use. num_inputs = random.randint(1, 10) # Create a slight bias for producing more utxos num_outputs = random.randint(1, 11) random.shuffle(temp_utxos) assert len(temp_utxos) > num_inputs tx = CTransaction() total_value = 0 for i in range(num_inputs): tx.vin.append(CTxIn(COutPoint(temp_utxos[i].sha256, temp_utxos[i].n), b"")) tx.wit.vtxinwit.append(CTxInWitness()) total_value += temp_utxos[i].nValue split_value = total_value // num_outputs for i in range(num_outputs): tx.vout.append(CTxOut(split_value, script_pubkey)) for i in range(num_inputs): # Now try to sign each input, using a random hashtype. anyonecanpay = 0 if random.randint(0, 1): anyonecanpay = SIGHASH_ANYONECANPAY hashtype = random.randint(1, 3) | anyonecanpay sign_p2pk_witness_input(witness_program, tx, i, hashtype, temp_utxos[i].nValue, key) if (hashtype == SIGHASH_SINGLE and i >= num_outputs): used_sighash_single_out_of_bounds = True tx.rehash() for i in range(num_outputs): temp_utxos.append(UTXO(tx.sha256, i, split_value)) temp_utxos = temp_utxos[num_inputs:] block.vtx.append(tx) # Test the block periodically, if we're close to maxblocksize if (get_virtual_size(block) > MAX_BLOCK_BASE_SIZE - 1000): self.update_witness_block_with_transactions(block, []) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) block = self.build_next_block() if (not used_sighash_single_out_of_bounds): self.log.info("WARNING: this test run didn't attempt SIGHASH_SINGLE with out-of-bounds index value") # Test the transactions we've added to the block if (len(block.vtx) > 1): self.update_witness_block_with_transactions(block, []) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) # Now test witness version 0 P2PKH transactions pubkeyhash = hash160(pubkey) script_pkh = CScript([OP_0, pubkeyhash]) tx = CTransaction() tx.vin.append(CTxIn(COutPoint(temp_utxos[0].sha256, temp_utxos[0].n), b"")) tx.vout.append(CTxOut(temp_utxos[0].nValue, script_pkh)) tx.wit.vtxinwit.append(CTxInWitness()) sign_p2pk_witness_input(witness_program, tx, 0, SIGHASH_ALL, temp_utxos[0].nValue, key) tx2 = CTransaction() tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), b"")) tx2.vout.append(CTxOut(tx.vout[0].nValue, CScript([OP_TRUE]))) script = get_p2pkh_script(pubkeyhash) sig_hash = SegwitVersion1SignatureHash(script, tx2, 0, SIGHASH_ALL, tx.vout[0].nValue) signature = key.sign_ecdsa(sig_hash) + b'\x01' # 0x1 is SIGHASH_ALL # Check that we can't have a scriptSig tx2.vin[0].scriptSig = CScript([signature, pubkey]) block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx, tx2]) test_witness_block(self.nodes[0], self.test_node, block, accepted=False) # Move the signature to the witness. block.vtx.pop() tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[0].scriptWitness.stack = [signature, pubkey] tx2.vin[0].scriptSig = b"" tx2.rehash() self.update_witness_block_with_transactions(block, [tx2]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) temp_utxos.pop(0) # Update self.utxos for later tests by creating two outputs # that consolidate all the coins in temp_utxos. output_value = sum(i.nValue for i in temp_utxos) // 2 tx = CTransaction() index = 0 # Just spend to our usual anyone-can-spend output tx.vout = [CTxOut(output_value, CScript([OP_TRUE]))] * 2 for i in temp_utxos: # Use SIGHASH_ALL|SIGHASH_ANYONECANPAY so we can build up # the signatures as we go. tx.vin.append(CTxIn(COutPoint(i.sha256, i.n), b"")) tx.wit.vtxinwit.append(CTxInWitness()) sign_p2pk_witness_input(witness_program, tx, index, SIGHASH_ALL | SIGHASH_ANYONECANPAY, i.nValue, key) index += 1 block = self.build_next_block() self.update_witness_block_with_transactions(block, [tx]) test_witness_block(self.nodes[0], self.test_node, block, accepted=True) for i in range(len(tx.vout)): self.utxo.append(UTXO(tx.sha256, i, tx.vout[i].nValue)) @subtest def test_non_standard_witness_blinding(self): """Test behavior of unnecessary witnesses in transactions does not blind the node for the transaction""" # Create a p2sh output -- this is so we can pass the standardness # rules (an anyone-can-spend OP_TRUE would be rejected, if not wrapped # in P2SH). p2sh_program = CScript([OP_TRUE]) p2sh_pubkey = hash160(p2sh_program) script_pubkey = CScript([OP_HASH160, p2sh_pubkey, OP_EQUAL]) # Now check that unnecessary witnesses can't be used to blind a node # to a transaction, eg by violating standardness checks. tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) tx.vout.append(CTxOut(self.utxo[0].nValue - 1000, script_pubkey)) tx.rehash() test_transaction_acceptance(self.nodes[0], self.test_node, tx, False, True) self.nodes[0].generate(1) self.sync_blocks() # We'll add an unnecessary witness to this transaction that would cause # it to be non-standard, to test that violating policy with a witness # doesn't blind a node to a transaction. Transactions # rejected for having a witness shouldn't be added # to the rejection cache. tx2 = CTransaction() tx2.vin.append(CTxIn(COutPoint(tx.sha256, 0), CScript([p2sh_program]))) tx2.vout.append(CTxOut(tx.vout[0].nValue - 1000, script_pubkey)) tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[0].scriptWitness.stack = [b'a' * 400] tx2.rehash() # This will be rejected due to a policy check: # No witness is allowed, since it is not a witness program but a p2sh program test_transaction_acceptance(self.nodes[1], self.std_node, tx2, True, False, 'bad-witness-nonstandard') # If we send without witness, it should be accepted. test_transaction_acceptance(self.nodes[1], self.std_node, tx2, False, True) # Now create a new anyone-can-spend utxo for the next test. tx3 = CTransaction() tx3.vin.append(CTxIn(COutPoint(tx2.sha256, 0), CScript([p2sh_program]))) tx3.vout.append(CTxOut(tx2.vout[0].nValue - 1000, CScript([OP_TRUE, OP_DROP] * 15 + [OP_TRUE]))) tx3.rehash() test_transaction_acceptance(self.nodes[0], self.test_node, tx2, False, True) test_transaction_acceptance(self.nodes[0], self.test_node, tx3, False, True) self.nodes[0].generate(1) self.sync_blocks() # Update our utxo list; we spent the first entry. self.utxo.pop(0) self.utxo.append(UTXO(tx3.sha256, 0, tx3.vout[0].nValue)) @subtest def test_non_standard_witness(self): """Test detection of non-standard P2WSH witness""" pad = chr(1).encode('latin-1') # Create scripts for tests scripts = [] scripts.append(CScript([OP_DROP] * 100)) scripts.append(CScript([OP_DROP] * 99)) scripts.append(CScript([pad * 59] * 59 + [OP_DROP] * 60)) scripts.append(CScript([pad * 59] * 59 + [OP_DROP] * 61)) p2wsh_scripts = [] tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) # For each script, generate a pair of P2WSH and P2SH-P2WSH output. outputvalue = (self.utxo[0].nValue - 1000) // (len(scripts) * 2) for i in scripts: p2wsh = CScript([OP_0, sha256(i)]) p2sh = hash160(p2wsh) p2wsh_scripts.append(p2wsh) tx.vout.append(CTxOut(outputvalue, p2wsh)) tx.vout.append(CTxOut(outputvalue, CScript([OP_HASH160, p2sh, OP_EQUAL]))) tx.rehash() txid = tx.sha256 test_transaction_acceptance(self.nodes[0], self.test_node, tx, with_witness=False, accepted=True) self.nodes[0].generate(1) self.sync_blocks() # Creating transactions for tests p2wsh_txs = [] p2sh_txs = [] for i in range(len(scripts)): p2wsh_tx = CTransaction() p2wsh_tx.vin.append(CTxIn(COutPoint(txid, i * 2))) p2wsh_tx.vout.append(CTxOut(outputvalue - 5000, CScript([OP_0, hash160(hex_str_to_bytes(""))]))) p2wsh_tx.wit.vtxinwit.append(CTxInWitness()) p2wsh_tx.rehash() p2wsh_txs.append(p2wsh_tx) p2sh_tx = CTransaction() p2sh_tx.vin.append(CTxIn(COutPoint(txid, i * 2 + 1), CScript([p2wsh_scripts[i]]))) p2sh_tx.vout.append(CTxOut(outputvalue - 5000, CScript([OP_0, hash160(hex_str_to_bytes(""))]))) p2sh_tx.wit.vtxinwit.append(CTxInWitness()) p2sh_tx.rehash() p2sh_txs.append(p2sh_tx) # Testing native P2WSH # Witness stack size, excluding witnessScript, over 100 is non-standard p2wsh_txs[0].wit.vtxinwit[0].scriptWitness.stack = [pad] * 101 + [scripts[0]] test_transaction_acceptance(self.nodes[1], self.std_node, p2wsh_txs[0], True, False, 'bad-witness-nonstandard') # Non-standard nodes should accept test_transaction_acceptance(self.nodes[0], self.test_node, p2wsh_txs[0], True, True) # Stack element size over 80 bytes is non-standard p2wsh_txs[1].wit.vtxinwit[0].scriptWitness.stack = [pad * 81] * 100 + [scripts[1]] test_transaction_acceptance(self.nodes[1], self.std_node, p2wsh_txs[1], True, False, 'bad-witness-nonstandard') # Non-standard nodes should accept test_transaction_acceptance(self.nodes[0], self.test_node, p2wsh_txs[1], True, True) # Standard nodes should accept if element size is not over 80 bytes p2wsh_txs[1].wit.vtxinwit[0].scriptWitness.stack = [pad * 80] * 100 + [scripts[1]] test_transaction_acceptance(self.nodes[1], self.std_node, p2wsh_txs[1], True, True) # witnessScript size at 3600 bytes is standard p2wsh_txs[2].wit.vtxinwit[0].scriptWitness.stack = [pad, pad, scripts[2]] test_transaction_acceptance(self.nodes[0], self.test_node, p2wsh_txs[2], True, True) test_transaction_acceptance(self.nodes[1], self.std_node, p2wsh_txs[2], True, True) # witnessScript size at 3601 bytes is non-standard p2wsh_txs[3].wit.vtxinwit[0].scriptWitness.stack = [pad, pad, pad, scripts[3]] test_transaction_acceptance(self.nodes[1], self.std_node, p2wsh_txs[3], True, False, 'bad-witness-nonstandard') # Non-standard nodes should accept test_transaction_acceptance(self.nodes[0], self.test_node, p2wsh_txs[3], True, True) # Repeating the same tests with P2SH-P2WSH p2sh_txs[0].wit.vtxinwit[0].scriptWitness.stack = [pad] * 101 + [scripts[0]] test_transaction_acceptance(self.nodes[1], self.std_node, p2sh_txs[0], True, False, 'bad-witness-nonstandard') test_transaction_acceptance(self.nodes[0], self.test_node, p2sh_txs[0], True, True) p2sh_txs[1].wit.vtxinwit[0].scriptWitness.stack = [pad * 81] * 100 + [scripts[1]] test_transaction_acceptance(self.nodes[1], self.std_node, p2sh_txs[1], True, False, 'bad-witness-nonstandard') test_transaction_acceptance(self.nodes[0], self.test_node, p2sh_txs[1], True, True) p2sh_txs[1].wit.vtxinwit[0].scriptWitness.stack = [pad * 80] * 100 + [scripts[1]] test_transaction_acceptance(self.nodes[1], self.std_node, p2sh_txs[1], True, True) p2sh_txs[2].wit.vtxinwit[0].scriptWitness.stack = [pad, pad, scripts[2]] test_transaction_acceptance(self.nodes[0], self.test_node, p2sh_txs[2], True, True) test_transaction_acceptance(self.nodes[1], self.std_node, p2sh_txs[2], True, True) p2sh_txs[3].wit.vtxinwit[0].scriptWitness.stack = [pad, pad, pad, scripts[3]] test_transaction_acceptance(self.nodes[1], self.std_node, p2sh_txs[3], True, False, 'bad-witness-nonstandard') test_transaction_acceptance(self.nodes[0], self.test_node, p2sh_txs[3], True, True) self.nodes[0].generate(1) # Mine and clean up the mempool of non-standard node # Valid but non-standard transactions in a block should be accepted by standard node self.sync_blocks() assert_equal(len(self.nodes[0].getrawmempool()), 0) assert_equal(len(self.nodes[1].getrawmempool()), 0) self.utxo.pop(0) @subtest def test_upgrade_after_activation(self): """Test the behavior of starting up a segwit-aware node after the softfork has activated.""" # Restart with the new binary self.stop_node(2) self.start_node(2, extra_args=["-segwitheight={}".format(SEGWIT_HEIGHT)]) connect_nodes(self.nodes[0], 2) self.sync_blocks() # Make sure that this peer thinks segwit has activated. assert softfork_active(self.nodes[2], 'segwit') # Make sure this peer's blocks match those of node0. height = self.nodes[2].getblockcount() while height >= 0: block_hash = self.nodes[2].getblockhash(height) assert_equal(block_hash, self.nodes[0].getblockhash(height)) assert_equal(self.nodes[0].getblock(block_hash), self.nodes[2].getblock(block_hash)) height -= 1 @subtest def test_witness_sigops(self): """Test sigop counting is correct inside witnesses.""" # Keep this under MAX_OPS_PER_SCRIPT (201) witness_program = CScript([OP_TRUE, OP_IF, OP_TRUE, OP_ELSE] + [OP_CHECKMULTISIG] * 5 + [OP_CHECKSIG] * 193 + [OP_ENDIF]) witness_hash = sha256(witness_program) script_pubkey = CScript([OP_0, witness_hash]) sigops_per_script = 20 * 5 + 193 * 1 # We'll produce 2 extra outputs, one with a program that would take us # over max sig ops, and one with a program that would exactly reach max # sig ops outputs = (MAX_SIGOP_COST // sigops_per_script) + 2 extra_sigops_available = MAX_SIGOP_COST % sigops_per_script # We chose the number of checkmultisigs/checksigs to make this work: assert extra_sigops_available < 100 # steer clear of MAX_OPS_PER_SCRIPT # This script, when spent with the first # N(=MAX_SIGOP_COST//sigops_per_script) outputs of our transaction, # would push us just over the block sigop limit. witness_program_toomany = CScript([OP_TRUE, OP_IF, OP_TRUE, OP_ELSE] + [OP_CHECKSIG] * (extra_sigops_available + 1) + [OP_ENDIF]) witness_hash_toomany = sha256(witness_program_toomany) script_pubkey_toomany = CScript([OP_0, witness_hash_toomany]) # If we spend this script instead, we would exactly reach our sigop # limit (for witness sigops). witness_program_justright = CScript([OP_TRUE, OP_IF, OP_TRUE, OP_ELSE] + [OP_CHECKSIG] * (extra_sigops_available) + [OP_ENDIF]) witness_hash_justright = sha256(witness_program_justright) script_pubkey_justright = CScript([OP_0, witness_hash_justright]) # First split our available utxo into a bunch of outputs split_value = self.utxo[0].nValue // outputs tx = CTransaction() tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b"")) for i in range(outputs): tx.vout.append(CTxOut(split_value, script_pubkey)) tx.vout[-2].scriptPubKey = script_pubkey_toomany tx.vout[-1].scriptPubKey = script_pubkey_justright tx.rehash() block_1 = self.build_next_block() self.update_witness_block_with_transactions(block_1, [tx]) test_witness_block(self.nodes[0], self.test_node, block_1, accepted=True) tx2 = CTransaction() # If we try to spend the first n-1 outputs from tx, that should be # too many sigops. total_value = 0 for i in range(outputs - 1): tx2.vin.append(CTxIn(COutPoint(tx.sha256, i), b"")) tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[-1].scriptWitness.stack = [witness_program] total_value += tx.vout[i].nValue tx2.wit.vtxinwit[-1].scriptWitness.stack = [witness_program_toomany] tx2.vout.append(CTxOut(total_value, CScript([OP_TRUE]))) tx2.rehash() block_2 = self.build_next_block() self.update_witness_block_with_transactions(block_2, [tx2]) test_witness_block(self.nodes[0], self.test_node, block_2, accepted=False) # Try dropping the last input in tx2, and add an output that has # too many sigops (contributing to legacy sigop count). checksig_count = (extra_sigops_available // 4) + 1 script_pubkey_checksigs = CScript([OP_CHECKSIG] * checksig_count) tx2.vout.append(CTxOut(0, script_pubkey_checksigs)) tx2.vin.pop() tx2.wit.vtxinwit.pop() tx2.vout[0].nValue -= tx.vout[-2].nValue tx2.rehash() block_3 = self.build_next_block() self.update_witness_block_with_transactions(block_3, [tx2]) test_witness_block(self.nodes[0], self.test_node, block_3, accepted=False) # If we drop the last checksig in this output, the tx should succeed. block_4 = self.build_next_block() tx2.vout[-1].scriptPubKey = CScript([OP_CHECKSIG] * (checksig_count - 1)) tx2.rehash() self.update_witness_block_with_transactions(block_4, [tx2]) test_witness_block(self.nodes[0], self.test_node, block_4, accepted=True) # Reset the tip back down for the next test self.sync_blocks() for x in self.nodes: x.invalidateblock(block_4.hash) # Try replacing the last input of tx2 to be spending the last # output of tx block_5 = self.build_next_block() tx2.vout.pop() tx2.vin.append(CTxIn(COutPoint(tx.sha256, outputs - 1), b"")) tx2.wit.vtxinwit.append(CTxInWitness()) tx2.wit.vtxinwit[-1].scriptWitness.stack = [witness_program_justright] tx2.rehash() self.update_witness_block_with_transactions(block_5, [tx2]) test_witness_block(self.nodes[0], self.test_node, block_5, accepted=True) # TODO: test p2sh sigop counting def test_superfluous_witness(self): # Serialization of tx that puts witness flag to 3 always def serialize_with_bogus_witness(tx): flags = 3 r = b"" r += struct.pack("