#!/usr/bin/env python3 # Copyright (c) 2015-2021 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 BIP65 (CHECKLOCKTIMEVERIFY). Test that the CHECKLOCKTIMEVERIFY soft-fork activates. """ from test_framework.blocktools import ( create_block, create_coinbase, ) from test_framework.messages import ( CTransaction, SEQUENCE_FINAL, msg_block, ) from test_framework.p2p import P2PInterface from test_framework.script import ( CScript, CScriptNum, OP_1NEGATE, OP_CHECKLOCKTIMEVERIFY, OP_DROP, ) from test_framework.test_framework import BitcoinTestFramework from test_framework.util import assert_equal from test_framework.wallet import ( MiniWallet, MiniWalletMode, ) # Helper function to modify a transaction by # 1) prepending a given script to the scriptSig of vin 0 and # 2) (optionally) modify the nSequence of vin 0 and the tx's nLockTime def cltv_modify_tx(tx, prepend_scriptsig, nsequence=None, nlocktime=None): assert_equal(len(tx.vin), 1) if nsequence is not None: tx.vin[0].nSequence = nsequence tx.nLockTime = nlocktime tx.vin[0].scriptSig = CScript(prepend_scriptsig + list(CScript(tx.vin[0].scriptSig))) tx.rehash() def cltv_invalidate(tx, failure_reason): # Modify the signature in vin 0 and nSequence/nLockTime of the tx to fail CLTV # # According to BIP65, OP_CHECKLOCKTIMEVERIFY can fail due the following reasons: # 1) the stack is empty # 2) the top item on the stack is less than 0 # 3) the lock-time type (height vs. timestamp) of the top stack item and the # nLockTime field are not the same # 4) the top stack item is greater than the transaction's nLockTime field # 5) the nSequence field of the txin is 0xffffffff (SEQUENCE_FINAL) assert failure_reason in range(5) scheme = [ # | Script to prepend to scriptSig | nSequence | nLockTime | # +-------------------------------------------------+------------+--------------+ [[OP_CHECKLOCKTIMEVERIFY], None, None], [[OP_1NEGATE, OP_CHECKLOCKTIMEVERIFY, OP_DROP], None, None], [[CScriptNum(100), OP_CHECKLOCKTIMEVERIFY, OP_DROP], 0, 1296688602], # timestamp of genesis block [[CScriptNum(100), OP_CHECKLOCKTIMEVERIFY, OP_DROP], 0, 50], [[CScriptNum(50), OP_CHECKLOCKTIMEVERIFY, OP_DROP], SEQUENCE_FINAL, 50], ][failure_reason] cltv_modify_tx(tx, prepend_scriptsig=scheme[0], nsequence=scheme[1], nlocktime=scheme[2]) def cltv_validate(tx, height): # Modify the signature in vin 0 and nSequence/nLockTime of the tx to pass CLTV scheme = [[CScriptNum(height), OP_CHECKLOCKTIMEVERIFY, OP_DROP], 0, height] cltv_modify_tx(tx, prepend_scriptsig=scheme[0], nsequence=scheme[1], nlocktime=scheme[2]) CLTV_HEIGHT = 111 class BIP65Test(BitcoinTestFramework): def set_test_params(self): self.num_nodes = 1 self.extra_args = [[ f'-testactivationheight=cltv@{CLTV_HEIGHT}', '-whitelist=noban@127.0.0.1', '-par=1', # Use only one script thread to get the exact reject reason for testing '-acceptnonstdtxn=1', # cltv_invalidate is nonstandard ]] self.setup_clean_chain = True self.rpc_timeout = 480 def test_cltv_info(self, *, is_active): assert_equal(self.nodes[0].getblockchaininfo()['softforks']['bip65'], { "active": is_active, "height": CLTV_HEIGHT, "type": "buried", }, ) def run_test(self): peer = self.nodes[0].add_p2p_connection(P2PInterface()) wallet = MiniWallet(self.nodes[0], mode=MiniWalletMode.RAW_OP_TRUE) self.test_cltv_info(is_active=False) self.log.info("Mining %d blocks", CLTV_HEIGHT - 2) self.generate(wallet, 10) self.generate(self.nodes[0], CLTV_HEIGHT - 2 - 10) assert_equal(self.nodes[0].getblockcount(), CLTV_HEIGHT - 2) self.log.info("Test that invalid-according-to-CLTV transactions can still appear in a block") # create one invalid tx per CLTV failure reason (5 in total) and collect them invalid_cltv_txs = [] for i in range(5): spendtx = wallet.create_self_transfer()['tx'] cltv_invalidate(spendtx, i) invalid_cltv_txs.append(spendtx) tip = self.nodes[0].getbestblockhash() block_time = self.nodes[0].getblockheader(tip)['mediantime'] + 1 block = create_block(int(tip, 16), create_coinbase(CLTV_HEIGHT - 1), block_time, version=3, txlist=invalid_cltv_txs) block.solve() self.test_cltv_info(is_active=False) # Not active as of current tip and next block does not need to obey rules peer.send_and_ping(msg_block(block)) self.test_cltv_info(is_active=True) # Not active as of current tip, but next block must obey rules assert_equal(self.nodes[0].getbestblockhash(), block.hash) self.log.info("Test that blocks must now be at least version 4") tip = block.sha256 block_time += 1 block = create_block(tip, create_coinbase(CLTV_HEIGHT), block_time, version=3) block.solve() with self.nodes[0].assert_debug_log(expected_msgs=[f'{block.hash}, bad-version(0x00000003)']): peer.send_and_ping(msg_block(block)) assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip) peer.sync_with_ping() self.log.info("Test that invalid-according-to-CLTV transactions cannot appear in a block") block.nVersion = 4 block.vtx.append(CTransaction()) # dummy tx after coinbase that will be replaced later # create and test one invalid tx per CLTV failure reason (5 in total) for i in range(5): spendtx = wallet.create_self_transfer()['tx'] cltv_invalidate(spendtx, i) expected_cltv_reject_reason = [ "non-mandatory-script-verify-flag (Operation not valid with the current stack size)", "non-mandatory-script-verify-flag (Negative locktime)", "non-mandatory-script-verify-flag (Locktime requirement not satisfied)", "non-mandatory-script-verify-flag (Locktime requirement not satisfied)", "non-mandatory-script-verify-flag (Locktime requirement not satisfied)", ][i] # First we show that this tx is valid except for CLTV by getting it # rejected from the mempool for exactly that reason. assert_equal( [{ 'txid': spendtx.hash, 'wtxid': spendtx.getwtxid(), 'allowed': False, 'reject-reason': expected_cltv_reject_reason, }], self.nodes[0].testmempoolaccept(rawtxs=[spendtx.serialize().hex()], maxfeerate=0), ) # Now we verify that a block with this transaction is also invalid. block.vtx[1] = spendtx block.hashMerkleRoot = block.calc_merkle_root() block.solve() with self.nodes[0].assert_debug_log(expected_msgs=[f'CheckInputScripts on {block.vtx[-1].hash} failed with {expected_cltv_reject_reason}']): peer.send_and_ping(msg_block(block)) assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip) peer.sync_with_ping() self.log.info("Test that a version 4 block with a valid-according-to-CLTV transaction is accepted") cltv_validate(spendtx, CLTV_HEIGHT - 1) block.vtx.pop(1) block.vtx.append(spendtx) block.hashMerkleRoot = block.calc_merkle_root() block.solve() self.test_cltv_info(is_active=True) # Not active as of current tip, but next block must obey rules peer.send_and_ping(msg_block(block)) self.test_cltv_info(is_active=True) # Active as of current tip assert_equal(int(self.nodes[0].getbestblockhash(), 16), block.sha256) if __name__ == '__main__': BIP65Test().main()