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1#!/usr/bin/env python3
2# Copyright (c) 2019-present The Bitcoin Core developers
3# Distributed under the MIT software license, see the accompanying
4# file COPYING or http://www.opensource.org/licenses/mit-license.php.
5"""Useful Script constants and utils."""
6import unittest
7
8from copy import deepcopy
9
10from test_framework.messages import (
11    COutPoint,
12    CTransaction,
13    CTxIn,
14    CTxInWitness,
15    CTxOut,
16    ser_compact_size,
17    sha256,
18)
19from test_framework.script import (
20    CScript,
21    OP_0,
22    OP_1,
23    OP_15,
24    OP_16,
25    OP_CHECKMULTISIG,
26    OP_CHECKSIG,
27    OP_DUP,
28    OP_ELSE,
29    OP_ENDIF,
30    OP_EQUAL,
31    OP_EQUALVERIFY,
32    OP_HASH160,
33    OP_IF,
34    OP_RETURN,
35    OP_TRUE,
36    hash160,
37)
38
39from test_framework.util import (
40    assert_greater_than_or_equal,
41    assert_equal,
42)
43
44# Maximum number of potentially executed legacy signature operations in validating a transaction.
45MAX_STD_LEGACY_SIGOPS = 2_500
46
47# Maximum number of sigops per standard P2SH redeemScript.
48MAX_STD_P2SH_SIGOPS = 15
49
50# To prevent a "tx-size-small" policy rule error, a transaction has to have a
51# non-witness size of at least 65 bytes (MIN_STANDARD_TX_NONWITNESS_SIZE in
52# src/policy/policy.h). Considering a Tx with the smallest possible single
53# input (blank, empty scriptSig), and with an output omitting the scriptPubKey,
54# we get to a minimum size of 60 bytes:
55#
56# Tx Skeleton: 4 [Version] + 1 [InCount] + 1 [OutCount] + 4 [LockTime] = 10 bytes
57# Blank Input: 32 [PrevTxHash] + 4 [Index] + 1 [scriptSigLen] + 4 [SeqNo] = 41 bytes
58# Output:      8 [Amount] + 1 [scriptPubKeyLen] = 9 bytes
59#
60# Hence, the scriptPubKey of the single output has to have a size of at
61# least 5 bytes.
62MIN_STANDARD_TX_NONWITNESS_SIZE = 65
63MIN_PADDING = MIN_STANDARD_TX_NONWITNESS_SIZE - 10 - 41 - 9
64assert_equal(MIN_PADDING, 5)
65
66# This script cannot be spent, allowing dust output values under
67# standardness checks
68DUMMY_MIN_OP_RETURN_SCRIPT = CScript([OP_RETURN] + ([OP_0] * (MIN_PADDING - 1)))
69assert_equal(len(DUMMY_MIN_OP_RETURN_SCRIPT), MIN_PADDING)
70
71PAY_TO_ANCHOR = CScript([OP_1, bytes.fromhex("4e73")])
72ANCHOR_ADDRESS = "bcrt1pfeesnyr2tx"
73
74def key_to_p2pk_script(key):
75    key = check_key(key)
76    return CScript([key, OP_CHECKSIG])
77
78
79def keys_to_multisig_script(keys, *, k=None):
80    n = len(keys)
81    if k is None:  # n-of-n multisig by default
82        k = n
83    assert k <= n
84    checked_keys = [check_key(key) for key in keys]
85    return CScript([k] + checked_keys + [n, OP_CHECKMULTISIG])
86
87
88def keyhash_to_p2pkh_script(hash):
89    assert_equal(len(hash), 20)
90    return CScript([OP_DUP, OP_HASH160, hash, OP_EQUALVERIFY, OP_CHECKSIG])
91
92
93def scripthash_to_p2sh_script(hash):
94    assert_equal(len(hash), 20)
95    return CScript([OP_HASH160, hash, OP_EQUAL])
96
97
98def key_to_p2pkh_script(key):
99    key = check_key(key)
100    return keyhash_to_p2pkh_script(hash160(key))
101
102
103def script_to_p2sh_script(script):
104    script = check_script(script)
105    return scripthash_to_p2sh_script(hash160(script))
106
107
108def key_to_p2sh_p2wpkh_script(key):
109    key = check_key(key)
110    p2shscript = CScript([OP_0, hash160(key)])
111    return script_to_p2sh_script(p2shscript)
112
113
114def program_to_witness_script(version, program):
115    if isinstance(program, str):
116        program = bytes.fromhex(program)
117    assert 0 <= version <= 16
118    assert 2 <= len(program) <= 40
119    assert version > 0 or len(program) in [20, 32]
120    return CScript([version, program])
121
122
123def script_to_p2wsh_script(script):
124    script = check_script(script)
125    return program_to_witness_script(0, sha256(script))
126
127
128def key_to_p2wpkh_script(key):
129    key = check_key(key)
130    return program_to_witness_script(0, hash160(key))
131
132
133def script_to_p2sh_p2wsh_script(script):
134    script = check_script(script)
135    p2shscript = CScript([OP_0, sha256(script)])
136    return script_to_p2sh_script(p2shscript)
137
138def bulk_vout(tx, target_vsize):
139    if target_vsize < tx.get_vsize():
140        raise RuntimeError(f"target_vsize {target_vsize} is less than transaction virtual size {tx.get_vsize()}")
141    # determine number of needed padding bytes
142    dummy_vbytes = target_vsize - tx.get_vsize()
143    # compensate for the increase of the compact-size encoded script length
144    # (note that the length encoding of the unpadded output script needs one byte)
145    dummy_vbytes -= len(ser_compact_size(dummy_vbytes)) - 1
146    tx.vout[-1].scriptPubKey = CScript([OP_RETURN] + [OP_1] * dummy_vbytes)
147    assert_equal(tx.get_vsize(), target_vsize)
148
149def output_key_to_p2tr_script(key):
150    assert_equal(len(key), 32)
151    return program_to_witness_script(1, key)
152
153
154def check_key(key):
155    if isinstance(key, str):
156        key = bytes.fromhex(key)  # Assuming this is hex string
157    if isinstance(key, bytes) and (len(key) == 33 or len(key) == 65):
158        return key
159    assert False
160
161
162def check_script(script):
163    if isinstance(script, str):
164        script = bytes.fromhex(script)  # Assuming this is hex string
165    if isinstance(script, bytes) or isinstance(script, CScript):
166        return script
167    assert False
168
169
170def build_malleated_tx_package(*, parent: CTransaction, rebalance_parent_output_amount, child_amount):
171    """
172    Returns a transaction package with valid witness:
173    - Parent transaction whose last output contains a script that has two spending conditions
174    - Two malleated child transactions with same txid but different wtxids because of different witnesses
175
176    Args:
177        parent: Transaction with modifiable outputs. Either unsigned (sign after
178        calling this function) or anyone-can-spend (e.g., MiniWallet's OP_TRUE).
179    """
180    hashlock = hash160(b'Preimage')
181    witness_script = CScript([OP_IF, OP_HASH160, hashlock, OP_EQUAL, OP_ELSE, OP_TRUE, OP_ENDIF])
182    witness_program = sha256(witness_script)
183    script_pubkey = CScript([OP_0, witness_program])
184
185    # Append to the transaction the vout containing the script supporting 2 spending conditions
186    assert_greater_than_or_equal(len(parent.vout), 1)
187    last_output = parent.vout[len(parent.vout) - 1]
188    assert_greater_than_or_equal(last_output.nValue, rebalance_parent_output_amount)
189    last_output.nValue -= rebalance_parent_output_amount
190    parent.vout.append(CTxOut(rebalance_parent_output_amount, script_pubkey))
191
192
193    # Create 2 valid children that differ only in witness data.
194    # 1. Create a new transaction with witness solving first branch
195    child_witness_script = CScript([OP_TRUE])
196    child_witness_program = sha256(child_witness_script)
197    child_script_pubkey = CScript([OP_0, child_witness_program])
198    child_one = CTransaction()
199
200    child_one.vin.append(CTxIn(COutPoint(int(parent.txid_hex, 16), len(parent.vout) - 1), b""))
201    child_one.vout.append(CTxOut(child_amount, child_script_pubkey))
202    child_one.wit.vtxinwit.append(CTxInWitness())
203    child_one.wit.vtxinwit[0].scriptWitness.stack = [b'Preimage', b'\x01', witness_script]
204    # 2. Create another identical transaction with witness solving second branch
205    child_two = deepcopy(child_one)
206    child_two.wit.vtxinwit[0].scriptWitness.stack = [b'', witness_script]
207    return parent, child_one, child_two
208
209
210class TestFrameworkScriptUtil(unittest.TestCase):
211    def test_multisig(self):
212        fake_pubkey = bytes([0]*33)
213        # check correct encoding of P2MS script with n,k <= 16
214        normal_ms_script = keys_to_multisig_script([fake_pubkey]*16, k=15)
215        self.assertEqual(len(normal_ms_script), 1 + 16*34 + 1 + 1)
216        self.assertTrue(normal_ms_script.startswith(bytes([OP_15])))
217        self.assertTrue(normal_ms_script.endswith(bytes([OP_16, OP_CHECKMULTISIG])))
218
219        # check correct encoding of P2MS script with n,k > 16
220        max_ms_script = keys_to_multisig_script([fake_pubkey]*20, k=19)
221        self.assertEqual(len(max_ms_script), 2 + 20*34 + 2 + 1)
222        self.assertTrue(max_ms_script.startswith(bytes([1, 19])))  # using OP_PUSH1
223        self.assertTrue(max_ms_script.endswith(bytes([1, 20, OP_CHECKMULTISIG])))
224

src/wallet/receive.cpp

src/wallet/coinselection.cpp

src/consensus/validation.h

src/primitives/transaction.cpp

src/script/descriptor.cpp

src/bitcoin-cli.cpp

src/rpc/blockchain.cpp

src/rpc/rawtransaction.cpp

src/init.cpp

src/crypto/sha256.cpp

src/consensus/merkle.h

src/consensus/tx_check.h

src/consensus/tx_verify.h

src/policy/feerate.h

src/policy/feerate.cpp

src/primitives/transaction_identifier.h

src/chainparamsbase.h

src/chainparamsbase.cpp

src/util/moneystr.cpp

src/crypto/ripemd160.h

src/crypto/sha1.h

src/crypto/sha512.h

src/crypto/hmac_sha256.h

src/crypto/hmac_sha512.h

src/crypto/hmac_sha256.cpp

src/crypto/hmac_sha512.cpp

src/crypto/hkdf_sha256_32.h

src/crypto/hkdf_sha256_32.cpp

src/support/cleanse.h

src/support/cleanse.cpp

src/crypto/siphash.cpp

src/crypto/muhash.h

src/crypto/chacha20.h

src/crypto/poly1305.h

src/crypto/chacha20poly1305.h

src/crypto/chacha20poly1305.cpp

src/util/chaintype.cpp

src/util/obfuscation.h

src/util/byte_units.h

src/util/overflow.h

src/blockencodings.cpp

src/net_permissions.cpp

src/policy/packages.cpp

src/policy/rbf.cpp

src/policy/truc_policy.cpp

src/policy/ephemeral_policy.cpp

src/policy/settings.cpp

src/policy/policy.cpp

src/node/transaction.cpp

src/node/coin.cpp

src/rpc/client.cpp

src/rpc/external_signer.cpp

src/rpc/request.cpp

src/rpc/server_util.cpp

src/rpc/fees.cpp

src/rpc/output_script.cpp

src/rpc/rawtransaction_util.cpp

src/rpc/rawtransaction_util.h

src/rpc/register.h

src/rpc/request.h

src/rpc/server_util.h

src/rpc/protocol.h

src/rpc/server.h

src/rpc/signmessage.cpp

src/rpc/txoutproof.cpp

src/rpc/util.cpp

src/rpc/util.h

src/wallet/rpc/addresses.cpp

src/wallet/rpc/backup.cpp

src/wallet/rpc/coins.cpp

src/wallet/rpc/encrypt.cpp

src/wallet/rpc/signmessage.cpp

src/wallet/rpc/util.cpp

src/wallet/rpc/util.h

src/wallet/coincontrol.cpp

src/wallet/coincontrol.h

src/wallet/context.cpp

src/wallet/context.h

src/wallet/crypter.cpp

src/wallet/crypter.h

src/wallet/db.cpp

src/wallet/export.cpp

src/wallet/external_signer_scriptpubkeyman.cpp

src/wallet/rpc/spend.cpp

src/wallet/rpc/transactions.cpp

src/wallet/rpc/wallet.cpp

src/wallet/feebumper.cpp

src/wallet/feebumper.h

src/index/base.h

src/index/base.cpp

src/index/txindex.h

src/index/txindex.cpp

src/index/txindex_key.h

src/index/txospenderindex.h

src/index/txospenderindex.cpp

src/index/blockfilterindex.h

src/index/blockfilterindex.cpp

src/index/coinstatsindex.h

src/index/coinstatsindex.cpp

src/index/db_key.h

src/index/disktxpos.h

src/kernel/chain.cpp

src/kernel/chain.h

src/kernel/checks.cpp

src/kernel/checks.h

src/kernel/context.cpp

src/kernel/context.h

src/kernel/cs_main.cpp

src/kernel/cs_main.h

src/kernel/disconnected_transactions.cpp

src/kernel/disconnected_transactions.h

src/kernel/mempool_removal_reason.cpp

src/kernel/mempool_removal_reason.h

src/kernel/coinstats.cpp

src/kernel/coinstats.h

src/kernel/chainparams.cpp

src/kernel/chainparams.h

src/wallet/sqlite.cpp

src/wallet/sqlite.h

src/wallet/transaction.cpp

src/wallet/transaction.h

src/wallet/dump.cpp

src/wallet/dump.h

src/wallet/init.cpp

src/wallet/walletutil.cpp

src/wallet/walletutil.h

src/wallet/wallettool.cpp

src/wallet/wallettool.h

src/wallet/export.h

src/wallet/migrate.cpp

src/wallet/migrate.h

src/wallet/db.h

src/wallet/walletdb.cpp

src/wallet/interfaces.cpp

src/wallet/scriptpubkeyman.cpp

src/wallet/scriptpubkeyman.h

src/kernel/bitcoinkernel.cpp

src/kernel/bitcoinkernel.h

src/kernel/bitcoinkernel_wrapper.h

src/node/chainstate.cpp

src/node/chainstate.h

src/node/blockstorage.cpp

src/node/blockstorage.h

src/node/mempool_persist.cpp

src/node/mempool_persist.h

src/node/utxo_snapshot.cpp

src/node/utxo_snapshot.h

src/node/kernel_notifications.cpp

src/node/kernel_notifications.h

src/node/blockmanager_args.cpp

src/kernel/blockmanager_opts.h

src/util/expected.cpp

src/policy/settings.h

src/util/types.h

src/kernel/messagestartchars.h

src/kernel/warning.h

src/util/exception.h

src/common/license_info.h

src/node/coins_view_args.h

src/node/database_args.h

src/util/batchpriority.h

src/util/ui_change_type.h

src/node/coins_view_args.cpp

src/node/peerman_args.h

src/util/serfloat.h

src/node/blockmanager_args.h

src/node/database_args.cpp

src/util/overloaded.h

src/interfaces/types.h

src/node/chainstatemanager_args.h

src/node/minisketchwrapper.h

src/util/macros.h

src/util/syserror.h

src/common/run_command.h

src/util/bytevectorhash.cpp

src/node/mempool_persist_args.cpp

src/util/exec.h

src/util/rbf.h

src/crypto/hex_base.h

src/node/mempool_persist_args.h

src/interfaces/echo.h

src/util/any.h

src/util/batchpriority.cpp

src/util/threadnames.h

src/node/coin.h

src/node/mempool_args.h

src/util/asmap.h

src/util/bytevectorhash.h

src/node/context.cpp

src/util/insert.h

src/util/readwritefile.h

src/node/peerman_args.cpp

src/node/interface_ui.cpp

src/interfaces/handler.h

src/node/mining_args.h

src/util/hasher.cpp

src/common/init.h

src/kernel/mempool_limits.h

src/common/system.h

src/crypto/sha3.h

src/util/threadinterrupt.cpp

src/node/protocol_version.h

src/util/exception.cpp

src/common/messages.h

src/node/connection_types.cpp

src/util/bip32.h

src/common/license_info.cpp

src/util/stdmutex.h

src/common/run_command.cpp

src/util/check.cpp

src/util/golombrice.h

src/node/types.h

src/node/timeoffsets.h

src/util/readwritefile.cpp

src/util/fastrange.h

src/util/signalinterrupt.h

src/util/task_runner.h

src/util/syserror.cpp

src/common/interfaces.cpp

src/common/types.h

src/util/threadinterrupt.h

src/kernel/chainstatemanager_opts.h

src/node/psbt.h

src/policy/ephemeral_policy.h

src/util/trace.h

src/common/url.cpp

src/kernel/mempool_options.h

src/util/serfloat.cpp

src/kernel/notifications_interface.h

src/node/timeoffsets.cpp

src/node/warnings.cpp

src/util/hash_type.h

src/crypto/hex_base.cpp

src/node/eviction.h

src/util/tokenbucket.h

src/crypto/aes.h

src/common/pcp.h

src/util/feefrac.cpp

src/node/transaction.h

src/util/threadnames.cpp

src/common/signmessage.h

src/util/exec.cpp

src/util/signalinterrupt.cpp

src/clientversion.cpp

src/common/signmessage.cpp

src/compat/assumptions.h

src/compat/byteswap.h

src/deploymentinfo.cpp

src/deploymentinfo.h

src/deploymentstatus.cpp

src/deploymentstatus.h

src/dummywallet.cpp

src/external_signer.h

src/init/bitcoin-gui.cpp

src/init/bitcoin-node.cpp

src/init/bitcoin-qt.cpp

src/init/bitcoin-wallet.cpp

src/init/bitcoind.cpp

src/init/common.h

src/interfaces/init.h

src/interfaces/ipc.h

src/key_io.h

src/logging/categories.h

src/logging/timer.h

src/mapport.h

src/musig.h

src/net_permissions.h

src/netgroup.h

src/netmessagemaker.h

src/node/chainstatemanager_args.cpp

src/node/connection_types.h

src/node/context.h

src/node/interface_ui.h

src/node/mempool_args.cpp

src/node/mining_args.cpp

src/node/minisketchwrapper.cpp

src/node/txreconciliation.h

src/policy/fees/estimator_args.cpp

src/policy/fees/estimator_args.h

src/policy/fees/estimator_man.cpp

src/policy/fees/estimator_man.h

src/policy/packages.h

src/policy/rbf.h

src/policy/truc_policy.h

src/pow.h

src/primitives/block.cpp

src/randomenv.h

src/rest.h

src/script/keyorigin.h

src/script/parsing.cpp

src/script/parsing.h

src/script/script_error.h

src/script/sigcache.cpp

src/script/sigcache.h

src/script/solver.h

src/script/verify_flags.h

src/semaphore_grant.h

src/signet.h

src/span.h

src/support/allocators/secure.h

src/support/allocators/zeroafterfree.h

src/util/tokenpipe.cpp

src/util/translation.h

src/util/vector.h

src/versionbits.h

src/versionbits_impl.h

src/wallet/external_signer_scriptpubkeyman.h

src/wallet/fees.h

src/wallet/load.h

src/wallet/receive.h

src/wallet/rpc/wallet.h

src/wallet/types.h

src/walletinitinterface.h

src/zmq/zmqabstractnotifier.cpp

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