READ THE CODE

Inside Bitcoin

The code behind the network, with room to understand it.

Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server440 file guides

Release published 2026-10-28 · Snapshot fetched 2026-11-01. Latest stable release at fetch time; development branches and Git history are excluded. Only the selected code window and visible folders load here.

12,732 bytes · SHA-256 97f9603301f57d9f… · View upstream ↗

1#!/usr/bin/env python3
2# Copyright (c) 2023-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"""Test sigop limit mempool policy (`-bytespersigop` parameter)"""
6from copy import deepcopy
7from decimal import Decimal
8from math import ceil
9
10from test_framework.messages import (
11    COutPoint,
12    CTransaction,
13    CTxIn,
14    CTxInWitness,
15    CTxOut,
16    WITNESS_SCALE_FACTOR,
17    tx_from_hex,
18)
19from test_framework.script import (
20    CScript,
21    OP_2DUP,
22    OP_CHECKMULTISIG,
23    OP_CHECKSIG,
24    OP_DROP,
25    OP_ENDIF,
26    OP_FALSE,
27    OP_IF,
28    OP_NOT,
29    OP_RETURN,
30    OP_TRUE,
31)
32from test_framework.script_util import (
33    keys_to_multisig_script,
34    script_to_p2wsh_script,
35    script_to_p2sh_script,
36    MAX_STD_LEGACY_SIGOPS,
37    MAX_STD_P2SH_SIGOPS,
38)
39from test_framework.test_framework import BitcoinTestFramework
40from test_framework.util import (
41    assert_equal,
42    assert_greater_than,
43    assert_greater_than_or_equal,
44    assert_not_equal,
45    assert_raises_rpc_error,
46)
47from test_framework.wallet import MiniWallet
48from test_framework.wallet_util import generate_keypair
49
50DEFAULT_BYTES_PER_SIGOP = 20  # default setting
51MAX_PUBKEYS_PER_MULTISIG = 20
52
53class BytesPerSigOpTest(BitcoinTestFramework):
54    def set_test_params(self):
55        self.num_nodes = 1
56
57    def create_p2wsh_spending_tx(self, witness_script, output_script):
58        """Create a 1-input-1-output P2WSH spending transaction with only the
59           witness script in the witness stack and the given output script."""
60        # create P2WSH address and fund it via MiniWallet first
61        fund = self.wallet.send_to(
62            from_node=self.nodes[0],
63            scriptPubKey=script_to_p2wsh_script(witness_script),
64            amount=1000000,
65        )
66
67        # create spending transaction
68        tx = CTransaction()
69        tx.vin = [CTxIn(COutPoint(int(fund["txid"], 16), fund["sent_vout"]))]
70        tx.wit.vtxinwit = [CTxInWitness()]
71        tx.wit.vtxinwit[0].scriptWitness.stack = [bytes(witness_script)]
72        tx.vout = [CTxOut(500000, output_script)]
73        return tx
74
75    def test_sigops_limit(self, bytes_per_sigop, num_sigops):
76        sigop_equivalent_vsize = ceil(num_sigops * bytes_per_sigop / WITNESS_SCALE_FACTOR)
77        self.log.info(f"- {num_sigops} sigops (equivalent size of {sigop_equivalent_vsize} vbytes)")
78
79        # create a template tx with the specified sigop cost in the witness script
80        # (note that the sigops count even though being in a branch that's not executed)
81        num_multisigops = num_sigops // 20
82        num_singlesigops = num_sigops % 20
83        witness_script = CScript(
84            [OP_FALSE, OP_IF] +
85            [OP_CHECKMULTISIG]*num_multisigops +
86            [OP_CHECKSIG]*num_singlesigops +
87            [OP_ENDIF, OP_TRUE]
88        )
89        # use a 256-byte data-push as lower bound in the output script, in order
90        # to avoid having to compensate for tx size changes caused by varying
91        # length serialization sizes (both for scriptPubKey and data-push lengths)
92        tx = self.create_p2wsh_spending_tx(witness_script, CScript([OP_RETURN, b'X'*256]))
93
94        # bump the tx to reach the sigop-limit equivalent size by padding the datacarrier output
95        assert_greater_than_or_equal(sigop_equivalent_vsize, tx.get_vsize())
96        vsize_to_pad = sigop_equivalent_vsize - tx.get_vsize()
97        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b'X'*(256+vsize_to_pad)])
98        assert_equal(sigop_equivalent_vsize, tx.get_vsize())
99
100        res = self.nodes[0].testmempoolaccept([tx.serialize().hex()])[0]
101        assert_equal(res['allowed'], True)
102        assert_equal(sigop_equivalent_vsize, tx.get_vsize())
103        assert_equal(res['vsize'], sigop_equivalent_vsize)
104        assert_equal(res['vsize_adjusted'], sigop_equivalent_vsize)
105        assert_equal(res['vsize_bip141'], tx.get_vsize())
106
107        # increase the tx's vsize to be right above the sigop-limit equivalent size
108        # => tx's vsize in mempool should also grow accordingly
109        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b'X'*(256+vsize_to_pad+1)])
110        res = self.nodes[0].testmempoolaccept([tx.serialize().hex()])[0]
111        assert_equal(res['allowed'], True)
112        assert_equal(sigop_equivalent_vsize + 1, tx.get_vsize())
113        assert_equal(res['vsize'], sigop_equivalent_vsize+1)
114        assert_equal(res['vsize_adjusted'], sigop_equivalent_vsize + 1)
115        assert_equal(res['vsize_bip141'], tx.get_vsize())
116
117        # decrease the tx's vsize to be right below the sigop-limit equivalent size
118        # => tx's vsize in mempool should stick at the sigop-limit equivalent
119        # bytes level, as it is higher than the tx's serialized vsize
120        # (the maximum of both is taken)
121        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b'X'*(256+vsize_to_pad-1)])
122        res = self.nodes[0].testmempoolaccept([tx.serialize().hex()])[0]
123        assert_equal(res['allowed'], True)
124        assert_not_equal(sigop_equivalent_vsize, tx.get_vsize())
125        assert_equal(res['vsize'], sigop_equivalent_vsize)
126        assert_equal(res['vsize_adjusted'], sigop_equivalent_vsize)
127        assert_equal(res['vsize_bip141'], tx.get_vsize())
128
129        # check that the ancestor and descendant size calculations in the mempool
130        # also use the same max(sigop_equivalent_vsize, serialized_vsize) logic
131        # (to keep it simple, we only test the case here where the sigop vsize
132        # is much larger than the serialized vsize, i.e. we create a small child
133        # tx by getting rid of the large padding output)
134        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b'test123'])
135        assert_greater_than(sigop_equivalent_vsize, tx.get_vsize())
136        self.nodes[0].sendrawtransaction(hexstring=tx.serialize().hex(), maxburnamount='1.0')
137
138        # fetch parent tx, which doesn't contain any sigops
139        parent_txid = tx.vin[0].prevout.hash.to_bytes(32, 'big').hex()
140        parent_tx = tx_from_hex(self.nodes[0].getrawtransaction(txid=parent_txid))
141
142        entry_child = self.nodes[0].getmempoolentry(tx.txid_hex)
143        assert_equal(entry_child['descendantcount'], 1)
144        assert_equal(entry_child['descendantsize'], sigop_equivalent_vsize)
145        assert_equal(entry_child['ancestorcount'], 2)
146        assert_equal(entry_child['ancestorsize'], sigop_equivalent_vsize + parent_tx.get_vsize())
147
148        entry_parent = self.nodes[0].getmempoolentry(parent_tx.txid_hex)
149        assert_equal(entry_parent['ancestorcount'], 1)
150        assert_equal(entry_parent['ancestorsize'], parent_tx.get_vsize())
151        assert_equal(entry_parent['descendantcount'], 2)
152        assert_equal(entry_parent['descendantsize'], parent_tx.get_vsize() + sigop_equivalent_vsize)
153
154        tx_hex = tx.serialize().hex()
155        txid = tx.txid_hex
156        self.log.info(f"Pushing padded tx {txid} into mempool for getrawtransaction sigopsize field check")
157        self.nodes[0].sendrawtransaction(hexstring=tx_hex, maxburnamount='1.0')
158        # Fetch with verbosity=1 and assert sigopsize is present and correct
159        raw = self.nodes[0].getrawtransaction(txid, 1)
160        sigop_equivalent_vsize = ceil(num_sigops * bytes_per_sigop / WITNESS_SCALE_FACTOR)
161        assert_equal(raw['vsize_adjusted'], sigop_equivalent_vsize)
162        assert_greater_than(raw['vsize_adjusted'], raw['vsize'])
163
164    def test_sigops_package(self):
165        self.log.info("Test a overly-large sigops-vbyte hits package limits")
166        # Make a 2-transaction package which fails vbyte checks even though
167        # separately they would work.
168        self.restart_node(0, extra_args=["-bytespersigop=5000","-permitbaremultisig=1"])
169
170        def create_bare_multisig_tx(utxo_to_spend=None):
171            _, pubkey = generate_keypair()
172            amount_for_bare = 50000
173            tx_dict = self.wallet.create_self_transfer(fee=Decimal("3"), utxo_to_spend=utxo_to_spend)
174            tx_utxo = tx_dict["new_utxo"]
175            tx = tx_dict["tx"]
176            tx.vout.append(CTxOut(amount_for_bare, keys_to_multisig_script([pubkey], k=1)))
177            tx.vout[0].nValue -= amount_for_bare
178            tx_utxo["txid"] = tx.txid_hex
179            tx_utxo["value"] -= Decimal("0.00005000")
180            return (tx_utxo, tx)
181
182        tx_parent_utxo, tx_parent = create_bare_multisig_tx()
183        _tx_child_utxo, tx_child = create_bare_multisig_tx(tx_parent_utxo)
184
185        # Separately, the parent tx is ok
186        parent_individual_testres = self.nodes[0].testmempoolaccept([tx_parent.serialize().hex()])[0]
187        assert parent_individual_testres["allowed"]
188        max_multisig_vsize = MAX_PUBKEYS_PER_MULTISIG * 5000
189        assert_equal(parent_individual_testres["vsize_adjusted"], max_multisig_vsize)
190
191        # But together, it's exceeding limits in the *package* context. If sigops adjusted vsize wasn't being checked
192        # here, it would get further in validation and give too-large-cluster error instead.
193        packet_test = self.nodes[0].testmempoolaccept([tx_parent.serialize().hex(), tx_child.serialize().hex()])
194        expected_package_error = "too-large-cluster"
195        assert_equal([x["package-error"] for x in packet_test], [expected_package_error] * 2)
196
197        # When we actually try to submit, the parent makes it into the mempool, but the child would exceed cluster vsize limits
198        res = self.nodes[0].submitpackage([tx_parent.serialize().hex(), tx_child.serialize().hex()])
199        assert "too-large-cluster" in res["tx-results"][tx_child.wtxid_hex]["error"]
200        assert tx_parent.txid_hex in self.nodes[0].getrawmempool()
201
202        # Transactions are tiny in weight
203        assert_greater_than(2000, tx_parent.get_weight() + tx_child.get_weight())
204
205    def test_legacy_sigops_stdness(self):
206        self.log.info("Test a transaction with too many legacy sigops in its inputs is non-standard.")
207
208        # Restart with the default settings
209        self.restart_node(0)
210
211        # Create a P2SH script with 15 sigops.
212        _, dummy_pubkey = generate_keypair()
213        packed_redeem_script = [dummy_pubkey]
214        for _ in range(MAX_STD_P2SH_SIGOPS - 1):
215            packed_redeem_script += [OP_2DUP, OP_CHECKSIG, OP_DROP]
216        packed_redeem_script = CScript(packed_redeem_script + [OP_CHECKSIG, OP_NOT])
217        packed_p2sh_script = script_to_p2sh_script(packed_redeem_script)
218
219        # Create enough outputs to reach the sigops limit when spending them all at once.
220        outpoints = []
221        for _ in range(int(MAX_STD_LEGACY_SIGOPS / MAX_STD_P2SH_SIGOPS) + 1):
222            res = self.wallet.send_to(from_node=self.nodes[0], scriptPubKey=packed_p2sh_script, amount=1_000)
223            txid = int.from_bytes(bytes.fromhex(res["txid"]), byteorder="big")
224            outpoints.append(COutPoint(txid, res["sent_vout"]))
225        self.generate(self.nodes[0], 1)
226
227        # Spending all these outputs at once accounts for 2505 legacy sigops and is non-standard.
228        nonstd_tx = CTransaction()
229        nonstd_tx.vin = [CTxIn(op, CScript([b"", packed_redeem_script])) for op in outpoints]
230        nonstd_tx.vout = [CTxOut(0, CScript([OP_RETURN, b""]))]
231        assert_raises_rpc_error(-26, "bad-txns-nonstandard-inputs, non-witness sigops exceed bip54 limit",
232                                        self.nodes[0].sendrawtransaction, nonstd_tx.serialize().hex())
233
234        # Spending one less accounts for 2490 legacy sigops and is standard.
235        std_tx = deepcopy(nonstd_tx)
236        std_tx.vin.pop()
237        self.nodes[0].sendrawtransaction(std_tx.serialize().hex())
238
239        # Make sure the original, non-standard, transaction can be mined.
240        self.generateblock(self.nodes[0], output="raw(42)", transactions=[nonstd_tx.serialize().hex()])
241
242    def run_test(self):
243        self.wallet = MiniWallet(self.nodes[0])
244
245        for bytes_per_sigop in (DEFAULT_BYTES_PER_SIGOP, 43, 81, 165, 327, 649, 1072):
246            if bytes_per_sigop == DEFAULT_BYTES_PER_SIGOP:
247                self.log.info(f"Test default sigops limit setting ({bytes_per_sigop} bytes per sigop)...")
248            else:
249                bytespersigop_parameter = f"-bytespersigop={bytes_per_sigop}"
250                self.log.info(f"Test sigops limit setting {bytespersigop_parameter}...")

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

Independent explanations by MyBitcoinExplorer. Not affiliated with or endorsed by Bitcoin Core. Guides are educational and do not replace the source or its tests.

Bitcoin Core source © its contributors, distributed under the MIT license. Original notices and bundled third-party licenses are retained in the source tree.