#include <consensus/consensus.h>
#include <policy/feerate.h>
#include <script/interpreter.h>
#include <script/standard.h>
#include <string>

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Functions
CAmount	GetDustThreshold (const CTxOut &txout, const CFeeRate &dustRelayFee)

bool	IsDust (const CTxOut &txout, const CFeeRate &dustRelayFee)

bool	IsStandard (const CScript &scriptPubKey, TxoutType &whichType)

bool	IsStandardTx (const CTransaction &tx, bool permit_bare_multisig, const CFeeRate &dust_relay_fee, std::string &reason)
	Check for standard transaction types. More...

bool	AreInputsStandard (const CTransaction &tx, const CCoinsViewCache &mapInputs, bool taproot_active)
	Check for standard transaction types. More...

bool	IsWitnessStandard (const CTransaction &tx, const CCoinsViewCache &mapInputs)
	Check if the transaction is over standard P2WSH resources limit: 3600bytes witnessScript size, 80bytes per witness stack element, 100 witness stack elements These limits are adequate for multisignatures up to n-of-100 using OP_CHECKSIG, OP_ADD, and OP_EQUAL. More...

int64_t	GetVirtualTransactionSize (int64_t nWeight, int64_t nSigOpCost, unsigned int bytes_per_sigop)
	Compute the virtual transaction size (weight reinterpreted as bytes). More...

int64_t	GetVirtualTransactionSize (const CTransaction &tx, int64_t nSigOpCost, unsigned int bytes_per_sigop)

int64_t	GetVirtualTransactionInputSize (const CTxIn &tx, int64_t nSigOpCost, unsigned int bytes_per_sigop)

static int64_t	GetVirtualTransactionSize (const CTransaction &tx)

static int64_t	GetVirtualTransactionInputSize (const CTxIn &tx)

Variables
static const unsigned int	DEFAULT_BLOCK_MAX_WEIGHT = MAX_BLOCK_WEIGHT - 4000
	Default for -blockmaxweight, which controls the range of block weights the mining code will create. More...

static const unsigned int	DEFAULT_BLOCK_MIN_TX_FEE = 1000
	Default for -blockmintxfee, which sets the minimum feerate for a transaction in blocks created by mining code. More...

static const unsigned int	MAX_STANDARD_TX_WEIGHT = 400000
	The maximum weight for transactions we're willing to relay/mine. More...

static const unsigned int	MIN_STANDARD_TX_NONWITNESS_SIZE = 82
	The minimum non-witness size for transactions we're willing to relay/mine (1 segwit input + 1 P2WPKH output = 82 bytes) More...

static const unsigned int	MAX_P2SH_SIGOPS = 15
	Maximum number of signature check operations in an IsStandard() P2SH script. More...

static const unsigned int	MAX_STANDARD_TX_SIGOPS_COST = MAX_BLOCK_SIGOPS_COST/5
	The maximum number of sigops we're willing to relay/mine in a single tx. More...

static const unsigned int	DEFAULT_MAX_MEMPOOL_SIZE = 300
	Default for -maxmempool, maximum megabytes of mempool memory usage. More...

static const unsigned int	DEFAULT_INCREMENTAL_RELAY_FEE = 1000
	Default for -incrementalrelayfee, which sets the minimum feerate increase for mempool limiting or BIP 125 replacement. More...

static const unsigned int	DEFAULT_BYTES_PER_SIGOP = 20
	Default for -bytespersigop. More...

static const bool	DEFAULT_PERMIT_BAREMULTISIG = true
	Default for -permitbaremultisig. More...

static const unsigned int	MAX_STANDARD_P2WSH_STACK_ITEMS = 100
	The maximum number of witness stack items in a standard P2WSH script. More...

static const unsigned int	MAX_STANDARD_P2WSH_STACK_ITEM_SIZE = 80
	The maximum size in bytes of each witness stack item in a standard P2WSH script. More...

static const unsigned int	MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE = 80
	The maximum size in bytes of each witness stack item in a standard BIP 342 script (Taproot, leaf version 0xc0) More...

static const unsigned int	MAX_STANDARD_P2WSH_SCRIPT_SIZE = 3600
	The maximum size in bytes of a standard witnessScript. More...

static const unsigned int	MAX_STANDARD_SCRIPTSIG_SIZE = 1650
	The maximum size of a standard ScriptSig. More...

static const unsigned int	DUST_RELAY_TX_FEE = 3000
	Min feerate for defining dust. More...

static constexpr unsigned int	STANDARD_SCRIPT_VERIFY_FLAGS
	Standard script verification flags that standard transactions will comply with. More...

static constexpr unsigned int	STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS
	For convenience, standard but not mandatory verify flags. More...

static constexpr unsigned int	STANDARD_LOCKTIME_VERIFY_FLAGS
	Used as the flags parameter to sequence and nLocktime checks in non-consensus code. More...

static decltype(CTransaction::nVersion) constexpr	TX_MAX_STANDARD_VERSION {2}

Function Documentation

◆ AreInputsStandard()

bool AreInputsStandard	(	const CTransaction &	tx,
		const CCoinsViewCache &	mapInputs,
		bool	taproot_active
	)

Check for standard transaction types.

Parameters

[in]	mapInputs	Map of previous transactions that have outputs we're spending
[in]	taproot_active	Whether or taproot consensus rules are active (used to decide whether spends of them are permitted)

Returns: True if all inputs (scriptSigs) use only standard transaction forms

Check for standard transaction types.

scriptSigs with extra data stuffed into them, not consumed by scriptPubKey (or P2SH script)
P2SH scripts with a crazy number of expensive CHECKSIG/CHECKMULTISIG operations

Why bother? To avoid denial-of-service attacks; an attacker can submit a standard HASH... OP_EQUAL transaction, which will get accepted into blocks. The redemption script can be anything; an attacker could use a very expensive-to-check-upon-redemption script like: DUP CHECKSIG DROP ... repeated 100 times... OP_1

Note that only the non-witness portion of the transaction is checked here.

Definition at line 159 of file policy.cpp.

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◆ GetDustThreshold()

CAmount GetDustThreshold	(	const CTxOut &	txout,
		const CFeeRate &	dustRelayFee
	)

Definition at line 14 of file policy.cpp.

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◆ GetVirtualTransactionInputSize() [1/2]

int64_t GetVirtualTransactionInputSize	(	const CTxIn &	tx,
		int64_t	nSigOpCost,
		unsigned int	bytes_per_sigop
	)

Definition at line 290 of file policy.cpp.

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◆ GetVirtualTransactionInputSize() [2/2]

static int64_t GetVirtualTransactionInputSize ( const CTxIn & tx )

inlinestatic

Definition at line 131 of file policy.h.

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◆ GetVirtualTransactionSize() [1/3]

int64_t GetVirtualTransactionSize	(	int64_t	nWeight,
		int64_t	nSigOpCost,
		unsigned int	bytes_per_sigop
	)

Compute the virtual transaction size (weight reinterpreted as bytes).

Definition at line 280 of file policy.cpp.

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◆ GetVirtualTransactionSize() [2/3]

int64_t GetVirtualTransactionSize	(	const CTransaction &	tx,
		int64_t	nSigOpCost,
		unsigned int	bytes_per_sigop
	)

Definition at line 285 of file policy.cpp.

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◆ GetVirtualTransactionSize() [3/3]

static int64_t GetVirtualTransactionSize ( const CTransaction & tx )

inlinestatic

Definition at line 126 of file policy.h.

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◆ IsDust()

bool IsDust	(	const CTxOut &	txout,
		const CFeeRate &	dustRelayFee
	)

Definition at line 48 of file policy.cpp.

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◆ IsStandard()

bool IsStandard	(	const CScript &	scriptPubKey,
		TxoutType &	whichType
	)

Definition at line 53 of file policy.cpp.

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◆ IsStandardTx()

bool IsStandardTx	(	const CTransaction &	tx,
		bool	permit_bare_multisig,
		const CFeeRate &	dust_relay_fee,
		std::string &	reason
	)

Check for standard transaction types.

Returns: True if all outputs (scriptPubKeys) use only standard transaction forms

Definition at line 76 of file policy.cpp.

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◆ IsWitnessStandard()

bool IsWitnessStandard	(	const CTransaction &	tx,
		const CCoinsViewCache &	mapInputs
	)

Check if the transaction is over standard P2WSH resources limit: 3600bytes witnessScript size, 80bytes per witness stack element, 100 witness stack elements These limits are adequate for multisignatures up to n-of-100 using OP_CHECKSIG, OP_ADD, and OP_EQUAL.

Also enforce a maximum stack item size limit and no annexes for tapscript spends.

Definition at line 196 of file policy.cpp.

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Variable Documentation

◆ DEFAULT_BLOCK_MAX_WEIGHT

const unsigned int DEFAULT_BLOCK_MAX_WEIGHT = MAX_BLOCK_WEIGHT - 4000

static

Default for -blockmaxweight, which controls the range of block weights the mining code will create.

Definition at line 20 of file policy.h.

◆ DEFAULT_BLOCK_MIN_TX_FEE

const unsigned int DEFAULT_BLOCK_MIN_TX_FEE = 1000

static

Default for -blockmintxfee, which sets the minimum feerate for a transaction in blocks created by mining code.

Definition at line 22 of file policy.h.

◆ DEFAULT_BYTES_PER_SIGOP

const unsigned int DEFAULT_BYTES_PER_SIGOP = 20

static

Default for -bytespersigop.

Definition at line 36 of file policy.h.

◆ DEFAULT_INCREMENTAL_RELAY_FEE

const unsigned int DEFAULT_INCREMENTAL_RELAY_FEE = 1000

static

Default for -incrementalrelayfee, which sets the minimum feerate increase for mempool limiting or BIP 125 replacement.

Definition at line 34 of file policy.h.

◆ DEFAULT_MAX_MEMPOOL_SIZE

const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300

static

Default for -maxmempool, maximum megabytes of mempool memory usage.

Definition at line 32 of file policy.h.

◆ DEFAULT_PERMIT_BAREMULTISIG

const bool DEFAULT_PERMIT_BAREMULTISIG = true

static

Default for -permitbaremultisig.

Definition at line 38 of file policy.h.

◆ DUST_RELAY_TX_FEE

const unsigned int DUST_RELAY_TX_FEE = 3000

static

Min feerate for defining dust.

Historically this has been based on the minRelayTxFee, however changing the dust limit changes which transactions are standard and should be done with care and ideally rarely. It makes sense to only increase the dust limit after prior releases were already not creating outputs below the new threshold

Definition at line 54 of file policy.h.

◆ MAX_P2SH_SIGOPS

const unsigned int MAX_P2SH_SIGOPS = 15

static

Maximum number of signature check operations in an IsStandard() P2SH script.

Definition at line 28 of file policy.h.

◆ MAX_STANDARD_P2WSH_SCRIPT_SIZE

const unsigned int MAX_STANDARD_P2WSH_SCRIPT_SIZE = 3600

static

The maximum size in bytes of a standard witnessScript.

Definition at line 46 of file policy.h.

◆ MAX_STANDARD_P2WSH_STACK_ITEM_SIZE

const unsigned int MAX_STANDARD_P2WSH_STACK_ITEM_SIZE = 80

static

The maximum size in bytes of each witness stack item in a standard P2WSH script.

Definition at line 42 of file policy.h.

◆ MAX_STANDARD_P2WSH_STACK_ITEMS

const unsigned int MAX_STANDARD_P2WSH_STACK_ITEMS = 100

static

The maximum number of witness stack items in a standard P2WSH script.

Definition at line 40 of file policy.h.

◆ MAX_STANDARD_SCRIPTSIG_SIZE

const unsigned int MAX_STANDARD_SCRIPTSIG_SIZE = 1650

static

The maximum size of a standard ScriptSig.

Definition at line 48 of file policy.h.

◆ MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE

const unsigned int MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE = 80

static

The maximum size in bytes of each witness stack item in a standard BIP 342 script (Taproot, leaf version 0xc0)

Definition at line 44 of file policy.h.

◆ MAX_STANDARD_TX_SIGOPS_COST

const unsigned int MAX_STANDARD_TX_SIGOPS_COST = MAX_BLOCK_SIGOPS_COST/5

static

The maximum number of sigops we're willing to relay/mine in a single tx.

Definition at line 30 of file policy.h.

◆ MAX_STANDARD_TX_WEIGHT

const unsigned int MAX_STANDARD_TX_WEIGHT = 400000

static

The maximum weight for transactions we're willing to relay/mine.

Definition at line 24 of file policy.h.

◆ MIN_STANDARD_TX_NONWITNESS_SIZE

const unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE = 82

static

The minimum non-witness size for transactions we're willing to relay/mine (1 segwit input + 1 P2WPKH output = 82 bytes)

Definition at line 26 of file policy.h.

◆ STANDARD_LOCKTIME_VERIFY_FLAGS

constexpr unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS

static

Initial value:

= LOCKTIME_VERIFY_SEQUENCE |

LOCKTIME_MEDIAN_TIME_PAST

LOCKTIME_VERIFY_SEQUENCE

static constexpr unsigned int LOCKTIME_VERIFY_SEQUENCE

Flags for nSequence and nLockTime locks.

Definition: consensus.h:28

LOCKTIME_MEDIAN_TIME_PAST

static constexpr unsigned int LOCKTIME_MEDIAN_TIME_PAST

Use GetMedianTimePast() instead of nTime for end point timestamp.

Definition: consensus.h:30

Used as the flags parameter to sequence and nLocktime checks in non-consensus code.

Definition at line 85 of file policy.h.

◆ STANDARD_NOT_MANDATORY_VERIFY_FLAGS

constexpr unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS

static

For convenience, standard but not mandatory verify flags.

Definition at line 82 of file policy.h.

◆ STANDARD_SCRIPT_VERIFY_FLAGS

constexpr unsigned int STANDARD_SCRIPT_VERIFY_FLAGS

static

Initial value:

= MANDATORY_SCRIPT_VERIFY_FLAGS |
                                                             SCRIPT_VERIFY_DERSIG |
                                                             SCRIPT_VERIFY_STRICTENC |
                                                             SCRIPT_VERIFY_MINIMALDATA |
                                                             SCRIPT_VERIFY_NULLDUMMY |
                                                             SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS |
                                                             SCRIPT_VERIFY_CLEANSTACK |
                                                             SCRIPT_VERIFY_MINIMALIF |
                                                             SCRIPT_VERIFY_NULLFAIL |
                                                             SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY |
                                                             SCRIPT_VERIFY_CHECKSEQUENCEVERIFY |
                                                             SCRIPT_VERIFY_LOW_S |
                                                             SCRIPT_VERIFY_WITNESS |
                                                             SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM |
                                                             SCRIPT_VERIFY_WITNESS_PUBKEYTYPE |
                                                             SCRIPT_VERIFY_CONST_SCRIPTCODE |
                                                             SCRIPT_VERIFY_TAPROOT |
                                                             SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_TAPROOT_VERSION |
                                                             SCRIPT_VERIFY_DISCOURAGE_OP_SUCCESS |
                                                             SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_PUBKEYTYPE

Standard script verification flags that standard transactions will comply with.

However scripts violating these flags may still be present in valid blocks and we must accept those blocks.

Definition at line 60 of file policy.h.

◆ TX_MAX_STANDARD_VERSION

decltype(CTransaction::nVersion) constexpr TX_MAX_STANDARD_VERSION {2}

static

Definition at line 98 of file policy.h.

Functions

Variables

Function Documentation

◆ AreInputsStandard()

◆ GetDustThreshold()

◆ GetVirtualTransactionInputSize() [1/2]

◆ GetVirtualTransactionInputSize() [2/2]

◆ GetVirtualTransactionSize() [1/3]

◆ GetVirtualTransactionSize() [2/3]

◆ GetVirtualTransactionSize() [3/3]

◆ IsDust()

◆ IsStandard()

◆ IsStandardTx()

◆ IsWitnessStandard()

Variable Documentation

◆ DEFAULT_BLOCK_MAX_WEIGHT

◆ DEFAULT_BLOCK_MIN_TX_FEE

◆ DEFAULT_BYTES_PER_SIGOP

◆ DEFAULT_INCREMENTAL_RELAY_FEE

◆ DEFAULT_MAX_MEMPOOL_SIZE

◆ DEFAULT_PERMIT_BAREMULTISIG

◆ DUST_RELAY_TX_FEE

◆ MAX_P2SH_SIGOPS

◆ MAX_STANDARD_P2WSH_SCRIPT_SIZE

◆ MAX_STANDARD_P2WSH_STACK_ITEM_SIZE

◆ MAX_STANDARD_P2WSH_STACK_ITEMS

◆ MAX_STANDARD_SCRIPTSIG_SIZE

◆ MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE

◆ MAX_STANDARD_TX_SIGOPS_COST

◆ MAX_STANDARD_TX_WEIGHT

◆ MIN_STANDARD_TX_NONWITNESS_SIZE

◆ STANDARD_LOCKTIME_VERIFY_FLAGS

◆ STANDARD_NOT_MANDATORY_VERIFY_FLAGS

◆ STANDARD_SCRIPT_VERIFY_FLAGS

◆ TX_MAX_STANDARD_VERSION