1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2019 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
6 #ifndef BITCOIN_POLICY_POLICY_H
7 #define BITCOIN_POLICY_POLICY_H
8
9 #include <consensus/consensus.h>
10 #include <policy/feerate.h>
11 #include <script/interpreter.h>
12 #include <script/standard.h>
13
14 #include <string>
15
16 class CCoinsViewCache;
17 class CTxOut;
18
19 /** Default for -blockmaxweight, which controls the range of block weights the mining code will create **/
20 static const unsigned int DEFAULT_BLOCK_MAX_WEIGHT = MAX_BLOCK_WEIGHT - 4000;
21 /** Default for -blockmintxfee, which sets the minimum feerate for a transaction in blocks created by mining code **/
22 static const unsigned int DEFAULT_BLOCK_MIN_TX_FEE = 1000;
23 /** The maximum weight for transactions we're willing to relay/mine */
24 static const unsigned int MAX_STANDARD_TX_WEIGHT = 400000;
25 /** The minimum non-witness size for transactions we're willing to relay/mine (1 segwit input + 1 P2WPKH output = 82 bytes) */
26 static const unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE = 82;
27 /** Maximum number of signature check operations in an IsStandard() P2SH script */
28 static const unsigned int MAX_P2SH_SIGOPS = 15;
29 /** The maximum number of sigops we're willing to relay/mine in a single tx */
30 static const unsigned int MAX_STANDARD_TX_SIGOPS_COST = MAX_BLOCK_SIGOPS_COST/5;
31 /** Default for -maxmempool, maximum megabytes of mempool memory usage */
32 static const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300;
33 /** Default for -incrementalrelayfee, which sets the minimum feerate increase for mempool limiting or BIP 125 replacement **/
34 static const unsigned int DEFAULT_INCREMENTAL_RELAY_FEE = 1000;
35 /** Default for -bytespersigop */
36 static const unsigned int DEFAULT_BYTES_PER_SIGOP = 20;
37 /** Default for -permitbaremultisig */
38 static const bool DEFAULT_PERMIT_BAREMULTISIG = true;
39 /** The maximum number of witness stack items in a standard P2WSH script */
40 static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEMS = 100;
41 /** The maximum size of each witness stack item in a standard P2WSH script */
42 static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEM_SIZE = 80;
43 /** The maximum size of each witness stack item in a standard BIP 342 script (Taproot, leaf version 0xc0) */
44 static const unsigned int MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE = 80;
45 /** The maximum size of a standard witnessScript */
46 static const unsigned int MAX_STANDARD_P2WSH_SCRIPT_SIZE = 3600;
47 /** Min feerate for defining dust. Historically this has been based on the
48 * minRelayTxFee, however changing the dust limit changes which transactions are
49 * standard and should be done with care and ideally rarely. It makes sense to
50 * only increase the dust limit after prior releases were already not creating
51 * outputs below the new threshold */
52 static const unsigned int DUST_RELAY_TX_FEE = 3000;
53 /**
54 * Standard script verification flags that standard transactions will comply
55 * with. However scripts violating these flags may still be present in valid
56 * blocks and we must accept those blocks.
57 */
58 static constexpr unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS |
59 SCRIPT_VERIFY_DERSIG |
60 SCRIPT_VERIFY_STRICTENC |
61 SCRIPT_VERIFY_MINIMALDATA |
62 SCRIPT_VERIFY_NULLDUMMY |
63 SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS |
64 SCRIPT_VERIFY_CLEANSTACK |
65 SCRIPT_VERIFY_MINIMALIF |
66 SCRIPT_VERIFY_NULLFAIL |
67 SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY |
68 SCRIPT_VERIFY_CHECKSEQUENCEVERIFY |
69 SCRIPT_VERIFY_LOW_S |
70 SCRIPT_VERIFY_WITNESS |
71 SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM |
72 SCRIPT_VERIFY_WITNESS_PUBKEYTYPE |
73 SCRIPT_VERIFY_CONST_SCRIPTCODE |
74 SCRIPT_VERIFY_TAPROOT |
75 SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_TAPROOT_VERSION |
76 SCRIPT_VERIFY_DISCOURAGE_OP_SUCCESS |
77 SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_PUBKEYTYPE;
78
79 /** For convenience, standard but not mandatory verify flags. */
80 static constexpr unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
81
82 /** Used as the flags parameter to sequence and nLocktime checks in non-consensus code. */
83 static constexpr unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS = LOCKTIME_VERIFY_SEQUENCE |
84 LOCKTIME_MEDIAN_TIME_PAST;
85
86 CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFee);
87
88 bool IsDust(const CTxOut& txout, const CFeeRate& dustRelayFee);
89
90 bool IsStandard(const CScript& scriptPubKey, TxoutType& whichType);
91 /**
92 * Check for standard transaction types
93 * @return True if all outputs (scriptPubKeys) use only standard transaction forms
94 */
95 bool IsStandardTx(const CTransaction& tx, bool permit_bare_multisig, const CFeeRate& dust_relay_fee, std::string& reason);
96 /**
97 * Check for standard transaction types
98 * @param[in] mapInputs Map of previous transactions that have outputs we're spending
99 * @param[in] taproot_active Whether or taproot consensus rules are active (used to decide whether spends of them are permitted)
100 * @return True if all inputs (scriptSigs) use only standard transaction forms
101 */
102 bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs, bool taproot_active);
103 /**
104 * Check if the transaction is over standard P2WSH resources limit:
105 * 3600bytes witnessScript size, 80bytes per witness stack element, 100 witness stack elements
106 * These limits are adequate for multi-signature up to n-of-100 using OP_CHECKSIG, OP_ADD, and OP_EQUAL,
107 */
108 bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
109
110 /** Compute the virtual transaction size (weight reinterpreted as bytes). */
111 int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost, unsigned int bytes_per_sigop);
112 int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOpCost, unsigned int bytes_per_sigop);
113 int64_t GetVirtualTransactionInputSize(const CTxIn& tx, int64_t nSigOpCost, unsigned int bytes_per_sigop);
114
GetVirtualTransactionSize(const CTransaction & tx)115 static inline int64_t GetVirtualTransactionSize(const CTransaction& tx)
116 {
117 return GetVirtualTransactionSize(tx, 0, 0);
118 }
119
GetVirtualTransactionInputSize(const CTxIn & tx)120 static inline int64_t GetVirtualTransactionInputSize(const CTxIn& tx)
121 {
122 return GetVirtualTransactionInputSize(tx, 0, 0);
123 }
124
125 #endif // BITCOIN_POLICY_POLICY_H
126