Crate bitcoin_policy

Constants

• DEFAULT_BLOCK_MAX_WEIGHT
  | Default for -blockmaxweight, which | controls the range of block weights | the mining code will create * |
• DEFAULT_BLOCK_MIN_TX_FEE
  | Default for -blockmintxfee, which | sets the minimum feerate for a transaction | in blocks created by mining code * |
• DEFAULT_BYTES_PER_SIGOP
  | Default for -bytespersigop |
• DEFAULT_INCREMENTAL_RELAY_FEE
  | Default for -incrementalrelayfee, | which sets the minimum feerate increase | for mempool limiting or BIP 125 replacement | * |
• DEFAULT_MAX_MEMPOOL_SIZE
  | Default for -maxmempool, maximum megabytes | of mempool memory usage |
• DEFAULT_PERMIT_BAREMULTISIG
  | Default for -permitbaremultisig |
• DUST_RELAY_TX_FEE
  | 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 |
• MAX_P2SH_SIGOPS
  | Maximum number of signature check operations | in an IsStandard() P2SH script |
• MAX_STANDARD_P2WSH_SCRIPT_SIZE
  | The maximum size in bytes of a standard | witnessScript |
• MAX_STANDARD_P2WSH_STACK_ITEMS
  | The maximum number of witness stack | items in a standard P2WSH script |
• MAX_STANDARD_P2WSH_STACK_ITEM_SIZE
  | The maximum size in bytes of each witness | stack item in a standard P2WSH script |
• MAX_STANDARD_SCRIPTSIG_SIZE
  | The maximum size of a standard ScriptSig |
• MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE
  | The maximum size in bytes of each witness | stack item in a standard BIP 342 script | (Taproot, leaf version 0xc0) |
• MAX_STANDARD_TX_SIGOPS_COST
  | The maximum number of sigops we’re willing | to relay/mine in a single tx |
• MAX_STANDARD_TX_WEIGHT
  | The maximum weight for transactions | we’re willing to relay/mine |
• MIN_STANDARD_TX_NONWITNESS_SIZE
  | The minimum non-witness size for transactions | we’re willing to relay/mine (1 segwit | input + 1 P2WPKH output = 82 bytes) |

Functions

• are_inputs_standard
  | Check for standard transaction types | | ———– | @param[in] mapInputs | | Map of previous transactions that have | outputs we’re spending | ––––– | @param[in] taproot_active | | Whether or taproot consensus rules | are active (used to decide whether spends | of them are permitted) | | ———– | @return | | True if all inputs (scriptSigs) use | only standard transaction forms | | ———– | Check transaction inputs to mitigate two | potential denial-of-service attacks: | | 1. scriptSigs with extra data stuffed into them, | not consumed by scriptPubKey (or P2SH script) | | 2. 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.
• get_dust_threshold
  | @note | | This file is intended to be customised | by the end user, and includes only local | node policy logic |
• get_virtual_transaction_input_size
• get_virtual_transaction_input_size_for_txin
• get_virtual_transaction_size_for_tx
• get_virtual_transaction_size_for_weight
  | Compute the virtual transaction size | (weight reinterpreted as bytes). |
• get_virtual_transaction_size_from_transaction
• is_dust
• is_standard
• is_standard_tx
  | Check for standard transaction types | | ———– | @return | | True if all outputs (scriptPubKeys) | use only standard transaction forms |
• is_witness_standard
  | 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. |