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"""
Original version: https://raw.githubusercontent.com/bitcoin-core/HWI/3fe369d0379212fae1c72729a179d133b0adc872/hwilib/_script.py
Distributed under the MIT License.
Bitcoin Script utilities
************************
"""
from typing import (
Optional,
Sequence,
Tuple,
)
def is_opreturn(script: bytes) -> bool:
"""
Determine whether a script is an OP_RETURN output script.
:param script: The script
:returns: Whether the script is an OP_RETURN output script
"""
return script[0] == 0x6a
def is_p2sh(script: bytes) -> bool:
"""
Determine whether a script is a P2SH output script.
:param script: The script
:returns: Whether the script is a P2SH output script
"""
return len(script) == 23 and script[0] == 0xa9 and script[1] == 0x14 and script[22] == 0x87
def is_p2pkh(script: bytes) -> bool:
"""
Determine whether a script is a P2PKH output script.
:param script: The script
:returns: Whether the script is a P2PKH output script
"""
return len(script) == 25 and script[0] == 0x76 and script[1] == 0xa9 and script[2] == 0x14 and script[23] == 0x88 and script[24] == 0xac
def is_p2pk(script: bytes) -> bool:
"""
Determine whether a script is a P2PK output script.
:param script: The script
:returns: Whether the script is a P2PK output script
"""
return (len(script) == 35 or len(script) == 67) and (script[0] == 0x21 or script[0] == 0x41) and script[-1] == 0xac
def is_p2tr(script: bytes) -> bool:
"""
Determine whether a script is a P2TR output script.
:param script: The script
:returns: Whether the script is a P2TR output script
"""
return len(script) == 34 and script[0] == 0x51 and script[1] == 0x20
def is_witness(script: bytes) -> Tuple[bool, int, bytes]:
"""
Determine whether a script is a segwit output script.
If so, also returns the witness version and witness program.
:param script: The script
:returns: A tuple of a bool indicating whether the script is a segwit output script,
an int representing the witness version,
and the bytes of the witness program.
"""
if len(script) < 4 or len(script) > 42:
return (False, 0, b"")
if script[0] != 0 and (script[0] < 81 or script[0] > 96):
return (False, 0, b"")
if script[1] + 2 == len(script):
return (True, script[0] - 0x50 if script[0] else 0, script[2:])
return (False, 0, b"")
def is_p2wpkh(script: bytes) -> bool:
"""
Determine whether a script is a P2WPKH output script.
:param script: The script
:returns: Whether the script is a P2WPKH output script
"""
is_wit, wit_ver, wit_prog = is_witness(script)
if not is_wit:
return False
elif wit_ver != 0:
return False
return len(wit_prog) == 20
def is_p2wsh(script: bytes) -> bool:
"""
Determine whether a script is a P2WSH output script.
:param script: The script
:returns: Whether the script is a P2WSH output script
"""
is_wit, wit_ver, wit_prog = is_witness(script)
if not is_wit:
return False
elif wit_ver != 0:
return False
return len(wit_prog) == 32
# Only handles up to 15 of 15. Returns None if this script is not a
# multisig script. Returns (m, pubkeys) otherwise.
def parse_multisig(script: bytes) -> Optional[Tuple[int, Sequence[bytes]]]:
"""
Determine whether a script is a multisig script. If so, determine the parameters of that multisig.
:param script: The script
:returns: ``None`` if the script is not multisig.
If multisig, returns a tuple of the number of signers required,
and a sequence of public key bytes.
"""
# Get m
m = script[0] - 80
if m < 1 or m > 15:
return None
# Get pubkeys
pubkeys = []
offset = 1
while True:
pubkey_len = script[offset]
if pubkey_len != 33:
break
offset += 1
pubkeys.append(script[offset:offset + 33])
offset += 33
# Check things at the end
n = script[offset] - 80
if n != len(pubkeys):
return None
offset += 1
op_cms = script[offset]
if op_cms != 174:
return None
return (m, pubkeys)
|
