# Copyright (c) 2026 Emanuele Bellocchia
#
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# of this software and associated documentation files (the "Software"), to deal
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# furnished to do so, subject to the following conditions:
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"""
Module for P2WPKH address encoding/decoding.
References:
https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki
https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki
"""
# Imports
from typing import Any, Union
from typing_extensions import override
from bip_utils.addr.addr_key_validator import AddrKeyValidator
from bip_utils.addr.iaddr_decoder import IAddrDecoder
from bip_utils.addr.iaddr_encoder import IAddrEncoder
from bip_utils.bech32 import Bech32ChecksumError, SegwitBech32Decoder, SegwitBech32Encoder
from bip_utils.ecc import IPublicKey
from bip_utils.utils.crypto import Hash160
class P2WPKHAddrConst:
"""Class container for P2WPKH constants."""
# Witness version is fixed to zero for P2WPKH
WITNESS_VER: int = 0
class P2WPKHAddrDecoder(IAddrDecoder):
"""
P2WPKH address decoder class.
It allows the Pay-to-Witness-Public-Key-Hash address decoding.
"""
@override
@staticmethod
def DecodeAddr(addr: str,
**kwargs: Any) -> bytes:
"""
Decode a P2WPKH address to bytes.
Args:
addr (str): Address string
Other Parameters:
hrp (str): Expected HRP
Returns:
bytes: Public key hash bytes
Raises:
ValueError: If the address encoding is not valid
"""
hrp = kwargs["hrp"]
try:
# SegwitBech32Decoder also validates the length
wit_ver_got, addr_dec_bytes = SegwitBech32Decoder.Decode(hrp, addr)
except Bech32ChecksumError as ex:
raise ValueError("Invalid bech32 checksum") from ex
# Check witness version
if wit_ver_got != P2WPKHAddrConst.WITNESS_VER:
raise ValueError(f"Invalid witness version (expected {P2WPKHAddrConst.WITNESS_VER}, "
f"got {wit_ver_got})")
return addr_dec_bytes
class P2WPKHAddrEncoder(IAddrEncoder):
"""
P2WPKH address encoder class.
It allows the Pay-to-Witness-Public-Key-Hash address encoding.
"""
@override
@staticmethod
def EncodeKey(pub_key: Union[bytes, IPublicKey],
**kwargs: Any) -> str:
"""
Encode a public key to P2WPKH address.
Args:
pub_key (bytes or IPublicKey): Public key bytes or object
Other Parameters:
hrp (str): HRP
Returns:
str: Address string
Raises:
ValueError: If the public key is not valid
TypeError: If the public key is not secp256k1
"""
hrp = kwargs["hrp"]
pub_key_obj = AddrKeyValidator.ValidateAndGetSecp256k1Key(pub_key)
return SegwitBech32Encoder.Encode(hrp,
P2WPKHAddrConst.WITNESS_VER,
Hash160.QuickDigest(pub_key_obj.RawCompressed().ToBytes()))
# Deprecated: only for compatibility, Encoder class shall be used instead
P2WPKHAddr = P2WPKHAddrEncoder