# 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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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# THE SOFTWARE.
"""Module for P2SH address encoding/decoding."""
# 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.addr.P2PKH_addr import BchP2PKHAddrDecoder, P2PKHAddrDecoder
from bip_utils.base58 import Base58Encoder
from bip_utils.bech32 import BchBech32Encoder
from bip_utils.ecc import IPublicKey
from bip_utils.utils.crypto import Hash160
class P2SHAddrConst:
"""Class container for P2SH constants."""
# Script bytes
SCRIPT_BYTES: bytes = b"\x00\x14"
class _P2SHAddrUtils:
"""Class container for P2SH utility functions."""
@staticmethod
def AddScriptSig(pub_key: IPublicKey) -> bytes:
"""
Add script signature to public key and get address bytes.
Args:
pub_key (IPublicKey object): Public key object
Returns:
bytes: Address bytes
"""
# Key hash: Hash160(public_key)
key_hash_bytes = Hash160.QuickDigest(pub_key.RawCompressed().ToBytes())
# Script signature: 0x0014 | Hash160(public_key)
script_sig_bytes = P2SHAddrConst.SCRIPT_BYTES + key_hash_bytes
# Address bytes = Hash160(script_signature)
return Hash160.QuickDigest(script_sig_bytes)
class P2SHAddrDecoder(IAddrDecoder):
"""
P2SH address decoder class.
It allows the Pay-to-Script-Hash address decoding.
"""
@override
@staticmethod
def DecodeAddr(addr: str,
**kwargs: Any) -> bytes:
"""
Decode a P2SH address to bytes.
Args:
addr (str): Address string
Other Parameters:
net_ver (bytes): Expected net address version
Returns:
bytes: Script signature hash bytes
Raises:
ValueError: If the address encoding is not valid
"""
# The decoding steps are the same of P2PKH
return P2PKHAddrDecoder.DecodeAddr(addr, net_ver=kwargs["net_ver"])
class P2SHAddrEncoder(IAddrEncoder):
"""
P2SH address encoder class.
It allows the Pay-to-Script-Hash address encoding.
"""
@override
@staticmethod
def EncodeKey(pub_key: Union[bytes, IPublicKey],
**kwargs: Any) -> str:
"""
Encode a public key to P2SH address.
Args:
pub_key (bytes or IPublicKey) : Public key bytes or object
Other Parameters:
net_ver (bytes): Net address version
Returns:
str: Address string
Raises:
ValueError: If the public key is not valid
TypeError: If the public key is not secp256k1
"""
net_ver_bytes = kwargs["net_ver"]
pub_key_obj = AddrKeyValidator.ValidateAndGetSecp256k1Key(pub_key)
return Base58Encoder.CheckEncode(net_ver_bytes + _P2SHAddrUtils.AddScriptSig(pub_key_obj))
class BchP2SHAddrDecoder(IAddrDecoder):
"""
Bitcoin Cash P2SH address decoder class.
It allows the Bitcoin Cash P2SH decoding.
"""
@override
@staticmethod
def DecodeAddr(addr: str,
**kwargs: Any) -> bytes:
"""
Decode a Bitcoin Cash P2SH address to bytes.
Args:
addr (str): Address string
Other Parameters:
hrp (str) : Expected HRP
net_ver (bytes): Expected net address version
Returns:
bytes: Script signature hash bytes
Raises:
ValueError: If the address encoding is not valid
"""
# The decoding steps are the same of P2PKH
return BchP2PKHAddrDecoder.DecodeAddr(addr, hrp=kwargs["hrp"], net_ver=kwargs["net_ver"])
class BchP2SHAddrEncoder(IAddrEncoder):
"""
Bitcoin Cash P2SH address encoder class.
It allows the Bitcoin Cash P2SH encoding.
"""
@override
@staticmethod
def EncodeKey(pub_key: Union[bytes, IPublicKey],
**kwargs: Any) -> str:
"""
Encode a public key to Bitcoin Cash P2SH address.
Args:
pub_key (bytes or IPublicKey): Public key bytes or object
Other Parameters:
hrp (str) : HRP
net_ver (bytes): Net address version
Returns:
str: Address string
Raises:
ValueError: If the public key is not valid
TypeError: If the public key is not secp256k1
"""
hrp = kwargs["hrp"]
net_ver_bytes = kwargs["net_ver"]
pub_key_obj = AddrKeyValidator.ValidateAndGetSecp256k1Key(pub_key)
return BchBech32Encoder.Encode(hrp, net_ver_bytes, _P2SHAddrUtils.AddScriptSig(pub_key_obj))
# Deprecated: only for compatibility, Encoder classes shall be used instead
P2SHAddr = P2SHAddrEncoder
BchP2SHAddr = BchP2SHAddrEncoder