# Copyright (c) 2026 Emanuele Bellocchia
#
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# furnished to do so, subject to the following conditions:
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"""Module for Ergo address encoding/decoding."""
# Imports
from enum import IntEnum, unique
from typing import Any, Union
from typing_extensions import override
from bip_utils.addr.addr_dec_utils import AddrDecUtils
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.base58 import Base58Decoder, Base58Encoder
from bip_utils.ecc import IPublicKey, Secp256k1PublicKey
from bip_utils.utils.crypto import Blake2b256
from bip_utils.utils.misc import IntegerUtils
@unique
class ErgoAddressTypes(IntEnum):
"""Enumerative for Ergo address types."""
P2PKH = 0x01
P2SH = 0x02
@unique
class ErgoNetworkTypes(IntEnum):
"""Enumerative for Ergo network types."""
MAINNET = 0x00
TESTNET = 0x10
class ErgoAddrConst:
"""Class container for Ergo address constants."""
# Checksum length in bytes
CHECKSUM_BYTE_LEN: int = 4
class _ErgoAddrUtils:
"""Ergo address utility class."""
@staticmethod
def ComputeChecksum(pub_key_bytes: bytes) -> bytes:
"""
Compute checksum in Ergo format.
Args:
pub_key_bytes (bytes): Public key bytes
Returns:
bytes: Computed checksum
"""
return Blake2b256.QuickDigest(pub_key_bytes)[:ErgoAddrConst.CHECKSUM_BYTE_LEN]
@staticmethod
def EncodePrefix(addr_type: ErgoAddressTypes,
net_type: ErgoNetworkTypes) -> bytes:
"""
Encode prefix.
Args:
addr_type (ErgoAddressTypes): Address type
net_type (ErgoNetworkTypes) : Network type
Returns:
bytes: Prefix byte
"""
return IntegerUtils.ToBytes(addr_type + net_type)
class ErgoP2PKHAddrDecoder(IAddrDecoder):
"""
Ergo P2PKH address decoder class.
It allows the Ergo P2PKH address decoding.
"""
@override
@staticmethod
def DecodeAddr(addr: str,
**kwargs: Any) -> bytes:
"""
Decode an Ergo P2PKH address to bytes.
Args:
addr (str): Address string
Other Parameters:
net_type (ErgoNetworkTypes): Expected network type (default: main net)
Returns:
bytes: Public key bytes
Raises:
ValueError: If the address encoding is not valid
TypeError: If the network tag is not a ErgoNetworkTypes enum
"""
net_type = kwargs.get("net_type", ErgoNetworkTypes.MAINNET)
if not isinstance(net_type, ErgoNetworkTypes):
raise TypeError("Address type is not an enumerative of ErgoNetworkTypes")
# Decode from base58
addr_dec_bytes = Base58Decoder.Decode(addr)
# Validate length
AddrDecUtils.ValidateLength(addr_dec_bytes,
Secp256k1PublicKey.CompressedLength() + ErgoAddrConst.CHECKSUM_BYTE_LEN + 1)
# Get back checksum and public key bytes
addr_with_prefix, checksum_bytes = AddrDecUtils.SplitPartsByChecksum(addr_dec_bytes,
ErgoAddrConst.CHECKSUM_BYTE_LEN)
# Validate checksum
AddrDecUtils.ValidateChecksum(addr_with_prefix, checksum_bytes, _ErgoAddrUtils.ComputeChecksum)
# Validate and remove prefix
pub_key_bytes = AddrDecUtils.ValidateAndRemovePrefix(
addr_with_prefix,
_ErgoAddrUtils.EncodePrefix(ErgoAddressTypes.P2PKH, net_type)
)
# Validate public key
AddrDecUtils.ValidatePubKey(pub_key_bytes, Secp256k1PublicKey)
return pub_key_bytes
class ErgoP2PKHAddrEncoder(IAddrEncoder):
"""
Ergo P2PKH address encoder class.
It allows the Ergo P2PKH address encoding.
"""
@override
@staticmethod
def EncodeKey(pub_key: Union[bytes, IPublicKey],
**kwargs: Any) -> str:
"""
Encode a public key to Ergo P2PKH address.
Args:
pub_key (bytes or IPublicKey): Public key bytes or object
Other Parameters:
net_type (ErgoNetworkTypes): Network type (default: main net)
Returns:
str: Address string
Raises:
ValueError: If the public key is not valid
TypeError: If the public key is not secp256k1 or the network tag is not a ErgoNetworkTypes enum
"""
net_type = kwargs.get("net_type", ErgoNetworkTypes.MAINNET)
if not isinstance(net_type, ErgoNetworkTypes):
raise TypeError("Address type is not an enumerative of ErgoNetworkTypes")
pub_key_obj = AddrKeyValidator.ValidateAndGetSecp256k1Key(pub_key)
pub_key_bytes = pub_key_obj.RawCompressed().ToBytes()
prefix_byte = _ErgoAddrUtils.EncodePrefix(ErgoAddressTypes.P2PKH, net_type)
addr_payload_bytes = prefix_byte + pub_key_bytes
return Base58Encoder.Encode(addr_payload_bytes + _ErgoAddrUtils.ComputeChecksum(addr_payload_bytes))
# Deprecated: only for compatibility, Encoder class shall be used instead
ErgoP2PKHAddr = ErgoP2PKHAddrEncoder