# Copyright (c) 2026 Emanuele Bellocchia
#
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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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"""Module for Stellar 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.ecc import Ed25519PublicKey, IPublicKey
from bip_utils.utils.crypto import XModemCrc
from bip_utils.utils.misc import Base32Decoder, Base32Encoder, BytesUtils, IntegerUtils
@unique
class XlmAddrTypes(IntEnum):
"""Enumerative for Stellar address types."""
PUB_KEY = 6 << 3
PRIV_KEY = 18 << 3
class XlmAddrConst:
"""Class container for Stellar address constants."""
# Checksum length in bytes
CHECKSUM_BYTE_LEN: int = 2
class _XlmAddrUtils:
"""Stellar address utility class."""
@staticmethod
def ComputeChecksum(payload_bytes: bytes) -> bytes:
"""
Compute checksum in Stellar format.
Args:
payload_bytes (bytes): Payload bytes
Returns:
bytes: Computed checksum
"""
return BytesUtils.Reverse(XModemCrc.QuickDigest(payload_bytes))
class XlmAddrDecoder(IAddrDecoder):
"""
Stellar address decoder class.
It allows the Stellar address decoding.
"""
@override
@staticmethod
def DecodeAddr(addr: str,
**kwargs: Any) -> bytes:
"""
Decode a Stellar address to bytes.
Args:
addr (str): Address string
Other Parameters:
addr_type (XlmAddrTypes): Expected address type (default: public key)
Returns:
bytes: Public key bytes
Raises:
ValueError: If the address encoding is not valid
TypeError: If the address type is not a XlmAddrTypes enum
"""
# Get and check address type
addr_type = kwargs.get("addr_type", XlmAddrTypes.PUB_KEY)
if not isinstance(addr_type, XlmAddrTypes):
raise TypeError("Address type is not an enumerative of XlmAddrTypes")
# Decode from base32
addr_dec_bytes = Base32Decoder.Decode(addr)
# Validate length
AddrDecUtils.ValidateLength(addr_dec_bytes,
Ed25519PublicKey.CompressedLength() + XlmAddrConst.CHECKSUM_BYTE_LEN)
# Get back checksum and payload bytes
payload_bytes, checksum_bytes = AddrDecUtils.SplitPartsByChecksum(addr_dec_bytes,
XlmAddrConst.CHECKSUM_BYTE_LEN)
# Check address type
addr_type_got = payload_bytes[0]
if addr_type != addr_type_got:
raise ValueError(f"Invalid address type (expected {addr_type.value}, "
f"got {addr_type_got})")
# Validate checksum
AddrDecUtils.ValidateChecksum(payload_bytes, checksum_bytes, _XlmAddrUtils.ComputeChecksum)
# Validate public key
pub_key_bytes = payload_bytes[1:]
AddrDecUtils.ValidatePubKey(pub_key_bytes, Ed25519PublicKey)
return pub_key_bytes
class XlmAddrEncoder(IAddrEncoder):
"""
Stellar address encoder class.
It allows the Stellar address encoding.
"""
@override
@staticmethod
def EncodeKey(pub_key: Union[bytes, IPublicKey],
**kwargs: Any) -> str:
"""
Encode a public key to Stellar address.
Args:
pub_key (bytes or IPublicKey): Public key bytes or object
Other Parameters:
addr_type (XlmAddrTypes): Address type (default: public key)
Returns:
str: Address string
Raises:
ValueError: If the public key is not valid
TypeError: If the public key is not ed25519 or address type is not a XlmAddrTypes enum
"""
# Get and check address type
addr_type = kwargs.get("addr_type", XlmAddrTypes.PUB_KEY)
if not isinstance(addr_type, XlmAddrTypes):
raise TypeError("Address type is not an enumerative of XlmAddrTypes")
# Get public key
pub_key_obj = AddrKeyValidator.ValidateAndGetEd25519Key(pub_key)
payload_bytes = IntegerUtils.ToBytes(addr_type) + pub_key_obj.RawCompressed().ToBytes()[1:]
# Compute checksum
checksum_bytes = _XlmAddrUtils.ComputeChecksum(payload_bytes)
# Encode to base32
return Base32Encoder.EncodeNoPadding(payload_bytes + checksum_bytes)
# Deprecated: only for compatibility, Encoder class shall be used instead
XlmAddr = XlmAddrEncoder