Syscoin Address Converter

A simple utility for converting between legacy Syscoin P2PKH address format (Base58) and SegWit v0 P2WPKH Bech32 Syscoin address format.

Supported Conversions:

• Legacy P2PKH (starts with 'S') <---> SegWit v0 P2WPKH (starts with 'sys1q')

Unsupported Conversions:

• Conversion involving legacy P2SH addresses is not supported due to the ambiguity in determining the original SegWit script type from the P2SH hash.
• This tool does not support conversion to or from Taproot (SegWit v1 / P2TR) addresses (starting with 'sys1p'). It will raise an error if a Taproot address is provided.

This tool helps bridge the gap created by the removal of the convertaddress RPC call in Syscoin Core, primarily for systems needing to handle both legacy P2PKH and standard SegWit v0 P2WPKH addresses.

Installation

Make sure you have Python 3.7+ installed. Then, install the required dependency:

pip install -r requirements.txt 
# (Installs the 'base58' library)

The tool also includes a local copy of the standard Bech32 reference implementation (bech32_ref.py), slightly modified for correct case-insensitive decoding, which is used internally.

Usage

Command-Line Interface (CLI)

The simplest way to use the converter is via the command line:

python converter.py <SYSCOIN_LEGACY_P2PKH_OR_SEGWIT_V0_P2WPKH_ADDRESS>

Examples:

# Convert Legacy P2PKH ('S') to Segwit v0 P2WPKH ('sys1q')
python converter.py SPd281HLz89nvKZ1js6eeefD3YsjcP78AX
# Output: sys1qrxy3qhgfzeer9pf9egh4zh3qcn82j9s6ah9sja

# Convert Segwit v0 P2WPKH ('sys1q') to Legacy P2PKH ('S')
python converter.py sys1qrxy3qhgfzeer9pf9egh4zh3qcn82j9s6ah9sja
# Output: SPd281HLz89nvKZ1js6eeefD3YsjcP78AX

# Attempting Taproot ('sys1p') conversion (will produce an error)
python converter.py sys1p2mnq5hr45h2zd7zvz8487zmedufrccp69ql2077q77le47hdhumq89cf5t
# Output (stderr): Error: Unsupported SegWit version (1): Taproot (v1) or future versions cannot be converted.

# Attempting P2SH-Segwit ('3') conversion (will produce an error)
python converter.py 38KSVy4NcgF8L6da8DeWxc8kwWxPkB55zw
# Output (stderr): Error: Invalid Base58 prefix: Expected 63, got 5

If an invalid or unsupported address is provided, an error message will be printed to stderr.

As a Python Module

You can also import the conversion function into your Python code:

from converter import convert_syscoin_address, InvalidAddressError

# Legacy P2PKH to Segwit v0 P2WPKH
legacy_p2pkh = 'SPd281HLz89nvKZ1js6eeefD3YsjcP78AX'
try:
    segwit_p2wpkh = convert_syscoin_address(legacy_p2pkh)
    print(f"Legacy {legacy_p2pkh} -> Segwit {segwit_p2wpkh}")
except InvalidAddressError as e:
    print(f"Error converting {legacy_p2pkh}: {e}")

# Segwit v0 P2WPKH to Legacy P2PKH
segwit_p2wpkh = 'sys1qrxy3qhgfzeer9pf9egh4zh3qcn82j9s6ah9sja'
try:
    legacy_p2pkh = convert_syscoin_address(segwit_p2wpkh)
    print(f"Segwit {segwit_p2wpkh} -> Legacy {legacy_p2pkh}")
except InvalidAddressError as e:
    print(f"Error converting {segwit_p2wpkh}: {e}")

# Attempt Taproot Conversion (will raise InvalidAddressError)
taproot_address = 'sys1p2mnq5hr45h2zd7zvz8487zmedufrccp69ql2077q77le47hdhumq89cf5t'
try:
    convert_syscoin_address(taproot_address)
except InvalidAddressError as e:
    print(f"Error converting {taproot_address}: {e}")

# Attempt P2SH Conversion (will raise InvalidAddressError)
legacy_p2sh = '38KSVy4NcgF8L6da8DeWxc8kwWxPkB55zw'
try:
    convert_syscoin_address(legacy_p2sh)
except InvalidAddressError as e:
    print(f"Error converting {legacy_p2sh}: {e}")

Testing

Run tests to validate functionality:

python -m unittest discover -s tests -p 'test_*.py'

Details

This tool uses the base58 library for Base58Check decoding/encoding and includes a local, slightly modified version of the standard Python Bech32 reference implementation (bech32_ref.py) for Bech32/Bech32m handling.

It uses the following Syscoin mainnet parameters:

• Legacy P2PKH Prefix: 63 (Addresses usually start with 'S')
• Legacy P2SH Prefix: 5 (conversion not supported)
• Bech32 HRP: sys
  • SegWit v0 addresses (P2WPKH) start with sys1q.
  • SegWit v1 addresses (Taproot/P2TR) start with sys1p (conversion not supported).

Contributions

Feel free to fork, open issues, or submit pull requests!

License

MIT