c4_asset_id.py

"""Avalanche-io C4 Framework - AssetID

Simplified from:
https://github.com/Avalanche-io/pyc4

"""

import hashlib


def _b58encode(bytes):
    """
    Base58 Encode bytes to string
    """
    b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
    b58base = 58

    long_value = int(bytes.encode("hex_codec"), 16)

    result = ''
    while long_value >= b58base:
        div, mod = divmod(long_value, b58base)
        result = b58chars[mod] + result
        long_value = div

    result = b58chars[long_value] + result

    return result


def c4_hash(file_path):

    hash_obj = hashlib.sha512()

    with open(file_path, "rb") as file:
        for chunk in iter(lambda: file.read(40960), b""):
            hash_obj.update(chunk)

    c4_id_length = 90
    b58_hash = _b58encode(hash_obj.digest())

    padding = ""
    if len(b58_hash) < (c4_id_length - 2):
        padding = "1" * (c4_id_length - 2 - len(b58_hash))

    c4id = "c4" + padding + b58_hash
    return c4id