trezor-firmware/core/src/apps/ethereum/address.py

from ubinascii import unhexlify

from trezor import wire


def address_from_bytes(address_bytes: bytes, network=None) -> str:
    """
    Converts address in bytes to a checksummed string as defined
    in https://github.com/ethereum/EIPs/blob/master/EIPS/eip-55.md
    """
    from ubinascii import hexlify
    from trezor.crypto.hashlib import sha3_256

    rskip60 = network is not None and network.rskip60

    hx = hexlify(address_bytes).decode()

    prefix = str(network.chain_id) + "0x" if rskip60 else ""
    hs = sha3_256(prefix + hx, keccak=True).digest()
    h = ""

    for i in range(20):
        l = hx[i * 2]
        if hs[i] & 0x80 and l >= "a" and l <= "f":
            l = l.upper()
        h += l
        l = hx[i * 2 + 1]
        if hs[i] & 0x08 and l >= "a" and l <= "f":
            l = l.upper()
        h += l

    return "0x" + h


def bytes_from_address(address: str) -> bytes:
    if len(address) == 40:
        return unhexlify(address)

    elif len(address) == 42:
        if address[0:2] not in ("0x", "0X"):
            raise wire.ProcessError("Ethereum: invalid beginning of an address")
        return unhexlify(address[2:])

    elif len(address) == 0:
        return bytes()

    raise wire.ProcessError("Ethereum: Invalid address length")