trezor-firmware/python/src/trezorlib/ethereum.py

# This file is part of the Trezor project.
#
# Copyright (C) 2012-2019 SatoshiLabs and contributors
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3
# as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the License along with this library.
# If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.

from . import exceptions, messages
from .tools import expect, normalize_nfc, session


def int_to_big_endian(value):
    return value.to_bytes((value.bit_length() + 7) // 8, "big")


# ====== Client functions ====== #


@expect(messages.EthereumAddress, field="address")
def get_address(client, n, show_display=False, multisig=None):
    return client.call(
        messages.EthereumGetAddress(address_n=n, show_display=show_display)
    )


@expect(messages.EthereumPublicKey)
def get_public_node(client, n, show_display=False):
    return client.call(
        messages.EthereumGetPublicKey(address_n=n, show_display=show_display)
    )


@session
def sign_tx(
    client,
    n,
    nonce,
    gas_price,
    gas_limit,
    to,
    value,
    data=None,
    chain_id=None,
    tx_type=None,
):
    msg = messages.EthereumSignTx(
        address_n=n,
        nonce=int_to_big_endian(nonce),
        gas_price=int_to_big_endian(gas_price),
        gas_limit=int_to_big_endian(gas_limit),
        value=int_to_big_endian(value),
        to=to,
        chain_id=chain_id,
        tx_type=tx_type,
    )

    if data:
        msg.data_length = len(data)
        data, chunk = data[1024:], data[:1024]
        msg.data_initial_chunk = chunk

    response = client.call(msg)

    while response.data_length is not None:
        data_length = response.data_length
        data, chunk = data[data_length:], data[:data_length]
        response = client.call(messages.EthereumTxAck(data_chunk=chunk))

    # https://github.com/trezor/trezor-core/pull/311
    # only signature bit returned. recalculate signature_v
    if response.signature_v <= 1:
        response.signature_v += 2 * chain_id + 35

    return response.signature_v, response.signature_r, response.signature_s


@expect(messages.EthereumMessageSignature)
def sign_message(client, n, message):
    message = normalize_nfc(message)
    return client.call(messages.EthereumSignMessage(address_n=n, message=message))


def verify_message(client, address, signature, message):
    message = normalize_nfc(message)
    try:
        resp = client.call(
            messages.EthereumVerifyMessage(
                address=address, signature=signature, message=message
            )
        )
    except exceptions.TrezorFailure:
        return False
    return isinstance(resp, messages.Success)