trezor-firmware/python/tools/build_tx.py

#!/usr/bin/env python3
# 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>.

import json

import click
import requests

from trezorlib import btc, messages, tools
from trezorlib.cli import ChoiceType
from trezorlib.cli.btc import INPUT_SCRIPTS, OUTPUT_SCRIPTS
from trezorlib.protobuf import to_dict


def echo(*args, **kwargs):
    return click.echo(*args, err=True, **kwargs)


def prompt(*args, **kwargs):
    return click.prompt(*args, err=True, **kwargs)


def _default_script_type(address_n, script_types):
    script_type = "address"

    if address_n is None:
        pass
    elif address_n[0] == tools.H_(49):
        script_type = "p2shsegwit"
    elif address_n[0] == tools.H_(84):
        script_type = "segwit"

    return script_type
    # return script_types[script_type]


def parse_vin(s):
    txid, vout = s.split(":")
    return bytes.fromhex(txid), int(vout)


def _get_inputs_interactive(blockbook_url):
    inputs = []
    txes = {}
    while True:
        echo()
        prev = prompt(
            "Previous output to spend (txid:vout)", type=parse_vin, default=""
        )
        if not prev:
            break
        prev_hash, prev_index = prev
        address_n = prompt("BIP-32 path to derive the key", type=tools.parse_path)

        txhash = prev_hash.hex()
        tx_url = blockbook_url + txhash
        r = requests.get(tx_url)
        if not r.ok:
            raise click.ClickException(f"Failed to fetch URL: {tx_url}")

        tx_json = r.json()
        if "error" in tx_json:
            raise click.ClickException(f"Transaction not found: {txhash}")

        tx = btc.from_json(tx_json)
        txes[txhash] = tx
        amount = tx.bin_outputs[prev_index].amount
        echo("Input amount: {}".format(amount))

        sequence = prompt(
            "Sequence Number to use (RBF opt-in enabled by default)",
            type=int,
            default=0xFFFFFFFD,
        )
        script_type = prompt(
            "Input type",
            type=ChoiceType(INPUT_SCRIPTS),
            default=_default_script_type(address_n, INPUT_SCRIPTS),
        )
        if isinstance(script_type, str):
            script_type = INPUT_SCRIPTS[script_type]

        new_input = messages.TxInputType(
            address_n=address_n,
            prev_hash=prev_hash,
            prev_index=prev_index,
            amount=amount,
            script_type=script_type,
            sequence=sequence,
        )

        inputs.append(new_input)

    return inputs, txes


def _get_outputs_interactive():
    outputs = []
    while True:
        echo()
        address = prompt("Output address (for non-change output)", default="")
        if address:
            address_n = None
            script_type = messages.OutputScriptType.PAYTOADDRESS
        else:
            address = None
            address_n = prompt(
                "BIP-32 path (for change output)", type=tools.parse_path, default=""
            )
            if not address_n:
                break
            script_type = prompt(
                "Output type",
                type=ChoiceType(OUTPUT_SCRIPTS),
                default=_default_script_type(address_n, OUTPUT_SCRIPTS),
            )
            if isinstance(script_type, str):
                script_type = OUTPUT_SCRIPTS[script_type]

        amount = prompt("Amount to spend (satoshis)", type=int)

        outputs.append(
            messages.TxOutputType(
                address_n=address_n,
                address=address,
                amount=amount,
                script_type=script_type,
            )
        )

    return outputs


@click.command()
def sign_interactive():
    coin = prompt("Coin name", default="Bitcoin")
    blockbook_host = prompt("Blockbook server", default="btc1.trezor.io")

    if not requests.get(f"https://{blockbook_host}/api").ok:
        raise click.ClickException("Could not connect to blockbook")

    blockbook_url = f"https://{blockbook_host}/api/tx-specific/"

    inputs, txes = _get_inputs_interactive(blockbook_url)
    outputs = _get_outputs_interactive()

    signtx = messages.SignTx()
    signtx.version = prompt("Transaction version", type=int, default=2)
    signtx.lock_time = prompt("Transaction locktime", type=int, default=0)

    result = {
        "coin_name": coin,
        "inputs": [to_dict(i, hexlify_bytes=True) for i in inputs],
        "outputs": [to_dict(o, hexlify_bytes=True) for o in outputs],
        "details": to_dict(signtx, hexlify_bytes=True),
        "prev_txes": {
            txhash: to_dict(txdata, hexlify_bytes=True)
            for txhash, txdata in txes.items()
        },
    }

    print(json.dumps(result, sort_keys=True, indent=2))


if __name__ == "__main__":
    sign_interactive()