app-ethereum/examples/ethBase.py

#!/usr/bin/env python
"""
*******************************************************************************
*   Ledger Ethereum App
*   (c) 2016-2019 Ledger
*
*  Licensed under the Apache License, Version 2.0 (the "License");
*  you may not use this file except in compliance with the License.
*  You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
*  Unless required by applicable law or agreed to in writing, software
*  distributed under the License is distributed on an "AS IS" BASIS,
*  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*  See the License for the specific language governing permissions and
*  limitations under the License.
********************************************************************************
"""

from rlp.sedes import big_endian_int, binary, Binary
from rlp import Serializable

try:
    from Crypto.Hash import keccak

    def sha3_256(x): return keccak.new(digest_bits=256, data=x).digest()
except:
    import sha3 as _sha3

    def sha3_256(x): return _sha3.sha3_256(x).digest()
address = Binary.fixed_length(20, allow_empty=True)


def sha3(seed):
    return sha3_256(str(seed))


class Transaction(Serializable):
    fields = [
        ('nonce', big_endian_int),
        ('gasprice', big_endian_int),
        ('startgas', big_endian_int),
        ('to', address),
        ('value', big_endian_int),
        ('data', binary),
        ('v', big_endian_int),
        ('r', big_endian_int),
        ('s', big_endian_int),
    ]

    def __init__(self, nonce, gasprice, startgas, to, value, data, v=0, r=0, s=0):
        super(Transaction, self).__init__(
            nonce, gasprice, startgas, to, value, data, v, r, s)


UnsignedTransaction = Transaction.exclude(['v', 'r', 's'])