transaction.py

from collections import OrderedDict

import binascii

from Crypto.Hash import SHA
from Crypto.PublicKey import RSA
from Crypto.Signature import PKCS1_v1_5


class Transaction:
    def __init__(self, sender_address, sender_private_key, recipient_address, value):
        self.sender_address = sender_address
        self.sender_private_key = sender_private_key
        self.recipient_address = recipient_address
        self.value = value

    def __getattr__(self, attr):
        return self.data[attr]

    def to_dict(self):
        return OrderedDict(
            {
                "sender_address": self.sender_address,
                "recipient_address": self.recipient_address,
                "value": self.value,
            }
        )

    def sign_transaction(self):
        """Sign transaction with private key"""
        private_key = RSA.importKey(binascii.unhexlify(self.sender_private_key))
        signer = PKCS1_v1_5.new(private_key)

        hash = SHA.new(str(self.to_dict()).encode("utf8"))
        return binascii.hexlify(signer.sign(hash)).decode("ascii")