blocksec2go-ethereum 0.2.0

Wrapper for blocksec2go allowing easy hardware-based signing of Ethereum transactions

Blocksec2Go-Ethereum

This repository contains the source code of blocksec2go-ethereum Python package which wraps the blocksec2go package to allow easier interaction with Ethereum blockchain.

Read more about rationale behind this package on our blog post

If you're unsure what Blockchain Security 2 Go is, you can find more info here.

Installation

pip install blocksec2go-ethereum

Usage

After creating an instance of Blocksec2Go you can use it to generate signatures for transaction dicts. When passed raw tx, sign_transaction() will return a hex string of RLP-encoded signed transaction that can be directly consumed by web3.eth.sendRawTransaction().

The replay attack protection introduced with EIP-155 is used by default. Set chain_id=None to force the legacy behaviour for backward compatibility.

Transfer Ether

Below you will find an example of signing a simple Ether transfer:

from blocksec2go_ethereum import Blocksec2GoSigner
from web3 import Web3

WEB3_ENDPOINT = 'YOUR_ENDPOINT_HERE'

web3 = Web3(Web3.HTTPProvider(WEB3_ENDPOINT))
chain_id = web3.eth.chainId

signer = Blocksec2GoSigner(chain_id=chain_id, key_id=1)
address = signer.get_address()

nonce = web3.eth.getTransactionCount(address)
raw_tx = {
    'to': '0xBaBC446aee039E99d624058b0875E519190C6758',
    'nonce': nonce,
    'value': Web3.toWei(0.00005, 'ether'),
    'gas': 21000,
    'gasPrice': Web3.toWei(5, 'gwei'),
}
signed_tx = signer.sign_transaction(raw_tx)

tx_hash = web3.eth.sendRawTransaction(signed_tx)
print(f'Sent transaction with hash: {tx_hash.hex()}')

Call a contract function

You can also sign any contract calls/creation transactions by leveraging buildTransaction().

Please note that for some contracts buildTransaction() may require explicitly setting from field to properly estimate gas.

import json

from blocksec2go_ethereum import Blocksec2GoSigner
from web3 import Web3

WEB3_ENDPOINT = 'YOUR_ENDPOINT_HERE'

web3 = Web3(Web3.HTTPProvider(WEB3_ENDPOINT))
chain_id = web3.eth.chainId

signer = Blocksec2GoSigner(chain_id=chain_id, key_id=1)
address = signer.get_address()

with open('artifact.json', 'r') as artifact_file:
    artifact = json.loads(artifact_file.read())
    contract = web3.eth.contract(address=artifact['address'], abi=artifact['abi'])

nonce = web3.eth.getTransactionCount(address)
raw_tx = contract.functions.setValue(42).buildTransaction({'nonce': nonce, 'from': address})
signed_tx = signer.sign_transaction(raw_tx)

tx_hash = web3.eth.sendRawTransaction(signed_tx)
print(f'Sent transaction with hash: {tx_hash.hex()}')

License

ISC © 2020 rexs.io