eth-signer 0.1.8

A Python library for transection signing using AWS Key Management Service.

eth-signer

A Python library for transection signing using AWS Key Management Service.

Dependencies

• Python 3.6+

QuickStart

This Package is available on PyPI. Install via pip as:

  pip install eth-signer

Usage

eth-signer needs AWS-KMS Client Object from boto3 to sign Ethereum transaction or message.

In the following example, the Basic use of eth-signer with boto3 has been given.

Step - 1 : Install required dependencies

$ pip3 install boto3 eth-signer web3

Step - 2 : Create a new key pair using boto3 ( Optional )

import boto3
from eth_signer.signer import AWSKMSKey
from web3 import Web3

# Get a kms_client Object From boto3
kms_client = boto3.client('kms', 'us-east-1')

# Generate new Key Pair using kms_client
new_key = kms.create_key(
    Description='New Eth Key',
    KeyUsage='SIGN_VERIFY',
    KeySpec='ECC_SECG_P256K1',
    Origin='AWS_KMS',
    MultiRegion=False
)

# Use KekId of newly generated key pair for AWSKMSKey Object
key_id = new_key['KeyMetadata']['KeyId']
kms_signer = AWSKMSKey(kms_client, key_id)

web3 = Web3(Web3.HTTPProvider('https://ropsten.infura.io/v3/<PROJECT_ID>'))

# Print Key ID and Eth address
print("KeyId: ", key_id)
print("Eth Address: ", kms_signer.address)

Step - 3 : Send a new transaction using web3, boto3 and eth-signer

Example: Transfer 0.01 ETH from AWS KMS managed Ethereum Account to another Ethereum Account. ( Please, do make you have sufficient balance in Account before executing the example code.)

import boto3
from eth_signer.signer import AWSKMSKey
from web3 import Web3

# Get a kms_client Object From boto3
kms_client = boto3.client('kms', 'us-east-1')

# User a KeyId of the AWS KMS Key
key_id = 'af8929db-010c-4476-00X0-0X00000X00X0'
kms_signer = AWSKMSKey(kms_client, key_id)

web3 = Web3(Web3.HTTPProvider('https://ropsten.infura.io/v3/<PROJECT_ID>'))
nonce = web3.eth.get_transaction_count(kms_signer.address)

print(web3.eth.getBalance(kms_signer.address))
# build a transaction in a dictionary
tx_obj = {
        "nonce": nonce,
        "from": kms_signer.address,
        "to": '0xBe0745cF5b82aB1de6fB1CEd849081BE06d9b3be',
        "value": web3.toWei(0.01, "ether"),
        "gas": 200000,
        "gasPrice": web3.toWei("50", "gwei"),
    }

signed_tx = kms_signer.sign_transaction(tx_obj)
tx_hash = web3.eth.send_raw_transaction(signed_tx.rawTransaction)

Output: HexBytes('0x826a52e59431a4be8780807cdd09da01d0dbbb00848fd7c9dff8383869c7372c')

Transaction on etherscan.io

Features

• Support for Ethereum Transaction and Message Signing using AWS Key Management Service

Contributors

• Kalpesh Sejpal
• Medium Article from Lucas Henning

Runtime dependencies

The distributed eth-signer contains software from the following projects from PyPi:

• eth-utils
• eth-typing
• hexbytes
• eth-rlp
• pycryptodome
• boto3
• flake8
• isort
• mypy
• Sphinx
• sphinx_rtd_theme
• towncrier
• bumpversion
• setuptools
• tox
• twine