Eth
A simple library to build and sign Ethereum transactions. Allows separation of key and node management. Sign transactions and handle keys anywhere you can run ruby, broadcast transactions through any node.
Installation
Add this line to your application’s Gemfile:
“by gem ‘eth’
“
And then execute:
$ bundle
Or install it yourself as:
$ gem install eth
Usage
Keys
Create a new public/private key and get its address:
“by key = Eth::Key.new key.private_hex key.public_hex key.address # EIP55 checksummed address
“
Import an existing key:
“by old_key = Eth::Key.new priv: private_key
“
Or decrypt an encrypted key:
“by decrypted_key = Eth::Key.decrypt File.read(‘./some/path.json’), ‘p455w0rD’
“
You can also encrypt your keys for use with other ethereum libraries:
“by encrypted_key_info = Eth::Key.encrypt key, ‘p455w0rD’
“
Transactions
Build a transaction from scratch:
“by tx = Eth::Tx.new({ data: hex_data, gas_limit: 21_000, gas_price: 3_141_592, nonce: 1, to: key2.address, value: 1_000_000_000_000, })
“
Or decode an encoded raw transaction:
“by tx = Eth::Tx.decode hex
“
Then sign the transaction:
“by tx.sign key
“
Get the raw transaction with tx.hex
, and broadcast it through any Ethereum node. Or, just get the TXID with tx.hash
.
Utils
Validate an EIP55 checksummed address:
“by Eth::Utils.valid_address? address
“
Or add a checksum to an existing address:
“by Eth::Utils.format_address “0x4bc787699093f11316e819b5692be04a712c4e69” # => “0x4bc787699093f11316e819B5692be04A712C4E69”
“
Personal Signatures
You can recover public keys and generate web3/metamask-compatible signatures:
“by
Generate signature
key.personal_sign(‘hello world’)
Recover signature
message = ‘test’ signature = ‘0x3eb24bd327df8c2b614c3f652ec86efe13aa721daf203820241c44861a26d37f2bffc6e03e68fc4c3d8d967054c9cb230ed34339b12ef89d512b42ae5bf8c2ae1c’ Eth::Key.personal_recover(message, signature) # => 043e5b33f0080491e21f9f5f7566de59a08faabf53edbc3c32aaacc438552b25fdde531f8d1053ced090e9879cbf2b0d1c054e4b25941dab9254d2070f39418afc
“
Configure
In order to prevent replay attacks, you must specify which Ethereum chain your transactions are created for. See EIP 155 for more detail.
“by Eth.configure do |config| config.chain_id = 1 # nil by default, meaning valid on any chain end
“
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/se3000/ethereum-tx. Tests are encouraged.
Tests
First install the Ethereum common tests:
“ell git submodule update –init
“
Then run the associated tests:
“ell rspec
“
License
The gem is available as open source under the terms of the MIT License.
TODO
- Better test suite.
- Expose API for HD keys.
- Support signing with libsecp256k1.