Ethereum for Ruby

A straightforward library to build, sign, and broadcast Ethereum transactions. It allows the separation of key and node management. Sign transactions and handle keys anywhere you can run Ruby and broadcast transactions through any local or remote node. Sign messages and recover signatures for authentication.

Note, this repository is just a long-term support branch of the minimally maintained eth gem version ~> 0.4. For the partial rewrite of version ~> 0.5 see q9f/eth.rb.

Installation ~> 0.4

Add this line to your application's Gemfile:

gem 'eth'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install eth

Usage ~> 0.4

Keys

Create a new public/private key and get its address:

key = Eth::Key.new
key.private_hex
key.public_hex
key.address # EIP55 checksummed address

Import an existing key:

old_key = Eth::Key.new priv: private_key

Or decrypt an encrypted key:

decrypted_key = Eth::Key.decrypt File.read('./some/path.json'), 'p455w0rD'

You can also encrypt your keys for use with other ethereum libraries:

encrypted_key_info = Eth::Key.encrypt key, 'p455w0rD'

Transactions ~> 0.4

Build a transaction from scratch:

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:

tx = Eth::Tx.decode hex

Then sign the transaction:

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:

Eth::Utils.valid_address? address

Or add a checksum to an existing address:

Eth::Utils.format_address "0x4bc787699093f11316e819b5692be04a712c4e69" # => "0x4bc787699093f11316e819B5692be04A712C4E69"

Personal Signatures

You can recover public keys and generate web3/metamask-compatible signatures:

# 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.

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 github.com/q9f/eth.rb. Tests are encouraged.

Tests

First install the Ethereum common tests:

git submodule update --init

Then run the associated tests:

rspec

License

The gem version ~> 0.4 is available as open-source software under the terms of the MIT License.