Devise::Web3

Devise-web3 allows to easily implement login with metamask or any other ethereum wallet providers. It works by providing a nonce for a user to sign and then cryptographically checking that signature is valid. This allows for a simple one click login popular among web3 apps.

1. Devise-web3 adds a new controller that generates a nonce for a wallet provider to sign(eg. metamask) along with nonce_id
2. nonce gets signed by a wallet provider
3. signature, nonce_id and wallet address is then sent by frontend to a regular sign_in endpoint provided by devise
4. Devise-web3 then checks the signature and authenticates user

Add this line to your application's Gemfile:

gem 'devise-web3'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install devise-web3

Add :web3_authenticatable module to your model along your other devise modules

Example

class User < ApplicationRecord
  devise :jwt_authenticatable,
    :web3_authenticatable
end

Generate migration

bin/rails g active_record:devise_web3 users

then run the migration

Generate config

bin/rails devise:web3:install

Provide your redis url in config

config.web3 do |web3|
  web3.redis_url = nil
end

You're all set. It's time to setup a frontend

For vue you can use a vue component or simply check the source code to see the general flow

1. Fetch user wallet address

const accounts = await window.ethereum.request({ method: "eth_requestAccounts" })
const address = accounts[0]

2. Fetch nonce and nonce_id through API
3. Sign the nonce

const web3 = new Web3()
const signature = await ethereum.request({
  method: "personal_sign",
  params: [web3.utils.fromUtf8(nonce), address],
})

4. Send { credenatils: { signature: signature, nonce_id: nonce_id, address: address }} to sign in endpoint

There are many possibible improvements to Devise-web3. Feel free to create an issue with your requests

The gem is available as open source under the terms of the MIT License.