siwe-ruby

A Ruby implementation of EIP-4361: Sign In With Ethereum.

Getting started

Dependencies

Additional packages may be required to install the gem:

macOS

brew install automake openssl libtool pkg-config gmp libffi

Linux

sudo apt-get install build-essential automake pkg-config libtool \
                     libffi-dev libssl-dev libgmp-dev python-dev

After installing any required dependencies SIWE can be easily installed with:

gem install siwe

Usage

SIWE provides a Message class which implements EIP-4361.

Creating a SIWE Message

require 'siwe'
require 'time'

# Only the mandatory arguments
Siwe::Message.new("domain.example", "0x9D85ca56217D2bb651b00f15e694EB7E713637D4", "some.uri", "1")

# Complete SIWE message with default values
Siwe::Message.new("domain.example", "0x9D85ca56217D2bb651b00f15e694EB7E713637D4", "some.uri", "1", {
                                   issued_at: Time.now.utc.iso8601,
                                   statement: "Example statement for SIWE",
                                   nonce: Siwe::Util.generate_nonce,
                                   chain_id: "1",
                                   expiration_time: "",
                                   not_before: "",
                                   request_id: "",
                                   resources: []
                                 })

Parsing a SIWE Message

To parse from EIP-4361 use Siwe::Message.from_message

require 'siwe'

Siwe::Message.from_message "domain.example wants you to sign in with your Ethereum account:\n0x9D85ca56217D2bb651b00f15e694EB7E713637D4\n\nExample statement for SIWE\n\nURI: some.uri\nVersion: 1\nChain ID: 1\nNonce: k1Ne4KWzBHYEFQo8\nIssued At: 2022-02-03T20:06:19Z"

Messages can be parsed to and from JSON strings, using Siwe::Message.from_json_string and Siwe::Message.to_json_string respectively:

require 'siwe'

Siwe::Message.from_json_string "{\"domain\":\"domain.example\",\"address\":\"0x9D85ca56217D2bb651b00f15e694EB7E713637D4\",\"uri\":\"some.uri\",\"version\":\"1\",\"chain_id\":\"1\",\"nonce\":\"k1Ne4KWzBHYEFQo8\",\"issued_at\":\"2022-02-03T20:06:19Z\",\"statement\":\"Example statement for SIWE\",\"expiration_time\":\"\",\"not_before\":\"\",\"request_id\":\"\",\"resources\":[]}"

Siwe::Message.new("domain.example", "0x9D85ca56217D2bb651b00f15e694EB7E713637D4", "some.uri", "1").to_json_string

Verifying and Authenticating a SIWE Message

Verification and authentication is performed via EIP-191, using the address field of the SiweMessage as the expected signer. The validate method checks message structural integrity, signature address validity, and time-based validity attributes.

begin
    message.verify(signature, domain, time, nonce) # returns true if valid throws otherwise
rescue Siwe::ExpiredMessage
    # Used when the message is already expired. (Expires At < Time.now)
rescue Siwe::NotValidMessage
    # Used when the message is not yet valid. (Not Before > Time.now)
rescue Siwe::InvalidSignature
    # Used when the signature doesn't correspond to the address of the message.
end

Serialization of a SIWE Message

Siwe::Message instances can also be serialized as their EIP-4361 string representations via the Siwe::Message.prepare_message method:

require 'siwe'

Siwe::Message.new("domain.example", "0x9D85ca56217D2bb651b00f15e694EB7E713637D4", "some.uri", "1").prepare_message

Example

Parsing and verifying a Siwe::Message:

require 'siwe'

begin
  message = Siwe::Message.from_message "login.xyz wants you to sign in with your Ethereum account:\n0x9D85ca56217D2bb651b00f15e694EB7E713637D4\n\nSign-In With Ethereum Example Statement\n\nURI: https://login.xyz\nVersion: 1\nChain ID: 1\nNonce: bTyXgcQxn2htgkjJn\nIssued At: 2022-01-27T17:09:38.578Z\nExpiration Time: 2100-01-07T14:31:43.952Z"
  message.verify("0xdc35c7f8ba2720df052e0092556456127f00f7707eaa8e3bbff7e56774e7f2e05a093cfc9e02964c33d86e8e066e221b7d153d27e5a2e97ccd5ca7d3f2ce06cb1b", "login.xyz", "2022-01-27T17:10:00Z", "bTyXgcQxn2htgkjJn")
    puts "Congrats, your message is valid"
rescue Siwe::ExpiredMessage
    # Used when the message is already expired. (Expires At < Time.now)
rescue Siwe::NotValidMessage
    # Used when the message is not yet valid. (Not Before > Time.now)
rescue Siwe::InvalidSignature
    # Used when the signature doesn't correspond to the address of the message.
end