Class: Siwe::Message

Inherits:
Object
  • Object
show all
Defined in:
lib/siwe/message.rb

Overview

Class that defines the EIP-4361 message fields and some utility methods to generate/validate the messages

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(domain, address, uri, version, options = {}) ⇒ Message

Returns a new instance of Message.



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# File 'lib/siwe/message.rb', line 80

def initialize(domain, address, uri, version, options = {})
  @domain = domain
  @address = address
  @uri = uri
  @version = version

  @statement = options.fetch :statement, ""
  @issued_at = options.fetch :issued_at, Time.now.utc.iso8601
  @nonce = options.fetch :nonce, Siwe::Util.generate_nonce
  @chain_id = options.fetch :chain_id, "1"
  @expiration_time = options.fetch :expiration_time, ""
  @not_before = options.fetch :not_before, ""
  @request_id = options.fetch :request_id, ""
  @resources = options.fetch :resources, []
  @signature = options.fetch :signature, ""
  validate(true)
end

Instance Attribute Details

#address ⇒ Object

Ethereum address performing the signing conformant to capitalization encoded checksum specified in EIP-55 where applicable.



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# File 'lib/siwe/message.rb', line 36

def address
  @address
end

#chain_id ⇒ Object

EIP-155 Chain ID to which the session is bound, and the network where Contract Accounts must be resolved.



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# File 'lib/siwe/message.rb', line 47

def chain_id
  @chain_id
end

#domain ⇒ Object

RFC 4501 dns authority that is requesting the signing.



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# File 'lib/siwe/message.rb', line 32

def domain
  @domain
end

#expiration_time ⇒ Object

ISO 8601 datetime string that, if present, indicates when the signed authentication message is no longer valid.



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# File 'lib/siwe/message.rb', line 62

def expiration_time
  @expiration_time
end

#issued_at ⇒ Object

ISO 8601 datetime string of the current time.



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# File 'lib/siwe/message.rb', line 54

def issued_at
  @issued_at
end

#nonce ⇒ Object

Randomized token used to prevent replay attacks, at least 8 alphanumeric characters.



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# File 'lib/siwe/message.rb', line 51

def nonce
  @nonce
end

#not_before ⇒ Object

ISO 8601 datetime string that, if present, indicates when the signed authentication message will become valid.



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# File 'lib/siwe/message.rb', line 66

def not_before
  @not_before
end

#request_id ⇒ Object

System-specific identifier that may be used to uniquely refer to the sign-in request.



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# File 'lib/siwe/message.rb', line 70

def request_id
  @request_id
end

#resources ⇒ Object

List of information or references to information the user wishes to have resolved as part of authentication by the relying party. They are expressed as RFC 3986 URIs separated by ‘n- `.



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# File 'lib/siwe/message.rb', line 75

def resources
  @resources
end

#signature ⇒ Object

Signature of the message signed by the wallet.



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# File 'lib/siwe/message.rb', line 78

def signature
  @signature
end

#statement ⇒ Object

Human-readable ASCII assertion that the user will sign, and it must not contain ‘n`.



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# File 'lib/siwe/message.rb', line 58

def statement
  @statement
end

#uri ⇒ Object

RFC 3986 URI referring to the resource that is the subject of the signing (as in the __subject__ of a claim).



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# File 'lib/siwe/message.rb', line 40

def uri
  @uri
end

#version ⇒ Object

Current version of the message.



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# File 'lib/siwe/message.rb', line 43

def version
  @version
end

Class Method Details

.from_json_string(str) ⇒ Object 



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# File 'lib/siwe/message.rb', line 142

def self.from_json_string(str)
  obj = JSON.parse str, { symbolize_names: true }
  msg = Siwe::Message.new(
    obj[:domain],
    obj[:address],
    obj[:uri],
    obj[:version], {
      chain_id: obj[:chain_id],
      nonce: obj[:nonce],
      issued_at: obj[:issued_at],
      statement: obj[:statement],
      expiration_time: obj[:expiration_time],
      not_before: obj[:not_before],
      request_id: obj[:request_id],
      resources: obj[:resources],
      signature: obj[:signature]
    }
  )
  msg.validate(true)
  msg
end

.from_message(msg) ⇒ Object 



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# File 'lib/siwe/message.rb', line 98

def self.from_message(msg)
  if (message = msg.match SIWE_MESSAGE)
    msg = new(
      message[:domain],
      message[:address],
      message[:uri],
      message[:version],
      {
        statement: message[:statement] || "",
        issued_at: message[:issued_at],
        nonce: message[:nonce],
        chain_id: message[:chain_id],
        expiration_time: message[:expiration_time] || "",
        not_before: message[:not_before] || "",
        request_id: message[:request_id] || "",
        resources: message[:resources]&.split("\n- ")&.drop(1) || []
      }
    )
    msg.validate(true)
    msg
  else
    throw "Invalid message input."
  end
end

Instance Method Details

#personal_sign ⇒ Object 



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# File 'lib/siwe/message.rb', line 179

def personal_sign
  greeting = "#{@domain} wants you to sign in with your Ethereum account:"
  address = @address
  statement = "\n#{@statement}\n"

  header = [greeting, address]

  if @statement.empty?
    header.push "\n"
  else
    header.push statement
  end

  header = header.join "\n"

  uri = "URI: #{@uri}"
  version = "Version: #{@version}"
  chain_id = "Chain ID: #{@chain_id}"
  nonce = "Nonce: #{@nonce}"
  issued_at = "Issued At: #{@issued_at}"

  body = [uri, version, chain_id, nonce, issued_at]

  expiration_time = "Expiration Time: #{@expiration_time}"
  not_before = "Not Before: #{@not_before}"
  request_id = "Request ID: #{@request_id}"
  resources = "Resources:\n#{@resources.map { |x| "- #{x}" }.join "\n"}"

  body.push expiration_time unless @expiration_time.to_s.strip.empty?

  body.push not_before unless @not_before.to_s.strip.empty?

  body.push request_id unless @request_id.to_s.strip.empty?

  body.push resources unless @resources.empty?

  body = body.join "\n"

  [header, body].join "\n"
end

#to_json_string ⇒ Object 



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# File 'lib/siwe/message.rb', line 123

def to_json_string
  obj = {
    domain: @domain,
    address: @address,
    uri: @uri,
    version: @version,
    chain_id: @chain_id,
    nonce: @nonce,
    issued_at: @issued_at,
    statement: @statement,
    expiration_time: @expiration_time,
    not_before: @not_before,
    request_id: @request_id,
    resources: @resources,
    signature: @signature
  }
  obj.to_json
end

#validate(skip_signature = false) ⇒ Object 



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# File 'lib/siwe/message.rb', line 164

def validate(skip_signature = false)
  raise "Message expired." if !@expiration_time.empty? && Time.now.utc > Time.parse(@expiration_time)
  raise "Message not yet valid." if !@not_before.empty? && Time.now.utc < Time.parse(@not_before)

  unless skip_signature
    raise "Missing signature field." if @signature.empty?

    pub_key = Eth::Signature.personal_recover personal_sign, @signature
    signature_address = Eth::Util.public_key_to_address pub_key
    raise "Signature doesn't match message." unless signature_address.to_s.downcase.eql? @address.to_s.downcase
  end

  true
end