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 78

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, []
  validate
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 37

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 48

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 33

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ISO 8601 datetime string that, if present, indicates when the signed authentication message is no longer valid.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 63

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 55

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 52

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 67

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 71

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 76

def resources
  @resources
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 59

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 41

def uri
  @uri
end

#version ⇒ Object

Current version of the message.



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# File 'lib/siwe/message.rb', line 44

def version
  @version
end

Class Method Details

.from_json_string(str) ⇒ Object 



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# File 'lib/siwe/message.rb', line 135

def self.from_json_string(str)
  obj = JSON.parse str, { symbolize_names: true }
  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]
    }
  )
end

.from_message(msg) ⇒ Object

Raises:



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# File 'lib/siwe/message.rb', line 94

def self.from_message(msg)
  message = msg.match SIWE_MESSAGE

  raise Siwe::UnableToParseMessage unless message.to_s == 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].to_i,
      expiration_time: message[:expiration_time],
      not_before: message[:not_before],
      request_id: message[:request_id],
      resources: message[:resources]&.split("\n- ")&.drop(1)
    }
  )
end

Instance Method Details

#prepare_message ⇒ Object 



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# File 'lib/siwe/message.rb', line 222

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

  header = [greeting, address]

  if @statement.nil? || @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}"

  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:\n#{@resources.map { |x| "- #{x}" }.join "\n"}" unless @resources.nil? || @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 117

def to_json_string
  obj = {
    domain: @domain,
    address: Eth::Address.new(@address).to_s,
    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
  }
  obj.to_json
end

#validate ⇒ Object

Raises:



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# File 'lib/siwe/message.rb', line 154

def validate
  # check domain
  raise Siwe::InvalidDomain unless @domain.match %r{[^/?#]*} || @domain.empty?

  # check address EIP-55
  raise Siwe::InvalidAddress unless Eth::Address.new(@address).to_s.eql? @address

  # check uri
  raise Siwe::InvalidURI unless URI.parse(@uri)

  # check version
  raise Siwe::InvalidMessageVersion unless @version == "1"

  # check if the nonce is alphanumeric and bigger then 8 characters
  raise Siwe::InvalidNonce unless @nonce.match(%r{[a-zA-Z0-9]{8,}})

  # check issued_at format
  begin
    Time.iso8601(@issued_at)
  rescue ArgumentError
    raise Siwe::InvalidTimeFormat, "issued_at"
  end

  # check exp_time
  begin
    Time.iso8601(@expiration_time) unless @expiration_time.nil? || @expiration_time.empty?
  rescue ArgumentError
    raise Siwe::InvalidTimeFormat, "expiration_time"
  end

  # check not_before
  begin
    Time.iso8601(@not_before) unless @not_before.nil? || @not_before.empty?
  rescue ArgumentError
    raise Siwe::InvalidTimeFormat, "not_before"
  end

  # check resources
  raise Siwe::InvalidURI unless @resources.nil? || @resources.empty? || @resources.each { |uri| URI.parse(uri) }
end

#verify(signature, domain, time, nonce) ⇒ Object

Raises:



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# File 'lib/siwe/message.rb', line 195

def verify(signature, domain, time, nonce)
  raise Siwe::DomainMismatch unless domain.nil? || domain.eql?(@domain)

  raise Siwe::NonceMismatch unless nonce.nil? || nonce.eql?(@nonce)

  check_time = time.nil? ? Time.now.utc : Time.iso8601(time)

  raise Siwe::ExpiredMessage if (!@expiration_time.nil? && !@expiration_time.empty?) && check_time > Time.iso8601(@expiration_time)

  raise Siwe::NotValidMessage if (!@not_before.nil? && !@not_before.empty?) && check_time < Time.iso8601(@not_before)

  raise Siwe::InvalidSignature if signature.nil? && signature.empty?

  raise Siwe::InvalidAddress unless @address.eql?(Eth::Address.new(@address).to_s)

  begin
    pub_key = Eth::Signature.personal_recover prepare_message, signature
    signature_address = Eth::Util.public_key_to_address pub_key
  rescue StandardError
    raise Siwe::InvalidSignature
  end

  raise Siwe::InvalidSignature unless signature_address.to_s.downcase.eql? @address.to_s.downcase

  true
end