Class: OmniAuth::Krystal::InitiatedLoginMiddleware

Inherits:
Object
  • Object
show all
Defined in:
lib/omniauth/krystal/initiated_login_middleware.rb

Defined Under Namespace

Classes: AntiReplayTokenAlreadyUsedError, Error, JWTDecodeError, JWTExpiredError

Constant Summary collapse

JWT_RESERVED_CLAIMS = 
%w[ar exp nbf iss aud jti iat sub].freeze

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ InitiatedLoginMiddleware

Returns a new instance of InitiatedLoginMiddleware.



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# File 'lib/omniauth/krystal/initiated_login_middleware.rb', line 23

def initialize(app, options = {})
  @app = app
  @options = options

  @options[:provider_name] ||= 'krystal'
  @options[:identity_url] ||= ENV.fetch('KRYSTAL_IDENTITY_URL', 'https://identity.krystal.io')
  @options[:anti_replay_expiry_seconds] ||= 60

  @keys = SigningKeys.new("#{@options[:identity_url]}/.well-known/signing.json")
end

Instance Method Details

#call(env) ⇒ Object

rubocop:disable Metrics/MethodLength rubocop:disable Metrics/AbcSize



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# File 'lib/omniauth/krystal/initiated_login_middleware.rb', line 36

def call(env)
  unless env['PATH_INFO'] == "/auth/#{@options[:provider_name]}/callback"
    # If it's not a Krystal Identity auth callback then we don't
    # need to do anything here.
    return @app.call(env)
  end

  request = Rack::Request.new(env)
  state = request.params['state']

  if state.nil? || !state.start_with?('kidil_')
    # Return to the app if the state is not a Krystal Identity
    # initiated login.
    return @app.call(env)
  end

  # Decode the JWT and ensure that the state is valid. JWT will check
  # the expiry.
  data = nil
  begin
    data, = JWT.decode(state.sub(/\Akidil_/, ''), nil, true, { algorithm: 'ES256', jwks: @keys })
  rescue JWT::ExpiredSignature
    raise JWTExpiredError, 'State parameter has expired'
  rescue JWT::DecodeError
    raise JWTDecodeError,
          'Invalid state parameter provided (either malformed, expired or signed with the wrong key)'
  end

  # Verify the replay token
  verify_anti_replay_token(data['ar'])

  # Set the expected omniauth state to the state that we have been given so it
  # thinks the session is trusted as normal.
  env['rack.session']['omniauth.state'] = state

  # Set any additional params that were passed in the state.
  env['rack.session']['omniauth.params'] = data.reject { |key| JWT_RESERVED_CLAIMS.include?(key) }

  @app.call(env)
end