パーフェクト Ruby on Rails 10章

basic_auth.rb

require 'base64'

class BasicAuth
  def initialize(app, user_name:, password:)
    @app = app
    @user_name = user_name
    @password = password
  end

  def call(env)
    if valid_credentials?(env['HTTP_AUTHORIZATION'])
      @app.call(env)
    else
      [401, { 'WWW-Authenticate' => 'Basic realm="Application"' }, ['Bad credentials']]
    end
  end

  private

  def valid_credentials?(credentials)
    return unless credentials.respond_to?(:match)

    credentials.match(/Basic\s+(.+)\z/) do |md|
      user_name, password = Base64.decode64(md[1]).scan(/\A(.+):(.*?)\z/).first
      user_name == @user_name && password == @password
    end
  end
end