SecGen/lib/readers/system_reader.rb

require 'nokogiri'

require_relative '../objects/system'
require_relative '../objects/module'

class SystemReader

  # uses nokogiri to extract all system information from scenario.xml
  # This includes module filters, which are module objects that contain filters for selecting
  # from the actual modules that are available
  # @return [Array] Array containing Systems objects
  def self.read_scenario(scenario_file)
    systems = []
    Print.verbose "Reading scenario file: #{scenario_file}"
    doc, xsd = nil
    begin
      doc = Nokogiri::XML(File.read(scenario_file))
    rescue
      Print.err "Failed to read scenario configuration file (#{scenario_file})"
      exit
    end

    # validate scenario XML against schema
    begin
      xsd = Nokogiri::XML::Schema(File.open(SCENARIO_SCHEMA_FILE))
      xsd.validate(doc).each do |error|
        Print.err "Error in scenario configuration file (#{scenario_file}):"
        Print.err '    ' + error.message
        exit
      end
    rescue Exception => e
      Print.err "Failed to validate scenario configuration file (#{scenario_file}): against schema (#{SCENARIO_SCHEMA_FILE})"
      Print.err e.message
      exit
    end

    # remove xml namespaces for ease of processing
    doc.remove_namespaces!

    doc.xpath('/scenario/system').each do |system_node|
      module_selectors = []
      system_attributes = {}

      system_name = system_node.at_xpath('system_name').text
      Print.verbose "system: #{system_name}"

      # system attributes, such as basebox selection
      system_node.xpath('@*').each do |attr|
        system_attributes["#{attr.name}"] = attr.text unless attr.text.nil? || attr.text == ''
      end

      # for each module selection
      system_node.xpath('vulnerability | service | network | base').each do |module_node|
        module_selector = Module.new("#{module_node.name}_selecter")
        module_node.xpath('@*').each do |attr|
          module_selector.attributes["#{attr.name}"] = attr.text unless attr.text.nil? || attr.text == ''
        end
        Print.verbose " #{module_node.name}, selecting based on:"
        module_selector.attributes.each do |attr|
          if attr[0] && attr[1] && attr[0].to_s != "module_type"
            Print.verbose "  - #{attr[0].to_s} ~= #{attr[1].to_s}"
          end
        end

        module_selectors << module_selector
      end
      systems << System.new(system_name, system_attributes, module_selectors)
    end

    return systems
  end
end