require "rex/parser/nokogiri_doc_mixin"

module Rex
	module Parser

		# If Nokogiri is available, define Template document class. 
		load_nokogiri && class MbsaDocument < Nokogiri::XML::SAX::Document

		include NokogiriDocMixin

		# Triggered every time a new element is encountered. We keep state
		# ourselves with the @state variable, turning things on when we
		# get here (and turning things off when we exit in end_element()).
		def start_element(name=nil,attrs=[])
			attrs = normalize_attrs(attrs)
			block = @block
			@state[:current_tag][name] = true
			case name
			when "SecScan"
				record_host(attrs)
			when "IP" # TODO: Check to see if IPList/IP is useful to import
			when "Check" # A list of MBSA checks. They have an ID and a Name.
				record_check(attrs)
			when "Advice" # Check advice. Free form text about the check
				@state[:has_text] = true
			when "Detail" # Check/Detail is where missing fixes are.
				record_detail(attrs)
			when "UpdateData" # Info about installed/missing hotfixes
				record_updatedata(attrs)
			when "Title" # MSB Title
				@state[:has_text] = true
			when "InformationURL" # Only use this if we don't have a Bulletin ID
				@state[:has_text] = true
			end
		end

		# This breaks xml-encoded characters, so need to append
		def characters(text)
			return unless @state[:has_text]
			@text ||= ""
			@text << text
		end

		# When we exit a tag, this is triggered.
		def end_element(name=nil)
			block = @block
			case name
			when "SecScan" # Wrap it up
				collect_host_data
				host_object = report_host &block
				if host_object
					db.report_import_note(@args[:wspace],host_object)
					report_fingerprint(host_object)
					report_vulns(host_object,&block)
				end
				# Reset the state once we close a host
				@state.delete_if {|k| k != :current_tag}
			when "Check"
				collect_check_data
			when "Advice" 
				@state[:has_text] = false
				collect_advice_data
			when "Detail"
				collect_detail_data
			when "UpdateData"
				collect_updatedata
			when "Title"
				@state[:has_text] = false
				collect_title
			when "InformationURL"
				collect_url
				@state[:has_text] = false
			end
			@state[:current_tag].delete name
		end
		
		def report_fingerprint(host_object)
			return unless host_object.kind_of? Msf::DBManager::Host
			return unless @report_data[:os_fingerprint]
			fp_note = @report_data[:os_fingerprint].merge(
				{
					:workspace => host_object.workspace,
					:host => host_object
			})
			db_report(:note, fp_note)
		end

		def collect_url
			return unless in_tag("References")
			return unless in_tag("UpdateData")
			return unless in_tag("Detail")
			return unless in_tag("Check")
			@state[:update][:url] = @text.to_s.strip
			@text = nil
		end

		def report_vulns(host_object, &block)
			return unless host_object.kind_of? Msf::DBManager::Host
			return unless @report_data[:vulns]
			return if @report_data[:vulns].empty?
			@report_data[:vulns].each do |vuln|
				next unless vuln[:refs]
				if vuln[:refs].empty?
					next
				end
				if block
					db.emit(:vuln, ["Missing #{vuln[:name]}",1], &block) if block
				end
				db_report(:vuln, vuln.merge(:host => host_object))
			end
		end

		def collect_title
			return unless in_tag("SecScan")
			return unless in_tag("Check")
			collect_bulletin_title
			@text = nil
		end

		def collect_bulletin_title
			return unless @state[:check_state]["ID"] == 500.to_s
			return unless in_tag("UpdateData")
			return unless @state[:update]
			return if @text.to_s.strip.empty?
			@state[:update]["Title"] = @text.to_s.strip
		end

		def collect_updatedata
			return unless in_tag("SecScan")
			return unless in_tag("Check")
			return unless in_tag("Detail")
			collect_missing_update
			@state[:updates] = {}
		end

		def collect_missing_update
			return unless @state[:check_state]["ID"] == 500.to_s
			return if @state[:update]["IsInstalled"] == "true"
			@report_data[:missing_updates] ||= []
			this_update = {}
			this_update[:name] = @state[:update]["Title"].to_s.strip
			this_update[:refs] = []
			if @state[:update]["BulletinID"].empty?
				this_update[:refs] << "URL-#{@state[:update][:url]}"
			else
				this_update[:refs] << "MSB-#{@state[:update]["BulletinID"]}"
			end
			@report_data[:missing_updates] << this_update
		end

		# So far, just care about Host OS
		# There is assuredly more interesting things going on in here.
		def collect_advice_data
			return unless in_tag("SecScan")
			return unless in_tag("Check")
			collect_os_name
			@text = nil
		end

		def collect_os_name
			return unless @state[:check_state]["ID"] == 10101.to_s
			return unless @text
			return if @text.strip.empty?
			os_match = @text.match(/Computer is running (.*)/)
			return unless os_match
			os_info = os_match[1] 
			os_vendor = os_info[/Microsoft/]
			os_family = os_info[/Windows/]
			os_version = os_info[/(XP|2000 Advanced Server|2000|2003|2008|SBS|Vista|7 .* Edition|7)/]
			if os_info
				@report_data[:os_fingerprint] = {}
				@report_data[:os_fingerprint][:type] = "host.os.mbsa_fingerprint"
				@report_data[:os_fingerprint][:data] = {
					:os_vendor => os_vendor,
					:os_family => os_family,
					:os_version => os_version,
					:os_accuracy => 100,
					:os_match => os_info.gsub(/\x2e$/,"")
				}
			end
		end

		def collect_detail_data
			return unless in_tag("SecScan")
			return unless in_tag("Check")
			if @report_data[:missing_updates]
				@report_data[:vulns] = @report_data[:missing_updates]
			end
		end

		def collect_check_data
			return unless in_tag("SecScan")
			@state[:check_state] = {}
		end

		def collect_host_data
			return unless @state[:address]
			return if @state[:address].strip.empty?
			@report_data[:host] = @state[:address].strip
			if @state[:hostname] && !@state[:hostname].empty?
				@report_data[:name] = @state[:hostname]
			end
			@report_data[:state] = Msf::HostState::Alive
		end

		def report_host(&block)
			if host_is_okay
				db.emit(:address,@report_data[:host],&block) if block
				host_info = @report_data.merge(:workspace => @args[:wspace])
				db_report(:host, host_info)
			end
		end

		def record_updatedata(attrs)
			return unless in_tag("SecScan")
			return unless in_tag("Check")
			return unless in_tag("Detail")
			update_attrs = attr_hash(attrs)
			@state[:update] = attr_hash(attrs)
		end

		def record_host(attrs)
			host_attrs = attr_hash(attrs)
			@state[:address] = host_attrs["IP"]
			@state[:hostname] = host_attrs["Machine"]
		end

		def record_check(attrs)
			return unless in_tag("SecScan")
			@state[:check_state] = attr_hash(attrs)
		end

		def record_detail(attrs)
			return unless in_tag("SecScan")
			return unless in_tag("Check")
			@state[:detail_state] = attr_hash(attrs)
		end

		# We need to override the usual host_is_okay because MBSA apparently
		# doesn't report on open ports at all.
		def host_is_okay
			return false unless @report_data[:host]
			return false unless valid_ip(@report_data[:host])
			return false unless @report_data[:state] == Msf::HostState::Alive
			if @args[:blacklist]
				return false if @args[:blacklist].include?(@report_data[:host])
			end
			return true
		end

	end

end
end