##
# $Id$
##

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##


require 'msf/core'


class Metasploit3 < Msf::Auxiliary

	include Msf::Auxiliary::Report
	include Msf::Auxiliary::Scanner

	def initialize
		super(
			'Name'        => 'SIP Endpoint Scanner (UDP)',
			'Version'     => '$Revision$',
			'Description' => 'Scan for SIP devices using OPTIONS requests',
			'Author'      => 'hdm',
			'License'     => MSF_LICENSE
		)

		register_options(
		[
			OptInt.new('BATCHSIZE', [true, 'The number of hosts to probe in each set', 256]),
			OptString.new('TO',   [ false, "The destination username to probe at each host", "nobody"]),
			Opt::RPORT(5060),
			Opt::CHOST,
			Opt::CPORT(5060)
		], self.class)
	end


	# Define our batch size
	def run_batch_size
		datastore['BATCHSIZE'].to_i
	end

	# Operate on an entire batch of hosts at once
	def run_batch(batch)

		begin
			udp_sock = nil
			idx = 0

			# Create an unbound UDP socket if no CHOST is specified, otherwise
			# create a UDP socket bound to CHOST (in order to avail of pivoting)
			udp_sock = Rex::Socket::Udp.create(
				{
					'LocalHost' => datastore['CHOST'] || nil,
					'LocalPort' => datastore['CPORT'].to_i,
					'Context' => {'Msf' => framework, 'MsfExploit' => self}
				}
			)
			add_socket(udp_sock)

			batch.each do |ip|
				data = create_probe(ip)

				begin
					udp_sock.sendto(data, ip, datastore['RPORT'].to_i, 0)
				rescue ::Interrupt
					raise $!
				rescue ::Rex::HostUnreachable, ::Rex::ConnectionTimeout, ::Rex::ConnectionRefused
					nil
				end

				if (idx % 10 == 0)
					while (r = udp_sock.recvfrom(65535, 0.01) and r[1])
						parse_reply(r)
					end
				end

				idx += 1
			end

			while (r = udp_sock.recvfrom(65535, 3) and r[1])
				parse_reply(r)
			end

		rescue ::Interrupt
			raise $!
		rescue ::Exception => e
			print_error("Unknown error: #{e.class} #{e}")
		ensure
			udp_sock.close if udp_sock
		end
	end

	#
	# The response parsers
	#
	def parse_reply(pkt)

		return if not pkt[1]

		if(pkt[1] =~ /^::ffff:/)
			pkt[1] = pkt[1].sub(/^::ffff:/, '')
		end

		resp  = pkt[0].split(/\s+/)[1]
		agent = ''
		verbs = ''
		serv  = ''
		prox  = ''

		if(pkt[0] =~ /^User-Agent:\s*(.*)$/i)
			agent = "agent='#{$1.strip}' "
		end

		if(pkt[0] =~ /^Allow:\s+(.*)$/i)
			verbs = "verbs='#{$1.strip}' "
		end

		if(pkt[0] =~ /^Server:\s+(.*)$/)
			serv = "server='#{$1.strip}' "
		end

		if(pkt[0] =~ /^Proxy-Require:\s+(.*)$/)
			serv = "proxy-required='#{$1.strip}' "
		end

		print_status("#{pkt[1]} #{resp} #{agent}#{serv}#{prox}#{verbs}")

		report_service(
			:host   => pkt[1],
			:port   => pkt[2],
			:proto  => 'udp',
			:name   => 'sip'
		)

		if(not agent.empty?)
			report_note(
				:host   => pkt[1],
				:type  => 'sip_useragent',
				:data   => agent
			)
		end
	end

	def create_probe(ip)
		suser = Rex::Text.rand_text_alphanumeric(rand(8)+1)
		shost = Rex::Socket.source_address(ip)
		src   = "#{shost}:#{datastore['CPORT']}"

		data  = "OPTIONS sip:#{datastore['TO']}@#{ip} SIP/2.0\r\n"
		data << "Via: SIP/2.0/UDP #{src};branch=z9hG4bK.#{"%.8x" % rand(0x100000000)};rport;alias\r\n"
		data << "From: sip:#{suser}@#{src};tag=70c00e8c\r\n"
		data << "To: sip:#{datastore['TO']}@#{ip}\r\n"
		data << "Call-ID: #{rand(0x100000000)}@#{shost}\r\n"
		data << "CSeq: 1 OPTIONS\r\n"
		data << "Contact:  sip:#{suser}@#{src}\r\n"
		data << "Content-Length: 0\r\n"
		data << "Max-Forwards: 20\r\n"
		data << "User-Agent: #{suser}\r\n"
		data << "Accept: text/plain\r\n"
	end


end