enum_dns.rb

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

require 'msf/core'
require "net/dns/resolver"

class Metasploit3 < Msf::Auxiliary
	include Msf::Auxiliary::Report

	def initialize(info = {})
		super(update_info(info,
			'Name'		   => 'DNS Record Scanner and Enumerator ',
			'Description'	=> %q{
				This module can be used to gather information about a domain from a
				given DNS server by performing various DNS queries such as zone
				transfers, reverse lookups, SRV record bruteforcing, and other techniques.

			},
			'Author'		=> [ 'Carlos Perez <carlos_perez[at]darkoperator.com>' ],
			'License'		=> MSF_LICENSE,
			'Version'		=> '$Revision$',
			'References' 	=>
				[
					['CVE', '1999-0532'],
					['OSVDB', '492'],
				]
			))

		register_options(
			[
				OptString.new('DOMAIN', [ true, "The target domain name"]),
				OptBool.new('ENUM_AXFR', [ true, 'Initiate a zone transfer against each NS record', true]),
				OptBool.new('ENUM_TLD', [ true, 'Perform a TLD expansion by replacing the TLD with the IANA TLD list', false]),
				OptBool.new('ENUM_STD', [ true, 'Enumerate standard record types (A,MX,NS,TXT and SOA)', true]),
				OptBool.new('ENUM_BRT', [ true, 'Brute force subdomains and hostnames via the supplied wordlist', false]),
				OptBool.new('ENUM_IP6', [ true, 'Brute force hosts with IPv6 AAAA records',false]),
				OptBool.new('ENUM_RVL', [ true, 'Reverse lookup a range of IP addresses', false]),
				OptBool.new('ENUM_SRV', [ true, 'Enumerate the most common SRV records', true]),
				OptPath.new('WORDLIST', [ false, "Wordlist for domain name bruteforcing", ::File.join(Msf::Config.install_root, "data", "wordlists", "namelist.txt")]),
				OptAddress.new('NS', [ false, "Specify the nameserver to use for queries (default is system DNS)" ]),
				OptAddressRange.new('IPRANGE', [false, "The target address range or CIDR identifier"]),
				OptBool.new('STOP_WLDCRD', [ true, 'Stops bruteforce enumeration if wildcard resolution is detected', false])
			], self.class)

		register_advanced_options(
			[
				OptInt.new('RETRY', [ false, "Number of times to try to resolve a record if no response is received", 2]),
				OptInt.new('RETRY_INTERVAL', [ false, "Number of seconds to wait before doing a retry", 2]),
				OptBool.new('TCP_DNS', [false, "Run queries over TCP", false]),
			], self.class)
	end

	#---------------------------------------------------------------------------------
	def switchdns(target)
		if not datastore['NS'].nil?
			print_status("Using DNS Server: #{datastore['NS']}")
			@res.nameserver=(datastore['NS'])
			@nsinuse = datastore['NS']
		else
			querysoa = @res.query(target, "SOA")
			if (querysoa)
				(querysoa.answer.select { |i| i.class == Net::DNS::RR::SOA}).each do |rr|
					query1soa = @res.search(rr.mname)
					if (query1soa and query1soa.answer[0])
						print_status("Setting DNS Server to #{target} NS: #{query1soa.answer[0].address}")
						@res.nameserver=(query1soa.answer[0].address)
						@nsinuse = query1soa.answer[0].address
					end
				end
			end
		end
	end
	#---------------------------------------------------------------------------------
	def wildcard(target)
		rendsub = rand(10000).to_s
		query = @res.query("#{rendsub}.#{target}", "A")
		if query.answer.length != 0
			print_status("This domain has wildcards enabled!!")
			query.answer.each do |rr|
				print_status("Wildcard IP for #{rendsub}.#{target} is: #{rr.address.to_s}") if rr.class != Net::DNS::RR::CNAME
			end
			return true
		else
			return false
		end
	end
	#---------------------------------------------------------------------------------
	def genrcd(target)
		print_status("Retrieving general DNS records")
		query = @res.search(target)
		if (query)
			query.answer.each do |rr|
				next unless rr.class == Net::DNS::RR::A
				print_status("Domain: #{target} IP address: #{rr.address} Record: A ")
				report_note(:host => @nsinuse.to_s,
					:proto => 'udp',
					:sname => 'dns',
					:port => 53 ,
					:type => 'dns.enum',
					:update => :unique_data,
					:data => "#{rr.address.to_s},#{target},A")
			end
		end
		query = @res.query(target, "SOA")
		if (query)
			(query.answer.select { |i| i.class == Net::DNS::RR::SOA}).each do |rr|
				query1 = @res.search(rr.mname)
				if (query1)
					query1.answer.each do |ip|
						print_status("Start of Authority: #{rr.mname} IP address: #{ip.address} Record: SOA")
						report_note(:host => @nsinuse.to_s,
							:proto => 'udp',
							:sname => 'dns',
							:port => 53 ,
							:type => 'dns.enum',
							:update => :unique_data,
							:data => "#{ip.address.to_s},#{rr.mname},SOA")
					end
				end
			end
		end
		query = @res.query(target, "NS")
		if (query)
			(query.answer.select { |i| i.class == Net::DNS::RR::NS}).each do |rr|
				query1 = @res.search(rr.nsdname)
				if (query1)
					query1.answer.each do |ip|
						next unless ip.class == Net::DNS::RR::A
						print_status("Name Server: #{rr.nsdname} IP address: #{ip.address} Record: NS")
						report_note(:host => @nsinuse.to_s,
							:proto => 'udp',
							:sname => 'dns',
							:port => 53 ,
							:type => 'dns.enum',
							:update => :unique_data,
							:data => "#{ip.address.to_s},#{rr.nsdname},NS")
					end
				end
			end
		end
		query = @res.query(target, "MX")
		if (query)
			(query.answer.select { |i| i.class == Net::DNS::RR::MX}).each do |rr|
				print_status("Name: #{rr.exchange} Preference: #{rr.preference} Record: MX")
				report_note(:host => @nsinuse.to_s,
					:proto => 'udp',
					:sname => 'dns',
					:port => 53 ,
					:type => 'dns.enum',
					:update => :unique_data,
					:data => "#{rr.exchange},MX")
			end
		end
		query = @res.query(target, "TXT")
		if (query)
			query.answer.each do |rr|
				print_status(rr.inspect)
				print_status("Text: #{rr.inspect}")
				report_note(:host => @nsinuse.to_s,
					:proto => 'udp',
					:sname => 'dns',
					:port => 53 ,
					:type => 'dns.enum',
					:update => :unique_data,
					:data => rr.inspect)
			end
		end
	end
	#---------------------------------------------------------------------------------
	def tldexpnd(targetdom,nssrv)
		target = targetdom.scan(/(\S*)[.]\w*\z/).join
		target.chomp!
		if not nssrv.nil?
			@res.nameserver=(nssrv)
			@nsinuse = nssrv
		end
		i, a = 0, []
		tlds = [
			"com", "org", "net", "edu", "mil", "gov", "uk", "af", "al", "dz",
			"as", "ad", "ao", "ai", "aq", "ag", "ar", "am", "aw", "ac","au",
			"at", "az", "bs", "bh", "bd", "bb", "by", "be", "bz", "bj", "bm",
			"bt", "bo", "ba", "bw", "bv", "br", "io", "bn", "bg", "bf", "bi",
			"kh", "cm", "ca", "cv", "ky", "cf", "td", "cl", "cn", "cx", "cc",
			"co", "km", "cd", "cg", "ck", "cr", "ci", "hr",	"cu", "cy", "cz",
			"dk", "dj", "dm", "do", "tp", "ec", "eg", "sv", "gq", "er", "ee",
			"et", "fk", "fo", "fj",	"fi", "fr", "gf", "pf", "tf", "ga", "gm",
			"ge", "de", "gh", "gi", "gr", "gl", "gd", "gp", "gu", "gt", "gg",
			"gn", "gw", "gy", "ht", "hm", "va", "hn", "hk", "hu", "is", "in",
			"id", "ir", "iq", "ie", "im", "il", "it", "jm", "jp", "je", "jo",
			"kz", "ke", "ki", "kp", "kr", "kw", "kg", "la", "lv", "lb", "ls",
			"lr", "ly", "li", "lt", "lu", "mo", "mk", "mg", "mw", "my", "mv",
			"ml", "mt", "mh", "mq", "mr", "mu", "yt", "mx", "fm", "md", "mc",
			"mn", "ms", "ma", "mz", "mm", "na", "nr", "np", "nl", "an", "nc",
			"nz", "ni", "ne", "ng", "nu", "nf", "mp", "no", "om", "pk", "pw",
			"pa", "pg", "py", "pe", "ph", "pn", "pl", "pt", "pr", "qa", "re",
			"ro", "ru", "rw", "kn", "lc", "vc", "ws", "sm", "st", "sa", "sn",
			"sc", "sl", "sg", "sk", "si", "sb", "so", "za", "gz", "es", "lk",
			"sh", "pm", "sd", "sr", "sj", "sz", "se", "ch", "sy", "tw", "tj",
			"tz", "th", "tg", "tk", "to", "tt", "tn", "tr", "tm", "tc", "tv",
			"ug", "ua", "ae", "gb", "us", "um", "uy", "uz", "vu", "ve", "vn",
			"vg", "vi", "wf", "eh", "ye", "yu", "za", "zr", "zm", "zw", "int",
			"gs", "info", "biz", "su", "name", "coop", "aero" ]
		print_status("Performing Top Level Domain expansion using #{tlds.size} TLDs")

		tlds.each do |tld|
			query1 = @res.search("#{target}.#{tld}")
			if (query1)
				query1.answer.each do |rr|
					print_status("Domain: #{target}.#{tld} Name: #{rr.name} IP address: #{rr.address} Record: A ") if rr.class == Net::DNS::RR::A
					report_note(:host => @nsinuse.to_s,
						:proto => 'udp',
						:sname => 'dns',
						:port => 53,
						:type => 'dns.enum',
						:update => :unique_data,
						:data => "#{rr.address.to_s},#{target}.#{tld},A") if rr.class == Net::DNS::RR::A
				end
			end
		end

	end

	#-------------------------------------------------------------------------------
	def dnsbrute(target, wordlist, nssrv)
		print_status("Running bruteforce against domain #{target}")
		arr = []
		i, a = 0, []
		::File.open(wordlist, "rb").each_line do |line|
			if not nssrv.nil?
				@res.nameserver=(nssrv)
				@nsinuse = nssrv
			end
			query1 = @res.search("#{line.chomp}.#{target}")
			if (query1)
				query1.answer.each do |rr|
					if rr.class == Net::DNS::RR::A
						print_status("Hostname: #{line.chomp}.#{target} IP address: #{rr.address.to_s}")
						report_note(:host => @nsinuse.to_s,
							:proto => 'udp',
							:sname => 'dns',
							:port => 53 ,
							:type => 'dns.enum',
							:update => :unique_data,
							:data => "#{rr.address.to_s},#{line.chomp}.#{target},A")
						next unless rr.class == Net::DNS::RR::CNAME
					end
				end
			end
		end
	end

	#-------------------------------------------------------------------------------
	def bruteipv6(target, wordlist, nssrv)
		print_status("Bruteforcing IPv6 addresses against domain #{target}")
		arr = []
		i, a = 0, []
		arr = IO.readlines(wordlist)
		if not nssrv.nil?
			@res.nameserver=(nssrv)
			@nsinuse = nssrv
		end
		arr.each do |line|
			query1 = @res.search("#{line.chomp}.#{target}", "AAAA")
			if (query1)
				query1.answer.each do |rr|
					if rr.class == Net::DNS::RR::AAAA
						print_status("Hostname: #{line.chomp}.#{target} IPv6 Address: #{rr.address.to_s}")
						report_note(:host => @nsinuse.to_s,
							:proto => 'udp',
							:sname => 'dns',
							:port => 53 ,
							:type => 'dns.enum',
							:update => :unique_data,
							:data => "#{rr.address.to_s},#{line.chomp}.#{target},AAAA")
						next unless rr.class == Net::DNS::RR::CNAME
					end
				end
			end

		end
	end



	#-------------------------------------------------------------------------------
	def reverselkp(iprange,nssrv)
		print_status("Running reverse lookup against IP range #{iprange}")
		if not nssrv.nil?
			@res.nameserver = (nssrv)
			@nsinuse = nssrv
		end
		ar = Rex::Socket::RangeWalker.new(iprange)
		tl = []
		while (true)
			# Spawn threads for each host
			while (tl.length < @threadnum)
				ip = ar.next_ip
				break if not ip
				tl << framework.threads.spawn("Module(#{self.refname})-#{ip}", false, ip.dup) do |tip|
					begin
						query = @res.query(tip)
						query.each_ptr do |addresstp|
							print_status("Hostname: #{addresstp} IP address: #{tip.to_s}")
							report_note(:host => @nsinuse.to_s,
								:proto => 'udp',
								:sname => 'dns',
								:port => 53 ,
								:type => 'dns.enum',
								:update => :unique_data,
								:data => "#{addresstp},#{tip},A")
						end
					rescue ::Interrupt
						raise $!
					rescue ::Rex::ConnectionError
					rescue ::Exception => e
						print_error("Error: #{tip}: #{e.message}")
						elog("Error running against host #{tip}: #{e.message}\n#{e.backtrace.join("\n")}")
					end
				end
			end
			# Exit once we run out of hosts
			if(tl.length == 0)
				break
			end
			tl.first.join
			tl.delete_if { |t| not t.alive? }
		end
	end
	#-------------------------------------------------------------------------------
	#SRV Record Enumeration
	def srvqry(dom,nssrv)
		print_status("Enumerating SRV records for #{dom}")
		i, a = 0, []
		#Most common SRV Records
		srvrcd = [
			"_gc._tcp.","_kerberos._tcp.", "_kerberos._udp.","_ldap._tcp","_test._tcp.",
			"_sips._tcp.","_sip._udp.","_sip._tcp.","_aix._tcp.","_aix._tcp.","_finger._tcp.",
			"_ftp._tcp.","_http._tcp.","_nntp._tcp.","_telnet._tcp.","_whois._tcp.","_h323cs._tcp.",
			"_h323cs._udp.","_h323be._tcp.","_h323be._udp.","_h323ls._tcp.","_h323ls._udp.",
			"_sipinternal._tcp.","_sipinternaltls._tcp.","_sip._tls.","_sipfederationtls._tcp.",
			"_jabber._tcp.","_xmpp-server._tcp.","_xmpp-client._tcp.","_imap._tcp.","_certificates._tcp.",
			"_crls._tcp.","_pgpkeys._tcp.","_pgprevokations._tcp.","_cmp._tcp.","_svcp._tcp.","_crl._tcp.",
			"_ocsp._tcp.","_PKIXREP._tcp.","_smtp._tcp.","_hkp._tcp.","_hkps._tcp.","_jabber._udp.",
			"_xmpp-server._udp.","_xmpp-client._udp.","_jabber-client._tcp.","_jabber-client._udp."]
		srvrcd.each do |srvt|
			trg = "#{srvt}#{dom}"
			query = @res.query(trg , Net::DNS::SRV)
			if query
				query.answer.each do |srv|
					print_status("SRV Record: #{trg} Host: #{srv.host} Port: #{srv.port} Priority: #{srv.priority}") if srv.type != "CNAME"
				end
			end
		end
	end

	#-------------------------------------------------------------------------------
	#For Performing Zone Transfers
	def axfr(target, nssrv)
		print_status("Performing zone transfer against all nameservers in #{target}")
		if not nssrv.nil?
			@res.nameserver=(nssrv)
			@nsinuse = nssrv
		end
		@res.tcp_timeout=15
		query = @res.query(target, "NS")
		if (query.answer.length != 0)
			(query.answer.select { |i| i.class == Net::DNS::RR::NS}).each do |nsrcd|
				print_status("Testing nameserver: #{nsrcd.nsdname}")
				nssrvquery = @res.query(nsrcd.nsdname, "A")
				if nssrvquery.answer.length == 0
					nssrvip = Rex::Socket.gethostbyname(nsrcd.nsdname)[3].bytes.reduce {|a,b| [a,b].join(".")}
				else
					nssrvip = nssrvquery.answer[0].address.to_s
				end
				begin
					@res.nameserver=(nssrvip)
					@nsinuse = nssrvip
					zone = []
					zone = @res.axfr(target)
					if zone.length != 0
						print_status("Zone transfer successful")
						report_note(:host => nssrvip,
							:proto => 'udp',
							:sname => 'dns',
							:port => 53 ,
							:type => 'dns.enum',
							:update => :unique_data,
							:data => "Zone transfer successful")
						#Prints each record according to its type
						zone.each do |response|
							response.answer.each do |rr|
								begin
								case rr.type
								when "A"
									print_status("Name: #{rr.name} IP address: #{rr.address} Record: A ")
									report_note(:host => nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => "#{rr.address.to_s},#{rr.name},A")
								when "SOA"
									print_status("Name: #{rr.mname} Record: SOA")
									report_note(:host => nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => "#{rr.name},SOA")
								when "MX"
									print_status("Name: #{rr.exchange} Preference: #{rr.preference} Record: MX")
									report_note(:host => nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => "#{rr.exchange},MX")
								when "CNAME"
									print_status("Name: #{rr.cname} Record: CNAME")
									report_note(:host => nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => "#{rr.cname},CNAME")
								when "HINFO"
									print_status("CPU: #{rr.cpu} OS: #{rr.os} Record: HINFO")
									report_note(:host => nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => "CPU:#{rr.cpu},OS:#{rr.os},HINFO")
								when "AAAA"
									print_status("IPv6 Address: #{rr.address} Record: AAAA")
									report_note(:host => nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => "#{rr.address.to_s}, AAAA")
								when "NS"
									print_status("Name: #{rr.nsdname} Record: NS")
									report_note(:host =>  nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => "#{rr.nsdname},NS")
								when "TXT"
									print_status("Text: #{rr.inspect}")
									report_note(:host =>  nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => rr.inspect)
								when "SRV"
									print_status("Host: #{rr.host} Port: #{rr.port} Priority: #{rr.priority} Record: SRV")
									report_note(:host =>  nssrvip,
										:proto => 'udp',
										:sname => 'dns',
										:port => 53 ,
										:type => 'dns.enum',
										:update => :unique_data,
										:data => "#{rr.host},#{rr.port},#{rr.priority},SRV")
								end
								rescue ActiveRecord::RecordInvalid
									#Do nothing. Probably tried to store :host => 127.0.0.1
								end
							end
						end
					else
						print_error("Zone transfer failed (length was zero)")
					end
				rescue Exception => e
					print_error("Error executing zone transfer: #{e.message}")
					elog("Error executing zone transfer: #{e.message}\n#{e.backtrace.join("\n")}")
				end
			end

		else
			print_error("Could not resolve domain #{target}")
		end
	end

	def run
		@res = Net::DNS::Resolver.new()
		if datastore['TCP_DNS']
			vprint_status("Using DNS/TCP")
			@res.use_tcp = true
		end
		@res.retry = datastore['RETRY'].to_i
		@res.retry_interval = datastore['RETRY_INTERVAL'].to_i
		@threadnum = datastore['THREADS'].to_i
		wldcrd = wildcard(datastore['DOMAIN'])
		switchdns(datastore['DOMAIN'])

		if(datastore['ENUM_STD'])
			genrcd(datastore['DOMAIN'])
		end

		if(datastore['ENUM_TLD'])
			tldexpnd(datastore['DOMAIN'],datastore['NS'])
		end

		if(datastore['ENUM_BRT'])
			if wldcrd and datastore['STOP_WLDCRD']
				print_error("Wildcard record found!")
			else
				dnsbrute(datastore['DOMAIN'],datastore['WORDLIST'],datastore['NS'])
			end
		end

		if(datastore['ENUM_IP6'])
			if wldcrd and datastore['STOP_WLDCRD']
				print_status("Wildcard Record Found!")
			else
				bruteipv6(datastore['DOMAIN'],datastore['WORDLIST'],datastore['NS'])
			end
		end

		if(datastore['ENUM_AXFR'])
			axfr(datastore['DOMAIN'],datastore['NS'])
		end

		if(datastore['ENUM_SRV'])
			srvqry(datastore['DOMAIN'],datastore['NS'])
		end

		if(datastore['ENUM_RVL'] and datastore['IPRANGE'] and not datastore['IPRANGE'].empty?)
			reverselkp(datastore['IPRANGE'],datastore['NS'])
		end
	end
end