local bin = require "bin"
local nmap = require "nmap"
local shortport = require "shortport"
local snmp = require "snmp"
local stdnse = require "stdnse"
local table = require "table"

description = [[
Attempts to enumerate installed software through SNMP.
]]

---
-- @output
-- | snmp-win32-software:  
-- |   Apache Tomcat 5.5 (remove only); 2007-09-15 15:13:18
-- |   Microsoft Internationalized Domain Names Mitigation APIs; 2007-09-15 15:13:18
-- |   Security Update for Windows Media Player (KB911564); 2007-09-15 15:13:18
-- |   Security Update for Windows Server 2003 (KB924667-v2); 2007-09-15 15:13:18
-- |   Security Update for Windows Media Player 6.4 (KB925398); 2007-09-15 15:13:18
-- |   Security Update for Windows Server 2003 (KB925902); 2007-09-15 15:13:18
-- |_  Windows Internet Explorer 7; 2007-09-15 15:13:18

author = "Patrik Karlsson"
license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
categories = {"default", "discovery", "safe"}
dependencies = {"snmp-brute"}

-- Version 0.3
-- Created 01/15/2010 - v0.1 - created by Patrik Karlsson <patrik@cqure.net>
-- Revised 01/19/2010 - v0.2 - fixed loop that would occure if a mib did not exist
-- Revised 04/11/2010 - v0.3 - moved snmp_walk to snmp library <patrik@cqure.net>


portrule = shortport.portnumber(161, "udp", {"open", "open|filtered"})

--- Gets a value for the specified oid
--
-- @param tbl table containing <code>oid</code> and <code>value</code>
-- @param oid string containing the object id for which the value should be extracted
-- @return value of relevant type or nil if oid was not found
function get_value_from_table( tbl, oid )
	
	for _, v in ipairs( tbl ) do
		if v.oid == oid then
			return v.value
		end
	end
	
	return nil
end

--- Processes the table and creates the script output
--
-- @param tbl table containing <code>oid</code> and <code>value</code>
-- @return table suitable for <code>stdnse.format_output</code>
function process_answer( tbl )
	
	local sw_name = "1.3.6.1.2.1.25.6.3.1.2"
	local sw_date = "1.3.6.1.2.1.25.6.3.1.5"
	local new_tbl = {}
	
	for _, v in ipairs( tbl ) do
		
		if ( v.oid:match("^" .. sw_name) ) then
			local objid = v.oid:gsub( "^" .. sw_name, sw_date) 
			local install_date = get_value_from_table( tbl, objid )
			local sw_item
			
			local _, year, month, day, hour, min, sec = bin.unpack( ">SCCCCC", install_date )
			install_date = ("%02d-%02d-%02d %02d:%02d:%02d"):format( year, month, day, hour, min, sec )	

			sw_item = ("%s; %s"):format(v.value ,install_date)
			table.insert( new_tbl, sw_item )
		end
	
	end
	
	table.sort( new_tbl )
	return new_tbl
	
end


action = function(host, port)

	local socket = nmap.new_socket()
	local catch = function() socket:close()	end
	local try = nmap.new_try(catch)	
	local data, snmpoid = nil, "1.3.6.1.2.1.25.6.3.1"
	local sw = {}
	local status

	socket:set_timeout(5000)
	try(socket:connect(host, port))
	
	status, sw = snmp.snmpWalk( socket, snmpoid )
	socket:close()

	if ( not(status) ) or ( sw == nil ) or ( #sw == 0 ) then
		return
	end
		
	sw = process_answer( sw )

	nmap.set_port_state(host, port, "open")

	return stdnse.format_output( true, sw )
end