local bin = require "bin" local comm = require "comm" local datetime = require "datetime" local os = require "os" local math = require "math" local nmap = require "nmap" local shortport = require "shortport" local stdnse = require "stdnse" local string = require "string" local table = require "table" local lpeg = require "lpeg" local U = require "lpeg-utility" description = [[ Gets the time and configuration variables from an NTP server. We send two requests: a time request and a "read variables" (opcode 2) control message. Without verbosity, the script shows the time and the value of the version, processor, system, refid, and stratum variables. With verbosity, all variables are shown. See RFC 1035 and the Network Time Protocol Version 4 Reference and Implementation Guide (http://www.eecis.udel.edu/~mills/database/reports/ntp4/ntp4.pdf) for documentation of the protocol. ]] --- -- @usage -- nmap -sU -p 123 --script ntp-info -- @output -- PORT STATE SERVICE VERSION -- 123/udp open ntp NTP v4.2.4p4@1.1520-o -- | ntp-info: -- | receive time stamp: Sat Dec 12 16:22:41 2009 -- | version: ntpd 4.2.4p4@1.1520-o Wed May 13 21:06:31 UTC 2009 (1) -- | processor: x86_64 -- | system: Linux/2.6.24-24-server -- | stratum: 2 -- |_ refid: 195.145.119.188 -- -- @xmloutput -- 2013-10-18T18:03:05 -- ntpd 4.2.6p3@1.2290-o Tue Jun 5 20:12:11 UTC 2012 (1) -- i686 -- Linux/3.9.3-24 -- 3 -- 16 -- -20 -- 0.000 -- 2502.720 -- INIT -- 0x00000000.00000000 -- 0xd60bf655.4cc0ba51 -- 0 -- 3 -- 3 -- 0.000 -- -46.015 -- 0.001 -- 0.000 author = "Richard Sammet" license = "Same as Nmap--See https://nmap.org/book/man-legal.html" categories = {"default", "discovery", "safe"} portrule = shortport.port_or_service(123, "ntp", {"udp", "tcp"}) -- This script run against open|filtered ports, so don't wait too long if -- there's no response. local TIMEOUT = 5000 -- Only these fields from the response are displayed with default verbosity. local DEFAULT_FIELDS = {"version", "processor", "system", "refid", "stratum"} -- comma-space-separated key=value pairs with optional quotes local kvmatch = U.localize( { lpeg.V "space"^0 * lpeg.V "kv" * lpeg.P ","^-1, kv = lpeg.V "key" * lpeg.P "="^-1 * lpeg.V "value", key = lpeg.C( (lpeg.V "alnum" + lpeg.S "_-.")^1 ), value = U.escaped_quote() + lpeg.C((lpeg.P(1) - ",")^0), } ) action = function(host, port) local status local buftres, bufrlres local output = stdnse.output_table() -- This is a ntp v2 mode3 (client) date/time request. local treq = string.char(0xd3, 0x00, 0x04, 0xfa, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00) -- This is a ntp v2 mode6 (control) rl (readlist/READVAR(2)) request. See -- appendix B of RFC 1305. local rlreq = string.char(0x16, 0x02, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00) status, buftres = comm.exchange(host, port, treq, {timeout=TIMEOUT}) if status then local recvtime = os.time() local _, sec, frac = bin.unpack(">II", buftres, 33) -- The NTP epoch is 1900-01-01, so subtract 70 years to bring the date into -- the range Lua expects. The number of seconds at 1970-01-01 is taken from -- the NTP4 reference above. local tstamp = sec - 2208988800 + frac / 0x10000000 datetime.record_skew(host, tstamp, recvtime) output["receive time stamp"] = stdnse.format_timestamp(tstamp) end status, bufrlres = comm.exchange(host, port, rlreq, {timeout=TIMEOUT}) if status then -- This only looks at the first fragment of what can possibly be several -- fragments in the response. local _, data, k, q, v -- Skip the first 10 bytes of the header, then get the data which is -- preceded by a 2-byte length. _, data = bin.unpack(">P", bufrlres, 11) -- loop over capture pairs which represent (key, value) local function accumulate_output (...) local k, v = ... if k == nil then return end output[k] = v return accumulate_output(select(3, ...)) end -- do the match and accumulate the captures local list = kvmatch^0 / accumulate_output list:match(data) end if(#output > 0) then stdnse.debug1("Test len: %d", #output) nmap.set_port_state(host, port, "open") if output['version'] then -- Look for the version string from the official ntpd and format it -- in a manner similar to the output of the standard Nmap version detection local version_num = string.match(output['version'],"^ntpd ([^ ]+)") if version_num then port.version.version = "v" .. version_num nmap.set_port_version(host, port, "hardmatched") end end if output['system'] then port.version.ostype = output['system'] nmap.set_port_version(host, port, "hardmatched") end if nmap.verbosity() < 1 then local mt = getmetatable(output) mt["__tostring"] = function(t) local out = {} for _,k in ipairs(DEFAULT_FIELDS) do if output[k] ~= nil then table.insert(out, ("%s: %s"):format(k, output[k])) end end return "\n " .. table.concat(out, "\n ") end end return output else return nil end end