o [NSE] Added script dns-nsid by John Bond, that retrieves name server ID and

version information.

o [NSE] Applied patch to DNS library by John Bond that adds support for the
  CHAOS class and NSID requests.

scripts/dns-nsid.nse

@@ -0,0 +1,69 @@
+description = [[
+Ateemps to get more information from a server by requesting the server nsid[1],
+and asking for id.server[2] and version.bind. This script dose the same as the
+following two dig commands:
+  - dig CH TXT bind.version @target
+  - dig +nsid CH TXT id.server @target
+
+[1]http://www.ietf.org/rfc/rfc5001.txt
+[2]http://www.ietf.org/rfc/rfc4892.txt
+]]
+
+---
+-- @usage
+-- nmap -sSU -p 53 --script dns-nsid <target>
+--
+-- @output
+-- 53/udp open  domain  udp-response
+-- | dns-nsid: 
+-- |   NSID dns.example.com (646E732E6578616D706C652E636F6D)
+-- |   id.server: dns.example.com
+-- |_  bind.version: 9.7.3-P3
+---
+
+author = "John Bond"
+license = "Simplified (2-clause) BSD license--See http://nmap.org/svn/docs/licenses/BSD-simplified"
+
+categories = {"discovery", "default"}
+
+require "stdnse"
+require "shortport"
+require "dns"
+
+portrule = shortport.port_or_service(53, "domain", {"tcp", "udp"})
+
+local function rr_filter(pktRR, label)
+	for _, rec in ipairs(pktRR, label) do
+		if ( rec[label] and 0 < #rec.data ) then
+			if ( dns.types.OPT == rec.dtype ) then
+				local pos, _, len = bin.unpack(">SS", rec.data)
+				if ( len ~= #rec.data - pos + 1 ) then
+					return false, "Failed to decode NSID"
+				end
+				return true, select(2, bin.unpack("A" .. len, rec.data, pos))
+			else
+				return true, select(2, bin.unpack("p", rec.data))
+			end
+		end
+	end
+end
+
+action = function(host, port)	
+	local result = {}
+	local status, resp = dns.query("id.server", {host = host.ip, dtype='TXT', class=dns.CLASS.CH, retAll=true, retPkt=true, nsid=true, dnssec=true})
+	if ( status ) then
+		local status, nsid = rr_filter(resp.add,'OPT')
+		if ( status ) then
+			table.insert(result, ("NSID: %s (%s)"):format(nsid, stdnse.tohex(nsid)))
+		end
+		local status, id_server = rr_filter(resp.answers,'TXT')
+		if ( status ) then
+			table.insert(result, ("id.server: %s"):format(id_server))
+		end
+	end
+	local status, bind_version = dns.query("version.bind", {host = host.ip, dtype='TXT', class=dns.CLASS.CH})
+	if ( status ) then
+		table.insert(result, ("bind.version: %s"):format(bind_version))
+	end
+	return stdnse.format_output(true, result)
+end

scripts/script.db

@@ -55,6 +55,7 @@ Entry { filename = "dns-brute.nse", categories = { "discovery", "intrusive", } }
 Entry { filename = "dns-cache-snoop.nse", categories = { "discovery", "intrusive", } }
 Entry { filename = "dns-fuzz.nse", categories = { "fuzzer", "intrusive", } }
 Entry { filename = "dns-nsec-enum.nse", categories = { "discovery", "intrusive", } }
+Entry { filename = "dns-nsid.nse", categories = { "default", "discovery", } }
 Entry { filename = "dns-random-srcport.nse", categories = { "external", "intrusive", } }
 Entry { filename = "dns-random-txid.nse", categories = { "external", "intrusive", } }
 Entry { filename = "dns-recursion.nse", categories = { "default", "safe", } }