code re-factoring and cleanup

nselib/tns.lua

@@ -25,8 +25,7 @@
 --        contain a function to parse the servers response.
 --
 --   o Comm
---		- Implements a number of functions to handle communication over the
---        the TNSSocket class.
+--		- Implements a number of functions to handle communication 
 --
 --   o Crypt
 -- 		- Implements encryption algorithms and functions to support 
@@ -35,10 +34,6 @@
 --   o Helper
 --		- A helper class that provides easy access to the rest of the library
 --
---   o TNSSocket
---      - This is a copy of the DB2Socket class which provides fundamental 
---        buffering
---
 --
 -- Example
 -- -------
@@ -117,6 +112,7 @@
 local bin = require "bin"
 local bit = require "bit"
 local math = require "math"
+local match = require "match"
 local nmap = require "nmap"
 local stdnse = require "stdnse"
 local string = require "string"
@@ -141,17 +137,15 @@ AuthOptions =
 	-- Creates a new AuthOptions instance
 	-- @return o new instance of AuthOptions
 	new = function( self )
-		local o = {}
+		local o = {
+			auth_term = "pts/" .. math.random(255),
+			auth_prog = ("sqlplus@nmap_%d (TNS V1-V3)"):format(math.random(32768)),
+			auth_machine = "nmap_target",
+			auth_pid = "" .. math.random(32768),
+			auth_sid = "nmap_" .. math.random(32768)
+		}
 		setmetatable(o, self)
 		self.__index = self
-
-		o.auth_user = nil
-		o.auth_term = "pts/" .. math.random(255)
-		o.auth_prog = ("sqlplus@nmap_%d (TNS V1-V3)"):format(math.random(32768))
-		o.auth_machine = "nmap_target"
-		o.auth_pid = "" .. math.random(32768)
-		o.auth_sid = "nmap_" .. math.random(32768)
-
 		return o
 	end,	
 	
@@ -188,10 +182,7 @@ DataTypeDecoders = {
 		
 		bytes = convert_bytes(bytes, positive)
 
-		local k = ( #bytes - 1 > bytes[1] +1 ) and 
-					( bytes[1] + 1 ) or 
-					#bytes - 1
-
+		local k = ( #bytes - 1 > bytes[1] +1 ) and ( bytes[1] + 1 ) or #bytes - 1
 		local l = 0
 		for m=1, k do l = l * 100 + bytes[m+1] end
 		for m=bytes[1]-#bytes - 1, 0, -1 do l = l * 100	end
@@ -250,11 +241,12 @@ Packet.TNS = {
 		MARKER = 12,
 	},
 
-	new = function( self, sock )
-		local o = {}
+	new = function( self, typ )
+		local o = {
+			type = typ
+		}
 		setmetatable(o, self)
 		self.__index = self
-		o.socket = sock
 		return o
 	end,
 	
@@ -263,23 +255,23 @@ Packet.TNS = {
 	-- @return true on success, false on failure
 	-- @return err string containing error message on failure
 	recv = function( self )
-		local _
-		local status, data = self.socket:recv( 2 )
+		local status, data = self.socket:receive_buf( match.numbytes(2), true )
 
 		if ( not(status) ) then
 			return status, data
 		end
 
+		local _
 		_, self.length = bin.unpack(">S", data )
 		
-		status, data = self.socket:recv( 6 ) -- self.length - 2 )
+		status, data = self.socket:receive_buf( match.numbytes(6), true )
 		if ( not(status) ) then
 			return status, data
 		end
 		
 		_, self.checksum, self.type, self.reserved, self.hdr_checksum = bin.unpack(">SCCS", data)
 		
-		status, data = self.socket:recv( self.length - 8)
+		status, data = self.socket:receive_buf( match.numbytes(self.length - 8), true )
 		if ( status ) then
 			self.data = data
 		end
@@ -287,12 +279,19 @@ Packet.TNS = {
 		return true
 	end,
 	
+	parse = function(data)
+		local tns = Packet.TNS:new()
+		local pos
+		pos, tns.length, tns.checksum, tns.type, tns.reserved, tns.hdr_checksum = bin.unpack(">SSCCS", data)
+		pos, tns.data = bin.unpack("A" .. ( tns.length - 8 ), data, pos)
+		return tns
+	end,
+	
 	--- Converts the TNS packet to string suitable to be sent over the socket
 	--
 	-- @return string containing the TNS packet
 	__tostring = function( self )
-		local data = bin.pack(">SSCCSA", self.length, self.checksum, self.type, 
-										self.reserved, self.hdr_checksum, self.data )
+		local data = bin.pack(">SSCCSA", self.length, self.checksum, self.type, self.reserved, self.hdr_checksum, self.data )
 		return data
 	end,
 	
@@ -393,14 +392,13 @@ Packet.Data = {
 
 	-- Createas a new Data instance
 	-- @return o new instance of Data
-	new = function( self, sock, data )
-		local o = {}
+	new = function( self, data )
+		local o = {
+			TNS = Packet.TNS:new( Packet.TNS.Type.DATA ),
+			data = data
+		}
 		setmetatable(o, self)
 		self.__index = self
-		o.TNS = Packet.TNS:new( sock )
-		o.TNS.type = Packet.TNS.Type.DATA
-		o.socket = sock
-		o.data = data
 		return o
 	end,
 	
@@ -444,7 +442,6 @@ Packet.PreAuth = {
 	
 	tns_type = Packet.TNS.Type.DATA,
 	flags = 0,	
-		
 	param_order = { 
 		{ ["AUTH_TERMINAL"] = "auth_term" },
 		{ ["AUTH_PROGRAM_NM"] = "auth_prog" },
@@ -453,7 +450,6 @@ Packet.PreAuth = {
 		{ ["AUTH_SID"] = "auth_sid" }
 	},
 	
-	
 	--- Creates a new PreAuth packet
 	--
 	-- @param user string containing the user name
@@ -495,15 +491,12 @@ Packet.PreAuth = {
 	-- @param tns Packet.TNS containing the TNS packet recieved from the server
 	-- @return table containing the keys and values returned by the server
 	parseResponse = function( self, tns )
-
-		local kvp_count, key, val, kvp_flags
 		local kvps = {}
-		
-		local pos = 4
-		pos, kvp_count = bin.unpack( "C", tns.data, pos )
+		local pos, kvp_count = bin.unpack( "C", tns.data, 4 )
 		pos = 6
 		
 		for kvp_itr=1, kvp_count do
+			local key, val, kvp_flags
 			pos, key, val, kvp_flags = Marshaller.unmarshalKvp( tns.data, pos )
 			-- we don't actually do anything with the flags currently, but they're there
 			kvps[key] = val
@@ -519,8 +512,6 @@ Packet.Auth = {
 	
 	tns_type = Packet.TNS.Type.DATA,
 	flags = 0,
-
-
 	param_order = { 
 		{ ['key'] = "AUTH_RTT", ['def'] = "25456" },
 		{ ['key'] = "AUTH_CLNT_MEM", ['def'] = "4096" },
@@ -588,14 +579,12 @@ Packet.Auth = {
 	-- @param tns Packet.TNS containing the TNS packet recieved from the server
 	-- @return table containing the key pair values from the Auth packet
 	parseResponse = function( self, tns )
-		local kvp_count, key, val, kvp_flags
 		local kvps = {}
-		
-		local pos = 4
-		pos, kvp_count = bin.unpack( "C", tns.data, pos )
+		local pos, kvp_count = bin.unpack( "C", tns.data, 4 )
 		pos = 6
 		
 		for kvp_itr=1, kvp_count do
+			local key, val, kvp_flags
 			pos, key, val, kvp_flags = Marshaller.unmarshalKvp( tns.data, pos )
 			-- we don't actually do anything with the flags currently, but they're there
 			kvps[key] = val
@@ -662,9 +651,7 @@ Packet.ProtoNeg = {
 	--
 	-- @param tns Packet.TNS containing the response from the server
 	parseResponse = function( self, tns )
-		local flags, neg, ver, srv, pos, _
-	
-		pos, flags, neg, ver, _, srv = bin.unpack(">SCCCz", tns.data)
+		local pos, flags, neg, ver, _, srv = bin.unpack(">SCCCz", tns.data)
 		if ( neg ~= 1 ) then
 			return false, "Error protocol negotiation failed"
 		end
@@ -672,7 +659,6 @@ Packet.ProtoNeg = {
 		if ( ver ~= 6 ) then
 			return false, ("Error protocol version (%d) not supported"):format(ver)
 		end
-		
 		return true, srv
 	end
 
@@ -1189,14 +1175,9 @@ Marshaller = {
 	-- @param flags The flags
 	-- @return A binary packed string representing the KVP structure
 	marshalKvp = function( key, value, flags )
-		flags = flags or 0
-		
-		local result = ""
-		result = result .. Marshaller.marshalKvpComponent( key )
-		result = result .. Marshaller.marshalKvpComponent( value )
-		result = result .. bin.pack( "<I", flags )
-		
-		return result
+		return Marshaller.marshalKvpComponent( key ) .. 
+			Marshaller.marshalKvpComponent( value ) ..
+			bin.pack( "<I", ( flags or 0 ) )
 	end,
 	
 	--- Parses a TNS key-value pair data structure.
@@ -1250,7 +1231,6 @@ Marshaller = {
 					local write_value = value:sub( 1, write_length )
 					-- ...and remove that piece from the remaining string
 					value = value:sub( write_length + 1 )
-					
 					result = result .. bin.pack( "p", write_value )
 				end
 
@@ -1311,8 +1291,9 @@ Comm = {
 	-- @return new instance of Comm
 	new = function(self, socket)
 		local o = { 
-				tnssocket = socket, 
-				data_counter = 06 }
+			socket = socket, 
+			data_counter = 06
+		}
 		setmetatable(o, self)
 		self.__index = self
 		return o
@@ -1324,8 +1305,7 @@ Comm = {
 	-- @return Status (true or false).
 	-- @return Error code (if status is false).
 	sendTNSPacket = function( self, pkt )
-		local tns = Packet.TNS:new( self.tnssocket )
-		tns.type = pkt.tns_type
+		local tns = Packet.TNS:new( pkt.tns_type )
 		if ( pkt.setCounter ) then
 			pkt:setCounter(self.data_counter)
 			self.data_counter = self.data_counter + 1
@@ -1336,7 +1316,7 @@ Comm = {
 		-- buffer incase of RESEND
 		self.pkt = pkt
 
-		return self.tnssocket:send( tostring(tns) )
+		return self.socket:send( tostring(tns) )
 	end,
 
 	--- Handles communication when a MARKER packet is recieved and retrieves
@@ -1346,7 +1326,6 @@ Comm = {
 	-- @return msg containing the error message
 	handleMarker = function( self )
 		local status, tns = self:recvTNSPacket()
-		local pos, msg, b1
 
 		if ( not(status) or tns.type ~= Packet.TNS.Type.MARKER ) then
 			return false, "ERROR: failed to handle marker sent by server"
@@ -1365,15 +1344,11 @@ Comm = {
 
 		-- check if byte 12 is set or not, this should help us distinguish the offset
 		-- to the error message in Oracle 10g and 11g
-		pos, b1 = bin.unpack("C", tns.data, 10)
-		
-		if( b1 == 1 ) then
-			pos = 99
-		else
-			pos = 69
-		end
+		local pos, b1 = bin.unpack("C", tns.data, 10)
+		pos = (b1 == 1) and 99 or 69
 
 		-- fetch the oracle error and return it
+		local msg
 		pos, msg = bin.unpack("p", tns.data, pos )
 
 		return false, msg		
@@ -1384,11 +1359,25 @@ Comm = {
 	-- @return status true on success, false on failure
 	-- @return tns Packet.TNS containing the recieved packet or err on failure
 	recvTNSPacket = function( self )
-		local tns = Packet.TNS:new( self.tnssocket )
+		local tns
 		local retries = 5
 
 		repeat
-			local status = tns:recv()
+			local function recv()
+				local status, header = self.socket:receive_buf( match.numbytes(8), true )
+				if ( not(status) ) then return status, header end
+
+				local _, length = bin.unpack(">S", header )
+				local status, data = self.socket:receive_buf( match.numbytes(length - 8), true )
+				if ( not(status) ) then
+					return false, data
+				else
+					return status, Packet.TNS.parse(header .. data)
+				end
+			end
+
+			local status
+			status, tns = recv()
 			if ( not(status) ) then
 				if ( retries == 0 ) then
 					return false, "ERROR: recvTNSPacket failed to receive TNS headers"
@@ -1465,7 +1454,6 @@ Crypt = {
 	HashPassword10g = function( self, username, password )
 		local uspw = ( username .. password ):gsub("(%w)", "\0%1")
 		local key = bin.pack("H", "0123456789abcdef")
-		local enc, iv2, hash
 
 		-- do padding
 		if ( #uspw % 8 > 0 ) then
@@ -1474,8 +1462,8 @@ Crypt = {
 			end
 		end
 
-		iv2 = openssl.encrypt( "DES-CBC", key, nil, uspw, false ):sub(-8)
-		enc = openssl.encrypt( "DES-CBC", iv2, nil, uspw, false ):sub(-8)
+		local iv2 = openssl.encrypt( "DES-CBC", key, nil, uspw, false ):sub(-8)
+		local enc = openssl.encrypt( "DES-CBC", iv2, nil, uspw, false ):sub(-8)
 		return enc
 	end,
 
@@ -1527,9 +1515,7 @@ Crypt = {
 			combined_sesskey = combined_sesskey .. string.char( bit.bxor( string.byte(srv_sesskey, i), string.byte(cli_sesskey, i) ) )
 		end
 		combined_sesskey = openssl.md5( combined_sesskey )
-		
 		auth_pass = openssl.encrypt("AES-128-CBC", combined_sesskey, nil, rnd .. pass, true )
-		
 		auth_pass = select(2, bin.unpack("H" .. #auth_pass, auth_pass))
 		cli_sesskey_enc = select(2, bin.unpack("H" .. #cli_sesskey_enc, cli_sesskey_enc))
 		return cli_sesskey_enc, auth_pass
@@ -1584,12 +1570,10 @@ Helper = {
 		local o = { 
 			host = host,
 			port = port,
-			tnssocket = TNSSocket:new(),
-			-- fallback to the common ORCL instance if none was supplied
-			dbinstance = instance or
-							stdnse.get_script_args('tns.sid') or 
-							"orcl"
+			socket = nmap.new_socket(),
+			dbinstance = instance or stdnse.get_script_args('tns.sid') or "orcl"
 		}
+		o.socket:set_timeout(30000)
 		setmetatable(o, self)
 		self.__index = self
 		return o
@@ -1606,12 +1590,12 @@ Helper = {
 			"Linuxi386/Linux-2.0.34-8.1.0",
 			"x86_64/Linux 2.4.xx"
 		}
-		local status, data = self.tnssocket:connect( self.host.ip, self.port.number, "tcp" )
+		local status, data = self.socket:connect( self.host.ip, self.port.number, "tcp" )
 		local conn, packet, tns
 
 		if( not(status) ) then return status, data	end
 		
-		self.comm = Comm:new( self.tnssocket )
+		self.comm = Comm:new( self.socket )
 
 		status, self.version = self.comm:exchTNSPacket( Packet.Connect:new( self.host.ip, self.port.number, self.dbinstance ) )
 		if ( not(status) ) then	return false, self.version end
@@ -1693,15 +1677,14 @@ Helper = {
 	-- @param cmd string containing the command to send to the server
 	-- @return data string containing the result recieved from the server
 	lsnrCtl = function( self, cmd )
-		local status, data = self.tnssocket:connect( self.host.ip, self.port.number, "tcp" )
+		local status, data = self.socket:connect( self.host.ip, self.port.number, "tcp" )
 		local conn, packet, tns, pkt
 
 		if( not(status) ) then
 			return status, data
 		end
 
-		self.comm = Comm:new( self.tnssocket )
-								
+		self.comm = Comm:new( self.socket )
 		pkt = Packet.Connect:new( self.host.ip, self.port.number, self.dbinstance )
 		pkt:setCmd(cmd)
 
@@ -1768,8 +1751,7 @@ Helper = {
 		status, auth = self.comm:exchTNSPacket( Packet.PreAuth:new( user, auth_options, self.os ) )
 		if ( not(status) ) then
 			return false, auth
-		end
-		if ( auth["AUTH_SESSKEY"] ) then
+		elseif ( auth["AUTH_SESSKEY"] ) then
 			return true, auth
 		else
 			return false
@@ -1828,80 +1810,9 @@ Helper = {
 	Close = function( self )
 		-- We should probably stick some slick sqlplus termination stuff in here
 		local status = self.comm:sendTNSPacket( Packet.EOF:new( ) )
-		self.tnssocket:close()
+		self.socket:close()
 	end,
 	
 }
 
--- copy paste of DB2Socket aka VNCSocket
-TNSSocket =
-{	
-
-	new = function(self)
-		local o = {}
-       	setmetatable(o, self)
-        self.__index = self
-		o.Socket = nmap.new_socket()
-		-- We need this massive timeout due to Oracle 11g throttling of
-		-- repeated login attempts.
-		o.Socket:set_timeout(30000)
-		o.Buffer = nil
-		return o
-	end,
-	
-
-	--- Establishes a connection.
-	--
-	-- @param hostid Hostname or IP address.
-	-- @param port Port number.
-	-- @param protocol <code>"tcp"</code>, <code>"udp"</code>, or
-	-- @return Status (true or false).
-	-- @return Error code (if status is false).
-	connect = function( self, hostid, port, protocol )
-		return self.Socket:connect( hostid, port, protocol )
-	end,
-	
-	--- Closes an open connection.
-	--
-	-- @return Status (true or false).
-	-- @return Error code (if status is false).
-	close = function( self )
-		return self.Socket:close()
-	end,
-	
-	--- Opposed to the <code>socket:receive_bytes</code> function, that returns
-	-- at least x bytes, this function returns the amount of bytes requested.
-	--
-	-- @param count of bytes to read
-	-- @return true on success, false on failure
-	-- @return data containing bytes read from the socket
-	-- 		   err containing error message if status is false
-	recv = function( self, count )
-		local status, data
-	
-		self.Buffer = self.Buffer or ""
-	
-		if ( #self.Buffer < count ) then
-			status, data = self.Socket:receive_bytes( count - #self.Buffer )
-			if ( not(status) or #data < count - #self.Buffer ) then
-				return false, data
-			end
-			self.Buffer = self.Buffer .. data
-		end
-			
-		data = self.Buffer:sub( 1, count )
-		self.Buffer = self.Buffer:sub( count + 1)
-	
-		return true, data	
-	end,
-	
-	--- Sends data over the socket
-	--
-	-- @return Status (true or false).
-	-- @return Error code (if status is false).
-	send = function( self, data )
-		return self.Socket:send( data )
-	end,
-}
-
 return _ENV;