o [NSE] Added a Oracle TNS library and two new scripts that make use of it.

The scripts are:
  - oracle-brute uses the brute and tns library to perform password guessing
  - oracle-enum-users attempts to determine valid Oracle user names
  [Patrik]

scripts/oracle-brute.nse

@@ -0,0 +1,137 @@
+description = [[
+Performs password guessing against Oracle
+]]
+
+---
+-- @usage
+-- nmap --script oracle-brute -p 1521 --script-args oracle-brute.sid=ORCL <host>
+--
+-- @output
+-- PORT     STATE  SERVICE REASON
+-- 1521/tcp open  oracle  syn-ack
+-- | oracle-brute:  
+-- |   Accounts
+-- |     system:powell => Account locked
+-- |     haxxor:haxxor => Login correct
+-- |   Statistics
+-- |_    Perfomed 157 guesses in 8 seconds, average tps: 19
+--
+-- Summary
+-- -------
+--   x The Driver class contains the driver implementation used by the brute
+--     library
+--
+-- @args oracle-brute.sid the instance against which to perform password
+--       guessing
+--
+
+--
+-- Version 0.2
+-- Created 07/12/2010 - v0.1 - created by Patrik Karlsson <patrik@cqure.net>
+-- Revised 07/23/2010 - v0.2 - added script usage and output and 
+-- 							 - oracle-brute.sid argument
+
+author = "Patrik Karlsson"
+license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
+categories = {"intrusive", "auth"}
+
+require 'shortport'
+require 'brute'
+require 'tns'
+
+portrule = shortport.port_or_service(1521, "oracle-tns", "tcp", "open")
+
+Driver = 
+{
+
+	new = function(self, host, port)
+		local o = {}
+       	setmetatable(o, self)
+        self.__index = self
+		o.host = host
+		o.port = port
+		return o
+	end,
+	
+	--- Connects performs protocol negotiation
+	--
+	-- @return true on success, false on failure
+	connect = function( self )
+		local status, data 
+		self.helper = tns.Helper:new( self.host, self.port, nmap.registry.args['oracle-brute.sid'] )
+		
+		status, data = self.helper:Connect()
+		if ( not(status) ) then
+			return status, data
+		end
+		
+		return true
+	end,
+	
+	--- Attempts to login to the Oracle server
+	--
+	-- @param username string containing the login username
+	-- @param password string containing the login password
+	-- @return status, true on success, false on failure
+	-- @return brute.Error object on failure
+	--         brute.Account object on success
+	login = function( self, username, password )
+		local status, data = self.helper:Login( username, password )
+		
+		if ( status ) then
+			return true, brute.Account:new(username, password, "OPEN")
+		-- Check for account locked message
+		elseif ( data:match("ORA[-]28000") ) then
+			return true, brute.Account:new(username, password, "LOCKED")
+		-- check for any other message
+		elseif ( data:match("ORA[-]%d+")) then
+			stdnse.print_debug(3, "username: %s, password: %s, error: %s", username, password, data )
+			return false, brute.Error:new(data)
+		-- any other errors are likely communication related, attempt to re-try
+		else
+			local err = brute.Error:new(data)
+			err:setRetry(true)
+			return false, err
+		end
+
+		return false, brute.Error:new( data )
+
+	end,
+	
+	--- Disconnects and terminates the Oracle TNS communication
+	disconnect = function( self )
+		self.helper:Close()
+	end,
+	
+	--- Perform a connection with the helper, this makes sure that the Oracle
+	-- instance is correct.
+	--
+	-- @return status true on success false on failure
+	-- @return err containing the error message on failure
+	check = function( self )
+		local helper = tns.Helper:new( self.host, self.port, nmap.registry.args['oracle-brute.sid'] )
+		local status, err = helper:Connect()
+
+		if( status ) then
+			helper:Close()
+			return true
+		end
+
+		return false, err
+	end,
+	
+}
+
+
+action = function(host, port)
+	local status, result 
+	local engine = brute.Engine:new(Driver, host, port )
+	
+	if ( not( nmap.registry.args['oracle-brute.sid'] ) and not( nmap.registry.args['tns.sid'] ) ) then
+		return "ERROR: Oracle instance not set (see oracle-brute.sid or tns.sid)"
+	end
+	
+	status, result = engine:start()
+
+	return result
+end