Added pcanywhere-brute script

CHANGELOG

@@ -1,5 +1,8 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o [NSE] Added pcanywhere-brute script which bruteforces pcAnywhere server
+  for valid logins. [Aleksandar Nikolic]
+
 o [NSE] Added http-rfi-spider script that spiders webservers in search of
   remote file inclusion vulnerabilities. [Piotr Olma]
 

scripts/pcanywhere-brute.nse

@@ -0,0 +1,158 @@
+local brute = require "brute"
+local creds = require "creds"
+local nmap = require "nmap"
+local shortport = require "shortport"
+local stdnse = require "stdnse"
+local string = require "string"
+local bit = require "bit"
+local bin = require "bin"
+local table = require "table"
+description = [[
+Performs password guessing against pcAnywhere.
+
+Due to certain limitations of the protocol, bruteforcing
+is limited to single thread at a time.
+After a valid login pair is guessed the script waits 
+some time until server becomes available again.
+
+]]
+
+---
+-- @usage
+-- nmap --script=pcanywhere-brute <target>
+--
+-- @output
+-- 5631/tcp open  pcanywheredata syn-ack
+-- | pcanywhere-brute:
+-- |   Accounts
+-- |     administrator:administrator - Valid credentials
+-- |   Statistics
+-- |_    Performed 2 guesses in 55 seconds, average tps: 0
+
+
+author = "Aleksandar Nikolic"
+license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
+categories = {"intrusive", "brute"}
+
+
+portrule = shortport.port_or_service(5631, "pcanywheredata")
+
+local arg_timeout = stdnse.get_script_args(SCRIPT_NAME .. ".timeout") or 10
+
+-- implements simple xor based encryption which the server expects
+local function encrypt(data)
+	local result = {}
+	local xor_key = 0xab
+	local k = 0
+	if data then
+		result[1] = bit.bxor(string.byte(data),xor_key)
+		for i = 2,string.len(data) do
+			result[i] = bit.bxor(result[i-1],string.byte(data,i),i-2)
+		end
+	end 
+	return string.char(table.unpack(result))
+end
+
+local retry = false -- true means we found valid login and need to wait
+
+Driver = {
+
+	new = function(self, host, port)
+		local o = {}
+		setmetatable(o, self)
+		self.__index = self
+		o.host = host
+		o.port = port
+		return o
+	end,
+
+	connect = function( self )
+		self.socket = nmap.new_socket()
+		local response
+		local err
+		local status = false
+		
+		stdnse.sleep(2)
+		-- when we hit a valid login pair, server enters some kind of locked state
+		-- so we need to wait for some time before trying next pair
+		-- variable "retry" signifies if we need to wait or this is just not pcAnywhere server
+		while not status do 
+			status, err = self.socket:connect(self.host, self.port)
+			self.socket:set_timeout(tonumber(arg_timeout) * 1000)
+			if(not(status)) then
+				return false, brute.Error:new( "Couldn't connect to host: " .. err )
+			end
+			status, err = self.socket:send(bin.pack("H","00000000")) --initial hello
+			status, response = self.socket:receive_bytes(0)
+			if not status and not retry then 
+				break
+			end
+			stdnse.print_debug("in a loop")
+			stdnse.sleep(2) -- needs relatively big timeout between retries 			
+		end
+		if not status or string.find(response,"Please press <Enter>") == nil then
+			--probably not pcanywhere
+			stdnse.print_debug(1, "%s: not pcAnywhere", SCRIPT_NAME)
+			return false, brute.Error:new( "Probably not pcAnywhere." )
+		end	
+		retry = false
+		status, err = self.socket:send(bin.pack("H","6f06ff")) -- downgrade into legacy mode
+		status, response = self.socket:receive_bytes(0)
+
+		status, err = self.socket:send(bin.pack("H","6f61000900fe0000ffff00000000")) -- auth capabilities I
+		status, response = self.socket:receive_bytes(0)
+
+		status, err = self.socket:send(bin.pack("H","6f620102000000")) -- auth capabilities II
+		status, response = self.socket:receive_bytes(0)
+		if not status or (string.find(response,"Enter user name") == nil and string.find(response,"Enter login name") == nil) then
+			stdnse.print_debug(1, "%s: handshake failed", SCRIPT_NAME)
+			return false, brute.Error:new( "Handshake failed." )
+		end	
+		return true
+	end,
+
+	login = function (self, user, pass)
+		local response
+		local err
+		local status
+		stdnse.print_debug( "Trying %s/%s ...", user, pass )
+		-- send username and password
+		-- both are prefixed with 0x06, size and are encrypted
+		status, err = self.socket:send(bin.pack("C",0x06) .. bin.pack("C",string.len(user)) .. encrypt(user) ) -- send username
+		status, response = self.socket:receive_bytes(0)
+		if not status or string.find(response,"Enter password") == nil then
+			stdnse.print_debug(1, "%s: Sending username failed", SCRIPT_NAME)
+			return false, brute.Error:new( "Sending username failed." )
+		end	
+		-- send password
+		status, err = self.socket:send(bin.pack("C",0x06) .. bin.pack("C",string.len(pass)) .. encrypt(pass) ) -- send password
+		status, response = self.socket:receive_bytes(0)
+		if not status or string.find(response,"Login unsuccessful") or string.find(response,"Invalid login.")then
+			stdnse.print_debug(1, "%s: Incorrect username or password", SCRIPT_NAME)
+			return false, brute.Error:new( "Incorrect username or password." )
+		end	
+	
+		if status then
+			retry = true -- now the server is in "locked mode", we need to retry next connection a few times
+			return true, brute.Account:new( user, pass, creds.State.VALID)
+		end
+		return false,brute.Error:new( "Incorrect password" )
+	end,
+
+	disconnect = function( self )
+		self.socket:close()
+		return true
+	end
+
+}
+
+action = function( host, port )
+
+	local status, result
+	local engine = brute.Engine:new(Driver, host, port)
+	engine.options.script_name = SCRIPT_NAME
+	engine.max_threads = 1 -- pcAnywhere supports only one login at a time
+	status, result = engine:start()
+
+	return result
+end

scripts/script.db

@@ -279,6 +279,7 @@ Entry { filename = "oracle-sid-brute.nse", categories = { "brute", "intrusive",
 Entry { filename = "ovs-agent-version.nse", categories = { "version", } }
 Entry { filename = "p2p-conficker.nse", categories = { "default", "safe", } }
 Entry { filename = "path-mtu.nse", categories = { "discovery", "safe", } }
+Entry { filename = "pcanywhere-brute.nse", categories = { "brute", "intrusive", } }
 Entry { filename = "pgsql-brute.nse", categories = { "brute", "intrusive", } }
 Entry { filename = "pjl-ready-message.nse", categories = { "intrusive", } }
 Entry { filename = "pop3-brute.nse", categories = { "brute", "intrusive", } }