description = [[
Performs brute force password auditing against the MongoDB database.
]]

---
-- @usage
-- nmap -p 27017 <ip> --script mongodb-brute
--
-- @output
-- PORT      STATE SERVICE
-- 27017/tcp open  mongodb
-- | mongodb-brute: 
-- |   Accounts
-- |     root:Password1 - Valid credentials
-- |   Statistics
-- |_    Performed 3542 guesses in 9 seconds, average tps: 393
--

require 'brute'
require 'shortport'
require 'stdnse'
stdnse.silent_require('mongodb')

author = "Patrik Karlsson"
license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
categories = {"intrusive", "brute"}

local arg_db = stdnse.get_script_args(SCRIPT_NAME .. ".db") or "admin"

portrule = shortport.port_or_service({27017}, {"mongodb"})

Driver = {
	
	new = function(self, host, port, options)
		local o = { host = host, port = port, sock = nmap.new_socket() }
		setmetatable(o, self)
		self.__index = self
		return o
	end,
	
	connect = function(self)
		return self.sock:connect(self.host, self.port)
	end,
	
	login = function(self, username, password)
		local status, resp = mongodb.login(self.sock, arg_db, username, password)
		if ( status ) then
			return true, brute.Account:new(username, password, creds.State.VALID)
		elseif ( resp ~= "Authentication failed" ) then
			local err = brute.Error:new( err )
			err:setRetry( true )
			return false, err					
		end
		return false, brute.Error:new( "Incorrect password" )
	end,
	
	disconnect = function(self)
		return self.sock:close()
	end,
	
}

local function needsAuth(host, port)
	local socket = nmap.new_socket()
	local status, result = socket:connect(host, port)
	if ( not(status) ) then
		return false, "Failed to connect to server"
	end

	local packet
	status, packet = mongodb.listDbQuery()
	if ( not(status) ) then
		return false, result
	end
	
	--- Send packet
	status, result = mongodb.query(socket, packet)
	if ( not(status) ) then
		return false, result
	end
	
	socket:close()
	if ( status and result.errmsg ) then
		return true
	end
	return false
end

action = function(host, port)

	if ( not(needsAuth(host, port)) ) then
		return "No authentication needed"
	end

	local engine = brute.Engine:new(Driver, host, port )
	
	engine.options.script_name = SCRIPT_NAME
	engine.options.firstonly = true
	status, result = engine:start()

	return result
end