id = "Stealth SSH version"
description = [[
Connects to an SSH server and retrieves the version banner.

This typically does not result in any logs of the connection being made.
]]

---
-- @output
-- 22/tcp  open   ssh
-- |_ Stealth SSH version: SSH-2.0-OpenSSH_3.9p1

author = "Diman Todorov <diman.todorov@gmail.com>"

license = "Same as Nmap--See http://nmap.org/book/man-legal.html"

categories = {"demo"}

require "shortport"

portrule = shortport.service("ssh")

action = function(host, port)
	local result, socket

	local catch = function()
		socket:close()
	end

	local try = nmap.new_try(catch)

	result = ""
	socket = nmap.new_socket()

	try(socket:connect(host.ip, port.number))

	result = try(socket:receive_lines(1));
	try(socket:send(result))
	try(socket:close())

	return (string.gsub(result, "\n", ""))
end