local shortport = require "shortport"

description = [[
Get and return a page info
]]

---
-- @args http-get.path Path to get. Default /.
--
-- @usage nmap -p80 --script http-info.nse --script-args http-info.path=/ <target>
--
-- @output
-- status: 200
-- status-line: HTTP/1.1 200 OK\x0D
---

categories = {"discovery", "intrusive"}
author = "Adrien Malingrey"
license = "Same as Nmap--See https://nmap.org/book/man-legal.html"

portrule = shortport.service({"http", "https", "ssl"})


local http = require "http"
local stdnse = require "stdnse"

action = function(host, port)
  local scheme = ""
  local hostaddress = (host.name ~= '' and host.name) or host.ip
  local path = ""
  local answer
  local favicon_relative_uri = "favicon.ico"
  local favicon

  if (port.service == "ssl") then
    scheme = "https"
  else
    scheme = port.service
  end

  if(stdnse.get_script_args('http-get.path')) then
    path = "/" .. stdnse.get_script_args('http-info.path')
  end

  answer = http.get_url(scheme.."://"..hostaddress..":"..port.number.."/"..path)

  if (answer and answer.status == 200) then
    favicon_relative_uri = parseIcon(answer.body) or "favicon.ico"
  end
  
  favicon_absolute_uri = scheme.."://"..hostaddress..":"..port.number.."/"..favicon_relative_uri
  favicon = http.get_url(favicon_absolute_uri)

  if (favicon and favicon.status == 200) then
    return {status=answer.status, ["status-line"]=answer["status-line"], favicon=favicon_absolute_uri}
  else
    return {status=answer.status, ["status-line"]=answer["status-line"]}
  end
end

--- function taken from http_favicon.nse by Vlatko Kosturjak

function parseIcon( body )
  local _, i, j
  local rel, href, word

  -- Loop through link elements.
  i = 0
  while i do
    _, i = string.find(body, "<%s*[Ll][Ii][Nn][Kk]%s", i + 1)
    if not i then
      return nil
    end
    -- Loop through attributes.
    j = i
    while true do
      local name, quote, value
      _, j, name, quote, value = string.find(body, "^%s*(%w+)%s*=%s*([\"'])(.-)%2", j + 1)
      if not j then
        break
      end
      if string.lower(name) == "rel" then
        rel = value
      elseif string.lower(name) == "href" then
        href = value
      end
    end
    for word in string.gmatch(rel or "", "%S+") do
      if string.lower(word) == "icon" then
        return href
      end
    end
  end
end