1 files changed, 80 insertions, 0 deletions
diff --git a/scripts/auth-owners.nse b/scripts/auth-owners.nse
new file mode 100644
index 0000000..ab4bd1c
--- /dev/null
+++ b/scripts/auth-owners.nse
@@ -0,0 +1,80 @@
+local nmap = require "nmap"
+local string = require "string"
+
+description = [[
+Attempts to find the owner of an open TCP port by querying an auth
+daemon which must also be open on the target system. The auth service,
+also known as identd, normally runs on port 113.
+]]
+---
+--@output
+-- 21/tcp   open     ftp       ProFTPD 1.3.1
+-- |_ auth-owners: nobody
+-- 22/tcp   open     ssh       OpenSSH 4.3p2 Debian 9etch2 (protocol 2.0)
+-- |_ auth-owners: root
+-- 25/tcp   open     smtp      Postfix smtpd
+-- |_ auth-owners: postfix
+-- 80/tcp   open     http      Apache httpd 2.0.61 ((Unix) PHP/4.4.7 ...)
+-- |_ auth-owners: dhapache
+-- 113/tcp  open     auth?
+-- |_ auth-owners: nobody
+-- 587/tcp  open     submission Postfix smtpd
+-- |_ auth-owners: postfix
+-- 5666/tcp open     unknown
+-- |_ auth-owners: root
+
+-- The protocol is documented in RFC 1413.
+
+author = "Diman Todorov"
+
+license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
+
+categories = {"default", "safe"}
+
+portrule = function(host, port)
+  local auth_port = { number=113, protocol="tcp" }
+  local identd = nmap.get_port_state(host, auth_port)
+
+  return identd ~= nil
+    and identd.state == "open"
+    and port.protocol == "tcp"
+    and port.state == "open"
+end
+
+action = function(host, port)
+  local owner = ""
+
+  local client_ident = nmap.new_socket()
+  local client_service = nmap.new_socket()
+
+  local catch = function()
+    client_ident:close()
+    client_service:close()
+  end
+
+  local try = nmap.new_try(catch)
+
+  try(client_ident:connect(host, 113))
+  try(client_service:connect(host, port))
+
+  local localip, localport, remoteip, remoteport =
+    try(client_service:get_info())
+
+  local request = port.number .. ", " .. localport .. "\r\n"
+
+  try(client_ident:send(request))
+
+  owner = try(client_ident:receive_lines(1))
+
+  if string.match(owner, "ERROR") then
+    owner = nil
+  else
+    owner = string.match(owner,
+      "%d+%s*,%s*%d+%s*:%s*USERID%s*:%s*[^:]+%s*:[ \t]*([^\r\n]+)\r?\n")
+  end
+
+  try(client_ident:close())
+  try(client_service:close())
+
+  return owner
+end