Merge 3484ae6687 into c86a45ef6e

scripts/external-ip.nse

@@ -0,0 +1,142 @@
+-- external-ip.nse
+
+local http = require "http"
+local nmap = require "nmap"
+local stdnse = require "stdnse"
+local math = require "math"
+local target = require "target"
+
+description = [[
+Queries a randomly selected external IP provider to determine the public-facing
+IP address of the local (scanning) machine. Useful for verifying your egress
+address before running scans.
+
+If called with --script-args=newtargets, the discovered external IP will be
+added to nmap's target list for scanning.
+]]
+
+---
+-- @usage
+-- nmap --script external-ip
+-- nmap --script external-ip --script-args=newtargets
+--
+-- @output
+-- Pre-scan script results:
+-- | external-ip:
+-- |   external_ip: 203.0.113.42
+-- |_  added_to_targets: true
+
+author = "AI"
+license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
+categories = {"external", "safe", "discovery"}
+
+prerule = function()
+  return true
+end
+
+local providers = {
+  {
+    name = "ipify",
+    url  = "api.ipify.org",
+    path = "/",
+  },
+  {
+    name = "icanhazip",
+    url  = "icanhazip.com",
+    path = "/",
+  },
+  {
+    name = "ifconfig.me",
+    url  = "ifconfig.me",
+    path = "/ip",
+  },
+  {
+    name = "ipinfo.io",
+    url  = "ipinfo.io",
+    path = "/ip",
+  },
+  {
+    name = "checkip.amazonaws.com",
+    url  = "checkip.amazonaws.com",
+    path = "/",
+  },
+  {
+    name = "wtfismyip",
+    url  = "wtfismyip.com",
+    path = "/text",
+  },
+  {
+    name = "ip.me",
+    url  = "ip.me",
+    path = "/",
+  },
+}
+
+local function pick_random_provider()
+  math.randomseed(os.time())
+  local idx = math.random(1, #providers)
+  return providers[idx]
+end
+
+local function trim(s)
+  return s:match("^%s*(.-)%s*$")
+end
+
+action = function()
+  local provider = pick_random_provider()
+  local full_url = "https://" .. provider.url .. provider.path
+
+  stdnse.debug1("querying provider: %s (%s)", provider.name, full_url)
+
+  local response = http.get(provider.url, 443, provider.path, {
+    scheme = "https",
+    header = {
+      ["User-Agent"] = "curl/8.0",
+      ["Accept"]     = "text/plain",
+    },
+  })
+
+  if not response or not response.status then
+    return stdnse.format_output(false,
+      ("no response from %s"):format(provider.name))
+  end
+
+  if response.status ~= 200 then
+    return stdnse.format_output(false,
+      ("provider %s returned HTTP %d"):format(provider.name, response.status))
+  end
+
+  local ip = trim(response.body or "")
+
+  if ip == "" then
+    return stdnse.format_output(false,
+      ("empty response from %s"):format(provider.name))
+  end
+
+  -- basic sanity check: looks like an ipv4 or ipv6 address
+  if not ip:match("^%d+%.%d+%.%d+%.%d+$") and not ip:match(":") then
+    return stdnse.format_output(false,
+      ("unexpected response from %s: %s"):format(provider.name, ip))
+  end
+
+  -- add to target list if newtargets is enabled
+  local added = false
+  if target.ALLOW_NEW_TARGETS then
+    added = target.add(ip)
+    if added then
+      stdnse.debug1("added %s to target list", ip)
+    else
+      stdnse.debug1("failed to add %s to target list", ip)
+    end
+  end
+
+  local output = stdnse.output_table()
+  output.provider = full_url
+  output.external_ip = ip
+
+  if target.ALLOW_NEW_TARGETS then
+    output.added_to_targets = added
+  end
+
+  return output
+end