Add http-generator.nse by Michael Kohl.

scripts/http-generator.nse

@@ -0,0 +1,49 @@
+description = [[
+Displays the contents of the "generator" meta tag if there is one.
+]]
+
+author = "Michael Kohl"
+license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
+categories = {"discovery", "safe"}
+
+---
+-- @usage
+-- nmap -p 80,443 --script http-generator <host>
+-- @output
+-- PORT    STATE SERVICE
+-- 80/tcp  open  http
+-- |_http-generator: TYPO3 4.2 CMS
+-- 443/tcp open  https
+-- |_http-generator: TYPO3 4.2 CMS
+
+--- TODO:
+-- add arg for web path
+-- add arg for maximum number of redirects
+
+require('http')
+require('shortport')
+
+portrule = shortport.http
+
+action = function(host, port)
+   local response, loc, generator
+   -- Worst case: <meta name=Generator content="Microsoft Word 11">
+   local pattern = '<meta name="?generator"? content="([^\"]*)" ?/?>'
+
+   -- make pattern case-insensitive
+   pattern = pattern:gsub("%a", function (c)
+               return string.format("[%s%s]", string.lower(c),
+                                              string.upper(c))
+             end)
+
+   response = http.get(host, port, '/')
+
+   -- deals with only one redirect
+   if response['status-line']:lower():match("^http/1.1 30[12]") then
+      loc = response.header['location']
+      response = http.get_url(loc)
+   end
+
+   return response.body:match(pattern)
+
+end