Added a 'path' script-arg to http-headers.nse. Changed it to use 'HEAD' by default, and fail to using 'GET' the same way other scripts do (also added a 'useget' script-arg to turn it off). Also fixed some print_debugs in http.lua that were prefixed with 'http-enum.nse:'.

scripts/http-headers.nse

@@ -17,7 +17,8 @@ Does a GET request for the root folder ("/"), and displays the HTTP headers retu
 -- |   last-modified: Mon, 19 May 2008 04:49:49 GMT
 -- |_  server: Apache/2.2.2 (Fedora)
 -- 
---
+--@arg path The path to request, such as '/index.php'. Default: '/'. 
+--@arg useget Set to force GET requests instead of HEAD. 
 
 
 author = "Ron Bowes <ron@skullsecurity.org>"
@@ -45,25 +46,45 @@ portrule = function(host, port)
 end
 
 action = function(host, port)
-	local result = http.get(host, port, "/")
+	local path = nmap.registry.args.path
+	local request_type = "HEAD"
+	if(path == nil) then
+		path = '/'
+	end
+
+	local status = false
+	local result
+
+	-- Check if the user didn't want HEAD to be used
+	if(nmap.registry.args.useget == nil) then
+		-- Try using HEAD first
+		status, result = http.can_use_head(host, port, path)
+	end
+
+	-- If head failed, try using GET
+	if(status == false) then
+		stdnse.print_debug(1, "http-headers.nse: HEAD request failed, falling back to GET")
+		result = http.get(host, port, path)
+		request_type = "GET"
+	end
 
 	if(result == nil) then
 		if(nmap.debugging() > 0) then
-			return "ERROR: GET request failed"
+			return "ERROR: Header request failed"
 		else
 			return nil
 		end
 	end
 
-	if(result.header == nil) then
+	if(result.rawheader == nil) then
 		if(nmap.debugging() > 0) then
-			return "ERROR: GET request didn't return a proper header"
+			return "ERROR: Header request didn't return a proper header"
 		else
 			return nil
 		end
 	end
 
-	local response = " \n"
+	local response = "(" .. request_type .. " used)\n"
 	for _, header in pairs(result.rawheader) do
 		response = response .. header .. "\n"
 	end