Rewrite http-methods.nse to use the http.generic_request function

instead of doing its own socket handling. Also make the output more
concise.

scripts/http-methods.nse

@@ -15,13 +15,13 @@ individually to see if they are subject to e.g. IP address restrictions.
 -- possible.
 --
 -- @output
--- 80/tcp open  http    syn-ack Apache httpd 2.2.8 ((Ubuntu))
--- |  HTTP allowed methods: according to OPTIONS request: GET,HEAD,POST,OPTIONS,TRACE
--- |     HTTP Status for GET is 200 OK
--- |     HTTP Status for HEAD is 200 OK
--- |     HTTP Status for POST is 200 OK
--- |     HTTP Status for OPTIONS is 200 OK
--- |_    HTTP Status for TRACE is 200 OK
+-- 80/tcp open  http    syn-ack
+-- | http-methods: GET,HEAD,POST,OPTIONS,TRACE
+-- | GET / -> HTTP/1.1 200 OK
+-- | HEAD / -> HTTP/1.1 200 OK
+-- | POST / -> HTTP/1.1 200 OK
+-- | OPTIONS / -> HTTP/1.1 200 OK
+-- |_TRACE / -> HTTP/1.1 200 OK
 --
 -- @usage
 -- nmap --script=http-methods.nse --script-args http-methods.retest=1 <target>
@@ -33,7 +33,8 @@ license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
 
 categories = {"safe"}
 
-require "stdnse"
+require("http")
+require("stdnse")
 
 portrule = function(host, port)
 	if not (port.service == 'http' or port.service == 'https') 
@@ -48,91 +49,49 @@ portrule = function(host, port)
 	return(true)
 end
 
---- cleanup function for HTTP response header
---
--- in multi line strings any lines after the first one are removed
--- if the first line contains HTTP protocol version and response code
--- only the response code itself is kept (removing "HTTP/1.? ")
--- @param some_string gives the (probably multi line) string to clean up, 
--- normally a HTTP response header
--- @returns some_string as a clean string, single line
-
-local cleanup = function(some_string)
-	if (some_string ~= nil)
-	then
-		some_string = string.gsub(some_string , "[\n\r].*", "")
-		some_string = string.gsub(some_string, "HTTP/[0-9]\.[0-9] ", "")
-	end
-	return(some_string)
-end
-
 action = function(host, port)
-	local socket, request, result, methods, protocol, output, httpstatus, methodsarray, i, own_httpstatus, url_path, retest_http_methods, try, catch, location
+	local url_path, retest_http_methods
+	local response, methods, options_status_line, output
 
 	-- default vaules for script-args
 	url_path = nmap.registry.args["http-methods.url-path"] or "/"
 	retest_http_methods = nmap.registry.args["http-methods.retest"] ~= nil
 
-	catch = function()
-		socket:close()
+	response = http.generic_request(host, port, "OPTIONS", url_path)
+	if not response.status then
+		stdnse.print_debug("http-methods: OPTIONS %s failed.", url_path)
+		return
 	end
-	try = nmap.new_try(catch)
+	-- Cache in case retest is requested.
+	options_status_line = response["status-line"]
+	stdnse.print_debug("http-methods.nse: HTTP Status for OPTIONS is " .. response.status)
 
-	socket = nmap.new_socket()
-
-	if (port.service == 'https' or port.version.service_tunnel == 'ssl')
-	then
-		protocol = "ssl"
-	else
-		protocol = "tcp"
+	if not response.header["allow"] then
+		return string.format("No Allow header in OPTIONS response (status code %d)", response.status)
 	end
 
-	try(socket:connect(host.ip, port.number, protocol))
-	request = "OPTIONS " .. url_path .. " HTTP/1.0\r\n\r\n"
-	try(socket:send(request))
-	result = try(socket:receive_lines(1))
-	socket:close()
-	
-	own_httpstatus = cleanup(result)
-	stdnse.print_debug("http-methods.nse: HTTP Status for OPTIONS is " .. own_httpstatus)
-	methods = cleanup(string.match(result, "Allow: *(.+)[\n\r]"))
-
-	if (methods ~= nil)
-	then
-		-- got methods
-		output = "OPTIONS " .. url_path .. " request returned: " .. methods
-	else
-		-- got no methods
-		output = "OPTIONS " .. url_path .. " request returned no methods but response code " .. own_httpstatus
-	end
+	output = { response.header["allow"] }
 
 	-- retest http methods if requested
-	if (retest_http_methods and methods ~= nil)
-	then
-		methodsarray = stdnse.strsplit(",", methods)
-		for i=1, #methodsarray, 1
-		do
-			stdnse.print_debug("http-methods.nse: found method " .. i .. " " .. methodsarray[i])
-			if (methodsarray[i] == 'OPTIONS') 
-			then
-				stdnse.print_debug("http-methods.nse: no need to try method OPTIONS, using status of previous request");	
-				output = output .. "\n   HTTP Status for OPTIONS " .. url_path .. " is " .. own_httpstatus
+	if retest_http_methods then
+		local methods = stdnse.strsplit(",%s*", response.header["allow"])
+		local _
+		for _, method in ipairs(methods) do
+			local str
+			if method == "OPTIONS" then
+				-- Use the saved value.
+				str = options_status_line
 			else
-				stdnse.print_debug("http-methods.nse: trying method " .. methodsarray[i] .. " on " .. protocol);	
-
-				socket = nmap.new_socket()
-				try(socket:connect(host.ip, port.number, protocol))
-				request = methodsarray[i] .. " " .. url_path .. " HTTP/1.0\r\n\r\n"
-				try(socket:send(request))
-				httpstatus = cleanup(try(socket:receive_lines(1)))
-				socket:close()
-
-				stdnse.print_debug("http-methods.nse: HTTP Status for " .. methodsarray[i] .. " " .. url_path .. " is " .. httpstatus)
-				output = output .. "\n   HTTP Status for " .. methodsarray[i] .. " " .. url_path .. " is " .. httpstatus
+				response = http.generic_request(host, port, method, url_path)
+				if not response.status then
+					str = "Error getting response"
+				else
+					str = response["status-line"]
 				end
 			end
+			output[#output + 1] = string.format("%s %s -> %s", method, url_path, str)
+		end
 	end
 
-	return(output)
+	return stdnse.strjoin("\n", output)
 end
-