Adding the bittorrent library and bittorrent-discovery script which enables you to add bittorrent peers and DHT nodes as targets for scanning

scripts/bittorrent-discovery.nse

@@ -0,0 +1,131 @@
+description = [[
+Discovers bittorrent peers and nodes using the Bittorrent and DHT protocol when
+supplied with a valid torrent file or a magnet link. The peers implement the 
+Bittorrent protocol and share the torrent, whereas the nodes implement the DHT
+protocol and are used to track the peers. The sets of peers and nodes are not 
+the same, but they usually intersect.
+
+If the <code>newtargets</code> script-arg is supplied it adds the discovered 
+peers as targets.
+]]
+
+---
+-- @usage 
+-- nmap --script bittorrent-discovery --script-args bittorrent-discovery.torrent=<filename>,
+-- bittorrent-discovery.magnet=<magnet_link>[,bittorrent-discovery.dht_timeout=<seconds>]
+-- [,bittorrent-discovery.nodes-only][,bittorrent-discovery.peers-only][,newtargets]
+--
+-- @arg torrent, a string containing the filename of the torrent file
+-- @arg magnet, a string containing the magnet link of the torrent
+-- @arg timeout, desired (not actual) timeout for the DHT discovery (default = 30 s)
+-- @arg nodes-only, boolean selecting whether to show only nodes
+-- @arg peers-only, boolean selecting whether to show only peers
+--
+-- @output
+-- | bittorrent-peers:
+-- |   Peers:
+-- |     97.88.178.168
+-- |     89.100.184.36
+-- |     86.185.55.212
+-- |     Total of 3 peers discovered
+-- |   Nodes:
+-- |     68.103.0.189
+-- |     67.164.32.71
+-- |     24.121.13.69
+-- |     207.112.100.224
+-- |     Total of 4 nodes discovered
+-- |_  Use the newtargets script-arg to add the results as targets
+--
+
+author = "Gorjan Petrovski"
+license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
+categories = {"discovery","safe"}
+
+require "bittorrent"
+require "stdnse"
+require "target"
+
+prerule = function()
+	return true
+end
+
+action = function()
+	local timeout = stdnse.get_script_args(SCRIPT_NAME..".dht_timeout")
+	local filename = stdnse.get_script_args(SCRIPT_NAME..".torrent")
+	local magnet = stdnse.get_script_args(SCRIPT_NAME..".magnet")
+	local include_nodes = stdnse.get_script_args(SCRIPT_NAME..".include-nodes")
+	
+	if not (magnet or filename) then
+		stdnse.print_debug(SCRIPT_NAME.." not running. No magnet link or torrent file specified")
+		return
+	end
+	t = bittorrent.Torrent:new()
+	if filename then
+		t:load_from_file(filename)
+	elseif magnet then
+		t:load_from_magnet(magnet)
+	end
+	t:trackers_peers()
+	t:dht_peers(timeout)
+	
+	local output = {}
+	local peers = {}
+	peers.name = "Peers:"
+	local nodes = {}
+	nodes.name = "Nodes:"
+	
+	-- add peers
+	if target.ALLOW_NEW_TARGETS then
+		for peer_ip in pairs(t.peers) do
+			target.add(peer_ip)
+			table.insert(peers, peer_ip)
+		end
+		if #peers>0 then
+			table.insert(peers, "Total of "..#peers.." peers discovered")
+		end
+	else
+		for peer_ip in pairs(t.peers) do
+			table.insert(peers, peer_ip) 
+		end
+		if #peers>0 then
+			table.insert(peers, "Total of "..#peers.." peers discovered")
+		end
+	end
+	
+	-- add nodes
+	if target.ALLOW_NEW_TARGETS and include_nodes then
+		for node_ip in pairs(t.nodes) do
+			target.add(node_ip)
+			table.insert(nodes, node_ip)
+		end
+		if #nodes >0 then
+			table.insert(nodes, "Total of "..#nodes.." nodes discovered")
+		end
+	elseif include_nodes then
+		for node_ip in pairs(t.nodes) do
+			table.insert(nodes, node_ip)
+		end
+		if #nodes >0 then
+			table.insert(nodes, "Total of "..#nodes.." nodes discovered")
+		end
+	end
+	
+	local print_out = false
+
+	if #peers > 0 then 
+		table.insert(output, peers)
+		print_out = true
+	end
+
+	if include_nodes and #nodes > 0 then
+		table.insert(output, nodes)
+		print_out = true
+	end
+	
+	if print_out and not target.ALLOW_NEW_TARGETS then
+		table.insert(output,"Use the newtargets script-arg to add the results as targets")
+	end
+
+	return stdnse.format_output( print_out , output)
+end
+