view mod_ogp/mod_ogp.lua @ 5243:d5dc8edb2695

mod_http_oauth2: Use more compact IDs UUIDs are nice but so verbose! The reduction in entropy for the nonce should be fine since the timestamp is also counts towards this, and it changes every second (modulo clock shenanigans), so the chances of someone managing to get the same client_secret by registering with the same information at the same time as another entity should be negligible.
author Kim Alvefur <zash@zash.se>
date Sat, 11 Mar 2023 22:46:27 +0100
parents 09f0911c735d
children
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local mod_muc = module:depends("muc")
local http = require "net.http"
local st = require "util.stanza"
local url_pattern = [[https?://%S+]]
local domain_pattern = '^%w+://([^/]+)'
local xmlns_fasten = "urn:xmpp:fasten:0"
local xmlns_xhtml = "http://www.w3.org/1999/xhtml"
local allowlist = module:get_option_set("ogp_domain_allowlist", module:get_option_set("ogp_domain_whitelist", {}))
local denylist = module:get_option_set("ogp_domain_denylist", {})


local function is_allowed(domain)
	if allowlist:empty() then
		return true
	end
	if allowlist:contains(domain) then
		return true
	end
	return false
end

local function is_denied(domain)
	if denylist:empty() then
		return false
	end
	if denylist:contains(domain) then
		return true
	end
	return false
end


local function fetch_ogp_data(room, url, origin_id)
	if not url then
		return;
	end

	local domain = url:match(domain_pattern);
	if is_denied(domain) or not is_allowed(domain) then
		return;
	end

	http.request(
		url,
		nil,
		function(response_body, response_code, _)
			if response_code ~= 200 then
				module:log("debug", "Call to %s returned code %s and body %s", url, response_code, response_body)
				return
			end

			local to = room.jid
			local from = room and room.jid or module.host
			local fastening = st.message({to = to, from = from, type = 'groupchat'}):tag("apply-to", {xmlns = xmlns_fasten, id = origin_id})
			local found_metadata = false
			local message_body = ""

			local meta_pattern = [[<meta (.-)/?>]]
			for match in response_body:gmatch(meta_pattern) do
				local property = match:match([[property=%s*["']?(og:.-)["']?%s]])
				if not property then
					property = match:match([[property=["']?(og:.-)["']$]])
				end

				local content = match:match([[content=%s*["'](.-)["']%s]])
				if not content then
					content = match:match([[content=["']?(.-)["']$]])
				end
				if not content then
					content = match:match([[content=(.-) property]])
				end
				if not content then
					content = match:match([[content=(.-)$]])
				end

				if property and content then
					module:log("debug", property .. "\t" .. content)
					fastening:tag(
						"meta",
						{
							xmlns = xmlns_xhtml,
							property = property,
							content = content
						}
					):up()
					found_metadata = true
					message_body = message_body .. property .. "\t" .. content .. "\n"
				end
			end

			if found_metadata then
				mod_muc.get_room_from_jid(room.jid):broadcast_message(fastening)
			end
			module:log("debug", tostring(fastening))
		end
	)
end

local function ogp_handler(event)
	local room, stanza = event.room, st.clone(event.stanza)
	local body = stanza:get_child_text("body")

	if not body then return; end

	local origin_id = stanza:find("{urn:xmpp:sid:0}origin-id@id")
	if not origin_id then return; end

	for url in body:gmatch(url_pattern) do
		fetch_ogp_data(room, url, origin_id);
	end
end

module:hook("muc-occupant-groupchat", ogp_handler)


module:hook("muc-message-is-historic", function (event)
	local fastening = event.stanza:get_child('apply-to', xmlns_fasten)
	if fastening and fastening:get_child('meta', xmlns_xhtml) then
		return true
	end
end);