view mod_post_msg/mod_post_msg.lua @ 4651:8231774f5bfd

mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8 The `body:sub()` call risks splitting the string in the middle of a multi-byte UTF-8 sequence. This should have been caught by util.stanza validation, but that would have caused some havoc, at the very least causing the notification to not be sent. There have been no reports of this happening. Likely because this module isn't widely deployed among users with languages that use many longer UTF-8 sequences. The util.encodings.utf8.valid() function is O(n) where only the last sequence really needs to be checked, but it's in C and expected to be fast.
author Kim Alvefur <zash@zash.se>
date Sun, 22 Aug 2021 13:22:59 +0200
parents 926aaaeb0d21
children
line wrap: on
line source

module:depends"http"

local jid_split = require "util.jid".split;
local jid_prep = require "util.jid".prep;
local msg = require "util.stanza".message;
local test_password = require "core.usermanager".test_password;
local b64_decode = require "util.encodings".base64.decode;
local formdecode = require "net.http".formdecode;
local xml = require"util.xml";
local json = require "util.json";

local function require_valid_user(f)
	return function(event, path)
		local request = event.request;
		local response = event.response;
		local headers = request.headers;
		if not headers.authorization then
			response.headers.www_authenticate = ("Basic realm=%q"):format(module.host.."/"..module.name);
			return 401
		end
		local from_jid, password = b64_decode(headers.authorization:match"[^ ]*$"):match"([^:]*):(.*)";
		from_jid = jid_prep(from_jid);
		if from_jid and password then
			local user, host = jid_split(from_jid);
			local ok, err = test_password(user, host, password);
			if ok and user and host then
				module:log("debug", "Authed as %s", from_jid);
				return f(event, path, from_jid);
			elseif err then
				module:log("debug", "User failed authentication: %s", err);
			end
		end
		return 401
	end
end

local function handle_post(event, path, authed_user)
	local request = event.request;
	local response = event.response;
	local headers = request.headers;

	local body_type = headers.content_type;
	local to = jid_prep(path);
	local message;
	if body_type == "text/plain" then
		if to and request.body then
			message = msg({ to = to, from = authed_user, type = "chat"},request.body);
		end
	elseif body_type == "application/x-www-form-urlencoded" then
		local post_body = formdecode(request.body);
		message = msg({ to = post_body.to or to, from = authed_user,
		                type = post_body.type or "chat"}, post_body.body);
		if post_body.html then
			local html, err = xml.parse([[<body xmlns="http://www.w3.org/1999/xhtml">]]..post_body.html..[[</body>]]);
			if not html then
				module:log("warn", "mod_post_msg: invalid XML: %s", err);
				return 400;
			end
			message:tag("html", {xmlns="http://jabber.org/protocol/xhtml-im"}):add_child(html):up();
		end
	elseif body_type == "application/json" then
		local post_body = json.decode(request.body);
		if not post_body then return 400; end
		message = msg({ to = post_body.to or to, from = authed_user,
		                type = post_body.type or "chat"}, post_body.body);
	else
		return 415;
	end
	if message and message.attr.to then
		module:log("debug", "Sending %s", tostring(message));
		module:send(message);
		return 201;
	end
	return 422;
end

module:provides("http", {
	default_path = "/msg";
	route = {
		["POST /*"] = require_valid_user(handle_post);
		OPTIONS = function(e)
			local headers = e.response.headers;
			headers.allow = "POST";
			headers.accept = "application/x-www-form-urlencoded, text/plain";
			return 200;
		end;
	}
});