view mod_post_msg/mod_post_msg.lua @ 5193:2bb29ece216b

mod_http_oauth2: Implement stateless dynamic client registration Replaces previous explicit registration that required either the additional module mod_adhoc_oauth2_client or manually editing the database. That method was enough to have something to test with, but would not probably not scale easily. Dynamic client registration allows creating clients on the fly, which may be even easier in theory. In order to not allow basically unauthenticated writes to the database, we implement a stateless model here. per_host_key := HMAC(config -> oauth2_registration_key, hostname) client_id := JWT { client metadata } signed with per_host_key client_secret := HMAC(per_host_key, client_id) This should ensure everything we need to know is part of the client_id, allowing redirects etc to be validated, and the client_secret can be validated with only the client_id and the per_host_key. A nonce injected into the client_id JWT should ensure nobody can submit the same client metadata and retrieve the same client_secret
author Kim Alvefur <zash@zash.se>
date Fri, 03 Mar 2023 21:14:19 +0100
parents 926aaaeb0d21
children
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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;
	}
});