File

plugins/muc/occupant_id.lib.lua @ 11906:ba3344926e18

MUC: Add option to include form in registration query This was originally not done based on my interpretation of XEP-0045. Today's reading, however, revealed that it actually says the result > SHOULD contain **at least** a <username/> element (emphasis mine) I take this to mean that including a form **is** allowed (and I think this is sensible). Tigase already includes the form I believe. I've gated the new behaviour behind a (default off) option, because it hasn't been tested for compatibility with clients. My primary desire for it is in Snikket, where the clients will be tested to ensure compatibility with this. I don't anticipate that (m)any clients would break, so maybe after 0.12 we can experiment with enabling it by default and eventually remove the option.
author Matthew Wild <mwild1@gmail.com>
date Mon, 15 Nov 2021 16:11:03 +0000
parent 11215:9ce0a899ff07
child 12108:e9882c4c397f
line wrap: on
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-- Implementation of https://xmpp.org/extensions/inbox/occupant-id.html
-- XEP-0421: Anonymous unique occupant identifiers for MUCs

-- (C) 2020 Maxime “pep” Buquet <pep@bouah.net>
-- (C) 2020 Matthew Wild <mwild1@gmail.com>

local uuid = require "util.uuid";
local hmac_sha256 = require "util.hashes".hmac_sha256;
local b64encode = require "util.encodings".base64.encode;

local xmlns_occupant_id = "urn:xmpp:occupant-id:0";

local function get_occupant_id(room, occupant)
	if occupant.stable_id then
		return occupant.stable_id;
	end

	local salt = room._data.occupant_id_salt;
	if not salt then
		salt = uuid.generate();
		room._data.occupant_id_salt = salt;
	end

	occupant.stable_id = b64encode(hmac_sha256(occupant.bare_jid, salt));

	return occupant.stable_id;
end

local function update_occupant(event)
	local stanza, room, occupant, dest_occupant = event.stanza, event.room, event.occupant, event.dest_occupant;

	-- "muc-occupant-pre-change" provides "dest_occupant" but not "occupant".
	if dest_occupant ~= nil then
		occupant = dest_occupant;
	end

	-- strip any existing <occupant-id/> tags to avoid forgery
	stanza:remove_children("occupant-id", xmlns_occupant_id);

	local unique_id = get_occupant_id(room, occupant);
	stanza:tag("occupant-id", { xmlns = xmlns_occupant_id, id = unique_id }):up();
end

local function muc_private(event)
	local stanza, room = event.stanza, event.room;
	local occupant = room._occupants[stanza.attr.from];

	update_occupant({
		stanza = stanza,
		room = room,
		occupant = occupant,
	});
end

if module:get_option_boolean("muc_occupant_id", true) then
	module:add_feature(xmlns_occupant_id);
	module:hook("muc-disco#info", function (event)
		event.reply:tag("feature", { var = xmlns_occupant_id }):up();
	end);

	module:hook("muc-broadcast-presence", update_occupant);
	module:hook("muc-occupant-pre-join", update_occupant);
	module:hook("muc-occupant-pre-change", update_occupant);
	module:hook("muc-occupant-groupchat", update_occupant);
	module:hook("muc-private-message", muc_private);
end

return {
	get_occupant_id = get_occupant_id;
};