view mod_muc_occupant_id/mod_muc_occupant_id.lua @ 4974:807007913f67

mod_log_json: Prefer native Lua table.pack over Prosody util.table one Prosody is removing support for Lua 5.1, which was the reason for util.table.pack to exist in the first place, since Lua 5.2+ provides table.pack. In prosody rev 5eaf77114fdb everything was switched over to use table.pack, opening the door for removing util.table.pack at some point. This change here is to prepare for that future eventuality.
author Kim Alvefur <zash@zash.se>
date Mon, 11 Jul 2022 20:08:41 +0200
parents ae27f3359df8
children
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-- Implementation of https://xmpp.org/extensions/inbox/occupant-id.html
-- XEP-0421: Anonymous unique occupant identifiers for MUCs

module:depends("muc");

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 generate_id(occupant, room)
	local bare = occupant.bare_jid;

	if room._data.occupant_id_salt == nil then
		room._data.occupant_id_salt = uuid.generate();
	end

	-- XXX: Temporary not-so-important migration measure. Remove this next time
	-- somebody looks at it. This module used to store every participant's
	-- occupant-id all the time forever.
	room._data.occupant_ids = nil;

	return b64encode(hmac_sha256(bare, room._data.occupant_id_salt));
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 = generate_id(occupant, room);
	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

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);