view mod_muc_occupant_id/mod_muc_occupant_id.lua @ 5296:0f5657db1cfc

mod_isolate_host: handle server-generated stanzas The hook for setting the no_host_isolation is only called for c2s sessions. This does not work for stanzas generated by the server, such as PEP notifications or presence probe answers. To handle that, we do per-stanza checks for the case that the origin is local.
author Jonas Schäfer <jonas@wielicki.name>
date Sat, 01 Apr 2023 12:03:08 +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);