view mod_muc_occupant_id/mod_muc_occupant_id.lua @ 5265:f845c218e52c

mod_http_oauth2: Allow revoking a token without OAuth client credentials If you have a valid token, and you're not supposed to have it, revoking it seems the most responsible thing to do with it, so it should be allowed, while if you are supposed to have it, you should also be allowed to revoke it.
author Kim Alvefur <zash@zash.se>
date Tue, 21 Mar 2023 22:02:38 +0100
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);