Mercurial > prosody-modules
view mod_muc_occupant_id/mod_muc_occupant_id.lua @ 4651:8231774f5bfd
mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8
The `body:sub()` call risks splitting the string in the middle of a
multi-byte UTF-8 sequence. This should have been caught by util.stanza
validation, but that would have caused some havoc, at the very least causing
the notification to not be sent.
There have been no reports of this happening. Likely because this module
isn't widely deployed among users with languages that use many longer UTF-8
sequences.
The util.encodings.utf8.valid() function is O(n) where only the last
sequence really needs to be checked, but it's in C and expected to be fast.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sun, 22 Aug 2021 13:22:59 +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);