view mod_block_s2s_subscriptions/mod_block_s2s_subscriptions.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 70ff25db37fa
children
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local jid_split = require "util.jid".split;
local jid_bare = require "util.jid".bare;
local load_roster = require "core.rostermanager".load_roster;

local blocked_servers = module:get_option_set("block_s2s_subscriptions")._items;

function filter_presence(event)
	if blocked_servers[event.origin.from_host] and event.stanza.attr.type == "subscribe" then
		local stanza = event.stanza;
		local to_user, to_host = jid_split(stanza.attr.to);
		local roster = load_roster(to_user, to_host);
		if roster and roster[jid_bare(stanza.attr.from)] then
			return; -- In roster, pass through
		end
		return true; -- Drop
	end
end

module:hook("presence/bare", filter_presence, 200); -- Client receiving