view mod_block_strangers/mod_block_strangers.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 38365c1f1fe4
children
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local st = require"util.stanza";
local jid_split = require "util.jid".split;
local jid_bare = require "util.jid".bare;
local is_contact_subscribed = require "core.rostermanager".is_contact_subscribed;
local full_sessions = prosody.full_sessions;

local function has_directed_presence(user, jid)
	local session = full_sessions[user];
	if session then
		local directed = session.directed;
		if directed then
			return directed[jid];
		end
	end
end

function check_subscribed(event)
	local stanza = event.stanza;
	local to_user, to_host, to_resource = jid_split(stanza.attr.to);
	local from_jid = jid_bare(stanza.attr.from);
	if to_user and not has_directed_presence(stanza.attr.to, from_jid) and not is_contact_subscribed(to_user, to_host, from_jid) then
		-- Allow all messages from your own jid
		if from_jid == to_user.."@"..to_host then
			return nil; -- Pass through
		end
		if to_resource and stanza.attr.type == "groupchat"
		or stanza.name == "iq" and (stanza.attr.type == "result" or stanza.attr.type == "error") then
			return nil; -- Pass through
		end
		if stanza.name == "iq" and ( stanza.attr.type == "get" or stanza.attr.type == "set" ) then
			event.origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
		end
		return true; -- Drop stanza
	end
end

module:hook("message/bare", check_subscribed, 200);
module:hook("message/full", check_subscribed, 200);
module:hook("iq/full", check_subscribed, 200);