view mod_isolate_host/mod_isolate_host.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 8e19b943c2cd
children bc75fc9400ae
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local jid = require "util.jid";
local jid_bare, jid_split = jid.bare, jid.split;
local is_admin = require "core.usermanager".is_admin;
local set = require "util.set";
local st = require "util.stanza";

local stanza_types = set.new{"message", "presence", "iq"};
local jid_types = set.new{"bare", "full", "host"};

local except_domains = module:get_option_inherited_set("isolate_except_domains", {});
local except_users = module:get_option_inherited_set("isolate_except_users", {});

function check_stanza(event)
	local origin, stanza = event.origin, event.stanza;
	if origin.no_host_isolation then return; end
	local to_user, to_host = jid_split(event.stanza.attr.to);
	if to_host and to_host ~= origin.host and not except_domains:contains(to_host) then
		if to_host:match("^[^.]+%.(.+)$") == origin.host then -- Permit subdomains
			except_domains:add(to_host);
			return;
		end
		module:log("warn", "Forbidding stanza from %s to %s", stanza.attr.from or origin.full_jid, stanza.attr.to);
		origin.send(st.error_reply(stanza, "auth", "forbidden", "Communication with "..to_host.." is not available"));
		return true;
	end
end

for stanza_type in stanza_types do
	for jid_type in jid_types do
		module:hook("pre-"..stanza_type.."/"..jid_type, check_stanza, 1);
	end
end

function check_user_isolated(event)
	local session = event.session;
	local bare_jid = jid_bare(session.full_jid);
	if is_admin(bare_jid, module.host) or except_users:contains(bare_jid) then
		session.no_host_isolation = true;
	end
	module:log("debug", "%s is %sisolated", session.full_jid or "[?]", session.no_host_isolation and "" or "not ");
end

module:hook("resource-bind", check_user_isolated);