Software / code / prosody
File
util/logger.lua @ 13801:a5d5fefb8b68 13.0
mod_tls: Enable Prosody's certificate checking for incoming s2s connections (fixes #1916) (thanks Damian, Zash)
Various options in Prosody allow control over the behaviour of the certificate
verification process For example, some deployments choose to allow falling
back to traditional "dialback" authentication (XEP-0220), while others verify
via DANE, hard-coded fingerprints, or other custom plugins.
Implementing this flexibility requires us to override OpenSSL's default
certificate verification, to allow Prosody to verify the certificate itself,
apply custom policies and make decisions based on the outcome.
To enable our custom logic, we have to suppress OpenSSL's default behaviour of
aborting the connection with a TLS alert message. With LuaSec, this can be
achieved by using the verifyext "lsec_continue" flag.
We also need to use the lsec_ignore_purpose flag, because XMPP s2s uses server
certificates as "client" certificates (for mutual TLS verification in outgoing
s2s connections).
Commit 99d2100d2918 moved these settings out of the defaults and into mod_s2s,
because we only really need these changes for s2s, and they should be opt-in,
rather than automatically applied to all TLS services we offer.
That commit was incomplete, because it only added the flags for incoming
direct TLS connections. StartTLS connections are handled by mod_tls, which was
not applying the lsec_* flags. It previously worked because they were already
in the defaults.
This resulted in incoming s2s connections with "invalid" certificates being
aborted early by OpenSSL, even if settings such as `s2s_secure_auth = false`
or DANE were present in the config.
Outgoing s2s connections inherit verify "none" from the defaults, which means
OpenSSL will receive the cert but will not terminate the connection when it is
deemed invalid. This means we don't need lsec_continue there, and we also
don't need lsec_ignore_purpose (because the remote peer is a "server").
Wondering why we can't just use verify "none" for incoming s2s? It's because
in that mode, OpenSSL won't request a certificate from the peer for incoming
connections. Setting verify "peer" is how you ask OpenSSL to request a
certificate from the client, but also what triggers its built-in verification.
| author | Matthew Wild <mwild1@gmail.com> |
|---|---|
| date | Tue, 01 Apr 2025 17:26:56 +0100 |
| parent | 12975:d10957394a3c |
line wrap: on
line source
-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- -- luacheck: ignore 213/level local pairs = pairs; local ipairs = ipairs; local require = require; local t_remove = table.remove; local _ENV = nil; -- luacheck: std none local level_sinks = {}; local make_logger; local function init(name) local log_debug = make_logger(name, "debug"); local log_info = make_logger(name, "info"); local log_warn = make_logger(name, "warn"); local log_error = make_logger(name, "error"); return function (level, message, ...) if level == "debug" then return log_debug(message, ...); elseif level == "info" then return log_info(message, ...); elseif level == "warn" then return log_warn(message, ...); elseif level == "error" then return log_error(message, ...); end end end function make_logger(source_name, level) local level_handlers = level_sinks[level]; if not level_handlers then level_handlers = {}; level_sinks[level] = level_handlers; end local logger = function (message, ...) for i = 1,#level_handlers do level_handlers[i](source_name, level, message, ...); end end return logger; end local function reset() for level, handler_list in pairs(level_sinks) do -- Clear all handlers for this level for i = 1, #handler_list do handler_list[i] = nil; end end end local function add_level_sink(level, sink_function) if not level_sinks[level] then level_sinks[level] = { sink_function }; else level_sinks[level][#level_sinks[level] + 1 ] = sink_function; end end local function add_simple_sink(simple_sink_function, levels) local format = require "prosody.util.format".format; local function sink_function(name, level, msg, ...) return simple_sink_function(name, level, format(msg, ...)); end for _, level in ipairs(levels or {"debug", "info", "warn", "error"}) do add_level_sink(level, sink_function); end return sink_function; end local function remove_sink(sink_function) local removed; for level, sinks in pairs(level_sinks) do for i = #sinks, 1, -1 do if sinks[i] == sink_function then t_remove(sinks, i); removed = true; end end end return removed; end return { init = init; make_logger = make_logger; reset = reset; add_level_sink = add_level_sink; add_simple_sink = add_simple_sink; new = make_logger; remove_sink = remove_sink; };