From 8db7cdc71321f4a367338df87a7e90629e741ff9 Mon Sep 17 00:00:00 2001 From: Kim Alvefur Date: Wed, 1 Jun 2022 15:06:59 +0200 Subject: mod_saslauth: Implement RFC 9266 'tls-exporter' channel binding (#1760) Brings back SCRAM-SHA-*-PLUS from its hiatus brought on by the earlier channel binding method being undefined for TLS 1.3, and the increasing deployment of TLS 1.3. See 1bfd238e05ad and #1542 Requires future version of LuaSec, once support for this key material export method is merged. See https://github.com/brunoos/luasec/pull/187 --- plugins/mod_saslauth.lua | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'plugins') diff --git a/plugins/mod_saslauth.lua b/plugins/mod_saslauth.lua index 0b350c74..e94b2d78 100644 --- a/plugins/mod_saslauth.lua +++ b/plugins/mod_saslauth.lua @@ -245,6 +245,15 @@ local function tls_unique(self) return self.userdata["tls-unique"]:ssl_peerfinished(); end +local function tls_exporter(conn) + if not conn.ssl_exportkeyingmaterial then return end + return conn:ssl_exportkeyingmaterial("EXPORTER-Channel-Binding", 32, ""); +end + +local function sasl_tls_exporter(self) + return tls_exporter(self.userdata["tls-exporter"]); +end + local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' }; local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' }; local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' }; @@ -266,6 +275,11 @@ module:hook("stream-features", function(event) local info = origin.conn:ssl_info(); if info and info.protocol == "TLSv1.3" then log("debug", "Channel binding 'tls-unique' undefined in context of TLS 1.3"); + if tls_exporter(origin.conn) then + log("debug", "Channel binding 'tls-exporter' supported"); + sasl_handler:add_cb_handler("tls-exporter", sasl_tls_exporter); + channel_bindings:add("tls-exporter"); + end elseif origin.conn.ssl_peerfinished and origin.conn:ssl_peerfinished() then log("debug", "Channel binding 'tls-unique' supported"); sasl_handler:add_cb_handler("tls-unique", tls_unique); @@ -275,6 +289,7 @@ module:hook("stream-features", function(event) end sasl_handler["userdata"] = { ["tls-unique"] = origin.conn; + ["tls-exporter"] = origin.conn; }; else log("debug", "Channel binding not supported by SASL handler"); -- cgit v1.2.3