* Exim - an Internet mail transport agent *
*************************************************/
+/* Copyright (c) The Exim Maintainers 2020 - 2022 */
/* Copyright (c) University of Cambridge 1995 - 2018 */
/* Copyright (c) Phil Pennock 2012 */
-/* Copyright (c) The Exim Maintainers 2020 - 2021 */
/* See the file NOTICE for conditions of use and distribution. */
/* This file provides TLS/SSL support for Exim using the GnuTLS library,
# endif
#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030702
+# define HAVE_GNUTLS_EXPORTER
+#endif
+
#ifndef DISABLE_OCSP
# include <gnutls/ocsp.h>
#endif
#ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING
{
gnutls_datum_t channel = {.data = NULL, .size = 0};
- uschar * buf;
int rc;
-# ifdef HAVE_GNUTLS_PRF_RFC5705
+# ifdef HAVE_GNUTLS_EXPORTER
if (gnutls_protocol_get_version(state->session) >= GNUTLS_TLS1_3)
{
- buf = store_get(32, !!state->host);
+ rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_EXPORTER, &channel);
+ tlsp->channelbind_exporter = TRUE;
+ }
+ else
+# elif defined(HAVE_GNUTLS_PRF_RFC5705)
+ /* Older libraries may not have GNUTLS_TLS1_3 defined! */
+ if (gnutls_protocol_get_version(state->session) > GNUTLS_TLS1_2)
+ {
+ uschar * buf = store_get(32, state->host ? GET_TAINTED : GET_UNTAINTED);
rc = gnutls_prf_rfc5705(state->session,
(size_t)24, "EXPORTER-Channel-Binding", (size_t)0, "",
32, CS buf);
{
int old_pool = store_pool;
/* Declare the taintedness of the binding info. On server, untainted; on
- client, tainted - being the Finish msg from the server. */
+ client, tainted if we used the Finish msg from the server. */
store_pool = POOL_PERM;
tlsp->channelbinding = b64encode_taint(CUS channel.data, (int)channel.size,
- !!state->host);
+ !tlsp->channelbind_exporter && state->host ? GET_TAINTED : GET_UNTAINTED);
store_pool = old_pool;
DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage\n");
}
/* Preload whatever creds are static, onto a transport. The client can then
just copy the pointer as it starts up. */
+/*XXX this is not called for a cmdline send. But one needing to use >1 conn would benefit,
+and there seems little downside. */
+
static void
tls_client_creds_init(transport_instance * t, BOOL watch)
{
exim_gnutls_peer_err(US"getting size for cert DN failed");
return FAIL; /* should not happen */
}
-dn_buf = store_get_perm(sz, TRUE); /* tainted */
+dn_buf = store_get_perm(sz, GET_TAINTED);
rc = gnutls_x509_crt_get_dn(crt, CS dn_buf, &sz);
exim_gnutls_peer_err(US"failed to extract certificate DN [gnutls_x509_crt_get_dn(cert 0)]");
/* We now have a UTF-8 string in sni_name */
old_pool = store_pool;
store_pool = POOL_PERM;
-state->received_sni = string_copy_taint(US sni_name, TRUE);
+state->received_sni = string_copy_taint(US sni_name, GET_TAINTED);
store_pool = old_pool;
/* We set this one now so that variable expansions below will work */
*/
static BOOL
-tls_alpn_plist(const uschar * tls_alpn, const gnutls_datum_t ** plist, unsigned * plen,
+tls_alpn_plist(uschar ** tls_alpn, const gnutls_datum_t ** plist, unsigned * plen,
uschar ** errstr)
{
uschar * exp_alpn;
-if (!expand_check(tls_alpn, US"tls_alpn", &exp_alpn, errstr))
+if (!expand_check(*tls_alpn, US"tls_alpn", &exp_alpn, errstr))
return FALSE;
if (!exp_alpn)
static void
tls_server_set_acceptable_alpns(exim_gnutls_state_st * state, uschar ** errstr)
{
+uschar * local_alpn = string_copy(tls_alpn);
int rc;
const gnutls_datum_t * plist;
unsigned plen;
-if (tls_alpn_plist(tls_alpn, &plist, &plen, errstr) && plist)
+if (tls_alpn_plist(&local_alpn, &plist, &plen, errstr) && plist)
{
/* This seems to be only mandatory if the client sends an ALPN extension;
not trying ALPN is ok. Need to decide how to support server-side must-alpn. */
if (sigalrm_seen)
{
tls_error(US"gnutls_handshake", US"timed out", NULL, errstr);
+#ifndef DISABLE_EVENT
(void) event_raise(event_action, US"tls:fail:connect", *errstr, NULL);
+#endif
gnutls_db_remove_session(state->session);
}
else
{
tls_error_gnu(state, US"gnutls_handshake", rc, errstr);
+#ifndef DISABLE_EVENT
(void) event_raise(event_action, US"tls:fail:connect", *errstr, NULL);
+#endif
(void) gnutls_alert_send_appropriate(state->session, rc);
gnutls_deinit(state->session);
- gnutls_certificate_free_credentials(state->lib_state.x509_cred);
- state->lib_state = null_tls_preload;
millisleep(500);
shutdown(state->fd_out, SHUT_WR);
for (int i = 1024; fgetc(smtp_in) != EOF && i > 0; ) i--; /* drain skt */
static void
tls_retrieve_session(tls_support * tlsp, gnutls_session_t session,
- host_item * host, smtp_transport_options_block * ob)
+ smtp_connect_args * conn_args, smtp_transport_options_block * ob)
{
tlsp->resumption = RESUME_SUPPORTED;
-if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, host) == OK)
+
+if (!conn_args->have_lbserver)
+ { DEBUG(D_tls) debug_printf("resumption not supported on continued-connection\n"); }
+else if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, conn_args->host) == OK)
{
dbdata_tls_session * dt;
int len, rc;
open_db dbblock, * dbm_file;
- DEBUG(D_tls)
- debug_printf("check for resumable session for %s\n", host->address);
tlsp->host_resumable = TRUE;
+ tls_client_resmption_key(tlsp, conn_args, ob);
+
tlsp->resumption |= RESUME_CLIENT_REQUESTED;
if ((dbm_file = dbfn_open(US"tls", O_RDONLY, &dbblock, FALSE, FALSE)))
{
- /* Key for the db is the IP. We'd like to filter the retrieved session
- for ticket advisory expiry, but 3.6.1 seems to give no access to that */
+ /* We'd like to filter the retrieved session for ticket advisory expiry,
+ but 3.6.1 seems to give no access to that */
- if ((dt = dbfn_read_with_length(dbm_file, host->address, &len)))
+ if ((dt = dbfn_read_with_length(dbm_file, tlsp->resume_index, &len)))
if (!(rc = gnutls_session_set_data(session,
CUS dt->session, (size_t)len - sizeof(dbdata_tls_session))))
{
if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE)))
{
/* key for the db is the IP */
- dbfn_delete(dbm_file, host->address);
- dbfn_write(dbm_file, host->address, dt, dlen);
+ dbfn_write(dbm_file, tlsp->resume_index, dt, dlen);
dbfn_close(dbm_file);
DEBUG(D_tls)
static void
tls_client_resume_prehandshake(exim_gnutls_state_st * state,
- tls_support * tlsp, host_item * host,
+ tls_support * tlsp, smtp_connect_args * conn_args,
smtp_transport_options_block * ob)
{
gnutls_session_set_ptr(state->session, state);
gnutls_handshake_set_hook_function(state->session,
GNUTLS_HANDSHAKE_NEW_SESSION_TICKET, GNUTLS_HOOK_POST, tls_client_ticket_cb);
-tls_retrieve_session(tlsp, state->session, host, ob);
+tls_retrieve_session(tlsp, state->session, conn_args, ob);
}
static void
const gnutls_datum_t * plist;
unsigned plen;
- if (!tls_alpn_plist(ob->tls_alpn, &plist, &plen, errstr))
+ if (!tls_alpn_plist(&ob->tls_alpn, &plist, &plen, errstr))
return FALSE;
if (plist)
if (gnutls_alpn_set_protocols(state->session, plist, plen, 0) != 0)
#endif
#ifdef EXIM_HAVE_TLS_RESUME
-tls_client_resume_prehandshake(state, tlsp, host, ob);
+tls_client_resume_prehandshake(state, tlsp, conn_args, ob);
#endif
#ifndef DISABLE_EVENT
if (do_shutdown)
{
DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n",
- do_shutdown > 1 ? " (with response-wait)" : "");
+ do_shutdown > TLS_SHUTDOWN_NOWAIT ? " (with response-wait)" : "");
tls_write(ct_ctx, NULL, 0, FALSE); /* flush write buffer */
#ifdef EXIM_TCP_CORK
- if (do_shutdown > 1)
+ if (do_shutdown == TLS_SHUTDOWN_WAIT)
(void) setsockopt(tlsp->active.sock, IPPROTO_TCP, EXIM_TCP_CORK, US &off, sizeof(off));
#endif
+ /* The library seems to have no way to only wait for a peer's
+ shutdown, so handle the same as TLS_SHUTDOWN_WAIT */
+
ALARM(2);
- gnutls_bye(state->session, do_shutdown > 1 ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR);
+ gnutls_bye(state->session,
+ do_shutdown > TLS_SHUTDOWN_NOWAIT ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR);
ALARM_CLR(0);
}
}
gnutls_deinit(state->session);
-gnutls_certificate_free_credentials(state->lib_state.x509_cred);
-state->lib_state = null_tls_preload;
-
tlsp->active.sock = -1;
tlsp->active.tls_ctx = NULL;
/* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */