* Exim - an Internet mail transport agent *
*************************************************/
+/* Copyright (c) The Exim Maintainers 2020 - 2022 */
/* Copyright (c) University of Cambridge 1995 - 2018 */
-/* Copyright (c) The Exim Maintainers 2020 */
-/* See the file NOTICE for conditions of use and distribution. */
-
/* Copyright (c) Phil Pennock 2012 */
+/* See the file NOTICE for conditions of use and distribution. */
+/* SPDX-License-Identifier: GPL-2.0-or-later */
/* This file provides TLS/SSL support for Exim using the GnuTLS library,
one of the available supported implementations. This file is #included into
#if GNUTLS_VERSION_NUMBER >= 0x030506 && !defined(DISABLE_OCSP)
# define SUPPORT_SRV_OCSP_STACK
#endif
-#if GNUTLS_VERSION_NUMBER >= 0x030600
-# define GNUTLS_AUTO_DHPARAMS
-#endif
#if GNUTLS_VERSION_NUMBER >= 0x030603
# define EXIM_HAVE_TLS1_3
# define SUPPORT_GNUTLS_EXT_RAW_PARSE
# endif
#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030200
+# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE
+# define EXIM_HAVE_ALPN
+# endif
+#endif
+
+#if GNUTLS_VERSION_NUMBER >= 0x030702
+# define HAVE_GNUTLS_EXPORTER
+#endif
+
#ifndef DISABLE_OCSP
# include <gnutls/ocsp.h>
#endif
#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)
builtin_macro_create(US"_HAVE_TLS_CA_CACHE");
# endif
+# ifdef EXIM_HAVE_ALPN
+builtin_macro_create(US"_HAVE_TLS_ALPN");
+# endif
}
#else
.fd_out = -1,
};
-#ifndef GNUTLS_AUTO_DHPARAMS
/* dh_params are initialised once within the lifetime of a process using TLS;
if we used TLS in a long-lived daemon, we'd have to reconsider this. But we
don't want to repeat this. */
static gnutls_dh_params_t dh_server_params = NULL;
-#endif
static int ssl_session_timeout = 7200; /* Two hours */
static BOOL exim_testharness_disable_ocsp_validity_check = FALSE;
#endif
+#ifdef EXIM_HAVE_ALPN
+static int server_seen_alpn = -1; /* count of names */
+#endif
#ifdef EXIM_HAVE_TLS_RESUME
static gnutls_datum_t server_sessticket_key;
#endif
+
/* ------------------------------------------------------------------------ */
/* macros */
# endif /* AVOID_GNUTLS_PKCS11 */
#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030404
+# define HAVE_GNUTLS_PRF_RFC5705
+#endif
the connected host if setting up a client
errstr pointer to returned error string
-Returns: OK/DEFER/FAIL
+Returns: DEFER/FAIL
*/
static int
}
+/* Returns: DEFER/FAIL */
static int
-tls_error_gnu(const uschar *prefix, int err, const host_item *host,
+tls_error_gnu(exim_gnutls_state_st * state, const uschar *prefix, int err,
uschar ** errstr)
{
-return tls_error(prefix, US gnutls_strerror(err), host, errstr);
+return tls_error(prefix,
+ state && err == GNUTLS_E_FATAL_ALERT_RECEIVED
+ ? string_sprintf("rxd alert: %s",
+ US gnutls_alert_get_name(gnutls_alert_get(state->session)))
+ : US gnutls_strerror(err),
+ state ? state->host : NULL,
+ errstr);
}
static int
if (!gnutls_allow_auto_pkcs11)
if ((rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL)))
- return tls_error_gnu(US"gnutls_pkcs11_init", rc, NULL, errstr);
+ return tls_error_gnu(NULL, US"gnutls_pkcs11_init", rc, errstr);
#endif
#ifndef GNUTLS_AUTO_GLOBAL_INIT
if ((rc = gnutls_global_init()))
- return tls_error_gnu(US"gnutls_global_init", rc, NULL, errstr);
+ return tls_error_gnu(NULL, US"gnutls_global_init", rc, errstr);
#endif
#if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0
static void
extract_exim_vars_from_tls_state(exim_gnutls_state_st * state)
{
-#ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING
-int old_pool;
-int rc;
-gnutls_datum_t channel;
-#endif
tls_support * tlsp = state->tlsp;
tlsp->active.sock = state->fd_out;
tlsp->channelbinding = NULL;
#ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING
-channel.data = NULL;
-channel.size = 0;
-if ((rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel)))
- { DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc)); }
-else
{
- /* Declare the taintedness of the binding info. On server, untainted; on
- client, tainted - being the Finish msg from the server. */
+ gnutls_datum_t channel = {.data = NULL, .size = 0};
+ int rc;
- old_pool = store_pool;
- store_pool = POOL_PERM;
- tlsp->channelbinding = b64encode_taint(CUS channel.data, (int)channel.size,
- !!state->host);
- store_pool = old_pool;
- DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage\n");
+# ifdef HAVE_GNUTLS_EXPORTER
+ if (gnutls_protocol_get_version(state->session) >= GNUTLS_TLS1_3)
+ {
+ 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);
+ channel.data = buf;
+ channel.size = 32;
+ }
+ else
+# endif
+ rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel);
+
+ if (rc)
+ { DEBUG(D_tls) debug_printf("extracting channel binding: %s\n", gnutls_strerror(rc)); }
+ else
+ {
+ int old_pool = store_pool;
+ /* Declare the taintedness of the binding info. On server, untainted; on
+ 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,
+ !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");
+ }
}
#endif
-#ifndef GNUTLS_AUTO_DHPARAMS
/*************************************************
* Setup up DH parameters *
*************************************************/
{
int fd, rc;
unsigned int dh_bits;
-gnutls_datum_t m = {.data = NULL, .size = 0};
+gnutls_datum_t m;
uschar filename_buf[PATH_MAX];
uschar *filename = NULL;
size_t sz;
DEBUG(D_tls) debug_printf("Initialising GnuTLS server params\n");
if ((rc = gnutls_dh_params_init(&dh_server_params)))
- return tls_error_gnu(US"gnutls_dh_params_init", rc, host, errstr);
+ return tls_error_gnu(NULL, US"gnutls_dh_params_init", rc, errstr);
+
+m.data = NULL;
+m.size = 0;
if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam, errstr))
return DEFER;
if (m.data)
{
if ((rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM)))
- return tls_error_gnu(US"gnutls_dh_params_import_pkcs3", rc, host, errstr);
+ return tls_error_gnu(NULL, US"gnutls_dh_params_import_pkcs3", rc, errstr);
DEBUG(D_tls) debug_printf("Loaded fixed standard D-H parameters\n");
return OK;
}
rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM);
store_free(m.data);
if (rc)
- return tls_error_gnu(US"gnutls_dh_params_import_pkcs3", rc, host, errstr);
+ return tls_error_gnu(NULL, US"gnutls_dh_params_import_pkcs3", rc, errstr);
DEBUG(D_tls) debug_printf("read D-H parameters from file \"%s\"\n", filename);
}
return tls_error(US"Filename too long to generate replacement",
filename, NULL, errstr);
- temp_fn = string_copy(US"%s.XXXXXXX");
+ temp_fn = string_copy(US"exim-dh.XXXXXXX");
if ((fd = mkstemp(CS temp_fn)) < 0) /* modifies temp_fn */
return tls_error_sys(US"Unable to open temp file", errno, NULL, errstr);
(void)exim_chown(temp_fn, exim_uid, exim_gid); /* Probably not necessary */
- /* GnuTLS overshoots! If we ask for 2236, we might get 2237 or more. But
- there's no way to ask GnuTLS how many bits there really are. We can ask
- how many bits were used in a TLS session, but that's it! The prime itself
- is hidden behind too much abstraction. So we ask for less, and proceed on
- a wing and a prayer. First attempt, subtracted 3 for 2233 and got 2240. */
-
+ /* GnuTLS overshoots!
+ * If we ask for 2236, we might get 2237 or more.
+ * But there's no way to ask GnuTLS how many bits there really are.
+ * We can ask how many bits were used in a TLS session, but that's it!
+ * The prime itself is hidden behind too much abstraction.
+ * So we ask for less, and proceed on a wing and a prayer.
+ * First attempt, subtracted 3 for 2233 and got 2240.
+ */
if (dh_bits >= EXIM_CLIENT_DH_MIN_BITS + 10)
{
dh_bits_gen = dh_bits - 10;
debug_printf("requesting generation of %d bit Diffie-Hellman prime ...\n",
dh_bits_gen);
if ((rc = gnutls_dh_params_generate2(dh_server_params, dh_bits_gen)))
- return tls_error_gnu(US"gnutls_dh_params_generate2", rc, host, errstr);
+ return tls_error_gnu(NULL, US"gnutls_dh_params_generate2", rc, errstr);
/* gnutls_dh_params_export_pkcs3() will tell us the exact size, every time,
and I confirmed that a NULL call to get the size first is how the GnuTLS
if ( (rc = gnutls_dh_params_export_pkcs3(dh_server_params,
GNUTLS_X509_FMT_PEM, m.data, &sz))
&& rc != GNUTLS_E_SHORT_MEMORY_BUFFER)
- return tls_error_gnu(US"gnutls_dh_params_export_pkcs3(NULL) sizing",
- rc, host, errstr);
+ return tls_error_gnu(NULL, US"gnutls_dh_params_export_pkcs3(NULL) sizing",
+ rc, errstr);
m.size = sz;
if (!(m.data = store_malloc(m.size)))
return tls_error_sys(US"memory allocation failed", errno, NULL, errstr);
m.data, &sz)))
{
store_free(m.data);
- return tls_error_gnu(US"gnutls_dh_params_export_pkcs3() real", rc, host, errstr);
+ return tls_error_gnu(NULL, US"gnutls_dh_params_export_pkcs3() real", rc, errstr);
}
m.size = sz; /* shrink by 1, probably */
DEBUG(D_tls) debug_printf("initialized server D-H parameters\n");
return OK;
}
-#endif
return rc;
err:
- rc = tls_error_gnu(where, rc, NULL, errstr);
+ rc = tls_error_gnu(state, where, rc, errstr);
goto out;
}
int rc = gnutls_certificate_set_x509_key_file(state->lib_state.x509_cred,
CCS certfile, CCS keyfile, GNUTLS_X509_FMT_PEM);
if (rc < 0)
- return tls_error_gnu(
+ return tls_error_gnu(state,
string_sprintf("cert/key setup: cert=%s key=%s", certfile, keyfile),
- rc, host, errstr);
+ rc, errstr);
return -rc;
}
/* Make a note that we saw a status-request */
static int
tls_server_clienthello_ext(void * ctx, unsigned tls_id,
- const unsigned char *data, unsigned size)
+ const uschar * data, unsigned size)
{
-/* https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */
-if (tls_id == 5) /* status_request */
+/* The values for tls_id are documented here:
+https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */
+switch (tls_id)
{
- DEBUG(D_tls) debug_printf("Seen status_request extension from client\n");
- tls_in.ocsp = OCSP_NOT_RESP;
+ case 5: /* Status Request */
+ DEBUG(D_tls) debug_printf("Seen status_request extension from client\n");
+ tls_in.ocsp = OCSP_NOT_RESP;
+ break;
+#ifdef EXIM_HAVE_ALPN
+ case 16: /* Application Layer Protocol Notification */
+ /* The format of "data" here doesn't seem to be documented, but appears
+ to be a 2-byte field with a (redundant, given the "size" arg) total length
+ then a sequence of one-byte size then string (not nul-term) names. The
+ latter is as described in OpenSSL documentation.
+ Note that we do not get called for a match_fail, making it hard to log
+ a single bad ALPN being offered (the common case). */
+ {
+ gstring * g = NULL;
+
+ DEBUG(D_tls) debug_printf("Seen ALPN extension from client (s=%u):", size);
+ for (const uschar * s = data+2; s-data < size-1; s += *s + 1)
+ {
+ server_seen_alpn++;
+ g = string_append_listele_n(g, ':', s+1, *s);
+ DEBUG(D_tls) debug_printf(" '%.*s'", (int)*s, s+1);
+ }
+ DEBUG(D_tls) debug_printf("\n");
+ if (server_seen_alpn > 1)
+ {
+ log_write(0, LOG_MAIN, "TLS ALPN (%Y) rejected", g);
+ DEBUG(D_tls) debug_printf("TLS: too many ALPNs presented in handshake\n");
+ return GNUTLS_E_NO_APPLICATION_PROTOCOL;
+ }
+ break;
+ }
+#endif
}
return 0;
}
unsigned when, unsigned int incoming, const gnutls_datum_t * msg)
{
/* Call fn for each extension seen. 3.6.3 onwards */
-return gnutls_ext_raw_parse(NULL, tls_server_clienthello_ext, msg,
+int rc = gnutls_ext_raw_parse(NULL, tls_server_clienthello_ext, msg,
GNUTLS_EXT_RAW_FLAG_TLS_CLIENT_HELLO);
+return rc == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE ? 0 : rc;
}
unsigned when, unsigned int incoming, const gnutls_datum_t * msg)
{
DEBUG(D_tls) debug_printf("Sending certificate-status\n"); /*XXX we get this for tls1.2 but not for 1.3 */
-#ifdef SUPPORT_SRV_OCSP_STACK
+# ifdef SUPPORT_SRV_OCSP_STACK
tls_in.ocsp = exim_testharness_disable_ocsp_validity_check
? OCSP_VFY_NOT_TRIED : OCSP_VFIED; /* We know that GnuTLS verifies responses */
-#else
+# else
tls_in.ocsp = OCSP_VFY_NOT_TRIED;
-#endif
+# endif
return 0;
}
debug_printf("TLS: basic cred init, %s\n", server ? "server" : "client");
}
+/* Returns OK/DEFER/FAIL */
static int
creds_load_server_certs(exim_gnutls_state_st * state, const uschar * cert,
const uschar * pkey, const uschar * ocsp, uschar ** errstr)
if (!(kfile = string_nextinlist(&klist, &ksep, NULL, 0)))
return tls_error(US"cert/key setup: out of keys", NULL, NULL, errstr);
- else if ((rc = tls_add_certfile(state, NULL, cfile, kfile, errstr)) > 0)
+ else if ((rc = tls_add_certfile(state, NULL, cfile, kfile, errstr)) > OK)
return rc;
else
{
if ((rc = gnutls_certificate_set_ocsp_status_request_file2(
state->lib_state.x509_cred, CCS ofile, gnutls_cert_index,
ocsp_fmt)) < 0)
- return tls_error_gnu(
+ return tls_error_gnu(state,
US"gnutls_certificate_set_ocsp_status_request_file2",
- rc, NULL, errstr);
+ rc, errstr);
DEBUG(D_tls)
debug_printf(" %d response%s loaded\n", rc, rc>1 ? "s":"");
if ((rc = gnutls_certificate_set_ocsp_status_request_function2(
state->lib_state.x509_cred, gnutls_cert_index,
server_ocsp_stapling_cb, ofile)))
- return tls_error_gnu(
+ return tls_error_gnu(state,
US"gnutls_certificate_set_ocsp_status_request_function2",
- rc, NULL, errstr);
+ rc, errstr);
else
# endif
{
}
#endif /* DISABLE_OCSP */
}
-return 0;
+return OK;
}
static int
int rc = tls_add_certfile(state, host, cert, pkey, errstr);
if (rc > 0) return rc;
DEBUG(D_tls) debug_printf("TLS: cert/key registered\n");
-return 0;
+return OK;
}
static int
}
if (cert_count < 0)
- return tls_error_gnu(US"setting certificate trust", cert_count, host, errstr);
+ return tls_error_gnu(state, US"setting certificate trust", cert_count, errstr);
DEBUG(D_tls)
debug_printf("Added %d certificate authorities\n", cert_count);
DEBUG(D_tls) debug_printf("loading CRL file = %s\n", crl);
if ((cert_count = gnutls_certificate_set_x509_crl_file(state->lib_state.x509_cred,
CS crl, GNUTLS_X509_FMT_PEM)) < 0)
- return tls_error_gnu(US"gnutls_certificate_set_x509_crl_file",
- cert_count, state->host, errstr);
+ return tls_error_gnu(state, US"gnutls_certificate_set_x509_crl_file",
+ cert_count, errstr);
DEBUG(D_tls) debug_printf("Processed %d CRLs\n", cert_count);
return OK;
else
DEBUG(D_tls) debug_printf("TLS: not preloading server certs\n");
-/* If tls_verify_certificates is non-empty and has no $, load CAs */
+/* If tls_verify_certificates is non-empty and has no $, load CAs.
+If none was configured and we can't handle "system", treat as empty. */
-if (opt_set_and_noexpand(tls_verify_certificates))
+if ( opt_set_and_noexpand(tls_verify_certificates)
+#ifndef SUPPORT_SYSDEFAULT_CABUNDLE
+ && Ustrcmp(tls_verify_certificates, "system") != 0
+#endif
+ )
{
if (tls_set_watch(tls_verify_certificates, FALSE))
{
/* 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)
{
DEBUG(D_tls)
debug_printf("TLS: not preloading client certs, for transport '%s'\n", t->name);
-if (opt_set_and_noexpand(ob->tls_verify_certificates))
+/* If tls_verify_certificates is non-empty and has no $, load CAs.
+If none was configured and we can't handle "system", treat as empty. */
+
+if ( opt_set_and_noexpand(ob->tls_verify_certificates)
+#ifndef SUPPORT_SYSDEFAULT_CABUNDLE
+ && Ustrcmp(ob->tls_verify_certificates, "system") != 0
+#endif
+ )
{
if (!watch || tls_set_watch(ob->tls_verify_certificates, FALSE))
{
{
if ((rc = gnutls_certificate_allocate_credentials(
(gnutls_certificate_credentials_t *) &state->lib_state.x509_cred)))
- return tls_error_gnu(US"gnutls_certificate_allocate_credentials",
- rc, host, errstr);
+ return tls_error_gnu(state, US"gnutls_certificate_allocate_credentials",
+ rc, errstr);
creds_basic_init(state->lib_state.x509_cred, !host);
}
if (!state->lib_state.conn_certs)
{
- if (!Expand_check_tlsvar(tls_certificate, errstr))
+ if ( !Expand_check_tlsvar(tls_certificate, errstr)
+ || f.expand_string_forcedfail)
+ {
+ if (f.expand_string_forcedfail)
+ *errstr = US"expansion of tls_certificate failed";
return DEFER;
+ }
/* certificate is mandatory in server, optional in client */
else
DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n");
- if (state->tls_privatekey && !Expand_check_tlsvar(tls_privatekey, errstr))
+ if ( state->tls_privatekey && !Expand_check_tlsvar(tls_privatekey, errstr)
+ || f.expand_string_forcedfail
+ )
+ {
+ if (f.expand_string_forcedfail)
+ *errstr = US"expansion of tls_privatekey failed";
return DEFER;
+ }
/* tls_privatekey is optional, defaulting to same file as certificate */
tls_ocsp_file,
#endif
errstr)
- ) ) return rc;
+ ) )
+ {
+ DEBUG(D_tls) debug_printf("load-cert: '%s'\n", *errstr);
+ return rc;
+ }
}
}
else
provided. Experiment shows that, if the certificate file is empty, an unhelpful
error message is provided. However, if we just refrain from setting anything up
in that case, certificate verification fails, which seems to be the correct
-behaviour. */
+behaviour.
+If none was configured and we can't handle "system", treat as empty. */
if (!state->lib_state.cabundle)
{
int rc;
const host_item *host = state->host; /* macro should be reconsidered? */
-#ifndef GNUTLS_AUTO_DHPARAMS
/* Create D-H parameters, or read them from the cache file. This function does
its own SMTP error messaging. This only happens for the server, TLS D-H ignores
client-side params. */
if (!dh_server_params)
if ((rc = init_server_dh(errstr)) != OK) return rc;
- /* Unnecessary & discouraged with 3.6.0 or later */
+ /* Unnecessary & discouraged with 3.6.0 or later, according to docs. But without it,
+ no DHE- ciphers are advertised. */
gnutls_certificate_set_dh_params(state->lib_state.x509_cred, dh_server_params);
}
-#endif
/* Link the credentials to the session. */
if ((rc = gnutls_credentials_set(state->session,
GNUTLS_CRD_CERTIFICATE, state->lib_state.x509_cred)))
- return tls_error_gnu(US"gnutls_credentials_set", rc, host, errstr);
+ return tls_error_gnu(state, US"gnutls_credentials_set", rc, errstr);
return OK;
}
int old_pool = store_pool;
store_pool = POOL_PERM;
- state = store_get(sizeof(exim_gnutls_state_st), FALSE);
+ state = store_get(sizeof(exim_gnutls_state_st), GET_UNTAINTED);
store_pool = old_pool;
memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init));
state->tls_crl = tls_crl;
}
if (rc)
- return tls_error_gnu(US"gnutls_init", rc, host, errstr);
+ return tls_error_gnu(state, US"gnutls_init", rc, errstr);
state->tls_require_ciphers = require_ciphers;
state->host = host;
sz = Ustrlen(state->tlsp->sni);
if ((rc = gnutls_server_name_set(state->session,
GNUTLS_NAME_DNS, state->tlsp->sni, sz)))
- return tls_error_gnu(US"gnutls_server_name_set", rc, host, errstr);
+ return tls_error_gnu(state, US"gnutls_server_name_set", rc, errstr);
}
}
else if (state->tls_sni)
}
if ((rc = creds_load_pristring(state, p, &errpos)))
- return tls_error_gnu(string_sprintf(
+ return tls_error_gnu(state, string_sprintf(
"gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"",
- p, errpos - CS p, errpos),
- rc, host, errstr);
+ p, (long)(errpos - CS p), errpos),
+ rc, errstr);
}
else
{
if ((rc = gnutls_priority_set(state->session, state->lib_state.pri_cache)))
- return tls_error_gnu(US"gnutls_priority_set", rc, host, errstr);
+ return tls_error_gnu(state, US"gnutls_priority_set", rc, errstr);
/* This also sets the server ticket expiration time to the same, and
the STEK rotation time to 3x. */
for (s++; (c = *s) && c != ')'; s++) g = string_catn(g, s, 1);
- tlsp->ver = string_copyn(g->s, g->ptr);
+ tlsp->ver = string_copy_from_gstring(g);
for (uschar * p = US tlsp->ver; *p; p++)
if (*p == '-') { *p = '\0'; break; } /* TLS1.0-PKIX -> TLS1.0 */
DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", \
(Label), gnutls_strerror(rc)); \
if (state->verify_requirement >= VERIFY_REQUIRED) \
- return tls_error_gnu((Label), rc, state->host, errstr); \
+ return tls_error_gnu(state, (Label), rc, errstr); \
return OK; \
} \
} while (0)
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)]");
for (nrec = 0; state->dane_data_len[nrec]; ) nrec++;
nrec++;
- dd = store_get(nrec * sizeof(uschar *), FALSE);
- ddl = store_get(nrec * sizeof(int), FALSE);
+ dd = store_get(nrec * sizeof(uschar *), GET_UNTAINTED);
+ ddl = store_get(nrec * sizeof(int), GET_UNTAINTED);
nrec--;
if ((rc = dane_state_init(&s, 0)))
)
{
DEBUG(D_tls)
- debug_printf("TLS certificate verification failed: cert name mismatch\n");
+ debug_printf("TLS certificate verification failed: cert name mismatch (per GnuTLS)\n");
if (state->verify_requirement >= VERIFY_REQUIRED)
goto badcert;
return TRUE;
/* 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 */
{
/* If the setup of certs/etc failed before handshake, TLS would not have
been offered. The best we can do now is abort. */
- return GNUTLS_E_APPLICATION_ERROR_MIN;
+ DEBUG(D_tls) debug_printf("expansion for SNI-dependent session files failed\n");
+ return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
}
rc = tls_set_remaining_x509(state, &dummy_errstr);
-if (rc != OK) return GNUTLS_E_APPLICATION_ERROR_MIN;
+if (rc != OK) return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
return 0;
}
if ((cert_list = gnutls_certificate_get_peers(session, &cert_list_size)))
while (cert_list_size--)
- {
- if ((rc = import_cert(&cert_list[cert_list_size], &crt)) != GNUTLS_E_SUCCESS)
{
- DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n",
- cert_list_size, gnutls_strerror(rc));
- break;
- }
+ if ((rc = import_cert(&cert_list[cert_list_size], &crt)) != GNUTLS_E_SUCCESS)
+ {
+ DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n",
+ cert_list_size, gnutls_strerror(rc));
+ break;
+ }
- state->tlsp->peercert = crt;
- if ((yield = event_raise(state->event_action,
- US"tls:cert", string_sprintf("%d", cert_list_size))))
- {
- log_write(0, LOG_MAIN,
- "SSL verify denied by event-action: depth=%d: %s",
- cert_list_size, yield);
- return 1; /* reject */
+ state->tlsp->peercert = crt;
+ if ((yield = event_raise(state->event_action,
+ US"tls:cert", string_sprintf("%d", cert_list_size), &errno)))
+ {
+ log_write(0, LOG_MAIN,
+ "SSL verify denied by event-action: depth=%d: %s",
+ cert_list_size, yield);
+ return 1; /* reject */
+ }
+ state->tlsp->peercert = NULL;
}
- state->tlsp->peercert = NULL;
- }
return 0;
}
DEBUG(D_tls) debug_printf("Session resumed\n");
}
}
-#endif
+#endif /* EXIM_HAVE_TLS_RESUME */
+
+
+#ifdef EXIM_HAVE_ALPN
+/* Expand and convert an Exim list to a gnutls_datum list. False return for fail.
+NULL plist return for silent no-ALPN.
+*/
+
+static BOOL
+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))
+ return FALSE;
+
+if (!exp_alpn)
+ {
+ DEBUG(D_tls) debug_printf("Setting TLS ALPN forced to fail, not sending\n");
+ *plist = NULL;
+ }
+else
+ {
+ const uschar * list = exp_alpn;
+ int sep = 0;
+ unsigned cnt = 0;
+ gnutls_datum_t * p;
+ uschar * s;
+
+ while (string_nextinlist(&list, &sep, NULL, 0)) cnt++;
+
+ p = store_get(sizeof(gnutls_datum_t) * cnt, exp_alpn);
+ list = exp_alpn;
+ for (int i = 0; s = string_nextinlist(&list, &sep, NULL, 0); i++)
+ { p[i].data = s; p[i].size = Ustrlen(s); }
+ *plist = (*plen = cnt) ? p : NULL;
+ }
+return TRUE;
+}
+
+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(&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. */
+
+ server_seen_alpn = 0;
+ if (!(rc = gnutls_alpn_set_protocols(state->session, plist, plen,
+ GNUTLS_ALPN_MANDATORY)))
+ gnutls_handshake_set_hook_function(state->session,
+ GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb);
+ else
+ DEBUG(D_tls)
+ debug_printf("setting alpn protocols: %s\n", US gnutls_strerror(rc));
+ }
+}
+#endif /* EXIM_HAVE_ALPN */
+
/* ------------------------------------------------------------------------ */
/* Exported functions */
#endif
}
+#ifdef EXIM_HAVE_ALPN
+tls_server_set_acceptable_alpns(state, errstr);
+#endif
+
#ifdef EXIM_HAVE_TLS_RESUME
tls_server_resume_prehandshake(state);
#endif
if (rc != GNUTLS_E_SUCCESS)
{
+ DEBUG(D_tls) debug_printf(" error %d from gnutls_handshake: %s\n",
+ rc, gnutls_strerror(rc));
+
/* It seems that, except in the case of a timeout, we have to close the
connection right here; otherwise if the other end is running OpenSSL it hangs
until the server times out. */
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(US"gnutls_handshake", rc, NULL, errstr);
+ 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 */
DEBUG(D_tls) post_handshake_debug(state);
+#ifdef EXIM_HAVE_ALPN
+if (server_seen_alpn > 0)
+ {
+ DEBUG(D_tls)
+ { /* The client offered ALPN. See what was negotiated. */
+ gnutls_datum_t p = {.size = 0};
+ int rc = gnutls_alpn_get_selected_protocol(state->session, &p);
+ if (!rc)
+ debug_printf("ALPN negotiated: %.*s\n", (int)p.size, p.data);
+ else
+ debug_printf("getting alpn protocol: %s\n", US gnutls_strerror(rc));
+
+ }
+ }
+else if (server_seen_alpn == 0)
+ if (verify_check_host(&hosts_require_alpn) == OK)
+ {
+ gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_NO_APPLICATION_PROTOCOL);
+ tls_error(US"handshake", US"ALPN required but not negotiated", NULL, errstr);
+ return FAIL;
+ }
+ else
+ DEBUG(D_tls) debug_printf("TLS: no ALPN presented in handshake\n");
+else
+ DEBUG(D_tls) debug_printf("TLS: was not watching for ALPN\n");
+#endif
+
/* Verify after the fact */
if (!verify_certificate(state, errstr))
receive_getc = tls_getc;
receive_getbuf = tls_getbuf;
receive_get_cache = tls_get_cache;
+receive_hasc = tls_hasc;
receive_ungetc = tls_ungetc;
receive_feof = tls_feof;
receive_ferror = tls_ferror;
-receive_smtp_buffered = tls_smtp_buffered;
return OK;
}
rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
) if (rr->type == T_TLSA) i++;
-dane_data = store_get(i * sizeof(uschar *), FALSE);
-dane_data_len = store_get(i * sizeof(int), FALSE);
+dane_data = store_get(i * sizeof(uschar *), GET_UNTAINTED);
+dane_data_len = store_get(i * sizeof(int), GET_UNTAINTED);
i = 0;
for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
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))))
{
{
open_db dbblock, * dbm_file;
int dlen = sizeof(dbdata_tls_session) + tkt.size;
- dbdata_tls_session * dt = store_get(dlen, TRUE);
+ dbdata_tls_session * dt = store_get(dlen, GET_TAINTED);
DEBUG(D_tls) debug_printf("session data size %u\n", (unsigned)tkt.size);
memcpy(dt->session, tkt.data, tkt.size);
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
#endif
}
+if (ob->tls_alpn)
+#ifdef EXIM_HAVE_ALPN
+ {
+ const gnutls_datum_t * plist;
+ unsigned plen;
+
+ 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)
+ {
+ tls_error(US"alpn init", NULL, state->host, errstr);
+ return FALSE;
+ }
+ else
+ DEBUG(D_tls) debug_printf("Setting TLS ALPN '%s'\n", ob->tls_alpn);
+ }
+#else
+ log_write(0, LOG_MAIN, "ALPN unusable with this GnuTLS library version; ignoring \"%s\"\n",
+ ob->tls_alpn);
+#endif
+
{
int dh_min_bits = ob->tls_dh_min_bits;
if (dh_min_bits < EXIM_CLIENT_DH_MIN_MIN_BITS)
if ((rc = gnutls_ocsp_status_request_enable_client(state->session,
NULL, 0, NULL)) != OK)
{
- tls_error_gnu(US"cert-status-req", rc, state->host, errstr);
+ tls_error_gnu(state, US"cert-status-req", rc, errstr);
return FALSE;
}
tlsp->ocsp = OCSP_NOT_RESP;
#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
tls_error(US"gnutls_handshake", US"timed out", state->host, errstr);
}
else
- tls_error_gnu(US"gnutls_handshake", rc, state->host, errstr);
+ tls_error_gnu(state, US"gnutls_handshake", rc, errstr);
return FALSE;
}
gnutls_free(printed.data);
}
else
- (void) tls_error_gnu(US"ocsp decode", rc, state->host, errstr);
+ (void) tls_error_gnu(state, US"ocsp decode", rc, errstr);
if (idx == 0 && rc)
- (void) tls_error_gnu(US"ocsp decode", rc, state->host, errstr);
+ (void) tls_error_gnu(state, US"ocsp decode", rc, errstr);
}
if (gnutls_ocsp_status_request_is_checked(state->session, 0) == 0)
tls_client_resume_posthandshake(state, tlsp, host);
#endif
+#ifdef EXIM_HAVE_ALPN
+if (ob->tls_alpn) /* We requested. See what was negotiated. */
+ {
+ gnutls_datum_t p = {.size = 0};
+
+ if (gnutls_alpn_get_selected_protocol(state->session, &p) == 0)
+ { DEBUG(D_tls) debug_printf("ALPN negotiated: '%.*s'\n", (int)p.size, p.data); }
+ else if (verify_check_given_host(CUSS &ob->hosts_require_alpn, host) == OK)
+ {
+ gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_NO_APPLICATION_PROTOCOL);
+ tls_error(US"handshake", US"ALPN required but not negotiated", state->host, errstr);
+ return FALSE;
+ }
+ else
+ DEBUG(D_tls) debug_printf("No ALPN negotiated");
+ }
+#endif
+
/* Sets various Exim expansion variables; may need to adjust for ACL callouts */
extract_exim_vars_from_tls_state(state);
+/*
+Arguments:
+ ct_ctx client TLS context pointer, or NULL for the one global server context
+*/
+
+void
+tls_shutdown_wr(void * ct_ctx)
+{
+exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server;
+tls_support * tlsp = state->tlsp;
+
+if (!tlsp || tlsp->active.sock < 0) return; /* TLS was not active */
+
+tls_write(ct_ctx, NULL, 0, FALSE); /* flush write buffer */
+
+HDEBUG(D_transport|D_tls|D_acl|D_v) debug_printf_indent(" SMTP(TLS shutdown)>>\n");
+gnutls_bye(state->session, GNUTLS_SHUT_WR);
+}
+
/*************************************************
* Close down a TLS session *
*************************************************/
Arguments:
ct_ctx client context pointer, or NULL for the one global server context
- shutdown 1 if TLS close-alert is to be sent,
- 2 if also response to be waited for
+ do_shutdown 0 no data-flush or TLS close-alert
+ 1 if TLS close-alert is to be sent,
+ 2 if also response to be waited for (2s timeout)
Returns: nothing
*/
void
-tls_close(void * ct_ctx, int shutdown)
+tls_close(void * ct_ctx, int do_shutdown)
{
exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server;
tls_support * tlsp = state->tlsp;
if (!tlsp || tlsp->active.sock < 0) return; /* TLS was not active */
-tls_write(ct_ctx, NULL, 0, FALSE); /* flush write buffer */
-
-if (shutdown)
+if (do_shutdown)
{
DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n",
- 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 == 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, 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);
}
receive_getc = smtp_getc;
receive_getbuf = smtp_getbuf;
receive_get_cache = smtp_get_cache;
+ receive_hasc = smtp_hasc;
receive_ungetc = smtp_ungetc;
receive_feof = smtp_feof;
receive_ferror = smtp_ferror;
- receive_smtp_buffered = smtp_buffered;
}
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 */
return state->xfer_buffer[state->xfer_buffer_lwm++];
}
+BOOL
+tls_hasc(void)
+{
+exim_gnutls_state_st * state = &state_server;
+return state->xfer_buffer_lwm < state->xfer_buffer_hwm;
+}
+
uschar *
tls_getbuf(unsigned * len)
{
}
+/* Get up to the given number of bytes from any cached data, and feed to dkim. */
void
-tls_get_cache()
+tls_get_cache(unsigned lim)
{
#ifndef DISABLE_DKIM
exim_gnutls_state_st * state = &state_server;
int n = state->xfer_buffer_hwm - state->xfer_buffer_lwm;
+if (n > lim)
+ n = lim;
if (n > 0)
dkim_exim_verify_feed(state->xfer_buffer+state->xfer_buffer_lwm, n);
#endif
BOOL
-tls_could_read(void)
+tls_could_getc(void)
{
return state_server.xfer_buffer_lwm < state_server.xfer_buffer_hwm
|| gnutls_record_check_pending(state_server.session) > 0;
}
-
-
/*************************************************
* Read bytes from TLS channel *
*************************************************/
rc = gnutls_priority_init(&priority_cache, CS expciphers, &errpos);
validate_check_rc(string_sprintf(
"gnutls_priority_init(%s) failed at offset %ld, \"%.8s..\"",
- expciphers, errpos - CS expciphers, errpos));
+ expciphers, (long)(errpos - CS expciphers), errpos));
#undef return_deinit
#undef validate_check_rc
/* See a description in tls-openssl.c for an explanation of why this exists.
-Arguments: a FILE* to print the results to
-Returns: nothing
+Arguments: string to append to
+Returns: string
*/
-void
-tls_version_report(FILE *f)
+gstring *
+tls_version_report(gstring * g)
{
-fprintf(f, "Library version: GnuTLS: Compile: %s\n"
- " Runtime: %s\n",
- LIBGNUTLS_VERSION,
- gnutls_check_version(NULL));
+return string_fmt_append(g,
+ "Library version: GnuTLS: Compile: %s\n"
+ " Runtime: %s\n",
+ LIBGNUTLS_VERSION,
+ gnutls_check_version(NULL));
}
#endif /*!MACRO_PREDEF*/
git://git.exim.org / exim.git / blobdiff