#endif
#if GNUTLS_VERSION_NUMBER >= 0x030200
-# define EXIM_HAVE_ALPN
+# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE
+# define EXIM_HAVE_ALPN
+# endif
#endif
#ifndef DISABLE_OCSP
#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
#endif
#ifdef EXIM_HAVE_ALPN
-static BOOL server_seen_alpn = FALSE;
+static int server_seen_alpn = -1; /* count of names */
#endif
#ifdef EXIM_HAVE_TLS_RESUME
static gnutls_datum_t server_sessticket_key;
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
+ ? 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
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);
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);
}
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 */
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 */
switch (tls_id)
{
- case 5: /* status_request */
+ 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 */
- DEBUG(D_tls) debug_printf("Seen ALPN extension from client\n");
- server_seen_alpn = TRUE;
+ /* 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. */
+
+ 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++;
+ DEBUG(D_tls) debug_printf(" '%.*s'", (int)*s, s+1);
+ }
+ DEBUG(D_tls) debug_printf("\n");
+ if (server_seen_alpn > 1)
+ {
+ DEBUG(D_tls) debug_printf("TLS: too many ALPNs presented in handshake\n");
+ return GNUTLS_E_NO_APPLICATION_PROTOCOL;
+ }
break;
#endif
}
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;
}
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
{
}
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))
{
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);
}
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)
{
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;
}
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. */
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)
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(const 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, is_tainted(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)
+tls_server_set_acceptable_alpns(exim_gnutls_state_st * state, uschar ** errstr)
{
int rc;
-gnutls_datum_t protocols[2] = {[0] = {.data = US"smtp", .size = 4},
- [1] = {.data = US"esmtp", .size = 5}};
+const gnutls_datum_t * plist;
+unsigned plen;
-/* Set non-mandatory set of protocol names */
-if (!(rc = gnutls_alpn_set_protocols(state->session, protocols, 2, 0)))
- 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));
+if (tls_alpn_plist(tls_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
+#endif /* EXIM_HAVE_ALPN */
/* ------------------------------------------------------------------------ */
/* Exported functions */
}
#ifdef EXIM_HAVE_ALPN
-tls_server_set_acceptable_alpns(state);
+tls_server_set_acceptable_alpns(state, errstr);
#endif
#ifdef EXIM_HAVE_TLS_RESUME
}
else
{
- tls_error_gnu(US"gnutls_handshake", rc, NULL, errstr);
+ tls_error_gnu(state, US"gnutls_handshake", rc, errstr);
(void) gnutls_alert_send_appropriate(state->session, rc);
gnutls_deinit(state->session);
gnutls_certificate_free_credentials(state->lib_state.x509_cred);
DEBUG(D_tls) post_handshake_debug(state);
#ifdef EXIM_HAVE_ALPN
-if (server_seen_alpn)
+if (server_seen_alpn > 0)
{
- /* The client offered ALPN. We were set up with a nonmandatory list;
- see what was negotiated. We require a match now, given that something
- was offered. */
- gnutls_datum_t p = {.size = 0};
- int rc = gnutls_alpn_get_selected_protocol(state->session, &p);
- if (!rc || rc == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
- {
- if (p.size == 0)
- {
- *errstr = US"ALPN rejected";
- return FAIL;
- }
- else
- DEBUG(D_tls)
+ 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(D_tls)
- debug_printf("getting alpn protocol: %s\n", US gnutls_strerror(rc));
+ 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 */
#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;
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);
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
git://git.exim.org / exim.git / blobdiff