+if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey, errstr))
+ return DEFER;
+
+/* tls_privatekey is optional, defaulting to same file as certificate */
+
+if (!state->tls_privatekey || !*state->tls_privatekey)
+ {
+ state->tls_privatekey = state->tls_certificate;
+ state->exp_tls_privatekey = state->exp_tls_certificate;
+ }
+
+
+if (state->exp_tls_certificate && *state->exp_tls_certificate)
+ {
+ DEBUG(D_tls) debug_printf("certificate file = %s\nkey file = %s\n",
+ state->exp_tls_certificate, state->exp_tls_privatekey);
+
+ if (state->received_sni)
+ if ( Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0
+ && Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0
+ )
+ {
+ DEBUG(D_tls) debug_printf("TLS SNI: cert and key unchanged\n");
+ }
+ else
+ {
+ DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair.\n");
+ }
+
+ if (!host) /* server */
+ {
+ const uschar * clist = state->exp_tls_certificate;
+ const uschar * klist = state->exp_tls_privatekey;
+ const uschar * olist;
+ int csep = 0, ksep = 0, osep = 0, cnt = 0;
+ uschar * cfile, * kfile, * ofile;
+#ifndef DISABLE_OCSP
+# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE
+ gnutls_x509_crt_fmt_t ocsp_fmt = GNUTLS_X509_FMT_DER;
+# endif
+
+ if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", &ofile, errstr))
+ return DEFER;
+ olist = ofile;
+#endif
+
+ while (cfile = string_nextinlist(&clist, &csep, NULL, 0))
+
+ if (!(kfile = string_nextinlist(&klist, &ksep, NULL, 0)))
+ return tls_error(US"cert/key setup: out of keys", NULL, host, errstr);
+ else if (0 < (rc = tls_add_certfile(state, host, cfile, kfile, errstr)))
+ return rc;
+ else
+ {
+ int gnutls_cert_index = -rc;
+ DEBUG(D_tls) debug_printf("TLS: cert/key %d %s registered\n",
+ gnutls_cert_index, cfile);
+
+#ifndef DISABLE_OCSP
+ if (tls_ocsp_file)
+ {
+ /* Set the OCSP stapling server info */
+ if (gnutls_buggy_ocsp)
+ {
+ DEBUG(D_tls)
+ debug_printf("GnuTLS library is buggy for OCSP; avoiding\n");
+ }
+ else if ((ofile = string_nextinlist(&olist, &osep, NULL, 0)))
+ {
+ DEBUG(D_tls) debug_printf("OCSP response file %d = %s\n",
+ gnutls_cert_index, ofile);
+# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE
+ if (Ustrncmp(ofile, US"PEM ", 4) == 0)
+ {
+ ocsp_fmt = GNUTLS_X509_FMT_PEM;
+ ofile += 4;
+ }
+ else if (Ustrncmp(ofile, US"DER ", 4) == 0)
+ {
+ ocsp_fmt = GNUTLS_X509_FMT_DER;
+ ofile += 4;
+ }
+
+ if ((rc = gnutls_certificate_set_ocsp_status_request_file2(
+ state->x509_cred, CCS ofile, gnutls_cert_index,
+ ocsp_fmt)) < 0)
+ return tls_error_gnu(
+ US"gnutls_certificate_set_ocsp_status_request_file2",
+ rc, host, errstr);
+ DEBUG(D_tls)
+ debug_printf(" %d response%s loaded\n", rc, rc>1 ? "s":"");
+
+ /* Arrange callbacks for OCSP request observability */
+
+ gnutls_handshake_set_hook_function(state->session,
+ GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb);
+
+# else
+# if defined(SUPPORT_SRV_OCSP_STACK)
+ if ((rc = gnutls_certificate_set_ocsp_status_request_function2(
+ state->x509_cred, gnutls_cert_index,
+ server_ocsp_stapling_cb, ofile)))
+ return tls_error_gnu(
+ US"gnutls_certificate_set_ocsp_status_request_function2",
+ rc, host, errstr);
+ else
+# endif
+ {
+ if (cnt++ > 0)
+ {
+ DEBUG(D_tls)
+ debug_printf("oops; multiple OCSP files not supported\n");
+ break;
+ }
+ gnutls_certificate_set_ocsp_status_request_function(
+ state->x509_cred, server_ocsp_stapling_cb, ofile);
+ }
+# endif /* SUPPORT_GNUTLS_EXT_RAW_PARSE */
+ }
+ else
+ DEBUG(D_tls) debug_printf("ran out of OCSP response files in list\n");
+ }
+#endif /* DISABLE_OCSP */
+ }
+ }
+ else /* client */
+ {
+ if (0 < (rc = tls_add_certfile(state, host,
+ state->exp_tls_certificate, state->exp_tls_privatekey, errstr)))
+ return rc;
+ DEBUG(D_tls) debug_printf("TLS: cert/key registered\n");
+ }
+
+ } /* tls_certificate */
+
+
+/* Set the trusted CAs file if one is provided, and then add the CRL if one is
+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. */
+
+if (state->tls_verify_certificates && *state->tls_verify_certificates)
+ {
+ if (!expand_check_tlsvar(tls_verify_certificates, errstr))
+ return DEFER;
+#ifndef SUPPORT_SYSDEFAULT_CABUNDLE
+ if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0)
+ state->exp_tls_verify_certificates = NULL;
+#endif
+ if (state->tls_crl && *state->tls_crl)
+ if (!expand_check_tlsvar(tls_crl, errstr))
+ return DEFER;
+
+ if (!(state->exp_tls_verify_certificates &&
+ *state->exp_tls_verify_certificates))
+ {
+ DEBUG(D_tls)
+ debug_printf("TLS: tls_verify_certificates expanded empty, ignoring\n");
+ /* With no tls_verify_certificates, we ignore tls_crl too */
+ return OK;
+ }
+ }
+else
+ {
+ DEBUG(D_tls)
+ debug_printf("TLS: tls_verify_certificates not set or empty, ignoring\n");
+ return OK;
+ }
+
+#ifdef SUPPORT_SYSDEFAULT_CABUNDLE
+if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0)
+ cert_count = gnutls_certificate_set_x509_system_trust(state->x509_cred);
+else
+#endif
+ {
+ if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "could not stat '%s' "
+ "(tls_verify_certificates): %s", state->exp_tls_verify_certificates,
+ strerror(errno));
+ return DEFER;
+ }
+
+#ifndef SUPPORT_CA_DIR
+ /* The test suite passes in /dev/null; we could check for that path explicitly,
+ but who knows if someone has some weird FIFO which always dumps some certs, or
+ other weirdness. The thing we really want to check is that it's not a
+ directory, since while OpenSSL supports that, GnuTLS does not.
+ So s/!S_ISREG/S_ISDIR/ and change some messaging ... */
+ if (S_ISDIR(statbuf.st_mode))
+ {
+ DEBUG(D_tls)
+ debug_printf("verify certificates path is a dir: \"%s\"\n",
+ state->exp_tls_verify_certificates);
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "tls_verify_certificates \"%s\" is a directory",
+ state->exp_tls_verify_certificates);
+ return DEFER;
+ }
+#endif
+
+ DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n",
+ state->exp_tls_verify_certificates, statbuf.st_size);
+
+ if (statbuf.st_size == 0)
+ {
+ DEBUG(D_tls)
+ debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n");
+ return OK;
+ }
+
+ cert_count =
+
+#ifdef SUPPORT_CA_DIR
+ (statbuf.st_mode & S_IFMT) == S_IFDIR
+ ?
+ gnutls_certificate_set_x509_trust_dir(state->x509_cred,
+ CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM)
+ :
+#endif
+ gnutls_certificate_set_x509_trust_file(state->x509_cred,
+ CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM);
+
+#ifdef SUPPORT_CA_DIR
+ /* Mimic the behaviour with OpenSSL of not advertising a usable-cert list
+ when using the directory-of-certs config model. */
+
+ if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
+ gnutls_certificate_send_x509_rdn_sequence(state->session, 1);
+#endif
+ }
+
+if (cert_count < 0)
+ return tls_error_gnu(US"setting certificate trust", cert_count, host, errstr);
+DEBUG(D_tls)
+ debug_printf("Added %d certificate authorities.\n", cert_count);
+
+if (state->tls_crl && *state->tls_crl &&
+ state->exp_tls_crl && *state->exp_tls_crl)
+ {
+ DEBUG(D_tls) debug_printf("loading CRL file = %s\n", state->exp_tls_crl);
+ if ((cert_count = gnutls_certificate_set_x509_crl_file(state->x509_cred,
+ CS state->exp_tls_crl, GNUTLS_X509_FMT_PEM)) < 0)
+ return tls_error_gnu(US"gnutls_certificate_set_x509_crl_file",
+ cert_count, host, errstr);
+
+ DEBUG(D_tls) debug_printf("Processed %d CRLs.\n", cert_count);
+ }
+
+return OK;
+}
+
+
+
+
+/*************************************************
+* Set X.509 state variables *
+*************************************************/
+
+/* In GnuTLS, the registered cert/key are not replaced by a later
+set of a cert/key, so for SNI support we need a whole new x509_cred
+structure. Which means various other non-re-expanded pieces of state
+need to be re-set in the new struct, so the setting logic is pulled
+out to this.
+
+Arguments:
+ state exim_gnutls_state_st *
+ errstr error string pointer
+
+Returns: OK/DEFER/FAIL
+*/
+
+static int
+tls_set_remaining_x509(exim_gnutls_state_st *state, uschar ** errstr)
+{
+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 (!state->host)
+ {
+ if (!dh_server_params)
+ if ((rc = init_server_dh(errstr)) != OK) return rc;
+
+ /* Unnecessary & discouraged with 3.6.0 or later */
+ gnutls_certificate_set_dh_params(state->x509_cred, dh_server_params);
+ }
+#endif
+
+/* Link the credentials to the session. */
+
+if ((rc = gnutls_credentials_set(state->session,
+ GNUTLS_CRD_CERTIFICATE, state->x509_cred)))
+ return tls_error_gnu(US"gnutls_credentials_set", rc, host, errstr);
+
+return OK;
+}
+
+/*************************************************
+* Initialize for GnuTLS *
+*************************************************/
+
+
+#ifndef DISABLE_OCSP