+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");
+ }
+ }
+
+ rc = gnutls_certificate_set_x509_key_file(state->x509_cred,
+ CS state->exp_tls_certificate, CS state->exp_tls_privatekey,
+ GNUTLS_X509_FMT_PEM);
+ exim_gnutls_err_check(
+ string_sprintf("cert/key setup: cert=%s key=%s",
+ state->exp_tls_certificate, state->exp_tls_privatekey));
+ DEBUG(D_tls) debug_printf("TLS: cert/key registered\n");
+ } /* tls_certificate */
+
+
+/* Set the OCSP stapling server info */
+
+#ifndef DISABLE_OCSP
+if ( !host /* server */
+ && tls_ocsp_file
+ )
+ {
+ if (!expand_check(tls_ocsp_file, US"tls_ocsp_file",
+ &state->exp_tls_ocsp_file))
+ return DEFER;
+
+ /* Use the full callback method for stapling just to get observability.
+ More efficient would be to read the file once only, if it never changed
+ (due to SNI). Would need restart on file update, or watch datestamp. */
+
+ gnutls_certificate_set_ocsp_status_request_function(state->x509_cred,
+ server_ocsp_stapling_cb, state->exp_tls_ocsp_file);
+
+ DEBUG(D_tls) debug_printf("Set OCSP response file %s\n", &state->exp_tls_ocsp_file);
+ }
+#endif
+
+
+/* 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))
+ return DEFER;
+ if (state->tls_crl && *state->tls_crl)
+ if (!expand_check_tlsvar(tls_crl))
+ 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;
+ }
+
+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;
+ }
+
+/* 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 messsaging ... */
+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;
+ }
+
+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;
+ }