+bio = BIO_new_file(CS cbinfo->ocsp_file_expanded, "rb");
+if (!bio)
+ {
+ DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n",
+ cbinfo->ocsp_file_expanded);
+ return;
+ }
+
+resp = d2i_OCSP_RESPONSE_bio(bio, NULL);
+BIO_free(bio);
+if (!resp)
+ {
+ DEBUG(D_tls) debug_printf("Error reading OCSP response.\n");
+ return;
+ }
+
+status = OCSP_response_status(resp);
+if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL)
+ {
+ DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n",
+ OCSP_response_status_str(status), status);
+ return;
+ }
+
+basic_response = OCSP_response_get1_basic(resp);
+if (!basic_response)
+ {
+ DEBUG(D_tls)
+ debug_printf("OCSP response parse error: unable to extract basic response.\n");
+ return;
+ }
+
+store = SSL_CTX_get_cert_store(sctx);
+verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */
+
+/* May need to expose ability to adjust those flags?
+OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT
+OCSP_TRUSTOTHER OCSP_NOINTERN */
+
+i = OCSP_basic_verify(basic_response, NULL, store, verify_flags);
+if (i <= 0)
+ {
+ DEBUG(D_tls) {
+ ERR_error_string(ERR_get_error(), ssl_errstring);
+ debug_printf("OCSP response verify failure: %s\n", US ssl_errstring);
+ }
+ return;
+ }
+
+/* Here's the simplifying assumption: there's only one response, for the
+one certificate we use, and nothing for anything else in a chain. If this
+proves false, we need to extract a cert id from our issued cert
+(tls_certificate) and use that for OCSP_resp_find_status() (which finds the
+right cert in the stack and then calls OCSP_single_get0_status()).
+
+I'm hoping to avoid reworking a bunch more of how we handle state here. */
+single_response = OCSP_resp_get0(basic_response, 0);
+if (!single_response)
+ {
+ DEBUG(D_tls)
+ debug_printf("Unable to get first response from OCSP basic response.\n");
+ return;
+ }
+
+status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd);
+/* how does this status differ from the one above? */
+if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL)
+ {
+ DEBUG(D_tls) debug_printf("OCSP response not valid (take 2): %s (%d)\n",
+ OCSP_response_status_str(status), status);
+ return;
+ }
+
+if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
+ {
+ DEBUG(D_tls) debug_printf("OCSP status invalid times.\n");
+ return;
+ }
+
+cbinfo->ocsp_response = resp;
+}
+#endif
+
+
+
+
+/*************************************************
+* Expand key and cert file specs *
+*************************************************/
+
+/* Called once during tls_init and possibly againt during TLS setup, for a
+new context, if Server Name Indication was used and tls_sni was seen in
+the certificate string.
+
+Arguments:
+ sctx the SSL_CTX* to update
+ cbinfo various parts of session state
+
+Returns: OK/DEFER/FAIL
+*/
+
+static int
+tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo)
+{
+uschar *expanded;
+
+if (cbinfo->certificate == NULL)
+ return OK;
+
+if (Ustrstr(cbinfo->certificate, US"tls_sni") ||
+ Ustrstr(cbinfo->certificate, US"tls_in_sni") ||
+ Ustrstr(cbinfo->certificate, US"tls_out_sni")
+ )
+ reexpand_tls_files_for_sni = TRUE;
+
+if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded))
+ return DEFER;
+
+if (expanded != NULL)
+ {
+ DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded);
+ if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded))
+ return tls_error(string_sprintf(
+ "SSL_CTX_use_certificate_chain_file file=%s", expanded),
+ cbinfo->host, NULL);
+ }
+
+if (cbinfo->privatekey != NULL &&
+ !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded))
+ return DEFER;
+
+/* If expansion was forced to fail, key_expanded will be NULL. If the result
+of the expansion is an empty string, ignore it also, and assume the private
+key is in the same file as the certificate. */
+
+if (expanded != NULL && *expanded != 0)
+ {
+ DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded);
+ if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM))
+ return tls_error(string_sprintf(
+ "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL);
+ }
+
+#ifdef EXPERIMENTAL_OCSP
+if (cbinfo->ocsp_file != NULL)
+ {
+ if (!expand_check(cbinfo->ocsp_file, US"tls_ocsp_file", &expanded))
+ return DEFER;
+
+ if (expanded != NULL && *expanded != 0)
+ {
+ DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded);
+ if (cbinfo->ocsp_file_expanded &&
+ (Ustrcmp(expanded, cbinfo->ocsp_file_expanded) == 0))
+ {
+ DEBUG(D_tls)
+ debug_printf("tls_ocsp_file value unchanged, using existing values.\n");
+ } else {
+ ocsp_load_response(sctx, cbinfo, expanded);
+ }
+ }
+ }
+#endif
+
+return OK;