Server configuration for OCSP stapling with ocsp_multi (RFC 6961)

This adds a new hostapd configuration parameter
ocsp_stapling_response_multi that can be used similarly to the existing
ocsp_stapling_response, but for the purpose of providing multiple cached
OCSP responses. This commit adds only the configuration parameter, but
does not yet add support for this mechanism with any of the supported
TLS implementations.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

hostapd/config_file.c

@@ -2132,6 +2132,9 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 	} else if (os_strcmp(buf, "ocsp_stapling_response") == 0) {
 		os_free(bss->ocsp_stapling_response);
 		bss->ocsp_stapling_response = os_strdup(pos);
+	} else if (os_strcmp(buf, "ocsp_stapling_response_multi") == 0) {
+		os_free(bss->ocsp_stapling_response_multi);
+		bss->ocsp_stapling_response_multi = os_strdup(pos);
 	} else if (os_strcmp(buf, "dh_file") == 0) {
 		os_free(bss->dh_file);
 		bss->dh_file = os_strdup(pos);

hostapd/hostapd.conf

@@ -795,6 +795,11 @@ eap_server=0
 #	-respout /tmp/ocsp-cache.der
 #ocsp_stapling_response=/tmp/ocsp-cache.der
 
+# Cached OCSP stapling response list (DER encoded OCSPResponseList)
+# This is similar to ocsp_stapling_response, but the extended version defined in
+# RFC 6961 to allow multiple OCSP responses to be provided.
+#ocsp_stapling_response_multi=/tmp/ocsp-multi-cache.der
+
 # dh_file: File path to DH/DSA parameters file (in PEM format)
 # This is an optional configuration file for setting parameters for an
 # ephemeral DH key exchange. In most cases, the default RSA authentication does

src/ap/ap_config.c

@@ -471,6 +471,7 @@ void hostapd_config_free_bss(struct hostapd_bss_config *conf)
 	os_free(conf->private_key);
 	os_free(conf->private_key_passwd);
 	os_free(conf->ocsp_stapling_response);
+	os_free(conf->ocsp_stapling_response_multi);
 	os_free(conf->dh_file);
 	os_free(conf->openssl_ciphers);
 	os_free(conf->pac_opaque_encr_key);

src/ap/ap_config.h

@@ -341,6 +341,7 @@ struct hostapd_bss_config {
 	int check_crl;
 	unsigned int tls_session_lifetime;
 	char *ocsp_stapling_response;
+	char *ocsp_stapling_response_multi;
 	char *dh_file;
 	char *openssl_ciphers;
 	u8 *pac_opaque_encr_key;

src/ap/authsrv.c

@@ -173,6 +173,8 @@ int authsrv_init(struct hostapd_data *hapd)
 		params.openssl_ciphers = hapd->conf->openssl_ciphers;
 		params.ocsp_stapling_response =
 			hapd->conf->ocsp_stapling_response;
+		params.ocsp_stapling_response_multi =
+			hapd->conf->ocsp_stapling_response_multi;
 
 		if (tls_global_set_params(hapd->ssl_ctx, &params)) {
 			wpa_printf(MSG_ERROR, "Failed to set TLS parameters");

src/crypto/tls.h

@@ -140,6 +140,9 @@ struct tls_config {
  * @flags: Parameter options (TLS_CONN_*)
  * @ocsp_stapling_response: DER encoded file with cached OCSP stapling response
  *	or %NULL if OCSP is not enabled
+ * @ocsp_stapling_response_multi: DER encoded file with cached OCSP stapling
+ *	response list (OCSPResponseList for ocsp_multi in RFC 6961) or %NULL if
+ *	ocsp_multi is not enabled
  *
  * TLS connection parameters to be configured with tls_connection_set_params()
  * and tls_global_set_params().
@@ -180,6 +183,7 @@ struct tls_connection_params {
 
 	unsigned int flags;
 	const char *ocsp_stapling_response;
+	const char *ocsp_stapling_response_multi;
 };