Make rend_authorized_client_free public

This is needed by control.c.

Also, check whether client_name is set before doing memwipe.

src/or/rendservice.c

@@ -183,14 +183,15 @@ num_rend_services(void)
 }
 
 /** Helper: free storage held by a single service authorized client entry. */
-static void
+void
 rend_authorized_client_free(rend_authorized_client_t *client)
 {
   if (!client)
     return;
   if (client->client_key)
     crypto_pk_free(client->client_key);
-  memwipe(client->client_name, 0, strlen(client->client_name));
+  if (client->client_name)
+    memwipe(client->client_name, 0, strlen(client->client_name));
   tor_free(client->client_name);
   memwipe(client->descriptor_cookie, 0, sizeof(client->descriptor_cookie));
   tor_free(client);

src/or/rendservice.h

@@ -106,6 +106,8 @@ rend_service_port_config_t *rend_service_parse_port_config(const char *string,
                                                            char **err_msg_out);
 void rend_service_port_config_free(rend_service_port_config_t *p);
 
+void rend_authorized_client_free(rend_authorized_client_t *client);
+
 /** Return value from rend_service_add_ephemeral. */
 typedef enum {
   RSAE_BADVIRTPORT = -4, /**< Invalid VIRTPORT/TARGET(s) */