hs-v3: Add ephemeral service support

The functions are now used by the ADD_ONION/DEL_ONION control port command as
well. This commits makes them fully functionnal with hidden service v3.

Part of #20699

Signed-off-by: David Goulet <dgoulet@torproject.org>

src/or/control.c

@@ -4447,19 +4447,14 @@ add_onion_helper_add_service(int hs_version, void *pk, smartlist_t *port_cfgs,
 
   switch (hs_version) {
   case HS_VERSION_TWO:
-  {
     ret = rend_service_add_ephemeral(pk, port_cfgs, max_streams,
                                      max_streams_close_circuit, auth_type,
                                      auth_clients, address_out);
     break;
-  }
   case HS_VERSION_THREE:
-  {
-    /* XXX: Not implemented yet. */
-    *address_out = tor_strdup("this is a v3 address");
-    ret = RSAE_OKAY;
+    ret = hs_service_add_ephemeral(pk, port_cfgs, max_streams,
+                                   max_streams_close_circuit, address_out);
     break;
-  }
   default:
     tor_assert_unreached();
   }
@@ -4971,6 +4966,7 @@ handle_control_del_onion(control_connection_t *conn,
                           uint32_t len,
                           const char *body)
 {
+  int hs_version = 0;
   smartlist_t *args;
   (void) len; /* body is nul-terminated; it's safe to ignore the length */
   args = getargs_helper("DEL_ONION", conn, body, 1, 1);
@@ -4978,7 +4974,11 @@ handle_control_del_onion(control_connection_t *conn,
     return 0;
 
   const char *service_id = smartlist_get(args, 0);
-  if (!rend_valid_v2_service_id(service_id)) {
+  if (rend_valid_v2_service_id(service_id)) {
+    hs_version = HS_VERSION_TWO;
+  } else if (hs_address_is_valid(service_id)) {
+    hs_version = HS_VERSION_THREE;
+  } else {
     connection_printf_to_buf(conn, "512 Malformed Onion Service id\r\n");
     goto out;
   }
@@ -5005,8 +5005,20 @@ handle_control_del_onion(control_connection_t *conn,
   if (onion_services == NULL) {
     connection_printf_to_buf(conn, "552 Unknown Onion Service id\r\n");
   } else {
-    int ret = rend_service_del_ephemeral(service_id);
-    if (ret) {
+    int ret = -1;
+    switch (hs_version) {
+    case HS_VERSION_TWO:
+      ret = rend_service_del_ephemeral(service_id);
+      break;
+    case HS_VERSION_THREE:
+      ret = hs_service_del_ephemeral(service_id);
+      break;
+    default:
+      /* The ret value will be -1 thus hitting the warning below. This should
+       * never happen because of the check at the start of the function. */
+      break;
+    }
+    if (ret < 0) {
       /* This should *NEVER* fail, since the service is on either the
        * per-control connection list, or the global one.
        */
@@ -5076,9 +5088,16 @@ connection_control_closed(control_connection_t *conn)
    * The list and it's contents are scrubbed/freed in connection_free_.
    */
   if (conn->ephemeral_onion_services) {
-    SMARTLIST_FOREACH(conn->ephemeral_onion_services, char *, cp, {
+    SMARTLIST_FOREACH_BEGIN(conn->ephemeral_onion_services, char *, cp) {
+      if (rend_valid_v2_service_id(cp)) {
         rend_service_del_ephemeral(cp);
-    });
+      } else if (hs_address_is_valid(cp)) {
+        hs_service_del_ephemeral(cp);
+      } else {
+        /* An invalid .onion in our list should NEVER happen */
+        tor_fragile_assert();
+      }
+    } SMARTLIST_FOREACH_END(cp);
   }
 
   if (conn->is_owning_control_connection) {

src/or/hs_service.c

@@ -2900,6 +2900,132 @@ service_add_fnames_to_list(const hs_service_t *service, smartlist_t *list)
 /* Public API */
 /* ========== */
 
+/* Add the ephemeral service using the secret key sk and ports. Both max
+ * streams parameter will be set in the newly created service.
+ *
+ * Ownership of sk and ports is passed to this routine.  Regardless of
+ * success/failure, callers should not touch these values after calling this
+ * routine, and may assume that correct cleanup has been done on failure.
+ *
+ * Return an appropriate hs_service_add_ephemeral_status_t. */
+hs_service_add_ephemeral_status_t
+hs_service_add_ephemeral(ed25519_secret_key_t *sk, smartlist_t *ports,
+                         int max_streams_per_rdv_circuit,
+                         int max_streams_close_circuit, char **address_out)
+{
+  hs_service_add_ephemeral_status_t ret;
+  hs_service_t *service = NULL;
+
+  tor_assert(sk);
+  tor_assert(ports);
+  tor_assert(address_out);
+
+  service = hs_service_new(get_options());
+
+  /* Setup the service configuration with specifics. A default service is
+   * HS_VERSION_TWO so explicitely set it. */
+  service->config.version = HS_VERSION_THREE;
+  service->config.max_streams_per_rdv_circuit = max_streams_per_rdv_circuit;
+  service->config.max_streams_close_circuit = !!max_streams_close_circuit;
+  service->config.is_ephemeral = 1;
+  smartlist_free(service->config.ports);
+  service->config.ports = ports;
+
+  /* Handle the keys. */
+  memcpy(&service->keys.identity_sk, sk, sizeof(service->keys.identity_sk));
+  if (ed25519_public_key_generate(&service->keys.identity_pk,
+                                  &service->keys.identity_sk) < 0) {
+    log_warn(LD_CONFIG, "Unable to generate ed25519 public key"
+                        "for v3 service.");
+    ret = RSAE_BADPRIVKEY;
+    goto err;
+  }
+
+  /* Make sure we have at least one port. */
+  if (smartlist_len(service->config.ports) == 0) {
+    log_warn(LD_CONFIG, "At least one VIRTPORT/TARGET must be specified "
+                        "for v3 service.");
+    ret = RSAE_BADVIRTPORT;
+    goto err;
+  }
+
+  /* The only way the registration can fail is if the service public key
+   * already exists. */
+  if (BUG(register_service(hs_service_map, service) < 0)) {
+    log_warn(LD_CONFIG, "Onion Service private key collides with an "
+                        "existing v3 service.");
+    ret = RSAE_ADDREXISTS;
+    goto err;
+  }
+
+  /* Last step is to build the onion address. */
+  hs_build_address(&service->keys.identity_pk,
+                   (uint8_t) service->config.version,
+                   service->onion_address);
+  *address_out = tor_strdup(service->onion_address);
+
+  log_info(LD_CONFIG, "Added ephemeral v3 onion service: %s",
+           safe_str_client(service->onion_address));
+  ret = RSAE_OKAY;
+  goto end;
+
+ err:
+  hs_service_free(service);
+
+ end:
+  memwipe(sk, 0, sizeof(ed25519_secret_key_t));
+  tor_free(sk);
+  return ret;
+}
+
+/* For the given onion address, delete the ephemeral service. Return 0 on
+ * success else -1 on error. */
+int
+hs_service_del_ephemeral(const char *address)
+{
+  uint8_t version;
+  ed25519_public_key_t pk;
+  hs_service_t *service = NULL;
+
+  tor_assert(address);
+
+  if (hs_parse_address(address, &pk, NULL, &version) < 0) {
+    log_warn(LD_CONFIG, "Requested malformed v3 onion address for removal.");
+    goto err;
+  }
+
+  if (version != HS_VERSION_THREE) {
+    log_warn(LD_CONFIG, "Requested version of onion address for removal "
+                        "is not supported.");
+    goto err;
+  }
+
+  service = find_service(hs_service_map, &pk);
+  if (service == NULL) {
+    log_warn(LD_CONFIG, "Requested non-existent v3 hidden service for "
+                        "removal.");
+    goto err;
+  }
+
+  if (!service->config.is_ephemeral) {
+    log_warn(LD_CONFIG, "Requested non-ephemeral v3 hidden service for "
+                        "removal.");
+    goto err;
+  }
+
+  /* Close circuits, remove from map and finally free. */
+  close_service_circuits(service);
+  remove_service(hs_service_map, service);
+  hs_service_free(service);
+
+  log_info(LD_CONFIG, "Removed ephemeral v3 hidden service: %s",
+           safe_str_client(address));
+  return 0;
+
+ err:
+  return -1;
+}
+
 /* Using the ed25519 public key pk, find a service for that key and return the
  * current encoded descriptor as a newly allocated string or NULL if not
  * found. This is used by the control port subsystem. */

src/or/hs_service.h

@@ -273,6 +273,12 @@ void hs_service_intro_circ_has_closed(origin_circuit_t *circ);
 
 char *hs_service_lookup_current_desc(const ed25519_public_key_t *pk);
 
+hs_service_add_ephemeral_status_t
+hs_service_add_ephemeral(ed25519_secret_key_t *sk, smartlist_t *ports,
+                         int max_streams_per_rdv_circuit,
+                         int max_streams_close_circuit, char **address_out);
+int hs_service_del_ephemeral(const char *address);
+
 #ifdef HS_SERVICE_PRIVATE
 
 #ifdef TOR_UNIT_TESTS

src/test/test_controller.c

@@ -14,7 +14,81 @@
 #include "test_helpers.h"
 
 static void
-test_add_onion_helper_keyarg(void *arg)
+test_add_onion_helper_keyarg_v3(void *arg)
+{
+  int ret, hs_version;
+  void *pk_ptr = NULL;
+  char *key_new_blob = NULL;
+  char *err_msg = NULL;
+  const char *key_new_alg = NULL;
+
+  (void) arg;
+
+  /* Test explicit ED25519-V3 key generation. */
+  ret = add_onion_helper_keyarg("NEW:ED25519-V3", 0, &key_new_alg,
+                                &key_new_blob, &pk_ptr, &hs_version,
+                                &err_msg);
+  tt_int_op(ret, OP_EQ, 0);
+  tt_int_op(hs_version, OP_EQ, HS_VERSION_THREE);
+  tt_assert(pk_ptr);
+  tt_str_op(key_new_alg, OP_EQ, "ED25519-V3");
+  tt_assert(key_new_blob);
+  tt_ptr_op(err_msg, OP_EQ, NULL);
+  tor_free(pk_ptr); pk_ptr = NULL;
+  tor_free(key_new_blob);
+
+  /* Test discarding the private key. */
+  ret = add_onion_helper_keyarg("NEW:ED25519-V3", 1, &key_new_alg,
+                                &key_new_blob, &pk_ptr, &hs_version,
+                                &err_msg);
+  tt_int_op(ret, OP_EQ, 0);
+  tt_int_op(hs_version, OP_EQ, HS_VERSION_THREE);
+  tt_assert(pk_ptr);
+  tt_ptr_op(key_new_alg, OP_EQ, NULL);
+  tt_ptr_op(key_new_blob, OP_EQ, NULL);
+  tt_ptr_op(err_msg, OP_EQ, NULL);
+  tor_free(pk_ptr); pk_ptr = NULL;
+  tor_free(key_new_blob);
+
+  /* Test passing a key blob. */
+  {
+    /* The base64 key and hex key are the same. Hex key is 64 bytes long. The
+     * sk has been generated randomly using python3. */
+    const char *base64_sk =
+      "a9bT19PqGC9Y+BmOo1IQvCGjjwxMiaaxEXZ+FKMxpEQW"
+      "6AmSV5roThUGMRCaqQSCnR2jI1vL2QxHORzI4RxMmw==";
+    const char *hex_sk =
+      "\x6b\xd6\xd3\xd7\xd3\xea\x18\x2f\x58\xf8\x19\x8e\xa3\x52\x10\xbc"
+      "\x21\xa3\x8f\x0c\x4c\x89\xa6\xb1\x11\x76\x7e\x14\xa3\x31\xa4\x44"
+      "\x16\xe8\x09\x92\x57\x9a\xe8\x4e\x15\x06\x31\x10\x9a\xa9\x04\x82"
+      "\x9d\x1d\xa3\x23\x5b\xcb\xd9\x0c\x47\x39\x1c\xc8\xe1\x1c\x4c\x9b";
+    char *key_blob = NULL;
+
+    tor_asprintf(&key_blob, "ED25519-V3:%s", base64_sk);
+    tt_assert(key_blob);
+    ret = add_onion_helper_keyarg(key_blob, 1, &key_new_alg,
+                                  &key_new_blob, &pk_ptr, &hs_version,
+                                  &err_msg);
+    tor_free(key_blob);
+    tt_int_op(ret, OP_EQ, 0);
+    tt_int_op(hs_version, OP_EQ, HS_VERSION_THREE);
+    tt_assert(pk_ptr);
+    tt_mem_op(pk_ptr, OP_EQ, hex_sk, 64);
+    tt_ptr_op(key_new_alg, OP_EQ, NULL);
+    tt_ptr_op(key_new_blob, OP_EQ, NULL);
+    tt_ptr_op(err_msg, OP_EQ, NULL);
+    tor_free(pk_ptr); pk_ptr = NULL;
+    tor_free(key_new_blob);
+  }
+
+ done:
+  tor_free(pk_ptr);
+  tor_free(key_new_blob);
+  tor_free(err_msg);
+}
+
+static void
+test_add_onion_helper_keyarg_v2(void *arg)
 {
   int ret, hs_version;
   void *pk_ptr = NULL;
@@ -1386,7 +1460,10 @@ test_download_status_bridge(void *arg)
 }
 
 struct testcase_t controller_tests[] = {
-  { "add_onion_helper_keyarg", test_add_onion_helper_keyarg, 0, NULL, NULL },
+  { "add_onion_helper_keyarg_v2", test_add_onion_helper_keyarg_v2, 0,
+    NULL, NULL },
+  { "add_onion_helper_keyarg_v3", test_add_onion_helper_keyarg_v3, 0,
+    NULL, NULL },
   { "getinfo_helper_onion", test_getinfo_helper_onion, 0, NULL, NULL },
   { "rend_service_parse_port_config", test_rend_service_parse_port_config, 0,
     NULL, NULL },