mesh: Fix Remote/Local dev key usage

When sending or receiving Device Key (privileged) mesh messages, the remote vs local device key must be specified. This allows Apps to specify Key Ring stored device keys, and sanity checks that the correct
key exists before allowing the transmission. Loopback messages to local
servers *must* use keys from the Key Ring to indicate privilege has been
granted.

---
 mesh/model.c | 11 +++++++----
 mesh/node.c  | 25 +++++++++++++++----------
 2 files changed, 22 insertions(+), 14 deletions(-)

mesh/model.c +6 -4

index a06b684a5..e9b346102 100644
@@ -735,14 +735,16 @@ static int add_sub(struct mesh_net *net, struct
 mesh_model *mod,
 }
 
 static void send_dev_key_msg_rcvd(struct mesh_node *node, uint8_t
 ele_idx,
-					uint16_t src, uint16_t net_idx,
-					uint16_t size, const uint8_t
 *data)
+					uint16_t src, uint16_t app_idx,
+					uint16_t net_idx, uint16_t
 size,
+					const uint8_t *data)
 {
 	struct l_dbus *dbus = dbus_get_bus();
 	struct l_dbus_message *msg;
 	struct l_dbus_message_builder *builder;
 	const char *owner;
 	const char *path;
+	bool remote = (app_idx != APP_IDX_DEV_LOCAL);
 
 	owner = node_get_owner(node);
 	path = node_get_element_path(node, ele_idx);

@@ -758,6 +760,7 @@ static void send_dev_key_msg_rcvd(struct
 mesh_node *node, uint8_t ele_idx,
 	builder = l_dbus_message_builder_new(msg);
 
 	l_dbus_message_builder_append_basic(builder, 'q', &src);
+	l_dbus_message_builder_append_basic(builder, 'b', &remote);
 	l_dbus_message_builder_append_basic(builder, 'q', &net_idx);
 	dbus_append_byte_array(builder, data, size);

@@ -936,8 +939,8 @@ bool mesh_model_rx(struct mesh_node *node, bool
 szmict, uint32_t seq0,
 			else if (decrypt_idx == APP_IDX_DEV_REMOTE ||
 				(decrypt_idx == APP_IDX_DEV_LOCAL &&
 				 mesh_net_is_local_address(net, src,
 1)))
-				send_dev_key_msg_rcvd(node, i, src, 0,
-						forward.size,
 forward.data);
+				send_dev_key_msg_rcvd(node, i, src,

decrypt_idx,

mesh/model.c +1 -0

+						0, forward.size,

forward.data);

mesh/model.c +0 -0

 		}
 
 		/*

mesh/node.c +2 -3

index b6824f505..833377e99 100644
@@ -1976,7 +1976,8 @@ static struct l_dbus_message
 *dev_key_send_call(struct l_dbus *dbus,
 	const char *sender, *ele_path;
 	struct l_dbus_message_iter iter_data;
 	struct node_element *ele;
-	uint16_t dst, net_idx, src;
+	uint16_t dst, app_idx, net_idx, src;
+	bool remote;
 	uint8_t *data;
 	uint32_t len;

@@ -1987,8 +1988,12 @@ static struct l_dbus_message
 *dev_key_send_call(struct l_dbus *dbus,
 	if (strcmp(sender, node->owner))
 		return dbus_error(msg, MESH_ERROR_NOT_AUTHORIZED,
 NULL);
 
-	if (!l_dbus_message_get_arguments(msg, "oqqay", &ele_path,
 &dst,
-							&net_idx,

&iter_data))

mesh/node.c +1 -0

+	if (!l_dbus_message_get_arguments(msg, "oqbqay", &ele_path,

&dst,

mesh/node.c +1 -0

+						&remote, &net_idx,

&iter_data))

mesh/node.c +4 -0

+		return dbus_error(msg, MESH_ERROR_INVALID_ARGS, NULL);
+
+	/* Loopbacks to local servers must use *remote* addressing */
+	if (!remote && mesh_net_is_local_address(node->net, dst, 1))
 		return dbus_error(msg, MESH_ERROR_INVALID_ARGS, NULL);
 
 	ele = l_queue_find(node->elements, match_element_path,

ele_path);

mesh/node.c +0 -0

@@ -1999,13 +2004,13 @@ static struct l_dbus_message
 *dev_key_send_call(struct l_dbus *dbus,
 	src = node_get_primary(node) + ele->idx;
 
 	if (!l_dbus_message_iter_get_fixed_array(&iter_data, &data,

&len) ||

mesh/node.c +1 -1

-					!len || len > MAX_MSG_LEN)
+						!len || len >

MAX_MSG_LEN)

mesh/node.c +0 -0

 		return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
 							"Incorrect

data");

mesh/node.c +0 -2

-	/* TODO: use net_idx */
-	if (!mesh_model_send(node, src, dst, APP_IDX_DEV_REMOTE,

net_idx,

mesh/node.c +0 -1

-							DEFAULT_TTL,

data, len))

mesh/node.c +2 -0

+	app_idx = remote ? APP_IDX_DEV_REMOTE : APP_IDX_DEV_LOCAL;
+	if (!mesh_model_send(node, src, dst, app_idx, net_idx,

DEFAULT_TTL,

mesh/node.c +1 -0

+								data,

len))
return dbus_error(msg, MESH_ERROR_NOT_FOUND, NULL);

mesh/node.c +0 -2

 	return l_dbus_message_new_method_return(msg);

@@ -2226,9 +2231,9 @@ static void setup_node_interface(struct
 l_dbus_interface *iface)
 						"element_path",
 "destination",
 						"key_index", "data");
 	l_dbus_interface_method(iface, "DevKeySend", 0,
 dev_key_send_call,
-						"", "oqqay",
 "element_path",
-						"destination",

"net_index",

mesh/node.c +1 -1

-						"data");
+						"", "oqbqay",

"element_path",

mesh/node.c +1 -0

+						"destination",

"remote",

mesh/node.c +1 -0

+						"net_index", "data");
 	l_dbus_interface_method(iface, "Publish", 0, publish_call, "",

"oqay",
"element_path", "model_id",
"data");
l_dbus_interface_method(iface, "VendorPublish", 0,
vendor_publish_call,

We do *not* automatically create populated key rings for imported or joined nodes,

but we also do not *forbid* any node from adding a key in it's possesion to the local key ring.

---
 mesh/manager.c |  5 -----
 mesh/node.c    | 15 ---------------
 2 files changed, 20 deletions(-)

mesh/manager.c +0 -1

index 501ec10fe..633597659 100644
@@ -282,7 +282,6 @@ static struct l_dbus_message
 *import_node_call(struct l_dbus *dbus,
 						void *user_data)
 {
 	struct mesh_node *node = user_data;
-	struct mesh_net *net = node_get_net(node);
 	struct l_dbus_message_iter iter_key;
 	uint16_t primary;

mesh/manager.c +0 -4

 	uint8_t num_ele;

@@ -298,10 +297,6 @@ static struct l_dbus_message
 *import_node_call(struct l_dbus *dbus,
 		return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
 							"Bad device
 key");
 
-	if (mesh_net_is_local_address(net, primary, num_ele))
-		return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
-					"Cannot overwrite local device
 key");
-

mesh/manager.c +0 -0

 	if (!keyring_put_remote_dev_key(node, primary, num_ele, key))
 		return dbus_error(msg, MESH_ERROR_FAILED, NULL);

mesh/node.c +0 -1

index 833377e99..af45a6130 100644
@@ -1681,7 +1681,6 @@ static void get_managed_objects_cb(struct
 l_dbus_message *msg, void *user_data)
 
 	} else if (req->type == REQUEST_TYPE_IMPORT) {
 		struct node_import *import = req->import;
-		struct keyring_net_key net_key;
 
 		if (!create_node_config(node, node->uuid))

mesh/node.c +0 -12

 			goto fail;

@@ -1692,23 +1691,9 @@ static void get_managed_objects_cb(struct
 l_dbus_message *msg, void *user_data)
 					import->net_idx, import-
 >net_key))
 			goto fail;
 
-		memcpy(net_key.old_key, import->net_key, 16);
-		net_key.net_idx = import->net_idx;
-		if (import->flags.kr)
-			net_key.phase = KEY_REFRESH_PHASE_TWO;
-		else
-			net_key.phase = KEY_REFRESH_PHASE_NONE;
-
 		/* Initialize directory for storing keyring info */
 		init_storage_dir(node);
 
-		if (!keyring_put_remote_dev_key(node, import->unicast,
-						num_ele, import-
 >dev_key))
-			goto fail;
-
-		if (!keyring_put_net_key(node, import->net_idx,

&net_key))

mesh/node.c +0 -2

-			goto fail;
-
 	} else {
 		/* Callback for create node request */
 		struct keyring_net_key net_key;

Hi Brian,

Quoted 2 lines · Brian Gix

We do *not* automatically create populated key rings for imported or joined nodes,

Why not for Import()? Since both the DevKey and NetKey are in the possesion of the node...

Quoted 75 lines

but we also do not *forbid* any node from adding a key in it's possesion to the local key ring.

---
 mesh/manager.c |  5 -----
 mesh/node.c    | 15 ---------------
 2 files changed, 20 deletions(-)

mesh/manager.c +0 -1

index 501ec10fe..633597659 100644
@@ -282,7 +282,6 @@ static struct l_dbus_message
 *import_node_call(struct l_dbus *dbus,
 						void *user_data)
 {
 	struct mesh_node *node = user_data;
-	struct mesh_net *net = node_get_net(node);
 	struct l_dbus_message_iter iter_key;
 	uint16_t primary;

mesh/manager.c +0 -4

 	uint8_t num_ele;

@@ -298,10 +297,6 @@ static struct l_dbus_message
 *import_node_call(struct l_dbus *dbus,
 		return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
 							"Bad device
 key");
 
-	if (mesh_net_is_local_address(net, primary, num_ele))
-		return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
-					"Cannot overwrite local device
 key");
-

mesh/manager.c +0 -0

 	if (!keyring_put_remote_dev_key(node, primary, num_ele, key))
 		return dbus_error(msg, MESH_ERROR_FAILED, NULL);

mesh/node.c +0 -1

index 833377e99..af45a6130 100644
@@ -1681,7 +1681,6 @@ static void get_managed_objects_cb(struct
 l_dbus_message *msg, void *user_data)
 
 	} else if (req->type == REQUEST_TYPE_IMPORT) {
 		struct node_import *import = req->import;
-		struct keyring_net_key net_key;
 
 		if (!create_node_config(node, node->uuid))

mesh/node.c +0 -12

 			goto fail;

@@ -1692,23 +1691,9 @@ static void get_managed_objects_cb(struct
 l_dbus_message *msg, void *user_data)
 					import->net_idx, import-
 > net_key))
 			goto fail;
 
-		memcpy(net_key.old_key, import->net_key, 16);
-		net_key.net_idx = import->net_idx;
-		if (import->flags.kr)
-			net_key.phase = KEY_REFRESH_PHASE_TWO;
-		else
-			net_key.phase = KEY_REFRESH_PHASE_NONE;
-
 		/* Initialize directory for storing keyring info */
 		init_storage_dir(node);
 
-		if (!keyring_put_remote_dev_key(node, import->unicast,
-						num_ele, import-
 > dev_key))
-			goto fail;
-
-		if (!keyring_put_net_key(node, import->net_idx,

&net_key))

mesh/node.c +0 -2

-			goto fail;
-
 	} else {
 		/* Callback for create node request */
 		struct keyring_net_key net_key;

Quoted 9 lines · Inga

Hi Brian,

Quoted 3 lines · Brian Gix

We do *not* automatically create populated key rings for imported or
joined nodes,

Why not for Import()? Since both the DevKey and NetKey are in the possesion of the node...

There are two (known) use cases for Import()

1. Node previously existed on a different physical piece of hardware, and is being migrated to this daemon.

2. Node was newly provisioned Out-Of-Band, and this is the net result of the provisioning.

In *neither* case is it a given that the Node should be able to provision another node (the effect of adding
the Net Key to the key ring). In neither case is it a given that the Node should be able to modify it's own
Config Server states (the effect of adding it's Device Key to the key ring).

However, if it *is* the case that one or more of these operations should be available to the Node, the
Application that performed the Import may call the ImportSubnet() and/or the ImportRemoteNode() methods. In
actuality, if this was the intent (particularily on a Node being migrated) a key-ring of some sort should have
existed on the other physical piece of hardware.

The point of this larger patch-set is to no longer assume that every Node has the ability to use it's own
network keys to provision other nodes, or use it's own Device Key to change it's own Config Server states.

Yes, that can still happen (as it can with non BlueZ nodes) but it should be by a deliberate mechanism, not as
a "time saving default".

Quoted 75 lines

Quoted 75 lines

but we also do not *forbid* any node from adding a key in it's possesion to the local key ring.

---
 mesh/manager.c |  5 -----
 mesh/node.c    | 15 ---------------
 2 files changed, 20 deletions(-)

mesh/manager.c +0 -1

index 501ec10fe..633597659 100644
@@ -282,7 +282,6 @@ static struct l_dbus_message
 *import_node_call(struct l_dbus *dbus,
 void *user_data)
 {
 struct mesh_node *node = user_data;
-struct mesh_net *net = node_get_net(node);
 struct l_dbus_message_iter iter_key;
 uint16_t primary;

uint8_t num_ele;

mesh/manager.c +0 -4

@@ -298,10 +297,6 @@ static struct l_dbus_message
 *import_node_call(struct l_dbus *dbus,
 return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
 "Bad device
 key");
 
-if (mesh_net_is_local_address(net, primary, num_ele))
-return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
-"Cannot overwrite local device
 key");
-

if (!keyring_put_remote_dev_key(node, primary, num_ele, key)) return dbus_error(msg, MESH_ERROR_FAILED, NULL);

mesh/node.c +0 -1

index 833377e99..af45a6130 100644
@@ -1681,7 +1681,6 @@ static void get_managed_objects_cb(struct
 l_dbus_message *msg, void *user_data)
 
 } else if (req->type == REQUEST_TYPE_IMPORT) {
 struct node_import *import = req->import;
-struct keyring_net_key net_key;
 
 if (!create_node_config(node, node->uuid))

goto fail;

mesh/node.c +0 -12

@@ -1692,23 +1691,9 @@ static void get_managed_objects_cb(struct
 l_dbus_message *msg, void *user_data)
 import->net_idx, import-
 > net_key))
 goto fail;
 
-memcpy(net_key.old_key, import->net_key, 16);
-net_key.net_idx = import->net_idx;
-if (import->flags.kr)
-net_key.phase = KEY_REFRESH_PHASE_TWO;
-else
-net_key.phase = KEY_REFRESH_PHASE_NONE;
-
 /* Initialize directory for storing keyring info */
 init_storage_dir(node);
 
-if (!keyring_put_remote_dev_key(node, import->unicast,
-num_ele, import-
 > dev_key))
-goto fail;
-
-if (!keyring_put_net_key(node, import->net_idx,

&net_key))

mesh/node.c +0 -2

-goto fail;
-
 } else {
 /* Callback for create node request */
 struct keyring_net_key net_key;

V3: By popular demand, the name "remote" is now used for both DevKeySend()
and DevKeyMessageReceived().

In DevKeySend(), setting remote == true means that the Key Ring *must* be
used to encrypt the outgoing message, and a failure will be returned if
the requested destination address does not include a device key in the
local key ring. For remote == false requests, the request will be rejected
if the destination is an element on the local node.

In DevKeyMessageReceived(), the remote boolean will be set == true if it
required the key ring to decrypot the message. If remote == false, this
means that the local nodes Device Key successfully decrypted the message,
and the message may be used to change or query privileged states.

Brian Gix (3):
mesh: Add local/remote bools to DevKey transactions
mesh: Use explicit Local vs Remote Device key usage

mesh: Fix Key Ring permissions for local nodes

 doc/mesh-api.txt | 17 ++++++++++++++---
 mesh/manager.c   |  5 -----
 mesh/model.c     | 11 +++++++----
 mesh/node.c      | 40 +++++++++++++++-------------------------
 4 files changed, 36 insertions(+), 37 deletions(-)

V3: By popular demand, the name "remote" is now used for both DevKeySend() and DevKeyMessageReceived().

In DevKeySend(), setting remote == true means that the Key Ring *must* be used to encrypt the outgoing message, and a failure will be returned if the requested destination address does not include a device key in the local key ring. For remote == false requests, the request will be rejected if the destination is an element on the local node.

In DevKeyMessageReceived(), the remote boolean will be set == true if it required the key ring to decrypot the message. If remote == false, this means that the local nodes Device Key successfully decrypted the message, and the message may be used to change or query privileged states.

Brian Gix (3):
mesh: Add local/remote bools to DevKey transactions
mesh: Use explicit Local vs Remote Device key usage
mesh: Fix Key Ring permissions for local nodes

 doc/mesh-api.txt | 17 ++++++++++++++---
 mesh/manager.c   |  5 -----
 mesh/model.c     | 11 +++++++----
 mesh/node.c      | 40 +++++++++++++++-------------------------
 4 files changed, 36 insertions(+), 37 deletions(-)