2019-07-03 11:42:53

by Michał Lowas-Rzechonek

[permalink] [raw]
Subject: [PATCH BlueZ v4 0/3] Add possibility to use remote device keys

+Fix build/checkpatch errors
+Remove unused APP_IDX_NET and APP_IDX_ANY
+Fix handling of incoming packets marked with APP_IDX_DEV_REMOTE


This patchset adds support for sending and receiving messages encrypted
with remote device keys.

This plugs a 'leak' in the API where it was possible to exchange such
messages using Send()/MessageReceived() API by using 0x7fff app key
index.

In order to allow the application to receive responses from a local
Config Server model, messages originating from a local node and
encrypted using local device key are also forwarded to the application
via D-Bus (assuming they were not handled by one of internal models).

Michał Lowas-Rzechonek (3):
mesh: Split APP_IDX_DEV into APP_IDX_DEV_LOCAL and APP_IDX_DEV_REMOTE
mesh: Implement DevKeySend() method on Node interface
mesh: Handle messages encrypted with a remote device key
*** BLURB HERE ***

Michał Lowas-Rzechonek (3):
mesh: Split APP_IDX_DEV into APP_IDX_DEV_LOCAL and APP_IDX_DEV_REMOTE
mesh: Implement DevKeySend() method on Node interface
mesh: Handle messages encrypted with a remote device key

mesh/cfgmod-server.c | 15 +++----
mesh/model.c | 98 +++++++++++++++++++++++++++++++++++++-------
mesh/net.h | 8 ++--
mesh/node.c | 59 +++++++++++++++++++++++++-
4 files changed, 152 insertions(+), 28 deletions(-)

--
2.19.1


2019-07-03 11:42:53

by Michał Lowas-Rzechonek

[permalink] [raw]
Subject: [PATCH BlueZ v4 2/3] mesh: Implement DevKeySend() method on Node interface

This patch implements D-Bus DevKeySend() method of org.bluez.mesh.Node1
interface, allowing the application to send messages encrypted using
a known remote device key.

At the moment the call ignores net_index argument and sends messages
using the primary subnet.

Also, it's no longer possible to use 'magic' key_index value 0x7fff
(denoting local device key) when calling regular Send(). Applications
should use DevKeySend() instead.
---
mesh/model.c | 9 +++++++-
mesh/node.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/mesh/model.c b/mesh/model.c
index 598615c5e..aae913d92 100644
--- a/mesh/model.c
+++ b/mesh/model.c
@@ -39,6 +39,7 @@
#include "mesh/dbus.h"
#include "mesh/util.h"
#include "mesh/model.h"
+#include "mesh/keyring.h"

/* Divide and round to ceiling (up) to calculate segment count */
#define CEILDIV(val, div) (((val) + (div) - 1) / (div))
@@ -941,6 +942,7 @@ bool mesh_model_send(struct mesh_node *node, uint16_t src, uint16_t target,
const void *msg, uint16_t msg_len)
{
uint8_t key_id;
+ uint8_t dev_key[16];
const uint8_t *key;

/* print_packet("Mod Tx", msg, msg_len); */
@@ -959,7 +961,12 @@ bool mesh_model_send(struct mesh_node *node, uint16_t src, uint16_t target,
if (!key)
return false;

- l_debug("(%x)", app_idx);
+ key_id = APP_ID_DEV;
+ } else if (app_idx == APP_IDX_DEV_REMOTE) {
+ if (!keyring_get_remote_dev_key(node, target, dev_key))
+ return false;
+
+ key = dev_key;
key_id = APP_ID_DEV;
} else {
key = appkey_get_key(node_get_net(node), app_idx, &key_id);
diff --git a/mesh/node.c b/mesh/node.c
index 1dcb74b4f..7133f5b2d 100644
--- a/mesh/node.c
+++ b/mesh/node.c
@@ -1974,7 +1974,11 @@ static struct l_dbus_message *send_call(struct l_dbus *dbus,
return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
"Incorrect data");

- if (!mesh_model_send(node, src, dst, app_idx,
+ if ((app_idx & APP_IDX_MASK) != app_idx)
+ return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
+ "Invalid key_index");
+
+ if (!mesh_model_send(node, src, dst, app_idx & APP_IDX_MASK,
mesh_net_get_default_ttl(node->net), data, len))
return dbus_error(msg, MESH_ERROR_FAILED, NULL);

@@ -1984,6 +1988,53 @@ static struct l_dbus_message *send_call(struct l_dbus *dbus,
return reply;
}

+static struct l_dbus_message *dev_key_send_call(struct l_dbus *dbus,
+ struct l_dbus_message *msg,
+ void *user_data)
+{
+ struct mesh_node *node = user_data;
+ const char *sender, *ele_path;
+ struct l_dbus_message_iter iter_data;
+ struct node_element *ele;
+ uint16_t dst, net_idx, src;
+ uint8_t *data;
+ uint32_t len;
+ struct l_dbus_message *reply;
+
+ l_debug("DevKeySend");
+
+ sender = l_dbus_message_get_sender(msg);
+
+ 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))
+ return dbus_error(msg, MESH_ERROR_INVALID_ARGS, NULL);
+
+ ele = l_queue_find(node->elements, match_element_path, ele_path);
+ if (!ele)
+ return dbus_error(msg, MESH_ERROR_NOT_FOUND,
+ "Element not found");
+
+ src = node_get_primary(node) + ele->idx;
+
+ if (!l_dbus_message_iter_get_fixed_array(&iter_data, &data, &len) ||
+ !len || len > MESH_MAX_ACCESS_PAYLOAD)
+ return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
+ "Incorrect data");
+
+ /* TODO: use net_idx */
+ if (!mesh_model_send(node, src, dst, APP_IDX_DEV_REMOTE,
+ mesh_net_get_default_ttl(node->net), data, len))
+ return dbus_error(msg, MESH_ERROR_NOT_FOUND, NULL);
+
+ reply = l_dbus_message_new_method_return(msg);
+ l_dbus_message_set_arguments(reply, "");
+
+ return reply;
+}
+
static struct l_dbus_message *publish_call(struct l_dbus *dbus,
struct l_dbus_message *msg,
void *user_data)
@@ -2089,7 +2140,11 @@ static void setup_node_interface(struct l_dbus_interface *iface)
{
l_dbus_interface_method(iface, "Send", 0, send_call, "", "oqqay",
"element_path", "destination",
- "key", "data");
+ "key_index", "data");
+ l_dbus_interface_method(iface, "DevKeySend", 0, dev_key_send_call,
+ "", "oqqay", "element_path",
+ "destination", "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,
--
2.19.1

2019-07-03 11:42:53

by Michał Lowas-Rzechonek

[permalink] [raw]
Subject: [PATCH BlueZ v4 3/3] mesh: Handle messages encrypted with a remote device key

This adds ability to receive messages encrypted using known remote
device key. Such a key must be added to the node's keyring using
ImportRemoteNode() method of org.bluez.mesh.Management1 interface.

Decrypted messages are then forwarded to the application using
DevKeyMessageReceived() D-Bus API.

Also, messages originating from a local node and encrypted using local
device key are forwarde to the application as well, if they weren't
handled by internal model. This allows e.g. receiving status messages
from a local Config Server in the application.
---
mesh/model.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 63 insertions(+), 6 deletions(-)

diff --git a/mesh/model.c b/mesh/model.c
index aae913d92..0ea45987f 100644
--- a/mesh/model.c
+++ b/mesh/model.c
@@ -308,7 +308,7 @@ static void forward_model(void *a, void *b)

l_debug("model %8.8x with idx %3.3x", mod->id, fwd->idx);

- if (fwd->idx != APP_IDX_DEV_LOCAL &&
+ if (fwd->idx != APP_IDX_DEV_LOCAL && fwd->idx != APP_IDX_DEV_REMOTE &&
!has_binding(mod->bindings, fwd->idx))
return;

@@ -359,16 +359,25 @@ static int dev_packet_decrypt(struct mesh_node *node, const uint8_t *data,
uint16_t dst, uint8_t key_id, uint32_t seq,
uint32_t iv_idx, uint8_t *out)
{
+ uint8_t dev_key[16];
const uint8_t *key;

key = node_get_device_key(node);
if (!key)
- return false;
+ return -1;

if (mesh_crypto_payload_decrypt(NULL, 0, data, size, szmict, src,
dst, key_id, seq, iv_idx, out, key))
return APP_IDX_DEV_LOCAL;

+ if (!keyring_get_remote_dev_key(node, src, dev_key))
+ return -1;
+
+ key = dev_key;
+ if (mesh_crypto_payload_decrypt(NULL, 0, data, size, szmict, src,
+ dst, key_id, seq, iv_idx, out, key))
+ return APP_IDX_DEV_REMOTE;
+
return -1;
}

@@ -695,6 +704,47 @@ static int add_sub(struct mesh_net *net, struct mesh_model *mod,
return MESH_STATUS_SUCCESS;
}

+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)
+{
+ struct l_dbus *dbus = dbus_get_bus();
+ struct l_dbus_message *msg;
+ struct l_dbus_message_builder *builder;
+ const char *owner;
+ const char *path;
+
+ owner = node_get_owner(node);
+ path = node_get_element_path(node, ele_idx);
+ if (!path || !owner)
+ return;
+
+ l_debug("Send \"DevKeyMessageReceived\"");
+
+ msg = l_dbus_message_new_method_call(dbus, owner, path,
+ MESH_ELEMENT_INTERFACE,
+ "DevKeyMessageReceived");
+
+ builder = l_dbus_message_builder_new(msg);
+
+ if (!l_dbus_message_builder_append_basic(builder, 'q', &src))
+ goto error;
+
+ if (!l_dbus_message_builder_append_basic(builder, 'q', &net_idx))
+ goto error;
+
+ if (!dbus_append_byte_array(builder, data, size))
+ goto error;
+
+ if (!l_dbus_message_builder_finalize(builder))
+ goto error;
+
+ l_dbus_send(dbus, msg);
+
+error:
+ l_dbus_message_builder_destroy(builder);
+}
+
static void send_msg_rcvd(struct mesh_node *node, uint8_t ele_idx, bool is_sub,
uint16_t src, uint16_t key_idx,
uint16_t size, const uint8_t *data)
@@ -843,10 +893,17 @@ bool mesh_model_rx(struct mesh_node *node, bool szmict, uint32_t seq0,
* Cycle through external models if the message has not been
* handled by internal models
*/
- if (forward.has_dst && !forward.done)
- send_msg_rcvd(node, i, is_subscription, src,
- forward.idx, forward.size,
- forward.data);
+ if (forward.has_dst && !forward.done) {
+ if ((decrypt_idx & APP_IDX_MASK) == decrypt_idx)
+ send_msg_rcvd(node, i, is_subscription, src,
+ forward.idx, forward.size,
+ forward.data);
+ else if (decrypt_idx == APP_IDX_DEV_REMOTE ||
+ (decrypt_idx == APP_IDX_DEV_LOCAL &&
+ mesh_net_is_local_address(net, src)))
+ send_dev_key_msg_rcvd(node, i, src, 0,
+ forward.size, forward.data);
+ }

/*
* Either the message has been processed internally or
--
2.19.1

2019-07-03 11:42:53

by Michał Lowas-Rzechonek

[permalink] [raw]
Subject: [PATCH BlueZ v4 1/3] mesh: Split APP_IDX_DEV into APP_IDX_DEV_LOCAL and APP_IDX_DEV_REMOTE

This is needed to distinguish incoming messages encrypted using a device
key: if the key is local, the message can be forwarded to internal
models. If the key is a known remote one, it will be forwarded to the
application via DevKeyMessageReceived() API.
---
mesh/cfgmod-server.c | 15 ++++++++-------
mesh/model.c | 22 +++++++++++++---------
mesh/net.h | 8 ++++----
3 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/mesh/cfgmod-server.c b/mesh/cfgmod-server.c
index 634ac006b..a849b5e99 100644
--- a/mesh/cfgmod-server.c
+++ b/mesh/cfgmod-server.c
@@ -69,7 +69,8 @@ static void send_pub_status(struct mesh_node *node, uint16_t src, uint16_t dst,
n += 2;
}

- mesh_model_send(node, dst, src, APP_IDX_DEV, DEFAULT_TTL, msg, n);
+ mesh_model_send(node, dst, src, APP_IDX_DEV_LOCAL, DEFAULT_TTL,
+ msg, n);
}

static bool config_pub_get(struct mesh_node *node, uint16_t src, uint16_t dst,
@@ -254,7 +255,7 @@ static void send_sub_status(struct mesh_node *node, uint16_t src, uint16_t dst,
n += 2;
}

- mesh_model_send(node, dst, src, APP_IDX_DEV, DEFAULT_TTL, msg, n);
+ mesh_model_send(node, dst, src, APP_IDX_DEV_LOCAL, DEFAULT_TTL, msg, n);
}

static bool config_sub_get(struct mesh_node *node, uint16_t src, uint16_t dst,
@@ -312,7 +313,7 @@ static bool config_sub_get(struct mesh_node *node, uint16_t src, uint16_t dst,

*msg_status = (uint8_t) status;

- mesh_model_send(node, dst, src, APP_IDX_DEV, DEFAULT_TTL, msg, n);
+ mesh_model_send(node, dst, src, APP_IDX_DEV_LOCAL, DEFAULT_TTL, msg, n);
return true;
}

@@ -487,7 +488,7 @@ static void send_model_app_status(struct mesh_node *node, uint16_t src,
l_put_le16(id, msg + n);
n += 2;

- mesh_model_send(node, dst, src, APP_IDX_DEV, DEFAULT_TTL, msg, n);
+ mesh_model_send(node, dst, src, APP_IDX_DEV_LOCAL, DEFAULT_TTL, msg, n);
}

static void model_app_list(struct mesh_node *node, uint16_t src, uint16_t dst,
@@ -540,7 +541,7 @@ static void model_app_list(struct mesh_node *node, uint16_t src, uint16_t dst,

if (result >= 0) {
*status = result;
- mesh_model_send(node, dst, src, APP_IDX_DEV, DEFAULT_TTL,
+ mesh_model_send(node, dst, src, APP_IDX_DEV_LOCAL, DEFAULT_TTL,
msg, n);
}

@@ -758,7 +759,7 @@ static bool cfg_srv_pkt(uint16_t src, uint32_t dst,
uint16_t interval;
uint16_t n;

- if (idx != APP_IDX_DEV)
+ if (idx != APP_IDX_DEV_LOCAL)
return false;

if (mesh_model_opcode_get(pkt, size, &opcode, &n)) {
@@ -1259,7 +1260,7 @@ static bool cfg_srv_pkt(uint16_t src, uint32_t dst,
if (n) {
/* print_packet("App Tx", long_msg ? long_msg : msg, n); */
mesh_model_send(node, unicast, src,
- APP_IDX_DEV, DEFAULT_TTL,
+ APP_IDX_DEV_LOCAL, DEFAULT_TTL,
long_msg ? long_msg : msg, n);
}
l_free(long_msg);
diff --git a/mesh/model.c b/mesh/model.c
index 7401dcecb..598615c5e 100644
--- a/mesh/model.c
+++ b/mesh/model.c
@@ -306,7 +306,9 @@ static void forward_model(void *a, void *b)
bool result;

l_debug("model %8.8x with idx %3.3x", mod->id, fwd->idx);
- if (fwd->idx != APP_IDX_DEV && !has_binding(mod->bindings, fwd->idx))
+
+ if (fwd->idx != APP_IDX_DEV_LOCAL &&
+ !has_binding(mod->bindings, fwd->idx))
return;

dst = fwd->dst;
@@ -356,15 +358,15 @@ static int dev_packet_decrypt(struct mesh_node *node, const uint8_t *data,
uint16_t dst, uint8_t key_id, uint32_t seq,
uint32_t iv_idx, uint8_t *out)
{
- const uint8_t *dev_key;
+ const uint8_t *key;

- dev_key = node_get_device_key(node);
- if (!dev_key)
+ key = node_get_device_key(node);
+ if (!key)
return false;

if (mesh_crypto_payload_decrypt(NULL, 0, data, size, szmict, src,
- dst, key_id, seq, iv_idx, out, dev_key))
- return APP_IDX_DEV;
+ dst, key_id, seq, iv_idx, out, key))
+ return APP_IDX_DEV_LOCAL;

return -1;
}
@@ -952,7 +954,7 @@ bool mesh_model_send(struct mesh_node *node, uint16_t src, uint16_t target,
if (IS_UNASSIGNED(target))
return false;

- if (app_idx == APP_IDX_DEV) {
+ if (app_idx == APP_IDX_DEV_LOCAL) {
key = node_get_device_key(node);
if (!key)
return false;
@@ -1381,12 +1383,14 @@ struct mesh_model *mesh_model_setup(struct mesh_node *node, uint8_t ele_idx,
if (ele_idx != PRIMARY_ELE_IDX)
return NULL;

- l_queue_push_head(mod->bindings, L_UINT_TO_PTR(APP_IDX_DEV));
+ l_queue_push_head(mod->bindings,
+ L_UINT_TO_PTR(APP_IDX_DEV_LOCAL));
return mod;
}

if (db_mod->id == CONFIG_CLI_MODEL) {
- l_queue_push_head(mod->bindings, L_UINT_TO_PTR(APP_IDX_DEV));
+ l_queue_push_head(mod->bindings,
+ L_UINT_TO_PTR(APP_IDX_DEV_LOCAL));
return mod;
}

diff --git a/mesh/net.h b/mesh/net.h
index f19024766..8848e6df0 100644
--- a/mesh/net.h
+++ b/mesh/net.h
@@ -37,10 +37,10 @@ struct mesh_node;
#define SEQ_MASK 0xffffff

#define CREDFLAG_MASK 0x1000
-#define APP_IDX_MASK 0x0fff
-#define APP_IDX_DEV 0x7fff
-#define APP_IDX_ANY 0x8000
-#define APP_IDX_NET 0xffff
+
+#define APP_IDX_MASK 0x0fff
+#define APP_IDX_DEV_REMOTE 0x6fff
+#define APP_IDX_DEV_LOCAL 0x7fff

#define NET_IDX_INVALID 0xffff
#define NET_NID_INVALID 0xff
--
2.19.1

2019-07-03 15:39:11

by Gix, Brian

[permalink] [raw]
Subject: Re: [PATCH BlueZ v4 2/3] mesh: Implement DevKeySend() method on Node interface

On Wed, 2019-07-03 at 13:42 +0200, Michał Lowas-Rzechonek wrote:
> This patch implements D-Bus DevKeySend() method of org.bluez.mesh.Node1
> interface, allowing the application to send messages encrypted using
> a known remote device key.
>
> At the moment the call ignores net_index argument and sends messages
> using the primary subnet.
>
> Also, it's no longer possible to use 'magic' key_index value 0x7fff
> (denoting local device key) when calling regular Send(). Applications
> should use DevKeySend() instead.
> ---
> mesh/model.c | 9 +++++++-
> mesh/node.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++--
> 2 files changed, 65 insertions(+), 3 deletions(-)
>
> diff --git a/mesh/model.c b/mesh/model.c
> index 598615c5e..aae913d92 100644
> --- a/mesh/model.c
> +++ b/mesh/model.c
> @@ -39,6 +39,7 @@
> #include "mesh/dbus.h"
> #include "mesh/util.h"
> #include "mesh/model.h"
> +#include "mesh/keyring.h"
>
> /* Divide and round to ceiling (up) to calculate segment count */
> #define CEILDIV(val, div) (((val) + (div) - 1) / (div))
> @@ -941,6 +942,7 @@ bool mesh_model_send(struct mesh_node *node, uint16_t src, uint16_t target,
> const void *msg, uint16_t msg_len)
> {
> uint8_t key_id;
> + uint8_t dev_key[16];
> const uint8_t *key;
>
> /* print_packet("Mod Tx", msg, msg_len); */
> @@ -959,7 +961,12 @@ bool mesh_model_send(struct mesh_node *node, uint16_t src, uint16_t target,
> if (!key)
> return false;
>
> - l_debug("(%x)", app_idx);
> + key_id = APP_ID_DEV;
> + } else if (app_idx == APP_IDX_DEV_REMOTE) {
> + if (!keyring_get_remote_dev_key(node, target, dev_key))
> + return false;
> +
> + key = dev_key;
> key_id = APP_ID_DEV;
> } else {
> key = appkey_get_key(node_get_net(node), app_idx, &key_id);
> diff --git a/mesh/node.c b/mesh/node.c
> index 1dcb74b4f..7133f5b2d 100644
> --- a/mesh/node.c
> +++ b/mesh/node.c
> @@ -1974,7 +1974,11 @@ static struct l_dbus_message *send_call(struct l_dbus *dbus,
> return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
> "Incorrect data");
>
> - if (!mesh_model_send(node, src, dst, app_idx,
> + if ((app_idx & APP_IDX_MASK) != app_idx)
> + return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
> + "Invalid key_index");
> +
> + if (!mesh_model_send(node, src, dst, app_idx & APP_IDX_MASK,
> mesh_net_get_default_ttl(node->net), data, len))
> return dbus_error(msg, MESH_ERROR_FAILED, NULL);
>
> @@ -1984,6 +1988,53 @@ static struct l_dbus_message *send_call(struct l_dbus *dbus,
> return reply;
> }
>
> +static struct l_dbus_message *dev_key_send_call(struct l_dbus *dbus,
> + struct l_dbus_message *msg,
> + void *user_data)
> +{
> + struct mesh_node *node = user_data;
> + const char *sender, *ele_path;
> + struct l_dbus_message_iter iter_data;
> + struct node_element *ele;
> + uint16_t dst, net_idx, src;
> + uint8_t *data;
> + uint32_t len;
> + struct l_dbus_message *reply;
> +
> + l_debug("DevKeySend");
> +
> + sender = l_dbus_message_get_sender(msg);
> +
> + 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))
> + return dbus_error(msg, MESH_ERROR_INVALID_ARGS, NULL);
> +
> + ele = l_queue_find(node->elements, match_element_path, ele_path);
> + if (!ele)
> + return dbus_error(msg, MESH_ERROR_NOT_FOUND,
> + "Element not found");
> +
> + src = node_get_primary(node) + ele->idx;
> +
> + if (!l_dbus_message_iter_get_fixed_array(&iter_data, &data, &len) ||
> + !len || len > MESH_MAX_ACCESS_PAYLOAD)
> + return dbus_error(msg, MESH_ERROR_INVALID_ARGS,
> + "Incorrect data");
> +
> + /* TODO: use net_idx */
> + if (!mesh_model_send(node, src, dst, APP_IDX_DEV_REMOTE,
> + mesh_net_get_default_ttl(node->net), data, len))
> + return dbus_error(msg, MESH_ERROR_NOT_FOUND, NULL);
> +
> + reply = l_dbus_message_new_method_return(msg);
> + l_dbus_message_set_arguments(reply, "");
> +
> + return reply;

This is technically correct, but if I apply, I will be deleting replay local and reducing the above three lines
to just:

return l_dbus_message_new_method_return(msg);

which is our prefered standard of successful returns with no parameters.



> +}
> +
> static struct l_dbus_message *publish_call(struct l_dbus *dbus,
> struct l_dbus_message *msg,
> void *user_data)
> @@ -2089,7 +2140,11 @@ static void setup_node_interface(struct l_dbus_interface *iface)
> {
> l_dbus_interface_method(iface, "Send", 0, send_call, "", "oqqay",
> "element_path", "destination",
> - "key", "data");
> + "key_index", "data");
> + l_dbus_interface_method(iface, "DevKeySend", 0, dev_key_send_call,
> + "", "oqqay", "element_path",
> + "destination", "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,

2019-07-03 15:46:05

by Gix, Brian

[permalink] [raw]
Subject: Re: [PATCH BlueZ v4 3/3] mesh: Handle messages encrypted with a remote device key

On Wed, 2019-07-03 at 13:42 +0200, Michał Lowas-Rzechonek wrote:
> This adds ability to receive messages encrypted using known remote
> device key. Such a key must be added to the node's keyring using
> ImportRemoteNode() method of org.bluez.mesh.Management1 interface.
>
> Decrypted messages are then forwarded to the application using
> DevKeyMessageReceived() D-Bus API.
>
> Also, messages originating from a local node and encrypted using local
> device key are forwarde to the application as well, if they weren't
> handled by internal model. This allows e.g. receiving status messages
> from a local Config Server in the application.
> ---
> mesh/model.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 63 insertions(+), 6 deletions(-)
>
> diff --git a/mesh/model.c b/mesh/model.c
> index aae913d92..0ea45987f 100644
> --- a/mesh/model.c
> +++ b/mesh/model.c
> @@ -308,7 +308,7 @@ static void forward_model(void *a, void *b)
>
> l_debug("model %8.8x with idx %3.3x", mod->id, fwd->idx);
>
> - if (fwd->idx != APP_IDX_DEV_LOCAL &&
> + if (fwd->idx != APP_IDX_DEV_LOCAL && fwd->idx != APP_IDX_DEV_REMOTE &&
> !has_binding(mod->bindings, fwd->idx))
> return;
>
> @@ -359,16 +359,25 @@ static int dev_packet_decrypt(struct mesh_node *node, const uint8_t *data,
> uint16_t dst, uint8_t key_id, uint32_t seq,
> uint32_t iv_idx, uint8_t *out)
> {
> + uint8_t dev_key[16];
> const uint8_t *key;
>
> key = node_get_device_key(node);
> if (!key)
> - return false;
> + return -1;
>
> if (mesh_crypto_payload_decrypt(NULL, 0, data, size, szmict, src,
> dst, key_id, seq, iv_idx, out, key))
> return APP_IDX_DEV_LOCAL;
>
> + if (!keyring_get_remote_dev_key(node, src, dev_key))
> + return -1;
> +
> + key = dev_key;
> + if (mesh_crypto_payload_decrypt(NULL, 0, data, size, szmict, src,
> + dst, key_id, seq, iv_idx, out, key))
> + return APP_IDX_DEV_REMOTE;
> +
> return -1;
> }
>
> @@ -695,6 +704,47 @@ static int add_sub(struct mesh_net *net, struct mesh_model *mod,
> return MESH_STATUS_SUCCESS;
> }
>
> +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)
> +{
> + struct l_dbus *dbus = dbus_get_bus();
> + struct l_dbus_message *msg;
> + struct l_dbus_message_builder *builder;
> + const char *owner;
> + const char *path;
> +
> + owner = node_get_owner(node);
> + path = node_get_element_path(node, ele_idx);
> + if (!path || !owner)
> + return;
> +
> + l_debug("Send \"DevKeyMessageReceived\"");
> +
> + msg = l_dbus_message_new_method_call(dbus, owner, path,
> + MESH_ELEMENT_INTERFACE,
> + "DevKeyMessageReceived");
> +
> + builder = l_dbus_message_builder_new(msg);
> +
> + if (!l_dbus_message_builder_append_basic(builder, 'q', &src))
> + goto error;
> +
> + if (!l_dbus_message_builder_append_basic(builder, 'q', &net_idx))
> + goto error;
> +
> + if (!dbus_append_byte_array(builder, data, size))
> + goto error;
> +
> + if (!l_dbus_message_builder_finalize(builder))
> + goto error;
> +
> + l_dbus_send(dbus, msg);
> +
> +error:
> + l_dbus_message_builder_destroy(builder);

I think there is a potential memory leak, not just here but in the other methods that use this technique to
construct method calls to the App (sorry I did not catch this in earlier situations)

To get to the error label, we will have a "msg" which is never sent or freed... I think here, and every where
else where we have a potentially failed builder, We need to call l_dbus_message_unref(msg) if we don't end up
sending the msg.

But I would like Inga's opinion on this judgement on this as well.

Otherwise, I think I will be ready to apply this whole patch-set.


> +}
> +
> static void send_msg_rcvd(struct mesh_node *node, uint8_t ele_idx, bool is_sub,
> uint16_t src, uint16_t key_idx,
> uint16_t size, const uint8_t *data)
> @@ -843,10 +893,17 @@ bool mesh_model_rx(struct mesh_node *node, bool szmict, uint32_t seq0,
> * Cycle through external models if the message has not been
> * handled by internal models
> */
> - if (forward.has_dst && !forward.done)
> - send_msg_rcvd(node, i, is_subscription, src,
> - forward.idx, forward.size,
> - forward.data);
> + if (forward.has_dst && !forward.done) {
> + if ((decrypt_idx & APP_IDX_MASK) == decrypt_idx)
> + send_msg_rcvd(node, i, is_subscription, src,
> + forward.idx, forward.size,
> + forward.data);
> + else if (decrypt_idx == APP_IDX_DEV_REMOTE ||
> + (decrypt_idx == APP_IDX_DEV_LOCAL &&
> + mesh_net_is_local_address(net, src)))
> + send_dev_key_msg_rcvd(node, i, src, 0,
> + forward.size, forward.data);
> + }
>
> /*
> * Either the message has been processed internally or