2019-12-05 17:52:16

by Alain Michaud

[permalink] [raw]
Subject: [RFC BlueZ v2] Adding support for blocking keys and mgmt tests.

Here's a newer version with most of your feedback addressed. Others
responses sent inline in the v1.

---
lib/mgmt.h | 17 +++++++++++++
src/adapter.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++-
unit/test-mgmt.c | 33 ++++++++++++++++++++++++
3 files changed, 114 insertions(+), 1 deletion(-)

diff --git a/lib/mgmt.h b/lib/mgmt.h
index 570dec997..3e2e26e68 100644
--- a/lib/mgmt.h
+++ b/lib/mgmt.h
@@ -583,6 +583,23 @@ struct mgmt_cp_set_phy_confguration {
uint32_t selected_phys;
} __packed;

+#define MGMT_OP_SET_BLOCKED_KEYS 0x0046
+
+#define HCI_BLOCKED_KEY_TYPE_LINKKEY 0x00
+#define HCI_BLOCKED_KEY_TYPE_LTK 0x01
+#define HCI_BLOCKED_KEY_TYPE_IRK 0x02
+
+struct mgmt_blocked_key_info {
+ uint8_t type;
+ uint8_t val[16];
+} __packed;
+
+struct mgmt_cp_set_blocked_keys {
+ uint16_t key_count;
+ struct mgmt_blocked_key_info keys[0];
+} __packed;
+#define MGMT_OP_SET_BLOCKED_KEYS_SIZE 0
+

#define MGMT_EV_CMD_COMPLETE 0x0001
struct mgmt_ev_cmd_complete {
diff --git a/src/adapter.c b/src/adapter.c
index cef25616f..f571961bb 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -99,10 +99,25 @@
#define DISTANCE_VAL_INVALID 0x7FFF
#define PATHLOSS_MAX 137

+/**
+ * These are known security keys that have been compromised.
+ * If this grows or there are needs to be platform specific, it is
+ * conceivable that these could be read from a config file.
+*/
+static const struct mgmt_blocked_key_info blocked_keys [] = {
+ // Google Titan Security Keys
+ { HCI_BLOCKED_KEY_TYPE_LTK, {0xbf, 0x01, 0xfb, 0x9d, 0x4e, 0xf3, 0xbc, 0x36,
+ 0xd8, 0x74, 0xf5, 0x39, 0x41, 0x38, 0x68, 0x4c}},
+ { HCI_BLOCKED_KEY_TYPE_IRK, {0xa5, 0x99, 0xba, 0xe4, 0xe1, 0x7c, 0xa6, 0x18,
+ 0x22, 0x8e, 0x07, 0x56, 0xb4, 0xe8, 0x5f, 0x01}},
+};
+
static DBusConnection *dbus_conn = NULL;

static bool kernel_conn_control = false;

+static bool kernel_blocked_keys_supported = false;
+
static GList *adapter_list = NULL;
static unsigned int adapter_remaining = 0;
static bool powering_down = false;
@@ -8568,6 +8583,40 @@ static bool set_static_addr(struct btd_adapter *adapter)
return false;
}

+static void set_blocked_keys_complete(uint8_t status, uint16_t length,
+ const void *param, void *user_data)
+{
+ struct btd_adapter *adapter = user_data;
+
+ if (status != MGMT_STATUS_SUCCESS) {
+ btd_error(adapter->dev_id,
+ "Failed to set blocked keys: %s (0x%02x)",
+ mgmt_errstr(status), status);
+ return;
+ }
+
+ DBG("Successfully set blocked keys for index %u", adapter->dev_id);
+}
+
+static bool set_blocked_keys(struct btd_adapter *adapter)
+{
+ uint8_t buffer[sizeof(struct mgmt_cp_set_blocked_keys) +
+ sizeof(blocked_keys)] = { 0 };
+ struct mgmt_cp_set_blocked_keys *cp =
+ (struct mgmt_cp_set_blocked_keys *)buffer;
+ int i;
+
+ cp->key_count = G_N_ELEMENTS(blocked_keys);
+ for (i = 0; i < cp->key_count; ++i) {
+ cp->keys[i].type = blocked_keys[i].type;
+ memcpy(cp->keys[i].val, blocked_keys[i].val, sizeof(cp->keys[i].val));
+ }
+
+ return mgmt_send(mgmt_master, MGMT_OP_SET_BLOCKED_KEYS, adapter->dev_id,
+ sizeof(buffer), buffer, set_blocked_keys_complete,
+ adapter, NULL);
+}
+
static void read_info_complete(uint8_t status, uint16_t length,
const void *param, void *user_data)
{
@@ -8795,6 +8844,12 @@ static void read_info_complete(uint8_t status, uint16_t length,

set_name(adapter, btd_adapter_get_name(adapter));

+ if (kernel_blocked_keys_supported && !set_blocked_keys(adapter)) {
+ btd_error(adapter->dev_id,
+ "Failed to set blocked keys for index %u", adapter->dev_id);
+ goto failed;
+ }
+
if (main_opts.pairable &&
!(adapter->current_settings & MGMT_SETTING_BONDABLE))
set_mode(adapter, MGMT_OP_SET_BONDABLE, 0x01);
@@ -8972,9 +9027,17 @@ static void read_commands_complete(uint8_t status, uint16_t length,
for (i = 0; i < num_commands; i++) {
uint16_t op = get_le16(rp->opcodes + i);

- if (op == MGMT_OP_ADD_DEVICE) {
+ switch (op){
+ case MGMT_OP_ADD_DEVICE:
DBG("enabling kernel-side connection control");
kernel_conn_control = true;
+ break;
+ case MGMT_OP_SET_BLOCKED_KEYS:
+ DBG("kernel supports the set_blocked_keys op");
+ kernel_blocked_keys_supported = true;
+ break;
+ default:
+ break;
}
}
}
diff --git a/unit/test-mgmt.c b/unit/test-mgmt.c
index c67678b9a..d73c03f61 100644
--- a/unit/test-mgmt.c
+++ b/unit/test-mgmt.c
@@ -256,6 +256,33 @@ static const struct command_test_data command_test_3 = {
.rsp_status = MGMT_STATUS_INVALID_INDEX,
};

+static const unsigned char invalid_key_buffer[] =
+ { 0x01, 0x02 };
+
+static const struct command_test_data command_test_set_blocked_keys1 = {
+ .opcode = MGMT_OP_SET_BLOCKED_KEYS,
+ .index = MGMT_INDEX_NONE,
+ .cmd_data = invalid_key_buffer,
+ .cmd_size = sizeof(invalid_key_buffer),
+ .rsp_data = NULL,
+ .rsp_size = 0,
+ .rsp_status = MGMT_STATUS_INVALID_PARAMS,
+};
+
+static const unsigned char valid_keys_buffer1[] =
+ { 0x01, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+ 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };
+
+static const struct command_test_data command_test_set_blocked_keys2 = {
+ .opcode = MGMT_OP_SET_BLOCKED_KEYS,
+ .index = MGMT_INDEX_NONE,
+ .cmd_data = valid_keys_buffer1,
+ .cmd_size = sizeof(valid_keys_buffer1),
+ .rsp_data = NULL,
+ .rsp_size = 0,
+ .rsp_status = MGMT_STATUS_SUCCESS,
+};
+
static const unsigned char event_index_added[] =
{ 0x04, 0x00, 0x01, 0x00, 0x00, 0x00 };

@@ -441,6 +468,12 @@ int main(int argc, char *argv[])
g_test_add_data_func("/mgmt/response/2", &command_test_3,
test_response);

+ g_test_add_data_func("/mgmt/command/set_blocked_keys1",
+ &command_test_set_blocked_keys1, test_command);
+
+ g_test_add_data_func("/mgmt/command/set_blocked_keys2",
+ &command_test_set_blocked_keys2, test_command);
+
g_test_add_data_func("/mgmt/event/1", &event_test_1, test_event);
g_test_add_data_func("/mgmt/event/2", &event_test_1, test_event2);

--
2.24.0.393.g34dc348eaf-goog


2019-12-08 10:00:54

by Marcel Holtmann

[permalink] [raw]
Subject: Re: [RFC BlueZ v2] Adding support for blocking keys and mgmt tests.

Hi Alain,

> Here's a newer version with most of your feedback addressed. Others
> responses sent inline in the v1.

commit message here please.

>
> ---
> lib/mgmt.h | 17 +++++++++++++
> src/adapter.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++-
> unit/test-mgmt.c | 33 ++++++++++++++++++++++++
> 3 files changed, 114 insertions(+), 1 deletion(-)

Comments for the reviewer here.

>
> diff --git a/lib/mgmt.h b/lib/mgmt.h
> index 570dec997..3e2e26e68 100644
> --- a/lib/mgmt.h
> +++ b/lib/mgmt.h
> @@ -583,6 +583,23 @@ struct mgmt_cp_set_phy_confguration {
> uint32_t selected_phys;
> } __packed;
>
> +#define MGMT_OP_SET_BLOCKED_KEYS 0x0046
> +
> +#define HCI_BLOCKED_KEY_TYPE_LINKKEY 0x00
> +#define HCI_BLOCKED_KEY_TYPE_LTK 0x01
> +#define HCI_BLOCKED_KEY_TYPE_IRK 0x02
> +
> +struct mgmt_blocked_key_info {
> + uint8_t type;
> + uint8_t val[16];
> +} __packed;
> +
> +struct mgmt_cp_set_blocked_keys {
> + uint16_t key_count;
> + struct mgmt_blocked_key_info keys[0];
> +} __packed;
> +#define MGMT_OP_SET_BLOCKED_KEYS_SIZE 0
> +
>
> #define MGMT_EV_CMD_COMPLETE 0x0001
> struct mgmt_ev_cmd_complete {
> diff --git a/src/adapter.c b/src/adapter.c
> index cef25616f..f571961bb 100644
> --- a/src/adapter.c
> +++ b/src/adapter.c
> @@ -99,10 +99,25 @@
> #define DISTANCE_VAL_INVALID 0x7FFF
> #define PATHLOSS_MAX 137
>
> +/**
> + * These are known security keys that have been compromised.
> + * If this grows or there are needs to be platform specific, it is
> + * conceivable that these could be read from a config file.
> +*/
> +static const struct mgmt_blocked_key_info blocked_keys [] = {
> + // Google Titan Security Keys

Lets use /* */ comment style here.

> + { HCI_BLOCKED_KEY_TYPE_LTK, {0xbf, 0x01, 0xfb, 0x9d, 0x4e, 0xf3, 0xbc, 0x36,
> + 0xd8, 0x74, 0xf5, 0x39, 0x41, 0x38, 0x68, 0x4c}},
> + { HCI_BLOCKED_KEY_TYPE_IRK, {0xa5, 0x99, 0xba, 0xe4, 0xe1, 0x7c, 0xa6, 0x18,
> + 0x22, 0x8e, 0x07, 0x56, 0xb4, 0xe8, 0x5f, 0x01}},

Lets indent both the same.

> +};
> +
> static DBusConnection *dbus_conn = NULL;
>
> static bool kernel_conn_control = false;
>
> +static bool kernel_blocked_keys_supported = false;
> +
> static GList *adapter_list = NULL;
> static unsigned int adapter_remaining = 0;
> static bool powering_down = false;
> @@ -8568,6 +8583,40 @@ static bool set_static_addr(struct btd_adapter *adapter)
> return false;
> }
>
> +static void set_blocked_keys_complete(uint8_t status, uint16_t length,
> + const void *param, void *user_data)
> +{
> + struct btd_adapter *adapter = user_data;
> +
> + if (status != MGMT_STATUS_SUCCESS) {
> + btd_error(adapter->dev_id,
> + "Failed to set blocked keys: %s (0x%02x)",
> + mgmt_errstr(status), status);
> + return;
> + }
> +
> + DBG("Successfully set blocked keys for index %u", adapter->dev_id);
> +}
> +
> +static bool set_blocked_keys(struct btd_adapter *adapter)
> +{
> + uint8_t buffer[sizeof(struct mgmt_cp_set_blocked_keys) +
> + sizeof(blocked_keys)] = { 0 };
> + struct mgmt_cp_set_blocked_keys *cp =
> + (struct mgmt_cp_set_blocked_keys *)buffer;
> + int i;
> +
> + cp->key_count = G_N_ELEMENTS(blocked_keys);
> + for (i = 0; i < cp->key_count; ++i) {
> + cp->keys[i].type = blocked_keys[i].type;
> + memcpy(cp->keys[i].val, blocked_keys[i].val, sizeof(cp->keys[i].val));
> + }
> +
> + return mgmt_send(mgmt_master, MGMT_OP_SET_BLOCKED_KEYS, adapter->dev_id,
> + sizeof(buffer), buffer, set_blocked_keys_complete,
> + adapter, NULL);
> +}
> +
> static void read_info_complete(uint8_t status, uint16_t length,
> const void *param, void *user_data)
> {
> @@ -8795,6 +8844,12 @@ static void read_info_complete(uint8_t status, uint16_t length,
>
> set_name(adapter, btd_adapter_get_name(adapter));
>

I would do this separate.

if (kernel_blocked_keys_supported) {
btd_warn(“Kernel doesn’t support blocking of vulnerable keys”);
goto failed;
}


> + if (kernel_blocked_keys_supported && !set_blocked_keys(adapter)) {
> + btd_error(adapter->dev_id,
> + "Failed to set blocked keys for index %u", adapter->dev_id);
> + goto failed;
> + }
> +
> if (main_opts.pairable &&
> !(adapter->current_settings & MGMT_SETTING_BONDABLE))
> set_mode(adapter, MGMT_OP_SET_BONDABLE, 0x01);
> @@ -8972,9 +9027,17 @@ static void read_commands_complete(uint8_t status, uint16_t length,
> for (i = 0; i < num_commands; i++) {
> uint16_t op = get_le16(rp->opcodes + i);
>
> - if (op == MGMT_OP_ADD_DEVICE) {
> + switch (op){
> + case MGMT_OP_ADD_DEVICE:
> DBG("enabling kernel-side connection control");
> kernel_conn_control = true;
> + break;
> + case MGMT_OP_SET_BLOCKED_KEYS:
> + DBG("kernel supports the set_blocked_keys op");
> + kernel_blocked_keys_supported = true;
> + break;
> + default:
> + break;
> }
> }
> }
> diff --git a/unit/test-mgmt.c b/unit/test-mgmt.c
> index c67678b9a..d73c03f61 100644
> --- a/unit/test-mgmt.c
> +++ b/unit/test-mgmt.c
> @@ -256,6 +256,33 @@ static const struct command_test_data command_test_3 = {
> .rsp_status = MGMT_STATUS_INVALID_INDEX,
> };
>
> +static const unsigned char invalid_key_buffer[] =
> + { 0x01, 0x02 };
> +
> +static const struct command_test_data command_test_set_blocked_keys1 = {
> + .opcode = MGMT_OP_SET_BLOCKED_KEYS,
> + .index = MGMT_INDEX_NONE,
> + .cmd_data = invalid_key_buffer,
> + .cmd_size = sizeof(invalid_key_buffer),
> + .rsp_data = NULL,
> + .rsp_size = 0,
> + .rsp_status = MGMT_STATUS_INVALID_PARAMS,
> +};
> +

Indentation is still off here.

> +static const unsigned char valid_keys_buffer1[] =
> + { 0x01, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
> + 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };
> +
> +static const struct command_test_data command_test_set_blocked_keys2 = {
> + .opcode = MGMT_OP_SET_BLOCKED_KEYS,
> + .index = MGMT_INDEX_NONE,
> + .cmd_data = valid_keys_buffer1,
> + .cmd_size = sizeof(valid_keys_buffer1),
> + .rsp_data = NULL,
> + .rsp_size = 0,
> + .rsp_status = MGMT_STATUS_SUCCESS,
> +};
> +
> static const unsigned char event_index_added[] =
> { 0x04, 0x00, 0x01, 0x00, 0x00, 0x00 };
>
> @@ -441,6 +468,12 @@ int main(int argc, char *argv[])
> g_test_add_data_func("/mgmt/response/2", &command_test_3,
> test_response);
>
> + g_test_add_data_func("/mgmt/command/set_blocked_keys1",
> + &command_test_set_blocked_keys1, test_command);
> +
> + g_test_add_data_func("/mgmt/command/set_blocked_keys2",
> + &command_test_set_blocked_keys2, test_command);
> +
> g_test_add_data_func("/mgmt/event/1", &event_test_1, test_event);
> g_test_add_data_func("/mgmt/event/2", &event_test_1, test_event2);

Regards

Marcel