DO NOT MERGE Don't persist bonds using sample LTK
Test: compilation, manual testing
Bug: 128843052
Merged-In: I52fd484d42bf87e96dbc9e6456090f231ed48111
Change-Id: I52fd484d42bf87e96dbc9e6456090f231ed48111
diff --git a/btif/src/btif_storage.cc b/btif/src/btif_storage.cc
index c8dfcde..d45790b 100644
--- a/btif/src/btif_storage.cc
+++ b/btif/src/btif_storage.cc
@@ -35,6 +35,7 @@
#include <alloca.h>
#include <base/logging.h>
#include <ctype.h>
+#include <log/log.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
@@ -779,6 +780,46 @@
return ret ? BT_STATUS_SUCCESS : BT_STATUS_FAIL;
}
+/* Some devices hardcode sample LTK value from spec, instead of generating one.
+ * Treat such devices as insecure, and remove such bonds when bluetooth
+ * restarts. Removing them after disconnection is handled separately.
+ *
+ * We still allow such devices to bond in order to give the user a chance to
+ * update firmware.
+ */
+static void remove_devices_with_sample_ltk() {
+ std::vector<bt_bdaddr_t> bad_ltk;
+ for (const btif_config_section_iter_t* iter = btif_config_section_begin();
+ iter != btif_config_section_end();
+ iter = btif_config_section_next(iter)) {
+ const char* name = btif_config_section_name(iter);
+ if (!string_is_bdaddr(name)) {
+ continue;
+ }
+
+ bt_bdaddr_t bda;
+ string_to_bdaddr(name, &bda);
+
+ tBTA_LE_KEY_VALUE key;
+ memset(&key, 0, sizeof(key));
+
+ if (btif_storage_get_ble_bonding_key(&bda, BTIF_DM_LE_KEY_PENC, (char*)&key,
+ sizeof(tBTM_LE_PENC_KEYS)) ==
+ BT_STATUS_SUCCESS) {
+ if (is_sample_ltk(key.penc_key.ltk)) {
+ bad_ltk.push_back(bda);
+ }
+ }
+ }
+
+ for (bt_bdaddr_t address : bad_ltk) {
+ android_errorWriteLog(0x534e4554, "128437297");
+ LOG(ERROR) << __func__ << ": removing bond to device using test TLK";
+
+ btif_storage_remove_bonded_device(&address);
+ }
+}
+
/*******************************************************************************
*
* Function btif_storage_load_bonded_devices
@@ -806,6 +847,8 @@
bt_uuid_t remote_uuids[BT_MAX_NUM_UUIDS];
bt_status_t status;
+ remove_devices_with_sample_ltk();
+
btif_in_fetch_bonded_devices(&bonded_devices, 1);
/* Now send the adapter_properties_cb with all adapter_properties */
diff --git a/stack/btm/btm_sec.cc b/stack/btm/btm_sec.cc
index 2c18a19..bcefa2a 100644
--- a/stack/btm/btm_sec.cc
+++ b/stack/btm/btm_sec.cc
@@ -24,6 +24,7 @@
#define LOG_TAG "bt_btm_sec"
+#include <log/log.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
@@ -42,6 +43,8 @@
#include "gatt_int.h"
+#include "bta/dm/bta_dm_int.h"
+
#define BTM_SEC_MAX_COLLISION_DELAY (5000)
extern fixed_queue_t* btu_general_alarm_queue;
@@ -4673,6 +4676,19 @@
BTM_SEC_ROLE_SWITCHED | BTM_SEC_16_DIGIT_PIN_AUTHED);
}
+ /* Some devices hardcode sample LTK value from spec, instead of generating
+ * one. Treat such devices as insecure, and remove such bonds on
+ * disconnection.
+ */
+ if (is_sample_ltk(p_dev_rec->ble.keys.pltk)) {
+ android_errorWriteLog(0x534e4554, "128437297");
+ LOG(INFO) << __func__ << " removing bond to device that used sample LTK";
+
+ tBTA_DM_MSG p_data;
+ memcpy(p_data.remove_dev.bd_addr, p_dev_rec->bd_addr, BD_ADDR_LEN);
+ bta_dm_remove_device(&p_data);
+ }
+
if (p_dev_rec->sec_state == BTM_SEC_STATE_DISCONNECTING_BOTH) {
p_dev_rec->sec_state = (transport == BT_TRANSPORT_LE)
? BTM_SEC_STATE_DISCONNECTING
diff --git a/stack/include/bt_types.h b/stack/include/bt_types.h
index da0baac..c41fd3d 100644
--- a/stack/include/bt_types.h
+++ b/stack/include/bt_types.h
@@ -21,6 +21,7 @@
#include <stdbool.h>
#include <stdint.h>
+#include <string.h>
#ifndef FALSE
#define FALSE false
@@ -1012,4 +1013,13 @@
*
******************************************************************************/
static inline void bdsetany(BD_ADDR a) { bdcpy(a, bd_addr_any); }
+
+static inline bool is_sample_ltk(const BT_OCTET16 ltk) {
+ /* Sample LTK from BT Spec 5.1 | Vol 6, Part C 1
+ * 0x4C68384139F574D836BCF34E9DFB01BF */
+ const uint8_t SAMPLE_LTK[] = {0xbf, 0x01, 0xfb, 0x9d, 0x4e, 0xf3, 0xbc, 0x36,
+ 0xd8, 0x74, 0xf5, 0x39, 0x41, 0x38, 0x68, 0x4c};
+ return memcmp(ltk, SAMPLE_LTK, BT_OCTET16_LEN) == 0;
+}
+
#endif
