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Commit 87e4e8ac authored by Jakub Pawlowski's avatar Jakub Pawlowski Committed by Myles Watson
Browse files

Don't persist bonds using sample LTK 

Test: compilation, manual testing
Bug: 128843052
Bug: 162497143
Merged-In: I52fd484d42bf87e96dbc9e6456090f231ed48111
Change-Id: I52fd484d42bf87e96dbc9e6456090f231ed48111
(cherry picked from commit 757c395f)
parent 142aad72

system/btif/src/btif_storage.cc

+43 −0
Original line number Diff line number Diff line
@@ -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 @@ bt_status_t btif_storage_remove_bonded_device(bt_bdaddr_t* remote_bd_addr) { 
  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_status_t btif_storage_load_bonded_devices(void) { 
  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 */

system/stack/btm/btm_sec.cc

+16 −0
Original line number Diff line number Diff line
@@ -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;
@@ -4693,6 +4696,19 @@ void btm_sec_disconnected(uint16_t handle, uint8_t reason) { 
          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

system/stack/include/bt_types.h

+10 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 


#include <stdbool.h>

#include <stdint.h>

#include <string.h>



#ifndef FALSE

#define FALSE false
@@ -1008,4 +1009,13 @@ static inline int bdcmpany(const BD_ADDR a) { return bdcmp(a, bd_addr_any); } 
 *

 ******************************************************************************/

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