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Commit a904a458 authored by Martin Brabham's avatar Martin Brabham
Browse files

OOB: Store keys and data generated for local OOB use. 

Bug: 190395922
Test: Manual, test app
Tag: #feature
Change-Id: Ib88abb866ce08b99c7fbf17ac9cfb85ee0f3441e
Merged-In: Ib88abb866ce08b99c7fbf17ac9cfb85ee0f3441e
parent 8b59e056

system/stack/smp/smp_act.cc

+18 −1
Original line number Diff line number Diff line
@@ -1440,7 +1440,13 @@ void smp_process_io_response(tSMP_CB* p_cb, tSMP_INT_DATA* p_data) { 
      return;

    }



    if (p_cb->selected_association_model == SMP_MODEL_SEC_CONN_OOB) {

    // If we are doing SMP_MODEL_SEC_CONN_OOB we don't need to request OOB data

    // locally if loc_oob_flag == 0x00 b/c there is no OOB data to give.  In the

    // event the loc_oob_flag is another value, we should request the OOB data

    // locally.  Which seems to cause it to make a TK REQUEST which is used for

    // the legacy flow which requires both sides to have OOB data.

    if (p_cb->selected_association_model == SMP_MODEL_SEC_CONN_OOB &&

        p_cb->loc_oob_flag != 0x00) {

      if (smp_request_oob_data(p_cb)) return;

    }
@@ -1931,10 +1937,21 @@ void smp_set_local_oob_random_commitment(tSMP_CB* p_cb, tSMP_INT_DATA* p_data) { 
                         p_cb->sc_oob_data.loc_oob_data.publ_key_used.x,

                         p_cb->sc_oob_data.loc_oob_data.randomizer, 0);



  p_cb->sc_oob_data.loc_oob_data.present = true;



  /* pass created OOB data up */

  p_cb->cb_evt = SMP_SC_LOC_OOB_DATA_UP_EVT;

  smp_send_app_cback(p_cb, NULL);



  // Store the data for later use when we are paired with

  // Event though the doc above says to pass up for safe keeping it never gets

  // kept safe. Additionally, when we need the data to make a decision we

  // wouldn't have it.  This will save the sc_oob_data in the smp_keys.cc such

  // that when we receive a request to create new keys we check to see if the

  // sc_oob_data exists and utilize the keys that are stored there otherwise the

  // connector will fail commitment check and dhkey exchange.

  smp_save_local_oob_data(p_cb);



  smp_cb_cleanup(p_cb);

}

system/stack/smp/smp_api.cc

+0 −3
Original line number Diff line number Diff line
@@ -567,9 +567,6 @@ void SMP_CrLocScOobData( 
                            const std::array<unsigned char, 16>&,

                            const std::array<unsigned char, 16>&)>

        callback) {

  smp_cb.local_random = bluetooth::os::GenerateRandom<16>();

  smp_cb.selected_association_model = SMP_MODEL_SEC_CONN_OOB;



  tSMP_INT_DATA smp_int_data;

  smp_sm_event(&smp_cb, SMP_CR_LOC_SC_OOB_DATA_EVT, &smp_int_data);

}

system/stack/smp/smp_int.h

+4 −0
Original line number Diff line number Diff line
@@ -461,4 +461,8 @@ extern bool smp_calculate_long_term_key_from_link_key(tSMP_CB* p_cb); 
extern void print128(const Octet16& x, const uint8_t* key_name);

extern void smp_xor_128(Octet16* a, const Octet16& b);



/* Save the p_cb->sc_oob_data.loc_oob_data for later, since the p_cb gets

 * cleaned up */

extern void smp_save_local_oob_data(tSMP_CB* p_cb);



#endif /* SMP_INT_H */

system/stack/smp/smp_keys.cc

+36 −0
Original line number Diff line number Diff line
@@ -55,6 +55,19 @@ static void smp_process_private_key(tSMP_CB* p_cb); 


#define SMP_PASSKEY_MASK 0xfff00000



// If there is data saved here, then use its info instead

// This needs to be cleared on a successfult pairing using the oob data

static tSMP_LOC_OOB_DATA saved_local_oob_data = {};



void smp_save_local_oob_data(tSMP_CB* p_cb) {

  saved_local_oob_data = p_cb->sc_oob_data.loc_oob_data;

}



static bool is_empty(tSMP_LOC_OOB_DATA* data) {

  tSMP_LOC_OOB_DATA empty_data = {};

  return memcmp(data, &empty_data, sizeof(tSMP_LOC_OOB_DATA)) == 0;

}



void smp_debug_print_nbyte_little_endian(uint8_t* p, const char* key_name,

                                         uint8_t len) {

}
@@ -573,6 +586,29 @@ Octet16 smp_calculate_legacy_short_term_key(tSMP_CB* p_cb) { 
void smp_create_private_key(tSMP_CB* p_cb, tSMP_INT_DATA* p_data) {

  SMP_TRACE_DEBUG("%s", __func__);



  // Only use the stored OOB data if we are in an oob association model

  if (p_cb->selected_association_model == SMP_MODEL_SEC_CONN_OOB) {

    LOG_WARN("OOB Association Model");

    // Make sure our data isn't empty, otherwise we generate new and eventually

    // pairing will fail Not much we can do about it at this point, just have to

    // generate new data The data will be cleared after the advertiser times

    // out, so if the advertiser times out we want the pairing to fail anyway.

    if (!is_empty(&saved_local_oob_data)) {

      LOG_WARN("Found OOB data, loading keys");

      memcpy(p_cb->private_key, saved_local_oob_data.private_key_used,

             BT_OCTET32_LEN);

      memcpy(p_cb->loc_publ_key.x, saved_local_oob_data.publ_key_used.x,

             BT_OCTET32_LEN);

      memcpy(p_cb->loc_publ_key.y, saved_local_oob_data.publ_key_used.y,

             BT_OCTET32_LEN);

      p_cb->sc_oob_data.loc_oob_data = saved_local_oob_data;

      p_cb->local_random = saved_local_oob_data.randomizer;

      smp_process_private_key(p_cb);

      return;

    }

    LOG_WARN("OOB Association Model with no saved data present");

  }



  btsnd_hcic_ble_rand(Bind(

      [](tSMP_CB* p_cb, BT_OCTET8 rand) {

        memcpy((void*)p_cb->private_key, rand, BT_OCTET8_LEN);