text: /******************************************************************************
   *
   *  Copyright (C) 1999-2012 Broadcom Corporation
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at:
   *
   *  http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   *
   ******************************************************************************/
  
  /******************************************************************************
   *
   *  This file contains security manager protocol utility functions
   *
   ******************************************************************************/
  #include "common/bt_target.h"
  
  #if SMP_INCLUDED == TRUE
  #if SMP_DEBUG == TRUE
  #include <stdio.h>
  #endif
  #include <string.h>
  //#include "bt_utils.h"
  #include "stack/btm_ble_api.h"
  #include "smp_int.h"
  #include "btm_int.h"
  #include "btm_ble_int.h"
  #include "stack/hcimsgs.h"
  #include "aes.h"
  #include "p_256_ecc_pp.h"
  #include "device/controller.h"
  
  #ifndef SMP_MAX_ENC_REPEAT
  #define SMP_MAX_ENC_REPEAT  3
  #endif
  
  static void smp_rand_back(tBTM_RAND_ENC *p);
  static void smp_generate_confirm(tSMP_CB *p_cb, tSMP_INT_DATA *p_data);
  static void smp_generate_ltk_cont(tSMP_CB *p_cb, tSMP_INT_DATA *p_data);
  static void smp_generate_y(tSMP_CB *p_cb, tSMP_INT_DATA *p);
  static void smp_generate_rand_vector (tSMP_CB *p_cb, tSMP_INT_DATA *p);
  static void smp_process_stk(tSMP_CB *p_cb, tSMP_ENC *p);
  static void smp_calculate_comfirm_cont(tSMP_CB *p_cb, tSMP_ENC *p);
  static void smp_process_confirm(tSMP_CB *p_cb, tSMP_ENC *p);
  static void smp_process_compare(tSMP_CB *p_cb, tSMP_ENC *p);
  static void smp_process_ediv(tSMP_CB *p_cb, tSMP_ENC *p);
  static BOOLEAN smp_calculate_legacy_short_term_key(tSMP_CB *p_cb, tSMP_ENC *output);
  static void smp_continue_private_key_creation(tSMP_CB *p_cb, tBTM_RAND_ENC *p);
  static void smp_process_private_key(tSMP_CB *p_cb);
  static void smp_finish_nonce_generation(tSMP_CB *p_cb);
  static void smp_process_new_nonce(tSMP_CB *p_cb);
  
  #if 0
  static const tSMP_ACT smp_encrypt_action[] = {
      smp_generate_compare,           /* SMP_GEN_COMPARE */
      smp_generate_confirm,          /* SMP_GEN_CONFIRM*/
      smp_generate_stk,               /* SMP_GEN_STK*/
      smp_generate_ltk_cont,          /* SMP_GEN_LTK */
      smp_generate_ltk,               /* SMP_GEN_DIV_LTK */
      smp_generate_rand_vector,        /* SMP_GEN_RAND_V */
      smp_generate_y,                  /* SMP_GEN_EDIV */
      smp_generate_passkey,           /* SMP_GEN_TK */
      smp_generate_srand_mrand_confirm, /* SMP_GEN_SRAND_MRAND */
      smp_generate_rand_cont         /* SMP_GEN_SRAND_MRAND_CONT */
  };
  #endif
  
  void smp_debug_print_nbyte_little_endian(UINT8 *p, const UINT8 *key_name, UINT8 len)
  {
  #if SMP_DEBUG == TRUE
      int     ind, x;
      int     col_count = 32;
      int     row_count;
      UINT8   p_buf[512];
  
      SMP_TRACE_WARNING("%s(LSB ~ MSB):\n", key_name);
      memset(p_buf, 0, sizeof(p_buf));
      row_count = len % col_count ? len / col_count + 1 : len / col_count;
  
      ind = 0;
      for (int row = 0; row <  row_count; row++) {
          for (int column = 0, x = 0; (ind < len) && (column < col_count); column++, ind++) {
              x += sprintf((char *)&p_buf[x], "%02x ", p[ind]);
          }
          SMP_TRACE_WARNING("  [%03d]: %s", row * col_count, p_buf);
      }
  #endif
  }
  
  void smp_debug_print_nbyte_big_endian (UINT8 *p, const UINT8 *key_name, UINT8 len)
  {
  #if SMP_DEBUG == TRUE
      UINT8  p_buf[512];
  
      SMP_TRACE_WARNING("%s(MSB ~ LSB):", key_name);
      memset(p_buf, 0, sizeof(p_buf));
      nrows = len % ncols ? len / ncols + 1 : len / ncols;
  
      int ind = 0;
      int  ncols = 32; /* num entries in one line */
      int  nrows;      /* num lines */
      int  x;
  
      for (int row = 0; row <  nrows; row++) {
          for (int col = 0, x = 0; (ind < len) && (col < ncols); col++, ind++) {
              x += sprintf ((char *)&p_buf[len - x - 1], "%02x ", p[ind]);
          }
          SMP_TRACE_WARNING("[%03d]: %s", row * ncols, p_buf);
      }
  #endif
  }
  
  /*******************************************************************************
  **
  ** Function         smp_encrypt_data
  **
  ** Description      This function is called to encrypt data.
  **                  It uses AES-128 encryption algorithm.
  **                  Plain_text is encrypted using key, the result is at p_out.
  **
  ** Returns          void
  **
  *******************************************************************************/
  BOOLEAN smp_encrypt_data (UINT8 *key, UINT8 key_len,
                            UINT8 *plain_text, UINT8 pt_len,
                            tSMP_ENC *p_out)
  {
      aes_context ctx;
      UINT8 *p_start = NULL;
      UINT8 *p = NULL;
      UINT8 *p_rev_data = NULL;    /* input data in big endilan format */
      UINT8 *p_rev_key = NULL;     /* input key in big endilan format */
      UINT8 *p_rev_output = NULL;  /* encrypted output in big endilan format */
  
      SMP_TRACE_DEBUG ("%s\n", __func__);
      if ( (p_out == NULL ) || (key_len != SMP_ENCRYT_KEY_SIZE) ) {
          SMP_TRACE_ERROR ("%s failed\n", __func__);
          return FALSE;
      }
  
      if ((p_start = (UINT8 *)osi_malloc((SMP_ENCRYT_DATA_SIZE * 4))) == NULL) {
          SMP_TRACE_ERROR ("%s failed unable to allocate buffer\n", __func__);
          return FALSE;
      }
  
      if (pt_len > SMP_ENCRYT_DATA_SIZE) {
          pt_len = SMP_ENCRYT_DATA_SIZE;
      }
  
      memset(p_start, 0, SMP_ENCRYT_DATA_SIZE * 4);
      p = p_start;
      ARRAY_TO_STREAM (p, plain_text, pt_len); /* byte 0 to byte 15 */
      p_rev_data = p = p_start + SMP_ENCRYT_DATA_SIZE; /* start at byte 16 */
      REVERSE_ARRAY_TO_STREAM (p, p_start, SMP_ENCRYT_DATA_SIZE);  /* byte 16 to byte 31 */
      p_rev_key = p; /* start at byte 32 */
      REVERSE_ARRAY_TO_STREAM (p, key, SMP_ENCRYT_KEY_SIZE); /* byte 32 to byte 47 */
  
  #if SMP_DEBUG == TRUE && SMP_DEBUG_VERBOSE == TRUE
      smp_debug_print_nbyte_little_endian(key, (const UINT8 *)"Key", SMP_ENCRYT_KEY_SIZE);
      smp_debug_print_nbyte_little_endian(p_start, (const UINT8 *)"Plain text", SMP_ENCRYT_DATA_SIZE);
  #endif
      p_rev_output = p;
      aes_set_key(p_rev_key, SMP_ENCRYT_KEY_SIZE, &ctx);
      bluedroid_aes_encrypt(p_rev_data, p, &ctx);  /* outputs in byte 48 to byte 63 */
  
      p = p_out->param_buf;
      REVERSE_ARRAY_TO_STREAM (p, p_rev_output, SMP_ENCRYT_DATA_SIZE);
  #if SMP_DEBUG == TRUE && SMP_DEBUG_VERBOSE == TRUE
      smp_debug_print_nbyte_little_endian(p_out->param_buf, (const UINT8 *)"Encrypted text", SMP_ENCRYT_KEY_SIZE);
  #endif
  
      p_out->param_len = SMP_ENCRYT_KEY_SIZE;
      p_out->status = HCI_SUCCESS;
      p_out->opcode =  HCI_BLE_ENCRYPT;
  
      osi_free(p_start);
  
      return TRUE;
  }
  
  void smp_use_static_passkey(void)
  {
      tSMP_CB *p_cb = &smp_cb;
      UINT8   *tt = p_cb->tk;
      tSMP_KEY    key;
      UINT32  passkey = p_cb->static_passkey;
      /* save the TK */
      memset(p_cb->tk, 0, BT_OCTET16_LEN);
      UINT32_TO_STREAM(tt, passkey);
  
      key.key_type = SMP_KEY_TYPE_TK;
      key.p_data  = p_cb->tk;
  
      if (p_cb->p_callback) {
          (*p_cb->p_callback)(SMP_PASSKEY_NOTIF_EVT, p_cb->pairing_bda, (tSMP_EVT_DATA *)&passkey);
      }
  
      if (p_cb->selected_association_model == SMP_MODEL_SEC_CONN_PASSKEY_DISP) {
          smp_sm_event(&smp_cb, SMP_KEY_READY_EVT, &passkey);
      } else {
          smp_sm_event(p_cb, SMP_KEY_READY_EVT, (tSMP_INT_DATA *)&key);
      }
  }
  /*******************************************************************************
  **
  ** Function         smp_generate_passkey
  **
  ** Description      This function is called to generate passkey.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_generate_passkey(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      if(p_cb->use_static_passkey) {
          SMP_TRACE_DEBUG ("%s use static passkey %6d", __func__, p_cb->static_passkey);
          smp_use_static_passkey();
          return;
      }
      SMP_TRACE_DEBUG ("%s generate rand passkey", __func__);
      p_cb->rand_enc_proc_state = SMP_GEN_TK;
  
      /* generate MRand or SRand */
      if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
          smp_rand_back(NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_proc_passkey
  **
  ** Description      This function is called to process a passkey.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_proc_passkey(tSMP_CB *p_cb , tBTM_RAND_ENC *p)
  {
      UINT8   *tt = p_cb->tk;
      tSMP_KEY    key;
      UINT32  passkey; /* 19655 test number; */
      UINT8 *pp = p->param_buf;
  
      SMP_TRACE_DEBUG ("%s", __func__);
      STREAM_TO_UINT32(passkey, pp);
      passkey &= ~SMP_PASSKEY_MASK;
  
      /* truncate by maximum value */
      while (passkey > BTM_MAX_PASSKEY_VAL) {
          passkey >>= 1;
      }
  
      /* save the TK */
      memset(p_cb->tk, 0, BT_OCTET16_LEN);
      UINT32_TO_STREAM(tt, passkey);
  
      key.key_type = SMP_KEY_TYPE_TK;
      key.p_data  = p_cb->tk;
  
      if (p_cb->p_callback) {
          (*p_cb->p_callback)(SMP_PASSKEY_NOTIF_EVT, p_cb->pairing_bda, (tSMP_EVT_DATA *)&passkey);
      }
  
      if (p_cb->selected_association_model == SMP_MODEL_SEC_CONN_PASSKEY_DISP) {
          smp_sm_event(&smp_cb, SMP_KEY_READY_EVT, &passkey);
      } else {
          smp_sm_event(p_cb, SMP_KEY_READY_EVT, (tSMP_INT_DATA *)&key);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_stk
  **
  ** Description      This function is called to generate STK calculated by running
  **                  AES with the TK value as key and a concatenation of the random
  **                  values.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_generate_stk(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      tSMP_ENC output;
      tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
  
      SMP_TRACE_DEBUG ("%s\n", __func__);
  
      if (p_cb->le_secure_connections_mode_is_used) {
          SMP_TRACE_WARNING ("FOR LE SC LTK IS USED INSTEAD OF STK");
          output.param_len = SMP_ENCRYT_KEY_SIZE;
          output.status = HCI_SUCCESS;
          output.opcode =  HCI_BLE_ENCRYPT;
          memcpy(output.param_buf, p_cb->ltk, SMP_ENCRYT_DATA_SIZE);
      } else if (!smp_calculate_legacy_short_term_key(p_cb, &output)) {
          SMP_TRACE_ERROR("%s failed", __func__);
          smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
          return;
      }
  
      smp_process_stk(p_cb, &output);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_srand_mrand_confirm
  **
  ** Description      This function is called to start the second pairing phase by
  **                  start generating random number.
  **
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_generate_srand_mrand_confirm(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      SMP_TRACE_DEBUG ("%s\n", __func__);
      p_cb->rand_enc_proc_state = SMP_GEN_SRAND_MRAND;
      /* generate MRand or SRand */
      if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
          smp_rand_back(NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_rand_cont
  **
  ** Description      This function is called to generate another 64 bits random for
  **                  MRand or Srand.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_generate_rand_cont(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      SMP_TRACE_DEBUG ("%s\n", __func__);
      p_cb->rand_enc_proc_state = SMP_GEN_SRAND_MRAND_CONT;
      /* generate 64 MSB of MRand or SRand */
      if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
          smp_rand_back(NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_ltk
  **
  ** Description      This function is called:
  **                  - in legacy pairing - to calculate LTK, starting with DIV
  **                    generation;
  **                  - in LE Secure Connections pairing over LE transport - to process LTK
  **                    already generated to encrypt LE link;
  **                  - in LE Secure Connections pairing over BR/EDR transport - to start
  **                    BR/EDR Link Key processing.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_generate_ltk(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      BOOLEAN div_status;
      SMP_TRACE_DEBUG ("%s\n", __FUNCTION__);
      if (smp_get_br_state() == SMP_BR_STATE_BOND_PENDING) {
          smp_br_process_link_key(p_cb, NULL);
          return;
      } else if (p_cb->le_secure_connections_mode_is_used) {
          smp_process_secure_connection_long_term_key();
          return;
      }
  
      div_status = btm_get_local_div(p_cb->pairing_bda, &p_cb->div);
  
      if (div_status) {
          smp_generate_ltk_cont(p_cb, NULL);
      } else {
          SMP_TRACE_DEBUG ("Generate DIV for LTK\n");
          p_cb->rand_enc_proc_state = SMP_GEN_DIV_LTK;
          /* generate MRand or SRand */
          if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
              smp_rand_back(NULL);
          }
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_compute_csrk
  **
  ** Description      This function is called to calculate CSRK
  **
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_compute_csrk(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      BT_OCTET16  er;
      UINT8       buffer[4]; /* for (r || DIV)  r=1*/
      UINT16      r = 1;
      UINT8       *p = buffer;
      tSMP_ENC    output;
      tSMP_STATUS   status = SMP_PAIR_FAIL_UNKNOWN;
  
      SMP_TRACE_DEBUG ("smp_compute_csrk div=%x\n", p_cb->div);
      BTM_GetDeviceEncRoot(er);
      /* CSRK = d1(ER, DIV, 1) */
      UINT16_TO_STREAM(p, p_cb->div);
      UINT16_TO_STREAM(p, r);
  
      if (!SMP_Encrypt(er, BT_OCTET16_LEN, buffer, 4, &output)) {
          SMP_TRACE_ERROR("smp_generate_csrk failed\n");
          if (p_cb->smp_over_br) {
              smp_br_state_machine_event(p_cb, SMP_BR_AUTH_CMPL_EVT, &status);
          } else {
              smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
          }
      } else {
          memcpy((void *)p_cb->csrk, output.param_buf, BT_OCTET16_LEN);
          smp_send_csrk_info(p_cb, NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_csrk
  **
  ** Description      This function is called to calculate CSRK, starting with DIV
  **                  generation.
  **
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_generate_csrk(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      BOOLEAN     div_status;
  
      SMP_TRACE_DEBUG ("smp_generate_csrk");
  
      div_status = btm_get_local_div(p_cb->pairing_bda, &p_cb->div);
      if (div_status) {
          smp_compute_csrk(p_cb, NULL);
      } else {
          SMP_TRACE_DEBUG ("Generate DIV for CSRK");
          p_cb->rand_enc_proc_state = SMP_GEN_DIV_CSRK;
          if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
              smp_rand_back(NULL);
          }
      }
  }
  
  /*******************************************************************************
  ** Function         smp_concatenate_peer
  **                  add pairing command sent from local device into p1.
  *******************************************************************************/
  void smp_concatenate_local( tSMP_CB *p_cb, UINT8 **p_data, UINT8 op_code)
  {
      UINT8   *p = *p_data;
  
      SMP_TRACE_DEBUG ("%s\n", __func__);
      UINT8_TO_STREAM(p, op_code);
      UINT8_TO_STREAM(p, p_cb->local_io_capability);
      UINT8_TO_STREAM(p, p_cb->loc_oob_flag);
      UINT8_TO_STREAM(p, p_cb->loc_auth_req);
      UINT8_TO_STREAM(p, p_cb->loc_enc_size);
      UINT8_TO_STREAM(p, p_cb->local_i_key);
      UINT8_TO_STREAM(p, p_cb->local_r_key);
  
      *p_data = p;
  }
  
  /*******************************************************************************
  ** Function         smp_concatenate_peer
  **                  add pairing command received from peer device into p1.
  *******************************************************************************/
  void smp_concatenate_peer( tSMP_CB *p_cb, UINT8 **p_data, UINT8 op_code)
  {
      UINT8   *p = *p_data;
  
      SMP_TRACE_DEBUG ("smp_concatenate_peer \n");
      UINT8_TO_STREAM(p, op_code);
      UINT8_TO_STREAM(p, p_cb->peer_io_caps);
      UINT8_TO_STREAM(p, p_cb->peer_oob_flag);
      UINT8_TO_STREAM(p, p_cb->peer_auth_req);
      UINT8_TO_STREAM(p, p_cb->peer_enc_size);
      UINT8_TO_STREAM(p, p_cb->peer_i_key);
      UINT8_TO_STREAM(p, p_cb->peer_r_key);
  
      *p_data = p;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_gen_p1_4_confirm
  **
  ** Description      Generate Confirm/Compare Step1:
  **                  p1 = pres || preq || rat' || iat'
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_gen_p1_4_confirm( tSMP_CB *p_cb, BT_OCTET16 p1)
  {
      UINT8 *p = (UINT8 *)p1;
      tBLE_ADDR_TYPE    addr_type = 0;
      BD_ADDR           remote_bda;
  
      SMP_TRACE_DEBUG ("smp_gen_p1_4_confirm\n");
  
      if (!BTM_ReadRemoteConnectionAddr(p_cb->pairing_bda, remote_bda, &addr_type)) {
          SMP_TRACE_ERROR("can not generate confirm for unknown device\n");
          return;
      }
  
      BTM_ReadConnectionAddr( p_cb->pairing_bda, p_cb->local_bda, &p_cb->addr_type);
  
      if (p_cb->role == HCI_ROLE_MASTER) {
          /* LSB : rat': initiator's(local) address type */
          UINT8_TO_STREAM(p, p_cb->addr_type);
          /* LSB : iat': responder's address type */
          UINT8_TO_STREAM(p, addr_type);
          /* concatinate preq */
          smp_concatenate_local(p_cb, &p, SMP_OPCODE_PAIRING_REQ);
          /* concatinate pres */
          smp_concatenate_peer(p_cb, &p, SMP_OPCODE_PAIRING_RSP);
      } else {
          /* LSB : iat': initiator's address type */
          UINT8_TO_STREAM(p, addr_type);
          /* LSB : rat': responder's(local) address type */
          UINT8_TO_STREAM(p, p_cb->addr_type);
          /* concatinate preq */
          smp_concatenate_peer(p_cb, &p, SMP_OPCODE_PAIRING_REQ);
          /* concatinate pres */
          smp_concatenate_local(p_cb, &p, SMP_OPCODE_PAIRING_RSP);
      }
  #if SMP_DEBUG == TRUE
      SMP_TRACE_DEBUG("p1 = pres || preq || rat' || iat'\n");
      smp_debug_print_nbyte_little_endian ((UINT8 *)p1, (const UINT8 *)"P1", 16);
  #endif
  }
  
  /*******************************************************************************
  **
  ** Function         smp_gen_p2_4_confirm
  **
  ** Description      Generate Confirm/Compare Step2:
  **                  p2 = padding || ia || ra
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_gen_p2_4_confirm( tSMP_CB *p_cb, BT_OCTET16 p2)
  {
      UINT8       *p = (UINT8 *)p2;
      BD_ADDR     remote_bda;
      tBLE_ADDR_TYPE  addr_type = 0;
      SMP_TRACE_DEBUG ("smp_gen_p2_4_confirm\n");
      if (!BTM_ReadRemoteConnectionAddr(p_cb->pairing_bda, remote_bda, &addr_type)) {
          SMP_TRACE_ERROR("can not generate confirm p2 for unknown device\n");
          return;
      }
  
      SMP_TRACE_DEBUG ("smp_gen_p2_4_confirm\n");
  
      memset(p, 0, sizeof(BT_OCTET16));
  
      if (p_cb->role == HCI_ROLE_MASTER) {
          /* LSB ra */
          BDADDR_TO_STREAM(p, remote_bda);
          /* ia */
          BDADDR_TO_STREAM(p, p_cb->local_bda);
      } else {
          /* LSB ra */
          BDADDR_TO_STREAM(p, p_cb->local_bda);
          /* ia */
          BDADDR_TO_STREAM(p, remote_bda);
      }
  #if SMP_DEBUG == TRUE
      SMP_TRACE_DEBUG("p2 = padding || ia || ra");
      smp_debug_print_nbyte_little_endian(p2, (const UINT8 *)"p2", 16);
  #endif
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_comfirm
  **
  ** Description      This function is called to calculate Confirm value.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_calculate_comfirm (tSMP_CB *p_cb, BT_OCTET16 rand, BD_ADDR bda)
  {
      UNUSED(bda);
  
      BT_OCTET16      p1;
      tSMP_ENC       output;
      tSMP_STATUS     status = SMP_PAIR_FAIL_UNKNOWN;
  
      SMP_TRACE_DEBUG ("smp_calculate_comfirm \n");
      /* generate p1 = pres || preq || rat' || iat' */
      smp_gen_p1_4_confirm(p_cb, p1);
  
      /* p1 = rand XOR p1 */
      smp_xor_128(p1, rand);
  
      smp_debug_print_nbyte_little_endian ((UINT8 *)p1, (const UINT8 *)"P1' = r XOR p1", 16);
  
      /* calculate e(k, r XOR p1), where k = TK */
      if (!SMP_Encrypt(p_cb->tk, BT_OCTET16_LEN, p1, BT_OCTET16_LEN, &output)) {
          SMP_TRACE_ERROR("smp_generate_csrk failed");
          smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
      } else {
          smp_calculate_comfirm_cont(p_cb, &output);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_comfirm_cont
  **
  ** Description      This function is called when SConfirm/MConfirm is generated
  **                  proceed to send the Confirm request/response to peer device.
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_calculate_comfirm_cont(tSMP_CB *p_cb, tSMP_ENC *p)
  {
      BT_OCTET16    p2;
      tSMP_ENC      output;
      tSMP_STATUS     status = SMP_PAIR_FAIL_UNKNOWN;
  
      SMP_TRACE_DEBUG ("smp_calculate_comfirm_cont \n");
  #if SMP_DEBUG == TRUE
      SMP_TRACE_DEBUG("Confirm step 1 p1' = e(k, r XOR p1)  Generated\n");
      smp_debug_print_nbyte_little_endian (p->param_buf, (const UINT8 *)"C1", 16);
  #endif
  
      smp_gen_p2_4_confirm(p_cb, p2);
  
      /* calculate p2 = (p1' XOR p2) */
      smp_xor_128(p2, p->param_buf);
      smp_debug_print_nbyte_little_endian ((UINT8 *)p2, (const UINT8 *)"p2' = C1 xor p2", 16);
  
      /* calculate: Confirm = E(k, p1' XOR p2) */
      if (!SMP_Encrypt(p_cb->tk, BT_OCTET16_LEN, p2, BT_OCTET16_LEN, &output)) {
          SMP_TRACE_ERROR("smp_calculate_comfirm_cont failed\n");
          smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
      } else {
          SMP_TRACE_DEBUG("p_cb->rand_enc_proc_state=%d\n", p_cb->rand_enc_proc_state);
          switch (p_cb->rand_enc_proc_state) {
          case SMP_GEN_CONFIRM:
              smp_process_confirm(p_cb, &output);
              break;
  
          case SMP_GEN_COMPARE:
              smp_process_compare(p_cb, &output);
              break;
          }
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_confirm
  **
  ** Description      This function is called when a 48 bits random number is generated
  **                  as SRand or MRand, continue to calculate Sconfirm or MConfirm.
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_generate_confirm(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      SMP_TRACE_DEBUG ("%s\n", __func__);
      p_cb->rand_enc_proc_state = SMP_GEN_CONFIRM;
      smp_debug_print_nbyte_little_endian ((UINT8 *)p_cb->rand,  (const UINT8 *)"local rand", 16);
      smp_calculate_comfirm(p_cb, p_cb->rand, p_cb->pairing_bda);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_compare
  **
  ** Description      This function is called to generate SConfirm for Slave device,
  **                  or MSlave for Master device. This function can be also used for
  **                  generating Compare number for confirm value check.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_generate_compare (tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      SMP_TRACE_DEBUG ("smp_generate_compare \n");
      p_cb->rand_enc_proc_state = SMP_GEN_COMPARE;
      smp_debug_print_nbyte_little_endian ((UINT8 *)p_cb->rrand,  (const UINT8 *)"peer rand", 16);
      smp_calculate_comfirm(p_cb, p_cb->rrand, p_cb->local_bda);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_process_confirm
  **
  ** Description      This function is called when SConfirm/MConfirm is generated
  **                  proceed to send the Confirm request/response to peer device.
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_process_confirm(tSMP_CB *p_cb, tSMP_ENC *p)
  {
      tSMP_KEY    key;
  
      SMP_TRACE_DEBUG ("%s\n", __FUNCTION__);
      memcpy(p_cb->confirm, p->param_buf, BT_OCTET16_LEN);
  
  #if (SMP_DEBUG == TRUE)
      SMP_TRACE_DEBUG("Confirm  Generated");
      smp_debug_print_nbyte_little_endian ((UINT8 *)p_cb->confirm,  (const UINT8 *)"Confirm", 16);
  #endif
  
      key.key_type = SMP_KEY_TYPE_CFM;
      key.p_data = p->param_buf;
  
      smp_sm_event(p_cb, SMP_KEY_READY_EVT, &key);
  
  }
  
  /*******************************************************************************
  **
  ** Function         smp_process_compare
  **
  ** Description      This function is called when Compare is generated using the
  **                  RRand and local BDA, TK information.
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_process_compare(tSMP_CB *p_cb, tSMP_ENC *p)
  {
      tSMP_KEY    key;
  
      SMP_TRACE_DEBUG ("smp_process_compare \n");
  #if (SMP_DEBUG == TRUE)
      SMP_TRACE_DEBUG("Compare Generated\n");
      smp_debug_print_nbyte_little_endian (p->param_buf,  (const UINT8 *)"Compare", 16);
  #endif
      key.key_type = SMP_KEY_TYPE_CMP;
      key.p_data   = p->param_buf;
      //smp_set_state(SMP_STATE_CONFIRM);
      smp_sm_event(p_cb, SMP_KEY_READY_EVT, &key);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_process_stk
  **
  ** Description      This function is called when STK is generated
  **                  proceed to send the encrypt the link using STK.
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_process_stk(tSMP_CB *p_cb, tSMP_ENC *p)
  {
      tSMP_KEY    key;
  
      SMP_TRACE_DEBUG ("smp_process_stk ");
  #if (SMP_DEBUG == TRUE)
      SMP_TRACE_ERROR("STK Generated");
  #endif
      smp_mask_enc_key(p_cb->loc_enc_size, p->param_buf);
  
      key.key_type = SMP_KEY_TYPE_STK;
      key.p_data   = p->param_buf;
  
      smp_sm_event(p_cb, SMP_KEY_READY_EVT, &key);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_ltk_cont
  **
  ** Description      This function is to calculate LTK = d1(ER, DIV, 0)= e(ER, DIV)
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_generate_ltk_cont(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UNUSED(p_data);
  
      BT_OCTET16  er;
      tSMP_ENC    output;
      tSMP_STATUS     status = SMP_PAIR_FAIL_UNKNOWN;
  
      SMP_TRACE_DEBUG ("%s\n", __func__);
      BTM_GetDeviceEncRoot(er);
  
      /* LTK = d1(ER, DIV, 0)= e(ER, DIV)*/
      if (!SMP_Encrypt(er, BT_OCTET16_LEN, (UINT8 *)&p_cb->div,
                       sizeof(UINT16), &output)) {
          SMP_TRACE_ERROR("%s failed\n", __func__);
          smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
      } else {
          /* mask the LTK */
          smp_mask_enc_key(p_cb->loc_enc_size, output.param_buf);
          memcpy((void *)p_cb->ltk, output.param_buf, BT_OCTET16_LEN);
          smp_generate_rand_vector(p_cb, NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_y
  **
  ** Description      This function is to proceed generate Y = E(DHK, Rand)
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_generate_y(tSMP_CB *p_cb, tSMP_INT_DATA *p)
  {
      UNUSED(p);
  
      BT_OCTET16  dhk;
      tSMP_ENC   output;
      tSMP_STATUS     status = SMP_PAIR_FAIL_UNKNOWN;
  
  
      SMP_TRACE_DEBUG ("smp_generate_y \n");
      BTM_GetDeviceDHK(dhk);
  
      if (!SMP_Encrypt(dhk, BT_OCTET16_LEN, p_cb->enc_rand,
                       BT_OCTET8_LEN, &output)) {
          SMP_TRACE_ERROR("smp_generate_y failed");
          smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
      } else {
          smp_process_ediv(p_cb, &output);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_generate_rand_vector
  **
  ** Description      This function is called when LTK is generated, send state machine
  **                  event to SMP.
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_generate_rand_vector (tSMP_CB *p_cb, tSMP_INT_DATA *p)
  {
      UNUSED(p);
  
      /* generate EDIV and rand now */
      /* generate random vector */
      SMP_TRACE_DEBUG ("smp_generate_rand_vector\n");
      p_cb->rand_enc_proc_state = SMP_GEN_RAND_V;
      if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
          smp_rand_back(NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_process_ediv
  **
  ** Description      This function is to calculate EDIV = Y xor DIV
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_process_ediv(tSMP_CB *p_cb, tSMP_ENC *p)
  {
      tSMP_KEY    key;
      UINT8 *pp = p->param_buf;
      UINT16  y;
  
      SMP_TRACE_DEBUG ("smp_process_ediv ");
      STREAM_TO_UINT16(y, pp);
  
      /* EDIV = Y xor DIV */
      p_cb->ediv = p_cb->div ^ y;
      /* send LTK ready */
      SMP_TRACE_DEBUG("LTK ready");
      key.key_type = SMP_KEY_TYPE_LTK;
      key.p_data   = p->param_buf;
  
      smp_sm_event(p_cb, SMP_KEY_READY_EVT, &key);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_legacy_short_term_key
  **
  ** Description      The function calculates legacy STK.
  **
  ** Returns          FALSE if out of resources, TRUE in other cases.
  **
  *******************************************************************************/
  BOOLEAN smp_calculate_legacy_short_term_key(tSMP_CB *p_cb, tSMP_ENC *output)
  {
      BT_OCTET16 ptext;
      UINT8 *p = ptext;
  
      SMP_TRACE_DEBUG ("%s\n", __func__);
      memset(p, 0, BT_OCTET16_LEN);
      if (p_cb->role == HCI_ROLE_MASTER) {
          memcpy(p, p_cb->rand, BT_OCTET8_LEN);
          memcpy(&p[BT_OCTET8_LEN], p_cb->rrand, BT_OCTET8_LEN);
      } else {
          memcpy(p, p_cb->rrand, BT_OCTET8_LEN);
          memcpy(&p[BT_OCTET8_LEN], p_cb->rand, BT_OCTET8_LEN);
      }
  
      BOOLEAN encrypted;
      /* generate STK = Etk(rand|rrand)*/
      encrypted = SMP_Encrypt( p_cb->tk, BT_OCTET16_LEN, ptext, BT_OCTET16_LEN, output);
      if (!encrypted) {
          SMP_TRACE_ERROR("%s failed\n", __func__);
      }
      return encrypted;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_create_private_key
  **
  ** Description      This function is called to create private key used to
  **                  calculate public key and DHKey.
  **                  The function starts private key creation requesting controller
  **                  to generate [0-7] octets of private key.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_create_private_key(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
      p_cb->rand_enc_proc_state = SMP_GENERATE_PRIVATE_KEY_0_7;
      if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
          smp_rand_back(NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_use_oob_private_key
  **
  ** Description      This function is called
  **                  - to save the secret key used to calculate the public key used
  **                    in calculations of commitment sent OOB to a peer
  **                  - to use this secret key to recalculate the public key and
  **                    start the process of sending this public key to the peer
  **                  if secret/public keys have to be reused.
  **                  If the keys aren't supposed to be reused, continue from the
  **                  point from which request for OOB data was issued.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_use_oob_private_key(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      SMP_TRACE_DEBUG ("%s req_oob_type: %d, role: %d\n",
                       __func__, p_cb->req_oob_type, p_cb->role);
  
      switch (p_cb->req_oob_type) {
      case SMP_OOB_BOTH:
      case SMP_OOB_LOCAL:
          SMP_TRACE_DEBUG("%s restore secret key\n", __func__);
          memcpy(p_cb->private_key, p_cb->sc_oob_data.loc_oob_data.private_key_used, BT_OCTET32_LEN);
          smp_process_private_key(p_cb);
          break;
      default:
          SMP_TRACE_DEBUG("%s create secret key anew\n", __func__);
          smp_set_state(SMP_STATE_PAIR_REQ_RSP);
          smp_decide_association_model(p_cb, NULL);
          break;
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_continue_private_key_creation
  **
  ** Description      This function is used to continue private key creation.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_continue_private_key_creation (tSMP_CB *p_cb, tBTM_RAND_ENC *p)
  {
      UINT8   state = p_cb->rand_enc_proc_state & ~0x80;
      SMP_TRACE_DEBUG ("%s state=0x%x\n", __func__, state);
  
      switch (state) {
      case SMP_GENERATE_PRIVATE_KEY_0_7:
          memcpy((void *)p_cb->private_key, p->param_buf, p->param_len);
          p_cb->rand_enc_proc_state = SMP_GENERATE_PRIVATE_KEY_8_15;
          if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
              smp_rand_back(NULL);
          }
          break;
  
      case SMP_GENERATE_PRIVATE_KEY_8_15:
          memcpy((void *)&p_cb->private_key[8], p->param_buf, p->param_len);
          p_cb->rand_enc_proc_state = SMP_GENERATE_PRIVATE_KEY_16_23;
          if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
              smp_rand_back(NULL);
          }
          break;
  
      case SMP_GENERATE_PRIVATE_KEY_16_23:
          memcpy((void *)&p_cb->private_key[16], p->param_buf, p->param_len);
          p_cb->rand_enc_proc_state = SMP_GENERATE_PRIVATE_KEY_24_31;
          if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
              smp_rand_back(NULL);
          }
          break;
  
      case SMP_GENERATE_PRIVATE_KEY_24_31:
          memcpy((void *)&p_cb->private_key[24], p->param_buf, p->param_len);
          smp_process_private_key (p_cb);
          break;
  
      default:
          break;
      }
  
      return;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_process_private_key
  **
  ** Description      This function processes private key.
  **                  It calculates public key and notifies SM that private key /
  **                  public key pair is created.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_process_private_key(tSMP_CB *p_cb)
  {
      Point       public_key;
      BT_OCTET32  private_key;
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  
      memcpy(private_key, p_cb->private_key, BT_OCTET32_LEN);
      ECC_PointMult(&public_key, &(curve_p256.G), (DWORD *) private_key, KEY_LENGTH_DWORDS_P256);
      memcpy(p_cb->loc_publ_key.x, public_key.x, BT_OCTET32_LEN);
      memcpy(p_cb->loc_publ_key.y, public_key.y, BT_OCTET32_LEN);
  
      smp_debug_print_nbyte_little_endian (p_cb->private_key, (const UINT8 *)"private",
                                           BT_OCTET32_LEN);
      smp_debug_print_nbyte_little_endian (p_cb->loc_publ_key.x, (const UINT8 *)"local public(x)",
                                           BT_OCTET32_LEN);
      smp_debug_print_nbyte_little_endian (p_cb->loc_publ_key.y, (const UINT8 *)"local public(y)",
                                           BT_OCTET32_LEN);
      p_cb->flags |= SMP_PAIR_FLAG_HAVE_LOCAL_PUBL_KEY;
      smp_sm_event(p_cb, SMP_LOC_PUBL_KEY_CRTD_EVT, NULL);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_compute_dhkey
  **
  ** Description      The function:
  **                  - calculates a new public key using as input local private
  **                    key and peer public key;
  **                  - saves the new public key x-coordinate as DHKey.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_compute_dhkey (tSMP_CB *p_cb)
  {
      Point       peer_publ_key, new_publ_key;
      BT_OCTET32  private_key;
  
      SMP_TRACE_DEBUG ("%s\n", __FUNCTION__);
  
      memcpy(private_key, p_cb->private_key, BT_OCTET32_LEN);
      memcpy(peer_publ_key.x, p_cb->peer_publ_key.x, BT_OCTET32_LEN);
      memcpy(peer_publ_key.y, p_cb->peer_publ_key.y, BT_OCTET32_LEN);
  
      ECC_PointMult(&new_publ_key, &peer_publ_key, (DWORD *) private_key, KEY_LENGTH_DWORDS_P256);
  
      memcpy(p_cb->dhkey, new_publ_key.x, BT_OCTET32_LEN);
  
      smp_debug_print_nbyte_little_endian (p_cb->dhkey, (const UINT8 *)"Old DHKey",
                                           BT_OCTET32_LEN);
  
      smp_debug_print_nbyte_little_endian (p_cb->private_key, (const UINT8 *)"private",
                                           BT_OCTET32_LEN);
      smp_debug_print_nbyte_little_endian (p_cb->peer_publ_key.x, (const UINT8 *)"rem public(x)",
                                           BT_OCTET32_LEN);
      smp_debug_print_nbyte_little_endian (p_cb->peer_publ_key.y, (const UINT8 *)"rem public(y)",
                                           BT_OCTET32_LEN);
      smp_debug_print_nbyte_little_endian (p_cb->dhkey, (const UINT8 *)"Reverted DHKey",
                                           BT_OCTET32_LEN);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_local_commitment
  **
  ** Description      The function calculates and saves local commmitment in CB.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_calculate_local_commitment(tSMP_CB *p_cb)
  {
      UINT8 random_input;
  
      SMP_TRACE_DEBUG("%s\n", __FUNCTION__);
  
      switch (p_cb->selected_association_model) {
      case SMP_MODEL_SEC_CONN_JUSTWORKS:
      case SMP_MODEL_SEC_CONN_NUM_COMP:
          if (p_cb->role  == HCI_ROLE_MASTER)
              SMP_TRACE_WARNING ("local commitment calc on master is not expected \
                                      for Just Works/Numeric Comparison models\n");
          smp_calculate_f4(p_cb->loc_publ_key.x, p_cb->peer_publ_key.x, p_cb->rand, 0,
                           p_cb->commitment);
          break;
      case SMP_MODEL_SEC_CONN_PASSKEY_ENT:
      case SMP_MODEL_SEC_CONN_PASSKEY_DISP:
          random_input = smp_calculate_random_input(p_cb->local_random, p_cb->round);
          smp_calculate_f4(p_cb->loc_publ_key.x, p_cb->peer_publ_key.x, p_cb->rand,
                           random_input, p_cb->commitment);
          break;
      case SMP_MODEL_SEC_CONN_OOB:
          SMP_TRACE_WARNING ("local commitment calc is expected for OOB model BEFORE pairing\n");
          smp_calculate_f4(p_cb->loc_publ_key.x, p_cb->loc_publ_key.x, p_cb->local_random, 0,
                           p_cb->commitment);
          break;
      default:
          SMP_TRACE_ERROR("Association Model = %d is not used in LE SC\n",
                          p_cb->selected_association_model);
          return;
      }
  
      SMP_TRACE_EVENT ("local commitment calculation is completed");
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_peer_commitment
  **
  ** Description      The function calculates and saves peer commmitment at the
  **                  provided output buffer.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_calculate_peer_commitment(tSMP_CB *p_cb, BT_OCTET16 output_buf)
  {
      UINT8 ri;
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  
      switch (p_cb->selected_association_model) {
      case SMP_MODEL_SEC_CONN_JUSTWORKS:
      case SMP_MODEL_SEC_CONN_NUM_COMP:
          if (p_cb->role  == HCI_ROLE_SLAVE)
              SMP_TRACE_WARNING ("peer commitment calc on slave is not expected \
                  for Just Works/Numeric Comparison models\n");
          smp_calculate_f4(p_cb->peer_publ_key.x, p_cb->loc_publ_key.x, p_cb->rrand, 0,
                           output_buf);
          break;
      case SMP_MODEL_SEC_CONN_PASSKEY_ENT:
      case SMP_MODEL_SEC_CONN_PASSKEY_DISP:
          ri = smp_calculate_random_input(p_cb->peer_random, p_cb->round);
          smp_calculate_f4(p_cb->peer_publ_key.x, p_cb->loc_publ_key.x, p_cb->rrand, ri,
                           output_buf);
          break;
      case SMP_MODEL_SEC_CONN_OOB:
          smp_calculate_f4(p_cb->peer_publ_key.x, p_cb->peer_publ_key.x, p_cb->peer_random, 0,
                           output_buf);
          break;
      default:
          SMP_TRACE_ERROR("Association Model = %d is not used in LE SC\n",
                          p_cb->selected_association_model);
          return;
      }
  
      SMP_TRACE_EVENT ("peer commitment calculation is completed\n");
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_f4
  **
  ** Description      The function calculates
  **                  C = f4(U, V, X, Z) = AES-CMAC (U||V||Z)
  **                                               X
  **                  where
  **                  input:  U is 256 bit,
  **                          V is 256 bit,
  **                          X is 128 bit,
  **                          Z is 8 bit,
  **                  output: C is 128 bit.
  **
  ** Returns          void
  **
  ** Note             The LSB is the first octet, the MSB is the last octet of
  **                  the AES-CMAC input/output stream.
  **
  *******************************************************************************/
  void smp_calculate_f4(UINT8 *u, UINT8 *v, UINT8 *x, UINT8 z, UINT8 *c)
  {
      UINT8   msg_len = BT_OCTET32_LEN /* U size */ + BT_OCTET32_LEN /* V size */ + 1 /* Z size */;
      UINT8   msg[BT_OCTET32_LEN + BT_OCTET32_LEN + 1];
      UINT8   key[BT_OCTET16_LEN];
      UINT8   cmac[BT_OCTET16_LEN];
      UINT8   *p = NULL;
  #if SMP_DEBUG == TRUE
      UINT8   *p_prnt = NULL;
  #endif
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  
  #if SMP_DEBUG == TRUE
      p_prnt = u;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"U", BT_OCTET32_LEN);
      p_prnt = v;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"V", BT_OCTET32_LEN);
      p_prnt = x;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"X", BT_OCTET16_LEN);
      p_prnt = &z;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"Z", 1);
  #endif
  
      p = msg;
      UINT8_TO_STREAM(p, z);
      ARRAY_TO_STREAM(p, v, BT_OCTET32_LEN);
      ARRAY_TO_STREAM(p, u, BT_OCTET32_LEN);
  #if SMP_DEBUG == TRUE
      p_prnt = msg;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"M", msg_len);
  #endif
  
      p = key;
      ARRAY_TO_STREAM(p, x, BT_OCTET16_LEN);
  #if SMP_DEBUG == TRUE
      p_prnt = key;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"K", BT_OCTET16_LEN);
  #endif
  
      aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac);
  #if SMP_DEBUG == TRUE
      p_prnt = cmac;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"AES_CMAC", BT_OCTET16_LEN);
  #endif
  
      p = c;
      ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_numeric_comparison_display_number
  **
  ** Description      The function calculates and saves number to display in numeric
  **                  comparison association mode.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_calculate_numeric_comparison_display_number(tSMP_CB *p_cb,
          tSMP_INT_DATA *p_data)
  {
      SMP_TRACE_DEBUG ("%s", __func__);
  
      if (p_cb->role == HCI_ROLE_MASTER) {
          p_cb->number_to_display =
              smp_calculate_g2(p_cb->loc_publ_key.x, p_cb->peer_publ_key.x, p_cb->rand,
                               p_cb->rrand);
      } else {
          p_cb->number_to_display =
              smp_calculate_g2(p_cb->peer_publ_key.x, p_cb->loc_publ_key.x, p_cb->rrand,
                               p_cb->rand);
      }
  
      if (p_cb->number_to_display >= (BTM_MAX_PASSKEY_VAL + 1)) {
          UINT8 reason;
          reason = p_cb->failure = SMP_PAIR_FAIL_UNKNOWN;
          smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &reason);
          return;
      }
  
      SMP_TRACE_EVENT("Number to display in numeric comparison = %d", p_cb->number_to_display);
      p_cb->cb_evt = SMP_NC_REQ_EVT;
      smp_sm_event(p_cb, SMP_SC_DSPL_NC_EVT, &p_cb->number_to_display);
      return;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_g2
  **
  ** Description      The function calculates
  **                  g2(U, V, X, Y) = AES-CMAC (U||V||Y) mod 2**32 mod 10**6
  **                                           X
  **                  and
  **                  Vres = g2(U, V, X, Y) mod 10**6
  **                  where
  **                  input:  U     is 256 bit,
  **                          V     is 256 bit,
  **                          X     is 128 bit,
  **                          Y     is 128 bit,
  **
  ** Returns          Vres.
  **                  Expected value has to be in the range [0 - 999999] i.e. [0 - 0xF423F].
  **                  Vres = 1000000 means that the calculation fails.
  **
  ** Note             The LSB is the first octet, the MSB is the last octet of
  **                  the AES-CMAC input/output stream.
  **
  *******************************************************************************/
  UINT32 smp_calculate_g2(UINT8 *u, UINT8 *v, UINT8 *x, UINT8 *y)
  {
      UINT8   msg_len = BT_OCTET32_LEN /* U size */ + BT_OCTET32_LEN /* V size */
                        + BT_OCTET16_LEN /* Y size */;
      UINT8   msg[BT_OCTET32_LEN + BT_OCTET32_LEN + BT_OCTET16_LEN];
      UINT8   key[BT_OCTET16_LEN];
      UINT8   cmac[BT_OCTET16_LEN];
      UINT8   *p = NULL;
      UINT32  vres;
  #if SMP_DEBUG == TRUE
      UINT8   *p_prnt = NULL;
  #endif
  
      SMP_TRACE_DEBUG ("%s\n", __FUNCTION__);
  
      p = msg;
      ARRAY_TO_STREAM(p, y, BT_OCTET16_LEN);
      ARRAY_TO_STREAM(p, v, BT_OCTET32_LEN);
      ARRAY_TO_STREAM(p, u, BT_OCTET32_LEN);
  #if SMP_DEBUG == TRUE
      p_prnt = u;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"U", BT_OCTET32_LEN);
      p_prnt = v;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"V", BT_OCTET32_LEN);
      p_prnt = x;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"X", BT_OCTET16_LEN);
      p_prnt = y;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"Y", BT_OCTET16_LEN);
  #endif
  
      p = key;
      ARRAY_TO_STREAM(p, x, BT_OCTET16_LEN);
  #if SMP_DEBUG == TRUE
      p_prnt = key;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"K", BT_OCTET16_LEN);
  #endif
  
      if (!aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac)) {
          SMP_TRACE_ERROR("%s failed", __FUNCTION__);
          return (BTM_MAX_PASSKEY_VAL + 1);
      }
  
  #if SMP_DEBUG == TRUE
      p_prnt = cmac;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"AES-CMAC", BT_OCTET16_LEN);
  #endif
  
      /* vres = cmac mod 2**32 mod 10**6 */
      p = &cmac[0];
      STREAM_TO_UINT32(vres, p);
  #if SMP_DEBUG == TRUE
      p_prnt = (UINT8 *) &vres;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"cmac mod 2**32", 4);
  #endif
  
      while (vres > BTM_MAX_PASSKEY_VAL) {
          vres -= (BTM_MAX_PASSKEY_VAL + 1);
      }
  #if SMP_DEBUG == TRUE
      p_prnt = (UINT8 *) &vres;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"cmac mod 2**32 mod 10**6", 4);
  #endif
  
      SMP_TRACE_ERROR("Value for numeric comparison = %d", vres);
      return vres;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_f5
  **
  ** Description      The function provides two AES-CMAC that are supposed to be used as
  **                  - MacKey (MacKey is used in pairing DHKey check calculation);
  **                  - LTK (LTK is used to ecrypt the link after completion of Phase 2
  **                    and on reconnection, to derive BR/EDR LK).
  **                  The function inputs are W, N1, N2, A1, A2.
  **                  F5 rules:
  **                  - the value used as key in MacKey/LTK (T) is calculated
  **                    (function smp_calculate_f5_key(...));
  **                    The formula is:
  **                          T = AES-CMAC    (W)
  **                                      salt
  **                    where salt is internal parameter of smp_calculate_f5_key(...).
  **                  - MacKey and LTK are calculated as AES-MAC values received with the
  **                    key T calculated in the previous step and the plaintext message
  **                    built from the external parameters N1, N2, A1, A2 and the internal
  **                    parameters counter, keyID, length.
  **                    The function smp_calculate_f5_mackey_or_long_term_key(...) is used in the
  **                    calculations.
  **                    The same formula is used in calculation of MacKey and LTK and the
  **                    same parameter values except the value of the internal parameter
  **                    counter:
  **                    - in MacKey calculations the value is 0;
  **                    - in LTK calculations the value is 1.
  **                      MacKey  = AES-CMAC (Counter=0||keyID||N1||N2||A1||A2||Length=256)
  **                                        T
  **                      LTK     = AES-CMAC (Counter=1||keyID||N1||N2||A1||A2||Length=256)
  **                                        T
  **                  The parameters are
  **                  input:
  **                          W       is 256 bits,
  **                          N1      is 128 bits,
  **                          N2      is 128 bits,
  **                          A1 is 56 bit,
  **                          A2 is 56 bit.
  **                  internal:
  **                          Counter is 8 bits,  its value is 0 for MacKey,
  **                                                          1 for LTK;
  **                          KeyId   is 32 bits, its value is
  **                                              0x62746c65 (MSB~LSB);
  **                          Length  is 16 bits, its value is 0x0100
  **                                              (MSB~LSB).
  **                  output:
  **                          MacKey  is 128 bits;
  **                          LTK     is 128 bits
  **
  ** Returns          FALSE if out of resources, TRUE in other cases.
  **
  ** Note             The LSB is the first octet, the MSB is the last octet of
  **                  the AES-CMAC input/output stream.
  **
  *******************************************************************************/
  BOOLEAN smp_calculate_f5(UINT8 *w, UINT8 *n1, UINT8 *n2, UINT8 *a1, UINT8 *a2,
                           UINT8 *mac_key, UINT8 *ltk)
  {
      BT_OCTET16  t;    /* AES-CMAC output in smp_calculate_f5_key(...), key in */
      /* smp_calculate_f5_mackey_or_long_term_key(...) */
  #if SMP_DEBUG == TRUE
      UINT8   *p_prnt = NULL;
  #endif
      /* internal parameters: */
  
      /*
          counter is 0 for MacKey,
                  is 1 for LTK
      */
      UINT8   counter_mac_key[1]  = {0};
      UINT8   counter_ltk[1]      = {1};
      /*
          keyID   62746c65
      */
      UINT8   key_id[4] = {0x65, 0x6c, 0x74, 0x62};
      /*
          length  0100
      */
      UINT8   length[2] = {0x00, 0x01};
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  #if SMP_DEBUG == TRUE
      p_prnt = w;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"W", BT_OCTET32_LEN);
      p_prnt = n1;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"N1", BT_OCTET16_LEN);
      p_prnt = n2;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"N2", BT_OCTET16_LEN);
      p_prnt = a1;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"A1", 7);
      p_prnt = a2;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *) "A2", 7);
  #endif
  
      if (!smp_calculate_f5_key(w, t)) {
          SMP_TRACE_ERROR("%s failed to calc T", __FUNCTION__);
          return FALSE;
      }
  #if SMP_DEBUG == TRUE
      p_prnt = t;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"T", BT_OCTET16_LEN);
  #endif
  
      if (!smp_calculate_f5_mackey_or_long_term_key(t, counter_mac_key, key_id, n1, n2, a1, a2,
              length, mac_key)) {
          SMP_TRACE_ERROR("%s failed to calc MacKey", __FUNCTION__);
          return FALSE;
      }
  #if SMP_DEBUG == TRUE
      p_prnt = mac_key;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"MacKey", BT_OCTET16_LEN);
  #endif
  
      if (!smp_calculate_f5_mackey_or_long_term_key(t, counter_ltk, key_id, n1, n2, a1, a2,
              length, ltk)) {
          SMP_TRACE_ERROR("%s failed to calc LTK", __FUNCTION__);
          return FALSE;
      }
  #if SMP_DEBUG == TRUE
      p_prnt = ltk;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"LTK", BT_OCTET16_LEN);
  #endif
  
      return TRUE;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_f5_mackey_or_long_term_key
  **
  ** Description      The function calculates the value of MacKey or LTK by the rules
  **                  defined for f5 function.
  **                  At the moment exactly the same formula is used to calculate
  **                  LTK and MacKey.
  **                  The difference is the value of input parameter Counter:
  **                  - in MacKey calculations the value is 0;
  **                  - in LTK calculations the value is 1.
  **                  The formula:
  **                  mac = AES-CMAC (Counter||keyID||N1||N2||A1||A2||Length)
  **                                T
  **                  where
  **                  input:      T       is 256 bits;
  **                              Counter is 8 bits, its value is 0 for MacKey,
  **                                                              1 for LTK;
  **                              keyID   is 32 bits, its value is 0x62746c65;
  **                              N1      is 128 bits;
  **                              N2      is 128 bits;
  **                              A1      is 56 bits;
  **                              A2      is 56 bits;
  **                              Length  is 16 bits, its value is 0x0100
  **                  output:     LTK     is 128 bit.
  **
  ** Returns          FALSE if out of resources, TRUE in other cases.
  **
  ** Note             The LSB is the first octet, the MSB is the last octet of
  **                  the AES-CMAC input/output stream.
  **
  *******************************************************************************/
  BOOLEAN smp_calculate_f5_mackey_or_long_term_key(UINT8 *t, UINT8 *counter,
          UINT8 *key_id, UINT8 *n1, UINT8 *n2, UINT8 *a1, UINT8 *a2,
          UINT8 *length, UINT8 *mac)
  {
      UINT8   *p = NULL;
      UINT8   cmac[BT_OCTET16_LEN];
      UINT8   key[BT_OCTET16_LEN];
      UINT8   msg_len = 1 /* Counter size */ + 4 /* keyID size */ +
                        BT_OCTET16_LEN /* N1 size */ + BT_OCTET16_LEN /* N2 size */ +
                        7 /* A1 size*/ + 7 /* A2 size*/ + 2 /* Length size */;
      UINT8   msg[1 + 4 + BT_OCTET16_LEN + BT_OCTET16_LEN + 7 + 7 + 2];
      BOOLEAN ret = TRUE;
  #if SMP_DEBUG == TRUE
      UINT8   *p_prnt = NULL;
  #endif
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  #if SMP_DEBUG == TRUE
      p_prnt = t;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"T", BT_OCTET16_LEN);
      p_prnt = counter;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"Counter", 1);
      p_prnt = key_id;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"KeyID", 4);
      p_prnt = n1;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"N1", BT_OCTET16_LEN);
      p_prnt = n2;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"N2", BT_OCTET16_LEN);
      p_prnt = a1;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"A1", 7);
      p_prnt = a2;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"A2", 7);
      p_prnt = length;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"Length", 2);
  #endif
  
      p = key;
      ARRAY_TO_STREAM(p, t, BT_OCTET16_LEN);
  #if SMP_DEBUG == TRUE
      p_prnt = key;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"K", BT_OCTET16_LEN);
  #endif
      p = msg;
      ARRAY_TO_STREAM(p, length, 2);
      ARRAY_TO_STREAM(p, a2, 7);
      ARRAY_TO_STREAM(p, a1, 7);
      ARRAY_TO_STREAM(p, n2, BT_OCTET16_LEN);
      ARRAY_TO_STREAM(p, n1, BT_OCTET16_LEN);
      ARRAY_TO_STREAM(p, key_id, 4);
      ARRAY_TO_STREAM(p, counter, 1);
  #if SMP_DEBUG == TRUE
      p_prnt = msg;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"M", msg_len);
  #endif
  
      if (!aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac)) {
          SMP_TRACE_ERROR("%s failed", __FUNCTION__);
          ret = FALSE;
      }
  
  #if SMP_DEBUG == TRUE
      p_prnt = cmac;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"AES-CMAC", BT_OCTET16_LEN);
  #endif
  
      p = mac;
      ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
      return ret;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_f5_key
  **
  ** Description      The function calculates key T used in calculation of
  **                  MacKey and LTK (f5 output is defined as MacKey || LTK).
  **                  T = AES-CMAC    (W)
  **                              salt
  **                  where
  **                  Internal:   salt    is 128 bit.
  **                  input:      W       is 256 bit.
  **                  Output:     T       is 128 bit.
  **
  ** Returns          FALSE if out of resources, TRUE in other cases.
  **
  ** Note             The LSB is the first octet, the MSB is the last octet of
  **                  the AES-CMAC input/output stream.
  **
  *******************************************************************************/
  BOOLEAN smp_calculate_f5_key(UINT8 *w, UINT8 *t)
  {
      UINT8 *p = NULL;
      /* Please see 2.2.7 LE Secure Connections Key Generation Function f5 */
      /*
          salt:   6C88 8391 AAF5 A538 6037 0BDB 5A60 83BE
      */
      BT_OCTET16  salt = {
          0xBE, 0x83, 0x60, 0x5A, 0xDB, 0x0B, 0x37, 0x60,
          0x38, 0xA5, 0xF5, 0xAA, 0x91, 0x83, 0x88, 0x6C
      };
  #if SMP_DEBUG == TRUE
      UINT8   *p_prnt = NULL;
  #endif
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  #if SMP_DEBUG == TRUE
      p_prnt = salt;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"salt", BT_OCTET16_LEN);
      p_prnt = w;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"W", BT_OCTET32_LEN);
  #endif
  
      BT_OCTET16 key;
      BT_OCTET32 msg;
  
      p = key;
      ARRAY_TO_STREAM(p, salt, BT_OCTET16_LEN);
      p = msg;
      ARRAY_TO_STREAM(p, w, BT_OCTET32_LEN);
  #if SMP_DEBUG == TRUE
      p_prnt = key;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"K", BT_OCTET16_LEN);
      p_prnt = msg;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"M", BT_OCTET32_LEN);
  #endif
  
      BT_OCTET16 cmac;
      BOOLEAN ret = TRUE;
      if (!aes_cipher_msg_auth_code(key, msg, BT_OCTET32_LEN, BT_OCTET16_LEN, cmac)) {
          SMP_TRACE_ERROR("%s failed", __FUNCTION__);
          ret = FALSE;
      }
  
  #if SMP_DEBUG == TRUE
      p_prnt = cmac;
      smp_debug_print_nbyte_little_endian (p_prnt, (const UINT8 *)"AES-CMAC", BT_OCTET16_LEN);
  #endif
  
      p = t;
      ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
      return ret;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_local_dhkey_check
  **
  ** Description      The function calculates and saves local device DHKey check
  **                  value in CB.
  **                  Before doing this it calls smp_calculate_f5_mackey_and_long_term_key(...).
  **                  to calculate MacKey and LTK.
  **                  MacKey is used in dhkey calculation.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_calculate_local_dhkey_check(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UINT8   iocap[3], a[7], b[7];
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  
      smp_calculate_f5_mackey_and_long_term_key(p_cb);
  
      smp_collect_local_io_capabilities(iocap, p_cb);
  
      smp_collect_local_ble_address(a, p_cb);
      smp_collect_peer_ble_address(b, p_cb);
      smp_calculate_f6(p_cb->mac_key, p_cb->rand, p_cb->rrand, p_cb->peer_random, iocap, a, b,
                       p_cb->dhkey_check);
  
      SMP_TRACE_EVENT ("local DHKey check calculation is completed");
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_peer_dhkey_check
  **
  ** Description      The function calculates peer device DHKey check value.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_calculate_peer_dhkey_check(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
  {
      UINT8       iocap[3], a[7], b[7];
      BT_OCTET16  param_buf;
      BOOLEAN     ret;
      tSMP_KEY    key;
      tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  
      smp_collect_peer_io_capabilities(iocap, p_cb);
  
      smp_collect_local_ble_address(a, p_cb);
      smp_collect_peer_ble_address(b, p_cb);
      ret = smp_calculate_f6(p_cb->mac_key, p_cb->rrand, p_cb->rand, p_cb->local_random, iocap,
                             b, a, param_buf);
  
      if (ret) {
          SMP_TRACE_EVENT ("peer DHKey check calculation is completed");
  #if (SMP_DEBUG == TRUE)
          smp_debug_print_nbyte_little_endian (param_buf, (const UINT8 *)"peer DHKey check",
                                               BT_OCTET16_LEN);
  #endif
          key.key_type = SMP_KEY_TYPE_PEER_DHK_CHCK;
          key.p_data   = param_buf;
          smp_sm_event(p_cb, SMP_SC_KEY_READY_EVT, &key);
      } else {
          SMP_TRACE_EVENT ("peer DHKey check calculation failed");
          smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_f6
  **
  ** Description      The function calculates
  **                  C = f6(W, N1, N2, R, IOcap, A1, A2) = AES-CMAC (N1||N2||R||IOcap||A1||A2)
  **                                                                W
  **                  where
  **                  input:  W is 128 bit,
  **                          N1 is 128 bit,
  **                          N2 is 128 bit,
  **                          R is 128 bit,
  **                          IOcap is 24 bit,
  **                          A1 is 56 bit,
  **                          A2 is 56 bit,
  **                  output: C is 128 bit.
  **
  ** Returns          FALSE if out of resources, TRUE in other cases.
  **
  ** Note             The LSB is the first octet, the MSB is the last octet of
  **                  the AES-CMAC input/output stream.
  **
  *******************************************************************************/
  BOOLEAN smp_calculate_f6(UINT8 *w, UINT8 *n1, UINT8 *n2, UINT8 *r, UINT8 *iocap, UINT8 *a1,
                           UINT8 *a2, UINT8 *c)
  {
      UINT8   *p = NULL;
      UINT8   msg_len = BT_OCTET16_LEN /* N1 size */ + BT_OCTET16_LEN /* N2 size */ +
                        BT_OCTET16_LEN /* R size */ + 3 /* IOcap size */ + 7 /* A1 size*/
                        + 7 /* A2 size*/;
      UINT8   msg[BT_OCTET16_LEN + BT_OCTET16_LEN + BT_OCTET16_LEN + 3 + 7 + 7];
  #if SMP_DEBUG == TRUE
      UINT8   *p_print = NULL;
  #endif
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  #if SMP_DEBUG == TRUE
      p_print = w;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"W", BT_OCTET16_LEN);
      p_print = n1;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"N1", BT_OCTET16_LEN);
      p_print = n2;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"N2", BT_OCTET16_LEN);
      p_print = r;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"R", BT_OCTET16_LEN);
      p_print = iocap;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"IOcap", 3);
      p_print = a1;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"A1", 7);
      p_print = a2;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"A2", 7);
  #endif
  
      UINT8 cmac[BT_OCTET16_LEN];
      UINT8 key[BT_OCTET16_LEN];
  
      p = key;
      ARRAY_TO_STREAM(p, w, BT_OCTET16_LEN);
  #if SMP_DEBUG == TRUE
      p_print = key;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"K", BT_OCTET16_LEN);
  #endif
  
      p = msg;
      ARRAY_TO_STREAM(p, a2, 7);
      ARRAY_TO_STREAM(p, a1, 7);
      ARRAY_TO_STREAM(p, iocap, 3);
      ARRAY_TO_STREAM(p, r, BT_OCTET16_LEN);
      ARRAY_TO_STREAM(p, n2, BT_OCTET16_LEN);
      ARRAY_TO_STREAM(p, n1, BT_OCTET16_LEN);
  #if SMP_DEBUG == TRUE
      p_print = msg;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"M", msg_len);
  #endif
  
      BOOLEAN ret = TRUE;
      if (!aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac)) {
          SMP_TRACE_ERROR("%s failed", __FUNCTION__);
          ret = FALSE;
      }
  
  #if SMP_DEBUG == TRUE
      p_print = cmac;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"AES-CMAC", BT_OCTET16_LEN);
  #endif
  
      p = c;
      ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
      return ret;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_link_key_from_long_term_key
  **
  ** Description      The function calculates and saves BR/EDR link key derived from
  **                  LE SC LTK.
  **
  ** Returns          FALSE if out of resources, TRUE in other cases.
  **
  *******************************************************************************/
  BOOLEAN smp_calculate_link_key_from_long_term_key(tSMP_CB *p_cb)
  {
      tBTM_SEC_DEV_REC *p_dev_rec;
      BD_ADDR bda_for_lk;
      tBLE_ADDR_TYPE conn_addr_type;
  
      SMP_TRACE_DEBUG ("%s", __func__);
  
      if (p_cb->id_addr_rcvd && p_cb->id_addr_type == BLE_ADDR_PUBLIC) {
          SMP_TRACE_DEBUG ("Use rcvd identity address as BD_ADDR of LK rcvd identity address");
          memcpy(bda_for_lk, p_cb->id_addr, BD_ADDR_LEN);
      } else if ((BTM_ReadRemoteConnectionAddr(p_cb->pairing_bda, bda_for_lk, &conn_addr_type)) &&
                 conn_addr_type == BLE_ADDR_PUBLIC) {
          SMP_TRACE_DEBUG ("Use rcvd connection address as BD_ADDR of LK");
      } else {
          SMP_TRACE_WARNING ("Don't have peer public address to associate with LK");
          return FALSE;
      }
  
      if ((p_dev_rec = btm_find_dev (p_cb->pairing_bda)) == NULL) {
          SMP_TRACE_ERROR("%s failed to find Security Record", __func__);
          return FALSE;
      }
  
      BT_OCTET16 intermediate_link_key;
      BOOLEAN ret = TRUE;
  
      ret = smp_calculate_h6(p_cb->ltk, (UINT8 *)"1pmt" /* reversed "tmp1" */, intermediate_link_key);
      if (!ret) {
          SMP_TRACE_ERROR("%s failed to derive intermediate_link_key", __func__);
          return ret;
      }
  
      BT_OCTET16 link_key;
      ret = smp_calculate_h6(intermediate_link_key, (UINT8 *) "rbel" /* reversed "lebr" */, link_key);
      if (!ret) {
          SMP_TRACE_ERROR("%s failed", __func__);
      } else {
          UINT8 link_key_type;
          if (btm_cb.security_mode == BTM_SEC_MODE_SC) {
              /* Secure Connections Only Mode */
              link_key_type = BTM_LKEY_TYPE_AUTH_COMB_P_256;
          } else if (controller_get_interface()->supports_secure_connections()) {
              /* both transports are SC capable */
              if (p_cb->sec_level == SMP_SEC_AUTHENTICATED) {
                  link_key_type = BTM_LKEY_TYPE_AUTH_COMB_P_256;
              } else {
                  link_key_type = BTM_LKEY_TYPE_UNAUTH_COMB_P_256;
              }
          } else if (btm_cb.security_mode == BTM_SEC_MODE_SP) {
              /* BR/EDR transport is SSP capable */
              if (p_cb->sec_level == SMP_SEC_AUTHENTICATED) {
                  link_key_type = BTM_LKEY_TYPE_AUTH_COMB;
              } else {
                  link_key_type = BTM_LKEY_TYPE_UNAUTH_COMB;
              }
          } else {
              SMP_TRACE_ERROR ("%s failed to update link_key. Sec Mode = %d, sm4 = 0x%02x",
                               __func__, btm_cb.security_mode, p_dev_rec->sm4);
              return FALSE;
          }
  
          link_key_type += BTM_LTK_DERIVED_LKEY_OFFSET;
  
          UINT8 *p;
          BT_OCTET16 notif_link_key;
          p = notif_link_key;
          ARRAY16_TO_STREAM(p, link_key);
  
          btm_sec_link_key_notification (bda_for_lk, notif_link_key, link_key_type);
  
          SMP_TRACE_EVENT ("%s is completed", __func__);
      }
  
      return ret;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_long_term_key_from_link_key
  **
  ** Description      The function calculates and saves SC LTK derived from BR/EDR
  **                  link key.
  **
  ** Returns          FALSE if out of resources, TRUE in other cases.
  **
  *******************************************************************************/
  BOOLEAN smp_calculate_long_term_key_from_link_key(tSMP_CB *p_cb)
  {
      BOOLEAN ret = TRUE;
      tBTM_SEC_DEV_REC *p_dev_rec;
      UINT8 rev_link_key[16];
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  
      if ((p_dev_rec = btm_find_dev (p_cb->pairing_bda)) == NULL) {
          SMP_TRACE_ERROR("%s failed to find Security Record", __FUNCTION__);
          return FALSE;
      }
  
      UINT8 br_link_key_type;
      if ((br_link_key_type = BTM_SecGetDeviceLinkKeyType (p_cb->pairing_bda))
              == BTM_LKEY_TYPE_IGNORE) {
          SMP_TRACE_ERROR("%s failed to retrieve BR link type", __FUNCTION__);
          return FALSE;
      }
  
      if ((br_link_key_type != BTM_LKEY_TYPE_AUTH_COMB_P_256) &&
              (br_link_key_type != BTM_LKEY_TYPE_UNAUTH_COMB_P_256)) {
          SMP_TRACE_ERROR("%s LE SC LTK can't be derived from LK %d",
                          __FUNCTION__, br_link_key_type);
          return FALSE;
      }
  
      UINT8 *p1;
      UINT8 *p2;
      p1 = rev_link_key;
      p2 = p_dev_rec->link_key;
      REVERSE_ARRAY_TO_STREAM(p1, p2, 16);
  
      BT_OCTET16 intermediate_long_term_key;
      /* "tmp2" obtained from the spec */
      ret = smp_calculate_h6(rev_link_key, (UINT8 *) "2pmt" /* reversed "tmp2" */,
                             intermediate_long_term_key);
  
      if (!ret) {
          SMP_TRACE_ERROR("%s failed to derive intermediate_long_term_key", __FUNCTION__);
          return ret;
      }
  
      /* "brle" obtained from the spec */
      ret = smp_calculate_h6(intermediate_long_term_key, (UINT8 *) "elrb" /* reversed "brle" */,
                             p_cb->ltk);
  
      if (!ret) {
          SMP_TRACE_ERROR("%s failed", __FUNCTION__);
      } else {
          p_cb->sec_level = (br_link_key_type == BTM_LKEY_TYPE_AUTH_COMB_P_256)
                            ? SMP_SEC_AUTHENTICATED : SMP_SEC_UNAUTHENTICATE;
          SMP_TRACE_EVENT ("%s is completed", __FUNCTION__);
      }
  
      return ret;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_calculate_h6
  **
  ** Description      The function calculates
  **                  C = h6(W, KeyID) = AES-CMAC (KeyID)
  **                                             W
  **                  where
  **                  input:  W is 128 bit,
  **                          KeyId is 32 bit,
  **                  output: C is 128 bit.
  **
  ** Returns          FALSE if out of resources, TRUE in other cases.
  **
  ** Note             The LSB is the first octet, the MSB is the last octet of
  **                  the AES-CMAC input/output stream.
  **
  *******************************************************************************/
  BOOLEAN smp_calculate_h6(UINT8 *w, UINT8 *keyid, UINT8 *c)
  {
  #if SMP_DEBUG == TRUE
      UINT8   *p_print = NULL;
  #endif
  
      SMP_TRACE_DEBUG ("%s", __FUNCTION__);
  #if SMP_DEBUG == TRUE
      p_print = w;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"W", BT_OCTET16_LEN);
      p_print = keyid;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"keyID", 4);
  #endif
  
      UINT8 *p = NULL;
      UINT8 key[BT_OCTET16_LEN];
  
      p = key;
      ARRAY_TO_STREAM(p, w, BT_OCTET16_LEN);
  
  #if SMP_DEBUG == TRUE
      p_print = key;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"K", BT_OCTET16_LEN);
  #endif
  
      UINT8 msg_len = 4 /* KeyID size */;
      UINT8 msg[4];
  
      p = msg;
      ARRAY_TO_STREAM(p, keyid, 4);
  
  #if SMP_DEBUG == TRUE
      p_print = msg;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *) "M", msg_len);
  #endif
  
      BOOLEAN ret = TRUE;
      UINT8 cmac[BT_OCTET16_LEN];
      if (!aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac)) {
          SMP_TRACE_ERROR("%s failed", __FUNCTION__);
          ret = FALSE;
      }
  
  #if SMP_DEBUG == TRUE
      p_print = cmac;
      smp_debug_print_nbyte_little_endian (p_print, (const UINT8 *)"AES-CMAC", BT_OCTET16_LEN);
  #endif
  
      p = c;
      ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
      return ret;
  }
  
  /*******************************************************************************
  **
  ** Function         smp_start_nonce_generation
  **
  ** Description      This function starts nonce generation.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_start_nonce_generation(tSMP_CB *p_cb)
  {
      SMP_TRACE_DEBUG("%s", __FUNCTION__);
      p_cb->rand_enc_proc_state = SMP_GEN_NONCE_0_7;
      if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
          smp_rand_back(NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_finish_nonce_generation
  **
  ** Description      This function finishes nonce generation.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_finish_nonce_generation(tSMP_CB *p_cb)
  {
      SMP_TRACE_DEBUG("%s", __FUNCTION__);
      p_cb->rand_enc_proc_state = SMP_GEN_NONCE_8_15;
      if (!btsnd_hcic_ble_rand((void *)smp_rand_back)) {
          smp_rand_back(NULL);
      }
  }
  
  /*******************************************************************************
  **
  ** Function         smp_process_new_nonce
  **
  ** Description      This function notifies SM that it has new nonce.
  **
  ** Returns          void
  **
  *******************************************************************************/
  void smp_process_new_nonce(tSMP_CB *p_cb)
  {
      SMP_TRACE_DEBUG ("%s round %d", __FUNCTION__, p_cb->round);
      smp_sm_event(p_cb, SMP_HAVE_LOC_NONCE_EVT, NULL);
  }
  
  /*******************************************************************************
  **
  ** Function         smp_rand_back
  **
  ** Description      This function is to process the rand command finished,
  **                  process the random/encrypted number for further action.
  **
  ** Returns          void
  **
  *******************************************************************************/
  static void smp_rand_back(tBTM_RAND_ENC *p)
  {
      tSMP_CB *p_cb = &smp_cb;
      UINT8   *pp = p->param_buf;
      UINT8   failure = SMP_PAIR_FAIL_UNKNOWN;
      UINT8   state = p_cb->rand_enc_proc_state & ~0x80;
  
      SMP_TRACE_DEBUG ("%s state=0x%x", __FUNCTION__, state);
      if (p && p->status == HCI_SUCCESS) {
          switch (state) {
          case SMP_GEN_SRAND_MRAND:
              memcpy((void *)p_cb->rand, p->param_buf, p->param_len);
              smp_generate_rand_cont(p_cb, NULL);
              break;
  
          case SMP_GEN_SRAND_MRAND_CONT:
              memcpy((void *)&p_cb->rand[8], p->param_buf, p->param_len);
              smp_generate_confirm(p_cb, NULL);
              break;
  
          case SMP_GEN_DIV_LTK:
              STREAM_TO_UINT16(p_cb->div, pp);
              smp_generate_ltk_cont(p_cb, NULL);
              break;
  
          case SMP_GEN_DIV_CSRK:
              STREAM_TO_UINT16(p_cb->div, pp);
              smp_compute_csrk(p_cb, NULL);
              break;
  
          case SMP_GEN_TK:
              smp_proc_passkey(p_cb, p);
              break;
  
          case SMP_GEN_RAND_V:
              memcpy(p_cb->enc_rand, p->param_buf, BT_OCTET8_LEN);
              smp_generate_y(p_cb, NULL);
              break;
  
          case SMP_GENERATE_PRIVATE_KEY_0_7:
          case SMP_GENERATE_PRIVATE_KEY_8_15:
          case SMP_GENERATE_PRIVATE_KEY_16_23:
          case SMP_GENERATE_PRIVATE_KEY_24_31:
              smp_continue_private_key_creation(p_cb, p);
              break;
  
          case SMP_GEN_NONCE_0_7:
              memcpy((void *)p_cb->rand, p->param_buf, p->param_len);
              smp_finish_nonce_generation(p_cb);
              break;
  
          case SMP_GEN_NONCE_8_15:
              memcpy((void *)&p_cb->rand[8], p->param_buf, p->param_len);
              smp_process_new_nonce(p_cb);
              break;
          }
  
          return;
      }
  
      SMP_TRACE_ERROR("%s key generation failed: (%d)", __FUNCTION__, p_cb->rand_enc_proc_state);
      smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &failure);
  }
  
  #endif
  
  