text: /*************************************************************************************************/
  /*!
   *  \file
   *
   *  \brief  WSF Security ECC implementation using HCI.
   *
   *  Copyright (c) 2010-2018 Arm Ltd. All Rights Reserved.
   *
   *  Copyright (c) 2019 Packetcraft, Inc.
   *  
   *  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.
   */
  /*************************************************************************************************/
  
  #include <stdlib.h>
  #include <time.h>
  #include <string.h>
  #include "wsf_types.h"
  #include "wsf_queue.h"
  #include "wsf_msg.h"
  #include "wsf_trace.h"
  #include "sec_api.h"
  #include "sec_main.h"
  #include "wsf_buf.h"
  #include "hci_api.h"
  #include "util/calc128.h"
  #include "util/wstr.h"
  
  #ifndef SEC_ECC_CFG
  #define SEC_ECC_CFG SEC_ECC_CFG_HCI
  #endif
  
  #if SEC_ECC_CFG == SEC_ECC_CFG_HCI
  
  /**************************************************************************************************
  External Variables
  **************************************************************************************************/
  
  extern secCb_t secCb;
  
  /**************************************************************************************************
  Local Variables
  **************************************************************************************************/
  
  /*************************************************************************************************/
  /*!
   *  \brief  Callback for HCI encryption for ECC operations.
   *
   *  \param  pBuf        Pointer to sec queue element.
   *  \param  pEvent      Pointer to HCI event.
   *  \param  handlerId   WSF handler ID.
   *
   *  \return none.
   */
  /*************************************************************************************************/
  void SecEccHciCback(secQueueBuf_t *pBuf, hciEvt_t *pEvent, wsfHandlerId_t handlerId)
  {
    secEccMsg_t *pMsg = (secEccMsg_t *) &pBuf->msg;
  
    if (pEvent->hdr.event == HCI_LE_READ_LOCAL_P256_PUB_KEY_CMPL_CBACK_EVT)
    {
      /* Reverse copy the public key (to big endian) */
      WStrReverseCpy(pMsg->data.key.pubKey_x, pEvent->leP256.key, SEC_ECC_KEY_LEN);
      WStrReverseCpy(pMsg->data.key.pubKey_y, pEvent->leP256.key + SEC_ECC_KEY_LEN, SEC_ECC_KEY_LEN);
  
      /* Send shared secret to handler */
      pMsg->hdr.status = pEvent->leP256.status;
      WsfMsgSend(handlerId, pMsg);
    }
    else if (pEvent->hdr.event == HCI_LE_GENERATE_DHKEY_CMPL_CBACK_EVT)
    {
      /* Reverse copy the DH key (to big endian) */
      WStrReverseCpy(pMsg->data.sharedSecret.secret, pEvent->leGenDHKey.key, SEC_ECC_KEY_LEN);
  
      /* Send shared secret to handler */
      pMsg->hdr.status = pEvent->leGenDHKey.status;
      WsfMsgSend(handlerId, pMsg);
    }
  }
  
  /*************************************************************************************************/
  /*!
   *  \brief  Generate an ECC key.
   *
   *  \param  handlerId   WSF handler ID for client.
   *  \param  param       Optional parameter sent to client's WSF handler.
   *  \param  event       Event for client's WSF handler.
   *
   *  \return TRUE if successful, else FALSE.
   */
  /*************************************************************************************************/
  bool_t SecEccGenKey(wsfHandlerId_t handlerId, uint16_t param, uint8_t event)
  {
    secQueueBuf_t *pBuf;
    uint16_t bufSize = sizeof(secQueueBuf_t) + sizeof(secEccMsg_t);
  
    if ((pBuf = WsfMsgAlloc(bufSize)) != NULL)
    {
      /* Record the event and parameter for use in the HCI response */
      pBuf->msg.hdr.param = param;
      pBuf->msg.hdr.event = event;
      pBuf->type = SEC_TYPE_DH;
  
      /* queue buffer */
      WsfMsgEnq(&secCb.pubKeyQueue, handlerId, pBuf);
  
      /* Request the local public key via HCI */
      HciLeReadLocalP256PubKey();
  
      return TRUE;
    }
  
    return FALSE;
  }
  
  /*************************************************************************************************/
  /*!
   *  \brief  Generate an ECC key.
   *
   *  \param  pKey        ECC Key structure.
   *  \param  handlerId   WSF handler ID for client.
   *  \param  param       Optional parameter sent to client's WSF handler.
   *  \param  event       Event for client's WSF handler.
   *
   *  \return TRUE if successful, else FALSE.
   */
  /*************************************************************************************************/
  bool_t SecEccGenSharedSecret(secEccKey_t *pKey, wsfHandlerId_t handlerId, uint16_t param, uint8_t event)
  {
    secQueueBuf_t *pBuf;
    uint16_t bufSize = sizeof(secQueueBuf_t) + sizeof(secEccMsg_t);
  
    if ((pBuf = WsfMsgAlloc(bufSize)) != NULL)
    {
      uint8_t pubKeyX[SEC_ECC_KEY_LEN];
      uint8_t pubKeyY[SEC_ECC_KEY_LEN];
  
      /* Record the event and parameter for use in the HCI response */
      pBuf->msg.hdr.param = param;
      pBuf->msg.hdr.event = event;
      pBuf->type = SEC_TYPE_DH;
  
      /* queue buffer */
      WsfMsgEnq(&secCb.dhKeyQueue, handlerId, pBuf);
  
      /* Reverse keys (to little endian) */
      WStrReverseCpy(pubKeyX, pKey->pubKey_x, SEC_ECC_KEY_LEN);
      WStrReverseCpy(pubKeyY, pKey->pubKey_y, SEC_ECC_KEY_LEN);
  
      /* Request the DH Key via HCI */
      HciLeGenerateDHKey(pubKeyX, pubKeyY);
  
      return TRUE;
    }
  
    return FALSE;
  }
  
  /*************************************************************************************************/
  /*!
   *  \brief  Called to initialize ECC security.
   *
   *  \param  None.
   *
   *  \return None.
   */
  /*************************************************************************************************/
  void SecEccInit()
  {
    secCb.hciCbackTbl[SEC_TYPE_DH] = SecEccHciCback;
  }
  
  #endif /* SEC_ECC_CFG */
  