text: /**
   * Copyright (c) 2018 - 2019, Nordic Semiconductor ASA
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form, except as embedded into a Nordic
   *    Semiconductor ASA integrated circuit in a product or a software update for
   *    such product, must reproduce the above copyright notice, this list of
   *    conditions and the following disclaimer in the documentation and/or other
   *    materials provided with the distribution.
   *
   * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
   *    contributors may be used to endorse or promote products derived from this
   *    software without specific prior written permission.
   *
   * 4. This software, with or without modification, must only be used with a
   *    Nordic Semiconductor ASA integrated circuit.
   *
   * 5. Any software provided in binary form under this license must not be reverse
   *    engineered, decompiled, modified and/or disassembled.
   *
   * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
   * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
   * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   */
  
  #include "sdk_config.h"
  #include "nordic_common.h"
  
  #if NRF_MODULE_ENABLED(NRF_CRYPTO) && NRF_MODULE_ENABLED(NRF_CRYPTO_BACKEND_OPTIGA)
  
  #include <stdint.h>
  #include <stdbool.h>
  #include <string.h>
  
  #include "nrf_crypto_ecc.h"
  #include "nrf_crypto_ecdsa.h"
  
  /*lint -save -e????*/
  #include "optiga/optiga_crypt.h"
  #include "ecdsa_utils.h"
  /*lint -restore*/
  
  ret_code_t nrf_crypto_backend_optiga_sign(
      void           * p_context,
      void     const * p_private_key,
      uint8_t  const * p_data,
      size_t           data_size,
      uint8_t        * p_signature)
  {
      optiga_lib_status_t res = OPTIGA_LIB_ERROR;
      nrf_crypto_backend_optiga_ecc_private_key_t * p_prv =
              (nrf_crypto_backend_optiga_ecc_private_key_t *)p_private_key;
  
      optiga_key_id_t oid = p_prv->oid;
  
      uint16_t der_sig_len = NRF_CRYPTO_ECDSA_SECP256R1_SIGNATURE_SIZE + ECDSA_RS_MAX_ASN1_OVERHEAD;
      uint8_t der_sig[NRF_CRYPTO_ECDSA_SECP256R1_SIGNATURE_SIZE + ECDSA_RS_MAX_ASN1_OVERHEAD] = {0};
  
      res = optiga_crypt_ecdsa_sign((uint8_t *)p_data, data_size, oid, der_sig, &der_sig_len);
      if(res != OPTIGA_LIB_SUCCESS) {
          return NRF_ERROR_CRYPTO_INTERNAL;
      }
  
      // convert signature to format suitable for nrf_crypto
      if (!asn1_to_ecdsa_rs(der_sig, der_sig_len,
                            p_signature, NRF_CRYPTO_ECDSA_SECP256R1_SIGNATURE_SIZE))
      {
          return NRF_ERROR_CRYPTO_INTERNAL;
      }
  
      return NRF_SUCCESS;
  }
  
  ret_code_t nrf_crypto_backend_optiga_verify(
      void           * p_context,
      void     const * p_public_key,
      uint8_t  const * p_data,
      size_t           data_size,
      uint8_t  const * p_signature)
  {
      nrf_crypto_backend_secp256r1_public_key_t * p_pub =
              (nrf_crypto_backend_secp256r1_public_key_t *)p_public_key;
  
      optiga_key_id_t oid = p_pub->oid;
  
      size_t der_sig_len = NRF_CRYPTO_ECDSA_SECP256R1_SIGNATURE_SIZE + ECDSA_RS_MAX_ASN1_OVERHEAD;
      uint8_t der_sig[NRF_CRYPTO_ECDSA_SECP256R1_SIGNATURE_SIZE + ECDSA_RS_MAX_ASN1_OVERHEAD] = {0};
  
      const size_t rs_size = NRF_CRYPTO_ECDSA_SECP256R1_SIGNATURE_SIZE/2;
  
      optiga_lib_status_t res = OPTIGA_LIB_ERROR;
  
      // Convert signature to DER format needed by OPTIGA
      if (!ecdsa_rs_to_asn1_integers(p_signature,
                                     p_signature + rs_size,
                                     rs_size,
                                     der_sig,
                                     &der_sig_len))
      {
          return  NRF_ERROR_CRYPTO_INTERNAL;
      }
  
      if (oid == NRF_CRYPTO_INFINEON_PUBKEY_HOST_OID)
      {
          // Create magic OID for pubkey from host
          public_key_from_host_t pub_key = {
              .public_key = p_pub->raw_pubkey,
              .length = NRF_CRYPTO_ECC_SECP256R1_RAW_PUBLIC_KEY_SIZE + 4,   // public key + DER BITSTRING header
              .curve = OPTIGA_ECC_NIST_P_256
          };
  
          res = optiga_crypt_ecdsa_verify((uint8_t *)p_data,
                                          data_size,
                                          der_sig,
                                          der_sig_len,
                                          OPTIGA_CRYPT_HOST_DATA,
                                          &pub_key);
      }
      else
      {
          // Public key is in OPTIGA, referenced by OID
          res = optiga_crypt_ecdsa_verify((uint8_t *)p_data,
                                          data_size,
                                          der_sig,
                                          der_sig_len,
                                          OPTIGA_CRYPT_OID_DATA,
                                          &oid);
      }
  
      // consider everything that is not success a signature failure
      if (res != OPTIGA_LIB_SUCCESS)
      {
          return NRF_ERROR_CRYPTO_ECDSA_INVALID_SIGNATURE;
      }
  
      return NRF_SUCCESS;
  }
  
  
  #endif // NRF_MODULE_ENABLED(NRF_CRYPTO) && NRF_MODULE_ENABLED(NRF_CRYPTO_BACKEND_OPTIGA)
  