/**
 * Copyright (c) 2018 - 2018, 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_MBEDTLS)

#include <stdint.h>
#include <stdbool.h>
#include <string.h>

#include "nrf_crypto_ecc.h"
#include "nrf_crypto_ecdsa.h"

/*lint -save -e????*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include "mbedtls/ecp.h"
#include "mbedtls/ecdsa.h"
#include "mbedtls/sha256.h"
#include "mbedtls/sha512.h"
/*lint -restore*/


ret_code_t nrf_crypto_backend_mbedtls_sign(
    void           * p_context,
    void     const * p_private_key,
    uint8_t  const * p_data,
    size_t           data_size,
    uint8_t        * p_signature)
{
    int               result;
    mbedtls_mpi       r_mpi;
    mbedtls_mpi       s_mpi;
    mbedtls_ecp_group group;

    nrf_crypto_backend_mbedtls_ecc_private_key_t const * p_prv =
        (nrf_crypto_backend_mbedtls_ecc_private_key_t const *)p_private_key;

    nrf_crypto_ecc_curve_info_t const * p_info = p_prv->header.p_info;

    if (!nrf_crypto_backend_mbedtls_ecc_group_load(&group, p_info))
    {
        return NRF_ERROR_CRYPTO_INTERNAL;
    }

    mbedtls_mpi_init(&r_mpi);
    mbedtls_mpi_init(&s_mpi);
    result = mbedtls_ecdsa_sign(&group,
                                &r_mpi,
                                &s_mpi,
                                &p_prv->key,
                                p_data,
                                data_size,
                                nrf_crypto_backend_mbedtls_ecc_mbedtls_rng,
                                NULL);

    mbedtls_ecp_group_free(&group);

    if (result == 0)
    {
        result = mbedtls_mpi_write_binary(&r_mpi, p_signature, p_info->raw_private_key_size);
        if (result == 0)
        {
            result = mbedtls_mpi_write_binary(&s_mpi,
                                              &p_signature[p_info->raw_private_key_size],
                                              p_info->raw_private_key_size);
        }
    }

    mbedtls_mpi_free(&r_mpi);
    mbedtls_mpi_free(&s_mpi);

    if (result != 0)
    {
        return NRF_ERROR_CRYPTO_INTERNAL;
    }
    return NRF_SUCCESS;
}


ret_code_t nrf_crypto_backend_mbedtls_verify(
    void           * p_context,
    void     const * p_public_key,
    uint8_t  const * p_data,
    size_t           data_size,
    uint8_t  const * p_signature)
{
    int               result;
    mbedtls_mpi       r_mpi;
    mbedtls_mpi       s_mpi;
    mbedtls_ecp_group group;

    nrf_crypto_backend_mbedtls_ecc_public_key_t const * p_pub =
        (nrf_crypto_backend_mbedtls_ecc_public_key_t const *)p_public_key;

    nrf_crypto_ecc_curve_info_t const * p_info = p_pub->header.p_info;

    if (!nrf_crypto_backend_mbedtls_ecc_group_load(&group, p_info))
    {
        return NRF_ERROR_CRYPTO_INTERNAL;
    }

    mbedtls_mpi_init(&r_mpi);
    mbedtls_mpi_init(&s_mpi);

    result = mbedtls_mpi_read_binary(&r_mpi, p_signature, p_info->raw_private_key_size);
    if (result == 0)
    {
        result = mbedtls_mpi_read_binary(&s_mpi,
                                         &p_signature[p_info->raw_private_key_size],
                                         p_info->raw_private_key_size);
        if (result == 0)
        {
            result = mbedtls_ecdsa_verify(&group, p_data, data_size, &p_pub->key, &r_mpi, &s_mpi);
        }
    }

    mbedtls_ecp_group_free(&group);
    mbedtls_mpi_free(&r_mpi);
    mbedtls_mpi_free(&s_mpi);

    if (result == MBEDTLS_ERR_ECP_VERIFY_FAILED)
    {
        return NRF_ERROR_CRYPTO_ECDSA_INVALID_SIGNATURE;
    }
    else if (result != 0)
    {
        return NRF_ERROR_CRYPTO_INTERNAL;
    }
    return NRF_SUCCESS;
}


#endif // NRF_MODULE_ENABLED(NRF_CRYPTO) && NRF_MODULE_ENABLED(NRF_CRYPTO_BACKEND_MBEDTLS)