/**
 * Copyright (c) 2016 - 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.
 *
 */
/**
 * @brief Elliptic Curve Cryptography Interface
 *
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nordic_common.h"
#include "app_timer.h"
#include "app_util.h"
#include "nrf_log.h"
#include "nrf_drv_rng.h"
#include "ecc.h"

#include "uECC.h"


static int ecc_rng(uint8_t *dest, unsigned size)
{
    nrf_drv_rng_block_rand(dest, (uint32_t) size);
    return 1;
}

void ecc_init(bool rng)
{
    if (rng)
    {
        uECC_set_rng(ecc_rng);
    }
}

ret_code_t ecc_p256_keypair_gen(uint8_t *p_le_sk, uint8_t *p_le_pk)
{
    const struct uECC_Curve_t * p_curve;

    if (!p_le_sk || !p_le_pk)
    {
        return NRF_ERROR_NULL;
    }

    if (!is_word_aligned(p_le_sk) || !is_word_aligned(p_le_pk))
    {
        return NRF_ERROR_INVALID_ADDR;
    }

    p_curve = uECC_secp256r1();

    int ret = uECC_make_key((uint8_t *) p_le_pk, (uint8_t *) p_le_sk, p_curve);
    if (!ret)
    {
        return NRF_ERROR_INTERNAL;
    }

    return NRF_SUCCESS;
}

ret_code_t ecc_p256_public_key_compute(uint8_t const *p_le_sk, uint8_t *p_le_pk)
{
    const struct uECC_Curve_t * p_curve;

    if (!p_le_sk || !p_le_pk)
    {
        return NRF_ERROR_NULL;
    }

    if (!is_word_aligned(p_le_sk) || !is_word_aligned(p_le_pk))
    {
        return NRF_ERROR_INVALID_ADDR;
    }

    p_curve = uECC_secp256r1();

    //NRF_LOG_INFO("uECC_compute_public_key");
    int ret = uECC_compute_public_key((uint8_t *) p_le_sk, (uint8_t *) p_le_pk, p_curve);
    if (!ret)
    {
        return NRF_ERROR_INTERNAL;
    }

    //NRF_LOG_INFO("uECC_compute_public_key complete: %d", ret);
    return NRF_SUCCESS;
}

ret_code_t ecc_p256_shared_secret_compute(uint8_t const *p_le_sk, uint8_t const *p_le_pk, uint8_t *p_le_ss)
{
    int ret;
    const struct uECC_Curve_t * p_curve;

    if (!p_le_sk || !p_le_pk || !p_le_ss)
    {
        return NRF_ERROR_NULL;
    }

    if (!is_word_aligned(p_le_sk) || !is_word_aligned(p_le_pk) || !is_word_aligned(p_le_ss))
    {
        return NRF_ERROR_INVALID_ADDR;
    }

    p_curve = uECC_secp256r1();
    
    
    // Validate the remote public key
    ret = uECC_valid_public_key((uint8_t*) p_le_pk, p_curve);
    if (!ret)
    {
        return NRF_ERROR_INTERNAL;
    }
    
    //NRF_LOG_INFO("uECC_shared_secret");
    ret = uECC_shared_secret((uint8_t *) p_le_pk, (uint8_t *) p_le_sk, p_le_ss, p_curve);
    if (!ret)
    {
        return NRF_ERROR_INTERNAL;
    }

    //NRF_LOG_INFO("uECC_shared_secret complete: %d", ret);
    return NRF_SUCCESS;
}

ret_code_t ecc_p256_sign(uint8_t const *p_le_sk, uint8_t const * p_le_hash, uint32_t hlen, uint8_t *p_le_sig)
{
    const struct uECC_Curve_t * p_curve;

    if (!p_le_sk || !p_le_hash || !p_le_sig)
    {
        return NRF_ERROR_NULL;
    }

    if (!is_word_aligned(p_le_sk) || !is_word_aligned(p_le_hash) || !is_word_aligned(p_le_sig))
    {
        return NRF_ERROR_INVALID_ADDR;
    }

    p_curve = uECC_secp256r1();

    //NRF_LOG_INFO("uECC_sign");
    int ret = uECC_sign((const uint8_t *) p_le_sk, (const uint8_t *) p_le_hash, (unsigned) hlen, (uint8_t *) p_le_sig, p_curve);
    if (!ret)
    {
        return NRF_ERROR_INTERNAL;
    }

    //NRF_LOG_INFO("uECC_sign complete: %d", ret);
    return NRF_SUCCESS;
}

ret_code_t ecc_p256_verify(uint8_t const *p_le_pk, uint8_t const * p_le_hash, uint32_t hlen, uint8_t const *p_le_sig)
{
    const struct uECC_Curve_t * p_curve;

    if (!p_le_pk || !p_le_hash || !p_le_sig)
    {
        return NRF_ERROR_NULL;
    }

    if (!is_word_aligned(p_le_pk) || !is_word_aligned(p_le_hash) || !is_word_aligned(p_le_sig))
    {
        return NRF_ERROR_INVALID_ADDR;
    }

    p_curve = uECC_secp256r1();

    //NRF_LOG_INFO("uECC_verify");
    int ret = uECC_verify((const uint8_t *) p_le_pk, (const uint8_t *) p_le_hash, (unsigned) hlen, (uint8_t *) p_le_sig, p_curve);
    if (!ret)
    {
        return NRF_ERROR_INVALID_DATA;
    }

    //NRF_LOG_INFO("uECC_verify complete: %d", ret);
    return NRF_SUCCESS;

}