/*
 *  Copyright (c) 2016, The OpenThread Authors.
 *  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 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 the copyright holder nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER 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
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 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file
 *   This file implements HMAC SHA-256.
 */

#include <crypto/hmac_sha256.hpp>

namespace Thread {
namespace Crypto {

void HmacSha256::Start(const uint8_t *aKey, uint16_t aKeyLength)
{
    const mbedtls_md_info_t *mdInfo = NULL;
    mbedtls_md_init(&mContext);
    mdInfo = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
    mbedtls_md_setup(&mContext, mdInfo, 1);
    mbedtls_md_hmac_starts(&mContext, aKey, aKeyLength);
}

void HmacSha256::Update(const uint8_t *aBuf, uint16_t aBufLength)
{
    mbedtls_md_hmac_update(&mContext, aBuf, aBufLength);
}

void HmacSha256::Finish(uint8_t aHash[kHashSize])
{
    mbedtls_md_hmac_finish(&mContext, aHash);
    mbedtls_md_free(&mContext);
}

}  // namespace Crypto
}  // namespace Thread
