/*
 *  Copyright (c) 2016, The OpenThread Authors.
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 *  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
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 */

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

#include "hmac_sha256.hpp"
#include "common/debug.hpp"
#include "common/error.hpp"
#include "common/message.hpp"

namespace ot {
namespace Crypto {

HmacSha256::HmacSha256(void)
{
    mContext.mContext     = mContextStorage;
    mContext.mContextSize = sizeof(mContextStorage);

    SuccessOrAssert(otPlatCryptoHmacSha256Init(&mContext));
}

HmacSha256::~HmacSha256(void)
{
    SuccessOrAssert(otPlatCryptoHmacSha256Deinit(&mContext));
}

void HmacSha256::Start(const Key &aKey)
{
    SuccessOrAssert(otPlatCryptoHmacSha256Start(&mContext, &aKey));
}

void HmacSha256::Update(const void *aBuf, uint16_t aBufLength)
{
    SuccessOrAssert(otPlatCryptoHmacSha256Update(&mContext, aBuf, aBufLength));
}

void HmacSha256::Finish(Hash &aHash)
{
    SuccessOrAssert(otPlatCryptoHmacSha256Finish(&mContext, aHash.m8, Hash::kSize));
}

void HmacSha256::Update(const Message &aMessage, uint16_t aOffset, uint16_t aLength)
{
    Message::Chunk chunk;

    aMessage.GetFirstChunk(aOffset, aLength, chunk);

    while (chunk.GetLength() > 0)
    {
        Update(chunk.GetBytes(), chunk.GetLength());
        aMessage.GetNextChunk(aLength, chunk);
    }
}

} // namespace Crypto
} // namespace ot
