OMAC.h

/*
 * Copyright (C) 2016 Southern Storm Software, Pty Ltd.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * DEALINGS IN THE SOFTWARE.
 */
 
#ifndef CRYPTO_OMAC_H
#define CRYPTO_OMAC_H
 
#include "BlockCipher.h"
 
class OMAC
{
public:
    OMAC();
    ~OMAC();
 
    BlockCipher *blockCipher() const { return _blockCipher; }
    void setBlockCipher(BlockCipher *cipher) { _blockCipher = cipher; }
 
    void initFirst(uint8_t omac[16]);
    void initNext(uint8_t omac[16], uint8_t tag);
    void update(uint8_t omac[16], const uint8_t *data, size_t size);
    void finalize(uint8_t omac[16]);
 
    void clear();
 
private:
    BlockCipher *_blockCipher;
    uint32_t b[4];
    uint8_t posn;
};
 
#endif