internal-grain128.h

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/*
 * Copyright (C) 2021 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
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#ifndef LW_INTERNAL_GRAIN128_H
#define LW_INTERNAL_GRAIN128_H

#include "internal-util.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef struct
{
    uint32_t lfsr[4];       
    uint32_t nfsr[4];       
    uint64_t accum;         
    uint64_t sr;            
    unsigned char ks[16];   
    unsigned posn;          
} grain128_state_t;

void grain128_core
    (grain128_state_t *state, uint32_t x, uint32_t x2);

uint32_t grain128_preoutput(const grain128_state_t *state);

void grain128_setup
    (grain128_state_t *state, const unsigned char *key,
     const unsigned char *nonce);

void grain128_authenticate
    (grain128_state_t *state, const unsigned char *data,
     size_t len);

void grain128_encrypt
    (grain128_state_t *state, unsigned char *c, const unsigned char *m,
     size_t len);

void grain128_decrypt
    (grain128_state_t *state, unsigned char *m, const unsigned char *c,
     size_t len);

void grain128_compute_tag(grain128_state_t *state);

#ifdef __cplusplus
}
#endif

#endif