utils.h

Go to the documentation of this file.

/* utils.h - TinyCrypt interface to platform-dependent run-time operations */
 
/*
 *  Copyright (C) 2017 by Intel Corporation, All Rights Reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *    - Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *
 *    - 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.
 *
 *    - Neither the name of Intel Corporation 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 OWNER 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.
 */
 
#ifndef __TC_UTILS_H__
#define __TC_UTILS_H__
 
#include <stdint.h>
#include <stddef.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
unsigned int _copy(uint8_t *to, unsigned int to_len,
               const uint8_t *from, unsigned int from_len);
 
void _set(void *to, uint8_t val, unsigned int len);
 
/*
 * @brief AES specific doubling function, which utilizes
 * the finite field used by AES.
 * @return Returns a^2
 *
 * @param a IN/OUT -- value to be doubled
 */
uint8_t _double_byte(uint8_t a);
 
/*
 * @brief Constant-time algorithm to compare if two sequences of bytes are equal
 * @return Returns 0 if equal, and non-zero otherwise
 *
 * @param a IN -- sequence of bytes a
 * @param b IN -- sequence of bytes b
 * @param size IN -- size of sequences a and b
 */
int _compare(const uint8_t *a, const uint8_t *b, size_t size);
 
#ifdef __cplusplus
}
#endif
 
#endif /* __TC_UTILS_H__ */