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/*
* SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
/*
* 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.
*/
/* utils.c - TinyCrypt platform-dependent run-time operations */
#include <tinycrypt/utils.h>
#include <tinycrypt/constants.h>
#include <string.h>
#define MASK_TWENTY_SEVEN 0x1b
unsigned int _copy(uint8_t *to, unsigned int to_len,
const uint8_t *from, unsigned int from_len)
{
if (from_len <= to_len) {
(void)memcpy(to, from, from_len);
return from_len;
} else {
return TC_CRYPTO_FAIL;
}
}
void _set(void *to, uint8_t val, unsigned int len)
{
(void)memset(to, val, len);
}
/*
* Doubles the value of a byte for values up to 127.
*/
uint8_t _double_byte(uint8_t a)
{
return ((a<<1) ^ ((a>>7) * MASK_TWENTY_SEVEN));
}
int _compare(const uint8_t *a, const uint8_t *b, size_t size)
{
const uint8_t *tempa = a;
const uint8_t *tempb = b;
uint8_t result = 0;
for (unsigned int i = 0; i < size; i++) {
result |= tempa[i] ^ tempb[i];
}
return result;
}
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