1 /* utils.h - TinyCrypt interface to platform-dependent run-time operations */ 2 3 /* 4 * Copyright (C) 2017 by Intel Corporation, All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are met: 8 * 9 * - Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * 12 * - Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * - Neither the name of Intel Corporation nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /** 34 * @file 35 * @brief Interface to platform-dependent run-time operations. 36 * 37 */ 38 39 #ifndef __TC_UTILS_H__ 40 #define __TC_UTILS_H__ 41 42 #include <stdint.h> 43 #include <stddef.h> 44 45 #ifdef __cplusplus 46 extern "C" { 47 #endif 48 49 /** 50 * @brief Copy the the buffer 'from' to the buffer 'to'. 51 * @return returns TC_CRYPTO_SUCCESS (1) 52 * returns TC_CRYPTO_FAIL (0) if: 53 * from_len > to_len. 54 * 55 * @param to OUT -- destination buffer 56 * @param to_len IN -- length of destination buffer 57 * @param from IN -- origin buffer 58 * @param from_len IN -- length of origin buffer 59 */ 60 unsigned int _copy(uint8_t *to, unsigned int to_len, 61 const uint8_t *from, unsigned int from_len); 62 63 /** 64 * @brief Set the value 'val' into the buffer 'to', 'len' times. 65 * 66 * @param to OUT -- destination buffer 67 * @param val IN -- value to be set in 'to' 68 * @param len IN -- number of times the value will be copied 69 */ 70 void _set(void *to, uint8_t val, unsigned int len); 71 72 /* 73 * @brief AES specific doubling function, which utilizes 74 * the finite field used by AES. 75 * @return Returns a^2 76 * 77 * @param a IN/OUT -- value to be doubled 78 */ 79 uint8_t _double_byte(uint8_t a); 80 81 /* 82 * @brief Constant-time algorithm to compare if two sequences of bytes are equal 83 * @return Returns 0 if equal, and non-zero otherwise 84 * 85 * @param a IN -- sequence of bytes a 86 * @param b IN -- sequence of bytes b 87 * @param size IN -- size of sequences a and b 88 */ 89 int _compare(const uint8_t *a, const uint8_t *b, size_t size); 90 91 #ifdef __cplusplus 92 } 93 #endif 94 95 #endif /* __TC_UTILS_H__ */ 96
