1 /* Copyright (c) 2023, Google LLC 2 * 3 * Permission to use, copy, modify, and/or distribute this software for any 4 * purpose with or without fee is hereby granted, provided that the above 5 * copyright notice and this permission notice appear in all copies. 6 * 7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ 14 15 #ifndef OPENSSL_HEADER_CRYPTO_SPX_UTIL_H 16 #define OPENSSL_HEADER_CRYPTO_SPX_UTIL_H 17 18 #include <openssl/base.h> 19 20 #if defined(__cplusplus) 21 extern "C" { 22 #endif 23 24 25 // Encodes the integer value of input to out_len bytes in big-endian order. 26 // Note that input < 2^(8*out_len), as otherwise this function will truncate 27 // the least significant bytes of the integer representation. 28 void spx_uint64_to_len_bytes(uint8_t *output, size_t out_len, uint64_t input); 29 30 uint64_t spx_to_uint64(const uint8_t *input, size_t input_len); 31 32 // Compute the base 2^log2_b representation of X. 33 // 34 // As some of the parameter sets in https://eprint.iacr.org/2022/1725.pdf use 35 // a FORS height > 16 we use a uint32_t to store the output. 36 void spx_base_b(uint32_t *output, size_t out_len, const uint8_t *input, 37 unsigned int log2_b); 38 39 40 #if defined(__cplusplus) 41 } // extern C 42 #endif 43 44 #endif // OPENSSL_HEADER_CRYPTO_SPX_UTIL_H 45