1 /* 2 * Copyright 2017-2022 The OpenSSL Project Authors. All Rights Reserved. 3 * Copyright 2014-2016 Cryptography Research, Inc. 4 * 5 * Licensed under the Apache License 2.0 (the "License"). You may not use 6 * this file except in compliance with the License. You can obtain a copy 7 * in the file LICENSE in the source distribution or at 8 * https://www.openssl.org/source/license.html 9 * 10 * Originally written by Mike Hamburg 11 */ 12 13 #ifndef OSSL_CRYPTO_EC_CURVE448_ARCH_64_F_IMPL_H 14 # define OSSL_CRYPTO_EC_CURVE448_ARCH_64_F_IMPL_H 15 16 # define GF_HEADROOM 9999 /* Everything is reduced anyway */ 17 # define FIELD_LITERAL(a,b,c,d,e,f,g,h) {{a,b,c,d,e,f,g,h}} 18 19 # define LIMB_PLACE_VALUE(i) 56 20 21 void gf_add_RAW(gf out, const gf a, const gf b) 22 { 23 unsigned int i; 24 25 for (i = 0; i < NLIMBS; i++) 26 out->limb[i] = a->limb[i] + b->limb[i]; 27 28 gf_weak_reduce(out); 29 } 30 31 void gf_sub_RAW(gf out, const gf a, const gf b) 32 { 33 uint64_t co1 = ((1ULL << 56) - 1) * 2, co2 = co1 - 2; 34 unsigned int i; 35 36 for (i = 0; i < NLIMBS; i++) 37 out->limb[i] = a->limb[i] - b->limb[i] + ((i == NLIMBS / 2) ? co2 : co1); 38 39 gf_weak_reduce(out); 40 } 41 42 void gf_bias(gf a, int amt) 43 { 44 } 45 46 void gf_weak_reduce(gf a) 47 { 48 uint64_t mask = (1ULL << 56) - 1; 49 uint64_t tmp = a->limb[NLIMBS - 1] >> 56; 50 unsigned int i; 51 52 a->limb[NLIMBS / 2] += tmp; 53 for (i = NLIMBS - 1; i > 0; i--) 54 a->limb[i] = (a->limb[i] & mask) + (a->limb[i - 1] >> 56); 55 a->limb[0] = (a->limb[0] & mask) + tmp; 56 } 57 58 #endif /* OSSL_CRYPTO_EC_CURVE448_ARCH_64_F_IMPL_H */ 59