2 * Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright 2014-2016 Cryptography Research, Inc.
5 * Licensed under the OpenSSL license (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
10 * Originally written by Mike Hamburg
13 #define LIMB(x) (x)&((1<<28)-1), (x)>>28
14 #define FIELD_LITERAL(a,b,c,d,e,f,g,h) \
15 {{LIMB(a),LIMB(b),LIMB(c),LIMB(d),LIMB(e),LIMB(f),LIMB(g),LIMB(h)}}
17 #define LIMB_PLACE_VALUE(i) 28
19 void gf_add_RAW(gf out, const gf a, const gf b)
23 for (i = 0; i < NLIMBS; i++) {
24 out->limb[i] = a->limb[i] + b->limb[i];
28 void gf_sub_RAW(gf out, const gf a, const gf b)
32 for (i = 0; i < NLIMBS; i++) {
33 out->limb[i] = a->limb[i] - b->limb[i];
37 void gf_bias(gf a, int amt)
40 uint32_t co1 = ((1 << 28) - 1) * amt, co2 = co1 - amt;
42 for (i = 0; i < NLIMBS; i++)
43 a->limb[i] += (i == sizeof(*a) / sizeof(a->limb[0]) / 2) ? co2 : co1;
46 void gf_weak_reduce(gf a)
48 uint32_t mask = (1 << 28) - 1;
49 uint32_t tmp = a->limb[15] >> 28;
53 for (i = 15; i > 0; i--)
54 a->limb[i] = (a->limb[i] & mask) + (a->limb[i - 1] >> 28);
55 a->limb[0] = (a->limb[0] & mask) + tmp;