/* Copyright (c) 2014-2016 Cryptography Research, Inc. * Released under the MIT License. See LICENSE.txt for license information. */ #define GF_HEADROOM 2 #define LIMB(x) (x##ull)&((1ull<<28)-1), (x##ull)>>28 #define FIELD_LITERAL(a,b,c,d,e,f,g,h) \ {{LIMB(a),LIMB(b),LIMB(c),LIMB(d),LIMB(e),LIMB(f),LIMB(g),LIMB(h)}} #define LIMB_PLACE_VALUE(i) 28 void gf_add_RAW (gf out, const gf a, const gf b) { for (unsigned int i=0; ilimb[0]); i++) { out->limb[i] = a->limb[i] + b->limb[i]; } } void gf_sub_RAW (gf out, const gf a, const gf b) { for (unsigned int i=0; ilimb[0]); i++) { out->limb[i] = a->limb[i] - b->limb[i]; } } void gf_bias (gf a, int amt) { uint32_t co1 = ((1ull<<28)-1)*amt, co2 = co1-amt; for (unsigned int i=0; ilimb[0]); i++) { a->limb[i] += (i==sizeof(*a)/sizeof(a->limb[0])/2) ? co2 : co1; } } void gf_weak_reduce (gf a) { uint32_t mask = (1ull<<28) - 1; uint32_t tmp = a->limb[15] >> 28; a->limb[8] += tmp; for (unsigned int i=15; i>0; i--) { a->limb[i] = (a->limb[i] & mask) + (a->limb[i-1]>>28); } a->limb[0] = (a->limb[0] & mask) + tmp; }