39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
/* Copyright (c) 2014-2016 Cryptography Research, Inc.
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* Released under the MIT License. See LICENSE.txt for license information.
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*/
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#define GF_HEADROOM 9999 /* Everything is reduced anyway */
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#define FIELD_LITERAL(a,b,c,d,e,f,g,h) {{a,b,c,d,e,f,g,h}}
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#define LIMB_PLACE_VALUE(i) 56
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void cryptonite_gf_add_RAW (gf out, const gf a, const gf b) {
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for (unsigned int i=0; i<8; i++) {
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out->limb[i] = a->limb[i] + b->limb[i];
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}
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cryptonite_gf_weak_reduce(out);
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}
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void cryptonite_gf_sub_RAW (gf out, const gf a, const gf b) {
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uint64_t co1 = ((1ull<<56)-1)*2, co2 = co1-2;
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for (unsigned int i=0; i<8; i++) {
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out->limb[i] = a->limb[i] - b->limb[i] + ((i==4) ? co2 : co1);
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}
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cryptonite_gf_weak_reduce(out);
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}
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void cryptonite_gf_bias (gf a, int amt) {
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(void) a;
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(void) amt;
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}
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void cryptonite_gf_weak_reduce (gf a) {
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uint64_t mask = (1ull<<56) - 1;
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uint64_t tmp = a->limb[7] >> 56;
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a->limb[4] += tmp;
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for (unsigned int i=7; i>0; i--) {
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a->limb[i] = (a->limb[i] & mask) + (a->limb[i-1]>>56);
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}
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a->limb[0] = (a->limb[0] & mask) + tmp;
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}
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