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/* This file is part of libbrandt.
* Copyright (C) 2016 GNUnet e.V.
*
* libbrandt is free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* libbrandt is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with
* libbrandt. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file smc.c
* @brief Implementation of the smc primitives.
*/
#include "util.h"
#include <pari/pari.h>
GEN
smc_hextodec (const char *s) /* int */
{
size_t i;
char c;
pari_sp ltop = avma;
GEN ret = gen_0; /* int */
for (i = 0; i < strlen (s); i++)
{
errno = 0;
if (1 != sscanf (&s[i], "%1hhx", &c))
{
brandt_eprintf ("failed to parse hex (\"%s\") to decimal:", s);
return NULL;
}
ret = addis (shifti (ret, 4), c);
}
return gerepilecopy (ltop, ret);
}
void
smc_genbid (struct AuctionData *ad, uint16_t bid)
{
uint16_t j;
pari_sp ltop = avma;
GEN ret = cgetg (itos (ad->k)+1, t_VEC); /* vec */
for (j = 1; j <= ad->k; j++)
{
gel (ret, j) = gpowgs (ad->g, bid == j);
}
ad->b = gerepilecopy (ltop, ret);
}
void
smc_genalpha (struct AuctionData *ad)
{
uint16_t j;
pari_sp ltop = avma;
GEN ret = cgetg (ad->k+1, t_VEC);
for (j = 1; j <= ad->k; ++j)
{
gel (ret, j) = gmul (gel (ad->b, j), gpowgi (ad->y, gel (ad->r, j)));
}
ad->alpha = gerepilecopy (ltop, ret);
}
void
smc_genbeta (struct AuctionData *ad)
{
uint16_t j;
pari_sp ltop = avma;
GEN ret = cgetg (ad->k+1, t_VEC);
for (j = 1; j <= ad->k; ++j)
{
gel (ret, j) = gpowgi (ad->g, gel (ad->r, j));
}
ad->beta = gerepilecopy (ltop, ret);
}
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