1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/nss/lib/freebl/ecl/ecp_fp192.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,143 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#include "ecp_fp.h"
1.9 +#include <stdlib.h>
1.10 +
1.11 +#define ECFP_BSIZE 192
1.12 +#define ECFP_NUMDOUBLES 8
1.13 +
1.14 +#include "ecp_fpinc.c"
1.15 +
1.16 +/* Performs a single step of reduction, just on the uppermost float
1.17 + * (assumes already tidied), and then retidies. Note, this does not
1.18 + * guarantee that the result will be less than p. */
1.19 +void
1.20 +ecfp192_singleReduce(double *d, const EC_group_fp * group)
1.21 +{
1.22 + double q;
1.23 +
1.24 + ECFP_ASSERT(group->doubleBitSize == 24);
1.25 + ECFP_ASSERT(group->primeBitSize == 192);
1.26 + ECFP_ASSERT(group->numDoubles == 8);
1.27 +
1.28 + q = d[ECFP_NUMDOUBLES - 1] - ecfp_beta_192;
1.29 + q += group->bitSize_alpha;
1.30 + q -= group->bitSize_alpha;
1.31 +
1.32 + d[ECFP_NUMDOUBLES - 1] -= q;
1.33 + d[0] += q * ecfp_twom192;
1.34 + d[2] += q * ecfp_twom128;
1.35 + ecfp_positiveTidy(d, group);
1.36 +}
1.37 +
1.38 +/*
1.39 + * Performs imperfect reduction. This might leave some negative terms,
1.40 + * and one more reduction might be required for the result to be between 0
1.41 + * and p-1. x should be be an array of at least 16, and r at least 8 x and
1.42 + * r can be the same, but then the upper parts of r are not zeroed */
1.43 +void
1.44 +ecfp_reduce_192(double *r, double *x, const EC_group_fp * group)
1.45 +{
1.46 + double x8, x9, x10, q;
1.47 +
1.48 + ECFP_ASSERT(group->doubleBitSize == 24);
1.49 + ECFP_ASSERT(group->primeBitSize == 192);
1.50 + ECFP_ASSERT(group->numDoubles == 8);
1.51 +
1.52 + /* Tidy just the upper portion, the lower part can wait */
1.53 + ecfp_tidyUpper(x, group);
1.54 +
1.55 + x8 = x[8] + x[14] * ecfp_twom128; /* adds bits 16-40 */
1.56 + x9 = x[9] + x[15] * ecfp_twom128; /* adds bits 16-40 */
1.57 +
1.58 + /* Tidy up, or we won't have enough bits later to add it in */
1.59 +
1.60 + q = x8 + group->alpha[9];
1.61 + q -= group->alpha[9];
1.62 + x8 -= q;
1.63 + x9 += q;
1.64 +
1.65 + q = x9 + group->alpha[10];
1.66 + q -= group->alpha[10];
1.67 + x9 -= q;
1.68 + x10 = x[10] + q;
1.69 +
1.70 + r[7] = x[7] + x[15] * ecfp_twom192 + x[13] * ecfp_twom128; /* adds
1.71 + * bits
1.72 + * 0-40 */
1.73 + r[6] = x[6] + x[14] * ecfp_twom192 + x[12] * ecfp_twom128;
1.74 + r[5] = x[5] + x[13] * ecfp_twom192 + x[11] * ecfp_twom128;
1.75 + r[4] = x[4] + x[12] * ecfp_twom192 + x10 * ecfp_twom128;
1.76 + r[3] = x[3] + x[11] * ecfp_twom192 + x9 * ecfp_twom128; /* adds bits
1.77 + * 0-40 */
1.78 + r[2] = x[2] + x10 * ecfp_twom192 + x8 * ecfp_twom128;
1.79 + r[1] = x[1] + x9 * ecfp_twom192; /* adds bits 16-40 */
1.80 + r[0] = x[0] + x8 * ecfp_twom192;
1.81 +
1.82 + /*
1.83 + * Tidy up just r[group->numDoubles-2] so that the number of
1.84 + * reductions is accurate plus or minus one. (Rather than tidy all to
1.85 + * make it totally accurate) */
1.86 + q = r[ECFP_NUMDOUBLES - 2] + group->alpha[ECFP_NUMDOUBLES - 1];
1.87 + q -= group->alpha[ECFP_NUMDOUBLES - 1];
1.88 + r[ECFP_NUMDOUBLES - 2] -= q;
1.89 + r[ECFP_NUMDOUBLES - 1] += q;
1.90 +
1.91 + /* Tidy up the excess bits on r[group->numDoubles-1] using reduction */
1.92 + /* Use ecfp_beta so we get a positive res */
1.93 + q = r[ECFP_NUMDOUBLES - 1] - ecfp_beta_192;
1.94 + q += group->bitSize_alpha;
1.95 + q -= group->bitSize_alpha;
1.96 +
1.97 + r[ECFP_NUMDOUBLES - 1] -= q;
1.98 + r[0] += q * ecfp_twom192;
1.99 + r[2] += q * ecfp_twom128;
1.100 +
1.101 + /* Tidy the result */
1.102 + ecfp_tidyShort(r, group);
1.103 +}
1.104 +
1.105 +/* Sets group to use optimized calculations in this file */
1.106 +mp_err
1.107 +ec_group_set_nistp192_fp(ECGroup *group)
1.108 +{
1.109 + EC_group_fp *fpg;
1.110 +
1.111 + /* Allocate memory for floating point group data */
1.112 + fpg = (EC_group_fp *) malloc(sizeof(EC_group_fp));
1.113 + if (fpg == NULL) {
1.114 + return MP_MEM;
1.115 + }
1.116 +
1.117 + fpg->numDoubles = ECFP_NUMDOUBLES;
1.118 + fpg->primeBitSize = ECFP_BSIZE;
1.119 + fpg->orderBitSize = 192;
1.120 + fpg->doubleBitSize = 24;
1.121 + fpg->numInts = (ECFP_BSIZE + ECL_BITS - 1) / ECL_BITS;
1.122 + fpg->aIsM3 = 1;
1.123 + fpg->ecfp_singleReduce = &ecfp192_singleReduce;
1.124 + fpg->ecfp_reduce = &ecfp_reduce_192;
1.125 + fpg->ecfp_tidy = &ecfp_tidy;
1.126 +
1.127 + fpg->pt_add_jac_aff = &ecfp192_pt_add_jac_aff;
1.128 + fpg->pt_add_jac = &ecfp192_pt_add_jac;
1.129 + fpg->pt_add_jm_chud = &ecfp192_pt_add_jm_chud;
1.130 + fpg->pt_add_chud = &ecfp192_pt_add_chud;
1.131 + fpg->pt_dbl_jac = &ecfp192_pt_dbl_jac;
1.132 + fpg->pt_dbl_jm = &ecfp192_pt_dbl_jm;
1.133 + fpg->pt_dbl_aff2chud = &ecfp192_pt_dbl_aff2chud;
1.134 + fpg->precompute_chud = &ecfp192_precompute_chud;
1.135 + fpg->precompute_jac = &ecfp192_precompute_jac;
1.136 +
1.137 + group->point_mul = &ec_GFp_point_mul_wNAF_fp;
1.138 + group->points_mul = &ec_pts_mul_basic;
1.139 + group->extra1 = fpg;
1.140 + group->extra_free = &ec_GFp_extra_free_fp;
1.141 +
1.142 + ec_set_fp_precision(fpg);
1.143 + fpg->bitSize_alpha = ECFP_TWO192 * fpg->alpha[0];
1.144 +
1.145 + return MP_OKAY;
1.146 +}
