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comparison: security/nss/lib/freebl/ecl/ecp_fp160.c
security/nss/lib/freebl/ecl/ecp_fp160.c
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| -1:000000000000 | 0:385506327c24 |
|---|---|
| 1 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 | |
| 5 #include "ecp_fp.h" | |
| 6 #include <stdlib.h> | |
| 7 | |
| 8 #define ECFP_BSIZE 160 | |
| 9 #define ECFP_NUMDOUBLES 7 | |
| 10 | |
| 11 #include "ecp_fpinc.c" | |
| 12 | |
| 13 /* Performs a single step of reduction, just on the uppermost float | |
| 14 * (assumes already tidied), and then retidies. Note, this does not | |
| 15 * guarantee that the result will be less than p, but truncates the number | |
| 16 * of bits. */ | |
| 17 void | |
| 18 ecfp160_singleReduce(double *d, const EC_group_fp * group) | |
| 19 { | |
| 20 double q; | |
| 21 | |
| 22 ECFP_ASSERT(group->doubleBitSize == 24); | |
| 23 ECFP_ASSERT(group->primeBitSize == 160); | |
| 24 ECFP_ASSERT(ECFP_NUMDOUBLES == 7); | |
| 25 | |
| 26 q = d[ECFP_NUMDOUBLES - 1] - ecfp_beta_160; | |
| 27 q += group->bitSize_alpha; | |
| 28 q -= group->bitSize_alpha; | |
| 29 | |
| 30 d[ECFP_NUMDOUBLES - 1] -= q; | |
| 31 d[0] += q * ecfp_twom160; | |
| 32 d[1] += q * ecfp_twom129; | |
| 33 ecfp_positiveTidy(d, group); | |
| 34 | |
| 35 /* Assertions for the highest order term */ | |
| 36 ECFP_ASSERT(d[ECFP_NUMDOUBLES - 1] / ecfp_exp[ECFP_NUMDOUBLES - 1] == | |
| 37 (unsigned long long) (d[ECFP_NUMDOUBLES - 1] / | |
| 38 ecfp_exp[ECFP_NUMDOUBLES - 1])); | |
| 39 ECFP_ASSERT(d[ECFP_NUMDOUBLES - 1] >= 0); | |
| 40 } | |
| 41 | |
| 42 /* Performs imperfect reduction. This might leave some negative terms, | |
| 43 * and one more reduction might be required for the result to be between 0 | |
| 44 * and p-1. x should not already be reduced, i.e. should have | |
| 45 * 2*ECFP_NUMDOUBLES significant terms. x and r can be the same, but then | |
| 46 * the upper parts of r are not zeroed */ | |
| 47 void | |
| 48 ecfp160_reduce(double *r, double *x, const EC_group_fp * group) | |
| 49 { | |
| 50 | |
| 51 double x7, x8, q; | |
| 52 | |
| 53 ECFP_ASSERT(group->doubleBitSize == 24); | |
| 54 ECFP_ASSERT(group->primeBitSize == 160); | |
| 55 ECFP_ASSERT(ECFP_NUMDOUBLES == 7); | |
| 56 | |
| 57 /* Tidy just the upper bits, the lower bits can wait. */ | |
| 58 ecfp_tidyUpper(x, group); | |
| 59 | |
| 60 /* Assume that this is already tidied so that we have enough extra | |
| 61 * bits */ | |
| 62 x7 = x[7] + x[13] * ecfp_twom129; /* adds bits 15-39 */ | |
| 63 | |
| 64 /* Tidy x7, or we won't have enough bits later to add it in */ | |
| 65 q = x7 + group->alpha[8]; | |
| 66 q -= group->alpha[8]; | |
| 67 x7 -= q; /* holds bits 0-24 */ | |
| 68 x8 = x[8] + q; /* holds bits 0-25 */ | |
| 69 | |
| 70 r[6] = x[6] + x[13] * ecfp_twom160 + x[12] * ecfp_twom129; /* adds | |
| 71 * bits | |
| 72 * 8-39 */ | |
| 73 r[5] = x[5] + x[12] * ecfp_twom160 + x[11] * ecfp_twom129; | |
| 74 r[4] = x[4] + x[11] * ecfp_twom160 + x[10] * ecfp_twom129; | |
| 75 r[3] = x[3] + x[10] * ecfp_twom160 + x[9] * ecfp_twom129; | |
| 76 r[2] = x[2] + x[9] * ecfp_twom160 + x8 * ecfp_twom129; /* adds bits | |
| 77 * 8-40 */ | |
| 78 r[1] = x[1] + x8 * ecfp_twom160 + x7 * ecfp_twom129; /* adds bits | |
| 79 * 8-39 */ | |
| 80 r[0] = x[0] + x7 * ecfp_twom160; | |
| 81 | |
| 82 /* Tidy up just r[ECFP_NUMDOUBLES-2] so that the number of reductions | |
| 83 * is accurate plus or minus one. (Rather than tidy all to make it | |
| 84 * totally accurate, which is more costly.) */ | |
| 85 q = r[ECFP_NUMDOUBLES - 2] + group->alpha[ECFP_NUMDOUBLES - 1]; | |
| 86 q -= group->alpha[ECFP_NUMDOUBLES - 1]; | |
| 87 r[ECFP_NUMDOUBLES - 2] -= q; | |
| 88 r[ECFP_NUMDOUBLES - 1] += q; | |
| 89 | |
| 90 /* Tidy up the excess bits on r[ECFP_NUMDOUBLES-1] using reduction */ | |
| 91 /* Use ecfp_beta so we get a positive result */ | |
| 92 q = r[ECFP_NUMDOUBLES - 1] - ecfp_beta_160; | |
| 93 q += group->bitSize_alpha; | |
| 94 q -= group->bitSize_alpha; | |
| 95 | |
| 96 r[ECFP_NUMDOUBLES - 1] -= q; | |
| 97 r[0] += q * ecfp_twom160; | |
| 98 r[1] += q * ecfp_twom129; | |
| 99 | |
| 100 /* Tidy the result */ | |
| 101 ecfp_tidyShort(r, group); | |
| 102 } | |
| 103 | |
| 104 /* Sets group to use optimized calculations in this file */ | |
| 105 mp_err | |
| 106 ec_group_set_secp160r1_fp(ECGroup *group) | |
| 107 { | |
| 108 | |
| 109 EC_group_fp *fpg = NULL; | |
| 110 | |
| 111 /* Allocate memory for floating point group data */ | |
| 112 fpg = (EC_group_fp *) malloc(sizeof(EC_group_fp)); | |
| 113 if (fpg == NULL) { | |
| 114 return MP_MEM; | |
| 115 } | |
| 116 | |
| 117 fpg->numDoubles = ECFP_NUMDOUBLES; | |
| 118 fpg->primeBitSize = ECFP_BSIZE; | |
| 119 fpg->orderBitSize = 161; | |
| 120 fpg->doubleBitSize = 24; | |
| 121 fpg->numInts = (ECFP_BSIZE + ECL_BITS - 1) / ECL_BITS; | |
| 122 fpg->aIsM3 = 1; | |
| 123 fpg->ecfp_singleReduce = &ecfp160_singleReduce; | |
| 124 fpg->ecfp_reduce = &ecfp160_reduce; | |
| 125 fpg->ecfp_tidy = &ecfp_tidy; | |
| 126 | |
| 127 fpg->pt_add_jac_aff = &ecfp160_pt_add_jac_aff; | |
| 128 fpg->pt_add_jac = &ecfp160_pt_add_jac; | |
| 129 fpg->pt_add_jm_chud = &ecfp160_pt_add_jm_chud; | |
| 130 fpg->pt_add_chud = &ecfp160_pt_add_chud; | |
| 131 fpg->pt_dbl_jac = &ecfp160_pt_dbl_jac; | |
| 132 fpg->pt_dbl_jm = &ecfp160_pt_dbl_jm; | |
| 133 fpg->pt_dbl_aff2chud = &ecfp160_pt_dbl_aff2chud; | |
| 134 fpg->precompute_chud = &ecfp160_precompute_chud; | |
| 135 fpg->precompute_jac = &ecfp160_precompute_jac; | |
| 136 | |
| 137 group->point_mul = &ec_GFp_point_mul_wNAF_fp; | |
| 138 group->points_mul = &ec_pts_mul_basic; | |
| 139 group->extra1 = fpg; | |
| 140 group->extra_free = &ec_GFp_extra_free_fp; | |
| 141 | |
| 142 ec_set_fp_precision(fpg); | |
| 143 fpg->bitSize_alpha = ECFP_TWO160 * fpg->alpha[0]; | |
| 144 return MP_OKAY; | |
| 145 } |
