The Tor Browser / file comparison
comparison: security/nss/lib/freebl/ecl/ecp_fp192.c
security/nss/lib/freebl/ecl/ecp_fp192.c
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:37560ecd930e |
|---|---|
| 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 192 | |
| 9 #define ECFP_NUMDOUBLES 8 | |
| 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. */ | |
| 16 void | |
| 17 ecfp192_singleReduce(double *d, const EC_group_fp * group) | |
| 18 { | |
| 19 double q; | |
| 20 | |
| 21 ECFP_ASSERT(group->doubleBitSize == 24); | |
| 22 ECFP_ASSERT(group->primeBitSize == 192); | |
| 23 ECFP_ASSERT(group->numDoubles == 8); | |
| 24 | |
| 25 q = d[ECFP_NUMDOUBLES - 1] - ecfp_beta_192; | |
| 26 q += group->bitSize_alpha; | |
| 27 q -= group->bitSize_alpha; | |
| 28 | |
| 29 d[ECFP_NUMDOUBLES - 1] -= q; | |
| 30 d[0] += q * ecfp_twom192; | |
| 31 d[2] += q * ecfp_twom128; | |
| 32 ecfp_positiveTidy(d, group); | |
| 33 } | |
| 34 | |
| 35 /* | |
| 36 * Performs imperfect reduction. This might leave some negative terms, | |
| 37 * and one more reduction might be required for the result to be between 0 | |
| 38 * and p-1. x should be be an array of at least 16, and r at least 8 x and | |
| 39 * r can be the same, but then the upper parts of r are not zeroed */ | |
| 40 void | |
| 41 ecfp_reduce_192(double *r, double *x, const EC_group_fp * group) | |
| 42 { | |
| 43 double x8, x9, x10, q; | |
| 44 | |
| 45 ECFP_ASSERT(group->doubleBitSize == 24); | |
| 46 ECFP_ASSERT(group->primeBitSize == 192); | |
| 47 ECFP_ASSERT(group->numDoubles == 8); | |
| 48 | |
| 49 /* Tidy just the upper portion, the lower part can wait */ | |
| 50 ecfp_tidyUpper(x, group); | |
| 51 | |
| 52 x8 = x[8] + x[14] * ecfp_twom128; /* adds bits 16-40 */ | |
| 53 x9 = x[9] + x[15] * ecfp_twom128; /* adds bits 16-40 */ | |
| 54 | |
| 55 /* Tidy up, or we won't have enough bits later to add it in */ | |
| 56 | |
| 57 q = x8 + group->alpha[9]; | |
| 58 q -= group->alpha[9]; | |
| 59 x8 -= q; | |
| 60 x9 += q; | |
| 61 | |
| 62 q = x9 + group->alpha[10]; | |
| 63 q -= group->alpha[10]; | |
| 64 x9 -= q; | |
| 65 x10 = x[10] + q; | |
| 66 | |
| 67 r[7] = x[7] + x[15] * ecfp_twom192 + x[13] * ecfp_twom128; /* adds | |
| 68 * bits | |
| 69 * 0-40 */ | |
| 70 r[6] = x[6] + x[14] * ecfp_twom192 + x[12] * ecfp_twom128; | |
| 71 r[5] = x[5] + x[13] * ecfp_twom192 + x[11] * ecfp_twom128; | |
| 72 r[4] = x[4] + x[12] * ecfp_twom192 + x10 * ecfp_twom128; | |
| 73 r[3] = x[3] + x[11] * ecfp_twom192 + x9 * ecfp_twom128; /* adds bits | |
| 74 * 0-40 */ | |
| 75 r[2] = x[2] + x10 * ecfp_twom192 + x8 * ecfp_twom128; | |
| 76 r[1] = x[1] + x9 * ecfp_twom192; /* adds bits 16-40 */ | |
| 77 r[0] = x[0] + x8 * ecfp_twom192; | |
| 78 | |
| 79 /* | |
| 80 * Tidy up just r[group->numDoubles-2] so that the number of | |
| 81 * reductions is accurate plus or minus one. (Rather than tidy all to | |
| 82 * make it totally accurate) */ | |
| 83 q = r[ECFP_NUMDOUBLES - 2] + group->alpha[ECFP_NUMDOUBLES - 1]; | |
| 84 q -= group->alpha[ECFP_NUMDOUBLES - 1]; | |
| 85 r[ECFP_NUMDOUBLES - 2] -= q; | |
| 86 r[ECFP_NUMDOUBLES - 1] += q; | |
| 87 | |
| 88 /* Tidy up the excess bits on r[group->numDoubles-1] using reduction */ | |
| 89 /* Use ecfp_beta so we get a positive res */ | |
| 90 q = r[ECFP_NUMDOUBLES - 1] - ecfp_beta_192; | |
| 91 q += group->bitSize_alpha; | |
| 92 q -= group->bitSize_alpha; | |
| 93 | |
| 94 r[ECFP_NUMDOUBLES - 1] -= q; | |
| 95 r[0] += q * ecfp_twom192; | |
| 96 r[2] += q * ecfp_twom128; | |
| 97 | |
| 98 /* Tidy the result */ | |
| 99 ecfp_tidyShort(r, group); | |
| 100 } | |
| 101 | |
| 102 /* Sets group to use optimized calculations in this file */ | |
| 103 mp_err | |
| 104 ec_group_set_nistp192_fp(ECGroup *group) | |
| 105 { | |
| 106 EC_group_fp *fpg; | |
| 107 | |
| 108 /* Allocate memory for floating point group data */ | |
| 109 fpg = (EC_group_fp *) malloc(sizeof(EC_group_fp)); | |
| 110 if (fpg == NULL) { | |
| 111 return MP_MEM; | |
| 112 } | |
| 113 | |
| 114 fpg->numDoubles = ECFP_NUMDOUBLES; | |
| 115 fpg->primeBitSize = ECFP_BSIZE; | |
| 116 fpg->orderBitSize = 192; | |
| 117 fpg->doubleBitSize = 24; | |
| 118 fpg->numInts = (ECFP_BSIZE + ECL_BITS - 1) / ECL_BITS; | |
| 119 fpg->aIsM3 = 1; | |
| 120 fpg->ecfp_singleReduce = &ecfp192_singleReduce; | |
| 121 fpg->ecfp_reduce = &ecfp_reduce_192; | |
| 122 fpg->ecfp_tidy = &ecfp_tidy; | |
| 123 | |
| 124 fpg->pt_add_jac_aff = &ecfp192_pt_add_jac_aff; | |
| 125 fpg->pt_add_jac = &ecfp192_pt_add_jac; | |
| 126 fpg->pt_add_jm_chud = &ecfp192_pt_add_jm_chud; | |
| 127 fpg->pt_add_chud = &ecfp192_pt_add_chud; | |
| 128 fpg->pt_dbl_jac = &ecfp192_pt_dbl_jac; | |
| 129 fpg->pt_dbl_jm = &ecfp192_pt_dbl_jm; | |
| 130 fpg->pt_dbl_aff2chud = &ecfp192_pt_dbl_aff2chud; | |
| 131 fpg->precompute_chud = &ecfp192_precompute_chud; | |
| 132 fpg->precompute_jac = &ecfp192_precompute_jac; | |
| 133 | |
| 134 group->point_mul = &ec_GFp_point_mul_wNAF_fp; | |
| 135 group->points_mul = &ec_pts_mul_basic; | |
| 136 group->extra1 = fpg; | |
| 137 group->extra_free = &ec_GFp_extra_free_fp; | |
| 138 | |
| 139 ec_set_fp_precision(fpg); | |
| 140 fpg->bitSize_alpha = ECFP_TWO192 * fpg->alpha[0]; | |
| 141 | |
| 142 return MP_OKAY; | |
| 143 } |
