frost/secp256k1-zkp
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Switch all EC/ECDSA logic from num to scalar

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This commit is contained in:
Pieter Wuille
2014-11-26 17:26:39 +01:00
parent 6794be6080
commit f24041d6aa
15 changed files with 285 additions and 192 deletions
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28
src/ecmult_impl.h
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@@ -7,7 +7,6 @@
#ifndef _SECP256K1_ECMULT_IMPL_H_
#define _SECP256K1_ECMULT_IMPL_H_
#include "num.h"
#include "group.h"
#include "scalar.h"
#include "ecmult.h"
@@ -125,22 +124,13 @@ static void secp256k1_ecmult_stop(void) {
* - the number of set values in wnaf is returned. This number is at most 256, and at most one more
* - than the number of bits in the (absolute value) of the input.
*/
static int secp256k1_ecmult_wnaf(int *wnaf, const secp256k1_num_t *a, int w) {
secp256k1_num_t x;
secp256k1_num_copy(&x, a);
int sign = 1;
if (secp256k1_num_is_neg(&x)) {
sign = -1;
secp256k1_num_negate(&x);
}
unsigned char cr[32];
secp256k1_num_get_bin(cr, 32, &x);
secp256k1_scalar_t s;
secp256k1_scalar_set_b32(&s, cr, NULL);
static int secp256k1_ecmult_wnaf(int *wnaf, const secp256k1_scalar_t *a, int w) {
secp256k1_scalar_t s = *a;
int sign = 1;
if (secp256k1_scalar_get_bits(&s, 255, 1)) {
secp256k1_scalar_negate(&s, &s);
sign *= -1;
sign = -1;
}
int set_bits = 0;
@@ -169,13 +159,13 @@ static int secp256k1_ecmult_wnaf(int *wnaf, const secp256k1_num_t *a, int w) {
return set_bits;
}
static void secp256k1_ecmult(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_num_t *na, const secp256k1_num_t *ng) {
static void secp256k1_ecmult(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_scalar_t *na, const secp256k1_scalar_t *ng) {
const secp256k1_ecmult_consts_t *c = secp256k1_ecmult_consts;
#ifdef USE_ENDOMORPHISM
secp256k1_num_t na_1, na_lam;
secp256k1_scalar_t na_1, na_lam;
/* split na into na_1 and na_lam (where na = na_1 + na_lam*lambda, and na_1 and na_lam are ~128 bit) */
secp256k1_gej_split_exp_var(&na_1, &na_lam, na);
secp256k1_scalar_split_lambda_var(&na_1, &na_lam, na);
/* build wnaf representation for na_1 and na_lam. */
int wnaf_na_1[129]; int bits_na_1 = secp256k1_ecmult_wnaf(wnaf_na_1, &na_1, WINDOW_A);
@@ -198,10 +188,10 @@ static void secp256k1_ecmult(secp256k1_gej_t *r, const secp256k1_gej_t *a, const
secp256k1_gej_mul_lambda(&pre_a_lam[i], &pre_a[i]);
/* Splitted G factors. */
secp256k1_num_t ng_1, ng_128;
secp256k1_scalar_t ng_1, ng_128;
/* split ng into ng_1 and ng_128 (where gn = gn_1 + gn_128*2^128, and gn_1 and gn_128 are ~128 bit) */
secp256k1_num_split(&ng_1, &ng_128, ng, 128);
secp256k1_scalar_split_128(&ng_1, &ng_128, ng);
/* Build wnaf representation for ng_1 and ng_128 */
int wnaf_ng_1[129]; int bits_ng_1 = secp256k1_ecmult_wnaf(wnaf_ng_1, &ng_1, WINDOW_G);