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Eliminate na_1 and na_lam state fields from ecmult_strauss_wnaf.

This commit is contained in:
Russell O'Connor 2021-02-27 08:36:22 -05:00
parent 7ba3ffcca0
commit 0397d00ba0
1 changed files with 4 additions and 4 deletions
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8
src/ecmult_impl.h
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@ -210,7 +210,6 @@ static int secp256k1_ecmult_wnaf(int *wnaf, int len, const secp256k1_scalar *a,
} }
struct secp256k1_strauss_point_state { struct secp256k1_strauss_point_state {
secp256k1_scalar na_1, na_lam;
int wnaf_na_1[129]; int wnaf_na_1[129];
int wnaf_na_lam[129]; int wnaf_na_lam[129];
int bits_na_1; int bits_na_1;
@ -240,16 +239,17 @@ static void secp256k1_ecmult_strauss_wnaf(const struct secp256k1_strauss_state *
size_t no = 0; size_t no = 0;
for (np = 0; np < num; ++np) { for (np = 0; np < num; ++np) {
secp256k1_scalar na_1, na_lam;
if (secp256k1_scalar_is_zero(&na[np]) || secp256k1_gej_is_infinity(&a[np])) { if (secp256k1_scalar_is_zero(&na[np]) || secp256k1_gej_is_infinity(&a[np])) {
continue; continue;
} }
state->ps[no].input_pos = np; state->ps[no].input_pos = np;
/* split na into na_1 and na_lam (where na = na_1 + na_lam*lambda, and na_1 and na_lam are ~128 bit) */ /* 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_scalar_split_lambda(&state->ps[no].na_1, &state->ps[no].na_lam, &na[np]); secp256k1_scalar_split_lambda(&na_1, &na_lam, &na[np]);
/* build wnaf representation for na_1 and na_lam. */ /* build wnaf representation for na_1 and na_lam. */
state->ps[no].bits_na_1 = secp256k1_ecmult_wnaf(state->ps[no].wnaf_na_1, 129, &state->ps[no].na_1, WINDOW_A); state->ps[no].bits_na_1 = secp256k1_ecmult_wnaf(state->ps[no].wnaf_na_1, 129, &na_1, WINDOW_A);
state->ps[no].bits_na_lam = secp256k1_ecmult_wnaf(state->ps[no].wnaf_na_lam, 129, &state->ps[no].na_lam, WINDOW_A); state->ps[no].bits_na_lam = secp256k1_ecmult_wnaf(state->ps[no].wnaf_na_lam, 129, &na_lam, WINDOW_A);
VERIFY_CHECK(state->ps[no].bits_na_1 <= 129); VERIFY_CHECK(state->ps[no].bits_na_1 <= 129);
VERIFY_CHECK(state->ps[no].bits_na_lam <= 129); VERIFY_CHECK(state->ps[no].bits_na_lam <= 129);
if (state->ps[no].bits_na_1 > bits) { if (state->ps[no].bits_na_1 > bits) {