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ecmult: Use size_t for array indices into tables

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Tim Ruffing
2026-01-07 11:30:16 +01:00
parent 2d9137ce9d
commit bb1d199de5
4 changed files with 17 additions and 16 deletions
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27
src/ecmult_impl.h
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@@ -311,8 +311,9 @@ static void secp256k1_ecmult_strauss_wnaf(const struct secp256k1_strauss_state *
}
for (np = 0; np < no; ++np) {
for (i = 0; i < ECMULT_TABLE_SIZE(WINDOW_A); i++) {
secp256k1_fe_mul(&state->aux[np * ECMULT_TABLE_SIZE(WINDOW_A) + i], &state->pre_a[np * ECMULT_TABLE_SIZE(WINDOW_A) + i].x, &secp256k1_const_beta);
size_t j;
for (j = 0; j < ECMULT_TABLE_SIZE(WINDOW_A); j++) {
secp256k1_fe_mul(&state->aux[np * ECMULT_TABLE_SIZE(WINDOW_A) + j], &state->pre_a[np * ECMULT_TABLE_SIZE(WINDOW_A) + j].x, &secp256k1_const_beta);
}
}
@@ -517,7 +518,6 @@ static int secp256k1_ecmult_pippenger_wnaf(secp256k1_gej *buckets, int bucket_wi
size_t np;
size_t no = 0;
int i;
int j;
for (np = 0; np < num; ++np) {
if (secp256k1_scalar_is_zero(&sc[np]) || secp256k1_ge_is_infinity(&pt[np])) {
@@ -535,16 +535,17 @@ static int secp256k1_ecmult_pippenger_wnaf(secp256k1_gej *buckets, int bucket_wi
for (i = n_wnaf - 1; i >= 0; i--) {
secp256k1_gej running_sum;
int j;
size_t buc;
for(j = 0; j < ECMULT_TABLE_SIZE(bucket_window+2); j++) {
secp256k1_gej_set_infinity(&buckets[j]);
for (buc = 0; buc < ECMULT_TABLE_SIZE(bucket_window+2); buc++) {
secp256k1_gej_set_infinity(&buckets[buc]);
}
for (np = 0; np < no; ++np) {
int n = state->wnaf_na[np*n_wnaf + i];
struct secp256k1_pippenger_point_state point_state = state->ps[np];
secp256k1_ge tmp;
int idx;
if (i == 0) {
/* correct for wnaf skew */
@@ -555,16 +556,16 @@ static int secp256k1_ecmult_pippenger_wnaf(secp256k1_gej *buckets, int bucket_wi
}
}
if (n > 0) {
idx = (n - 1)/2;
secp256k1_gej_add_ge_var(&buckets[idx], &buckets[idx], &pt[point_state.input_pos], NULL);
buc = (n - 1)/2;
secp256k1_gej_add_ge_var(&buckets[buc], &buckets[buc], &pt[point_state.input_pos], NULL);
} else if (n < 0) {
idx = -(n + 1)/2;
buc = -(n + 1)/2;
secp256k1_ge_neg(&tmp, &pt[point_state.input_pos]);
secp256k1_gej_add_ge_var(&buckets[idx], &buckets[idx], &tmp, NULL);
secp256k1_gej_add_ge_var(&buckets[buc], &buckets[buc], &tmp, NULL);
}
}
for(j = 0; j < bucket_window; j++) {
for (j = 0; j < bucket_window; j++) {
secp256k1_gej_double_var(r, r, NULL);
}
@@ -577,8 +578,8 @@ static int secp256k1_ecmult_pippenger_wnaf(secp256k1_gej *buckets, int bucket_wi
*
* The doubling is done implicitly by deferring the final window doubling (of 'r').
*/
for(j = ECMULT_TABLE_SIZE(bucket_window+2) - 1; j > 0; j--) {
secp256k1_gej_add_var(&running_sum, &running_sum, &buckets[j], NULL);
for (buc = ECMULT_TABLE_SIZE(bucket_window+2) - 1; buc > 0; buc--) {
secp256k1_gej_add_var(&running_sum, &running_sum, &buckets[buc], NULL);
secp256k1_gej_add_var(r, r, &running_sum, NULL);
}