Page MenuHomePhabricator
Differential D4985 Diff 15587 src/secp256k1/src/ecmult_impl.h

Changeset View

Standalone View

View Options

src/secp256k1/src/ecmult_impl.h

Show First 20 Lines • Show All 1,078 Lines • ▼ Show 20 Lines#endif
* would choose that then the caller couldn't safely use any number * would choose that then the caller couldn't safely use any number
* smaller than what this function returns */ * smaller than what this function returns */
break; break;
} }
} }
return res; return res;
} }
/* Computes ecmult_multi by simply multiplying and adding each point. Does not
* require a scratch space */
static int secp256k1_ecmult_multi_simple_var(const secp256k1_ecmult_context *ctx, secp256k1_gej *r, const secp256k1_scalar *inp_g_sc, secp256k1_ecmult_multi_callback cb, void *cbdata, size_t n_points) {
size_t point_idx;
secp256k1_scalar szero;
secp256k1_gej tmpj;
secp256k1_scalar_set_int(&szero, 0);
secp256k1_gej_set_infinity(r);
secp256k1_gej_set_infinity(&tmpj);
/* r = inp_g_sc*G */
secp256k1_ecmult(ctx, r, &tmpj, &szero, inp_g_sc);
for (point_idx = 0; point_idx < n_points; point_idx++) {
secp256k1_ge point;
secp256k1_gej pointj;
secp256k1_scalar scalar;
if (!cb(&scalar, &point, point_idx, cbdata)) {
return 0;
}
/* r += scalar*point */
secp256k1_gej_set_ge(&pointj, &point);
secp256k1_ecmult(ctx, &tmpj, &pointj, &scalar, NULL);
secp256k1_gej_add_var(r, r, &tmpj, NULL);
}
return 1;
}
typedef int (*secp256k1_ecmult_multi_func)(const secp256k1_ecmult_context*, secp256k1_scratch*, secp256k1_gej*, const secp256k1_scalar*, secp256k1_ecmult_multi_callback cb, void*, size_t); typedef int (*secp256k1_ecmult_multi_func)(const secp256k1_ecmult_context*, secp256k1_scratch*, secp256k1_gej*, const secp256k1_scalar*, secp256k1_ecmult_multi_callback cb, void*, size_t);
static int secp256k1_ecmult_multi_var(const secp256k1_ecmult_context *ctx, secp256k1_scratch *scratch, secp256k1_gej *r, const secp256k1_scalar *inp_g_sc, secp256k1_ecmult_multi_callback cb, void *cbdata, size_t n) { static int secp256k1_ecmult_multi_var(const secp256k1_ecmult_context *ctx, secp256k1_scratch *scratch, secp256k1_gej *r, const secp256k1_scalar *inp_g_sc, secp256k1_ecmult_multi_callback cb, void *cbdata, size_t n) {
size_t i; size_t i;
int (*f)(const secp256k1_ecmult_context*, secp256k1_scratch*, secp256k1_gej*, const secp256k1_scalar*, secp256k1_ecmult_multi_callback cb, void*, size_t, size_t); int (*f)(const secp256k1_ecmult_context*, secp256k1_scratch*, secp256k1_gej*, const secp256k1_scalar*, secp256k1_ecmult_multi_callback cb, void*, size_t, size_t);
size_t max_points; size_t max_points;
size_t n_batches; size_t n_batches;
size_t n_batch_points; size_t n_batch_points;
secp256k1_gej_set_infinity(r); secp256k1_gej_set_infinity(r);
if (inp_g_sc == NULL && n == 0) { if (inp_g_sc == NULL && n == 0) {
return 1; return 1;
} else if (n == 0) { } else if (n == 0) {
secp256k1_scalar szero; secp256k1_scalar szero;
secp256k1_scalar_set_int(&szero, 0); secp256k1_scalar_set_int(&szero, 0);
secp256k1_ecmult(ctx, r, r, &szero, inp_g_sc); secp256k1_ecmult(ctx, r, r, &szero, inp_g_sc);
return 1; return 1;
} }
if (scratch == NULL) {
return secp256k1_ecmult_multi_simple_var(ctx, r, inp_g_sc, cb, cbdata, n);
}
max_points = secp256k1_pippenger_max_points(scratch); max_points = secp256k1_pippenger_max_points(scratch);
if (max_points == 0) { if (max_points == 0) {
return 0; return 0;
} else if (max_points > ECMULT_MAX_POINTS_PER_BATCH) { } else if (max_points > ECMULT_MAX_POINTS_PER_BATCH) {
max_points = ECMULT_MAX_POINTS_PER_BATCH; max_points = ECMULT_MAX_POINTS_PER_BATCH;
} }
n_batches = (n+max_points-1)/max_points; n_batches = (n+max_points-1)/max_points;
Show All 27 Lines