Use trivial algorithm in ecmult_multi if scratch space is small

This commit is contained in:
Jonas Nick
2019-02-27 10:46:42 +00:00
parent aa15154a48
commit 9ab96f7b12
2 changed files with 37 additions and 15 deletions

View File

@@ -2572,7 +2572,6 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e
secp256k1_gej r;
secp256k1_gej r2;
ecmult_multi_data data;
secp256k1_scratch *scratch_empty;
data.sc = sc;
data.pt = pt;
@@ -2607,11 +2606,6 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e
secp256k1_gej_add_var(&r, &r, &r2, NULL);
CHECK(secp256k1_gej_is_infinity(&r));
/* Try to multiply 1 point, but scratch space is empty */
scratch_empty = secp256k1_scratch_create(&ctx->error_callback, 0);
CHECK(!ecmult_multi(&ctx->ecmult_ctx, scratch_empty, &r, &szero, ecmult_multi_callback, &data, 1));
secp256k1_scratch_destroy(scratch_empty);
/* Try to multiply 1 point, but callback returns false */
CHECK(!ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_false_callback, &data, 1));
@@ -2809,6 +2803,24 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e
}
}
void test_ecmult_multi_batch_single(secp256k1_ecmult_multi_func ecmult_multi) {
secp256k1_scalar szero;
secp256k1_scalar sc[32];
secp256k1_ge pt[32];
secp256k1_gej r;
ecmult_multi_data data;
secp256k1_scratch *scratch_empty;
data.sc = sc;
data.pt = pt;
secp256k1_scalar_set_int(&szero, 0);
/* Try to multiply 1 point, but scratch space is empty.*/
scratch_empty = secp256k1_scratch_create(&ctx->error_callback, 0);
CHECK(!ecmult_multi(&ctx->ecmult_ctx, scratch_empty, &r, &szero, ecmult_multi_callback, &data, 1));
secp256k1_scratch_destroy(scratch_empty);
}
void test_secp256k1_pippenger_bucket_window_inv(void) {
int i;
@@ -2932,19 +2944,25 @@ void test_ecmult_multi_batching(void) {
}
data.sc = sc;
data.pt = pt;
secp256k1_gej_neg(&r2, &r2);
/* Test with empty scratch space */
/* Test with empty scratch space. It should compute the correct result using
* ecmult_mult_simple algorithm which doesn't require a scratch space. */
scratch = secp256k1_scratch_create(&ctx->error_callback, 0);
CHECK(!secp256k1_ecmult_multi_var(&ctx->ecmult_ctx, scratch, &r, &scG, ecmult_multi_callback, &data, 1));
CHECK(secp256k1_ecmult_multi_var(&ctx->ecmult_ctx, scratch, &r, &scG, ecmult_multi_callback, &data, n_points));
secp256k1_gej_add_var(&r, &r, &r2, NULL);
CHECK(secp256k1_gej_is_infinity(&r));
secp256k1_scratch_destroy(scratch);
/* Test with space for 1 point in pippenger. That's not enough because
* ecmult_multi selects strauss which requires more memory. */
* ecmult_multi selects strauss which requires more memory. It should
* therefore select the simple algorithm. */
scratch = secp256k1_scratch_create(&ctx->error_callback, secp256k1_pippenger_scratch_size(1, 1) + PIPPENGER_SCRATCH_OBJECTS*ALIGNMENT);
CHECK(!secp256k1_ecmult_multi_var(&ctx->ecmult_ctx, scratch, &r, &scG, ecmult_multi_callback, &data, 1));
CHECK(secp256k1_ecmult_multi_var(&ctx->ecmult_ctx, scratch, &r, &scG, ecmult_multi_callback, &data, n_points));
secp256k1_gej_add_var(&r, &r, &r2, NULL);
CHECK(secp256k1_gej_is_infinity(&r));
secp256k1_scratch_destroy(scratch);
secp256k1_gej_neg(&r2, &r2);
for(i = 1; i <= n_points; i++) {
if (i > ECMULT_PIPPENGER_THRESHOLD) {
int bucket_window = secp256k1_pippenger_bucket_window(i);
@@ -2972,7 +2990,9 @@ void run_ecmult_multi_tests(void) {
test_ecmult_multi(scratch, secp256k1_ecmult_multi_var);
test_ecmult_multi(NULL, secp256k1_ecmult_multi_var);
test_ecmult_multi(scratch, secp256k1_ecmult_pippenger_batch_single);
test_ecmult_multi_batch_single(secp256k1_ecmult_pippenger_batch_single);
test_ecmult_multi(scratch, secp256k1_ecmult_strauss_batch_single);
test_ecmult_multi_batch_single(secp256k1_ecmult_strauss_batch_single);
secp256k1_scratch_destroy(scratch);
/* Run test_ecmult_multi with space for exactly one point */