X-Git-Url: https://repo.jachan.dev/secp256k1.git/blobdiff_plain/dcf392027b3d8b551a1a4fa2e31356504ca4b431..1669bb2865ff2231d7818cf26f42c696eac32227:/src/tests.c diff --git a/src/tests.c b/src/tests.c index d95b360..132df9b 100644 --- a/src/tests.c +++ b/src/tests.c @@ -335,40 +335,73 @@ void run_context_tests(int use_prealloc) { } void run_scratch_tests(void) { + const size_t adj_alloc = ((500 + ALIGNMENT - 1) / ALIGNMENT) * ALIGNMENT; + int32_t ecount = 0; + size_t checkpoint; + size_t checkpoint_2; secp256k1_context *none = secp256k1_context_create(SECP256K1_CONTEXT_NONE); secp256k1_scratch_space *scratch; + secp256k1_scratch_space local_scratch; /* Test public API */ secp256k1_context_set_illegal_callback(none, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_error_callback(none, counting_illegal_callback_fn, &ecount); scratch = secp256k1_scratch_space_create(none, 1000); CHECK(scratch != NULL); CHECK(ecount == 0); /* Test internal API */ - CHECK(secp256k1_scratch_max_allocation(scratch, 0) == 1000); - CHECK(secp256k1_scratch_max_allocation(scratch, 1) < 1000); - - /* Allocating 500 bytes with no frame fails */ - CHECK(secp256k1_scratch_alloc(scratch, 500) == NULL); - CHECK(secp256k1_scratch_max_allocation(scratch, 0) == 1000); - - /* ...but pushing a new stack frame does affect the max allocation */ - CHECK(secp256k1_scratch_allocate_frame(scratch, 500, 1 == 1)); - CHECK(secp256k1_scratch_max_allocation(scratch, 1) < 500); /* 500 - ALIGNMENT */ - CHECK(secp256k1_scratch_alloc(scratch, 500) != NULL); - CHECK(secp256k1_scratch_alloc(scratch, 500) == NULL); - - CHECK(secp256k1_scratch_allocate_frame(scratch, 500, 1) == 0); + CHECK(secp256k1_scratch_max_allocation(&none->error_callback, scratch, 0) == 1000); + CHECK(secp256k1_scratch_max_allocation(&none->error_callback, scratch, 1) == 1000 - (ALIGNMENT - 1)); + CHECK(scratch->alloc_size == 0); + CHECK(scratch->alloc_size % ALIGNMENT == 0); + + /* Allocating 500 bytes succeeds */ + checkpoint = secp256k1_scratch_checkpoint(&none->error_callback, scratch); + CHECK(secp256k1_scratch_alloc(&none->error_callback, scratch, 500) != NULL); + CHECK(secp256k1_scratch_max_allocation(&none->error_callback, scratch, 0) == 1000 - adj_alloc); + CHECK(secp256k1_scratch_max_allocation(&none->error_callback, scratch, 1) == 1000 - adj_alloc - (ALIGNMENT - 1)); + CHECK(scratch->alloc_size != 0); + CHECK(scratch->alloc_size % ALIGNMENT == 0); + + /* Allocating another 500 bytes fails */ + CHECK(secp256k1_scratch_alloc(&none->error_callback, scratch, 500) == NULL); + CHECK(secp256k1_scratch_max_allocation(&none->error_callback, scratch, 0) == 1000 - adj_alloc); + CHECK(secp256k1_scratch_max_allocation(&none->error_callback, scratch, 1) == 1000 - adj_alloc - (ALIGNMENT - 1)); + CHECK(scratch->alloc_size != 0); + CHECK(scratch->alloc_size % ALIGNMENT == 0); + + /* ...but it succeeds once we apply the checkpoint to undo it */ + secp256k1_scratch_apply_checkpoint(&none->error_callback, scratch, checkpoint); + CHECK(scratch->alloc_size == 0); + CHECK(secp256k1_scratch_max_allocation(&none->error_callback, scratch, 0) == 1000); + CHECK(secp256k1_scratch_alloc(&none->error_callback, scratch, 500) != NULL); + CHECK(scratch->alloc_size != 0); + + /* try to apply a bad checkpoint */ + checkpoint_2 = secp256k1_scratch_checkpoint(&none->error_callback, scratch); + secp256k1_scratch_apply_checkpoint(&none->error_callback, scratch, checkpoint); + CHECK(ecount == 0); + secp256k1_scratch_apply_checkpoint(&none->error_callback, scratch, checkpoint_2); /* checkpoint_2 is after checkpoint */ + CHECK(ecount == 1); + secp256k1_scratch_apply_checkpoint(&none->error_callback, scratch, (size_t) -1); /* this is just wildly invalid */ + CHECK(ecount == 2); - /* ...and this effect is undone by popping the frame */ - secp256k1_scratch_deallocate_frame(scratch); - CHECK(secp256k1_scratch_max_allocation(scratch, 0) == 1000); - CHECK(secp256k1_scratch_alloc(scratch, 500) == NULL); + /* try to use badly initialized scratch space */ + secp256k1_scratch_space_destroy(none, scratch); + memset(&local_scratch, 0, sizeof(local_scratch)); + scratch = &local_scratch; + CHECK(!secp256k1_scratch_max_allocation(&none->error_callback, scratch, 0)); + CHECK(ecount == 3); + CHECK(secp256k1_scratch_alloc(&none->error_callback, scratch, 500) == NULL); + CHECK(ecount == 4); + secp256k1_scratch_space_destroy(none, scratch); + CHECK(ecount == 5); /* cleanup */ - secp256k1_scratch_space_destroy(scratch); + secp256k1_scratch_space_destroy(none, NULL); /* no-op */ secp256k1_context_destroy(none); } @@ -2659,14 +2692,13 @@ 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; secp256k1_scalar_set_int(&szero, 0); /* No points to multiply */ - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, NULL, ecmult_multi_callback, &data, 0)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, NULL, ecmult_multi_callback, &data, 0)); /* Check 1- and 2-point multiplies against ecmult */ for (ncount = 0; ncount < count; ncount++) { @@ -2682,36 +2714,31 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e /* only G scalar */ secp256k1_ecmult(&ctx->ecmult_ctx, &r2, &ptgj, &szero, &sc[0]); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &sc[0], ecmult_multi_callback, &data, 0)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &sc[0], ecmult_multi_callback, &data, 0)); secp256k1_gej_neg(&r2, &r2); secp256k1_gej_add_var(&r, &r, &r2, NULL); CHECK(secp256k1_gej_is_infinity(&r)); /* 1-point */ secp256k1_ecmult(&ctx->ecmult_ctx, &r2, &ptgj, &sc[0], &szero); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 1)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 1)); secp256k1_gej_neg(&r2, &r2); 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)); + CHECK(!ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_false_callback, &data, 1)); /* 2-point */ secp256k1_ecmult(&ctx->ecmult_ctx, &r2, &ptgj, &sc[0], &sc[1]); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 2)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 2)); secp256k1_gej_neg(&r2, &r2); secp256k1_gej_add_var(&r, &r, &r2, NULL); CHECK(secp256k1_gej_is_infinity(&r)); /* 2-point with G scalar */ secp256k1_ecmult(&ctx->ecmult_ctx, &r2, &ptgj, &sc[0], &sc[1]); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &sc[1], ecmult_multi_callback, &data, 1)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &sc[1], ecmult_multi_callback, &data, 1)); secp256k1_gej_neg(&r2, &r2); secp256k1_gej_add_var(&r, &r, &r2, NULL); CHECK(secp256k1_gej_is_infinity(&r)); @@ -2728,7 +2755,7 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e random_scalar_order(&sc[i]); secp256k1_ge_set_infinity(&pt[i]); } - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, sizes[j])); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, sizes[j])); CHECK(secp256k1_gej_is_infinity(&r)); } @@ -2738,7 +2765,7 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e pt[i] = ptg; secp256k1_scalar_set_int(&sc[i], 0); } - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, sizes[j])); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, sizes[j])); CHECK(secp256k1_gej_is_infinity(&r)); } @@ -2751,7 +2778,7 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e pt[2 * i + 1] = ptg; } - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, sizes[j])); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, sizes[j])); CHECK(secp256k1_gej_is_infinity(&r)); random_scalar_order(&sc[0]); @@ -2764,7 +2791,7 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e secp256k1_ge_neg(&pt[2*i+1], &pt[2*i]); } - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, sizes[j])); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, sizes[j])); CHECK(secp256k1_gej_is_infinity(&r)); } @@ -2779,7 +2806,7 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e secp256k1_scalar_negate(&sc[i], &sc[i]); } - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 32)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 32)); CHECK(secp256k1_gej_is_infinity(&r)); } @@ -2798,7 +2825,7 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e } secp256k1_ecmult(&ctx->ecmult_ctx, &r2, &r, &sc[0], &szero); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 20)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 20)); secp256k1_gej_neg(&r2, &r2); secp256k1_gej_add_var(&r, &r, &r2, NULL); CHECK(secp256k1_gej_is_infinity(&r)); @@ -2821,7 +2848,7 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e secp256k1_gej_set_ge(&p0j, &pt[0]); secp256k1_ecmult(&ctx->ecmult_ctx, &r2, &p0j, &rs, &szero); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 20)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 20)); secp256k1_gej_neg(&r2, &r2); secp256k1_gej_add_var(&r, &r, &r2, NULL); CHECK(secp256k1_gej_is_infinity(&r)); @@ -2834,13 +2861,13 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e } secp256k1_scalar_clear(&sc[0]); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 20)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 20)); secp256k1_scalar_clear(&sc[1]); secp256k1_scalar_clear(&sc[2]); secp256k1_scalar_clear(&sc[3]); secp256k1_scalar_clear(&sc[4]); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 6)); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 5)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 6)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &r, &szero, ecmult_multi_callback, &data, 5)); CHECK(secp256k1_gej_is_infinity(&r)); /* Run through s0*(t0*P) + s1*(t1*P) exhaustively for many small values of s0, s1, t0, t1 */ @@ -2885,7 +2912,7 @@ void test_ecmult_multi(secp256k1_scratch *scratch, secp256k1_ecmult_multi_func e secp256k1_scalar_add(&tmp1, &tmp1, &tmp2); secp256k1_ecmult(&ctx->ecmult_ctx, &expected, &ptgj, &tmp1, &szero); - CHECK(ecmult_multi(&ctx->ecmult_ctx, scratch, &actual, &szero, ecmult_multi_callback, &data, 2)); + CHECK(ecmult_multi(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &actual, &szero, ecmult_multi_callback, &data, 2)); secp256k1_gej_neg(&expected, &expected); secp256k1_gej_add_var(&actual, &actual, &expected, NULL); CHECK(secp256k1_gej_is_infinity(&actual)); @@ -2896,6 +2923,24 @@ 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->error_callback, &ctx->ecmult_ctx, scratch_empty, &r, &szero, ecmult_multi_callback, &data, 1)); + secp256k1_scratch_destroy(&ctx->error_callback, scratch_empty); +} + void test_secp256k1_pippenger_bucket_window_inv(void) { int i; @@ -2926,17 +2971,27 @@ void test_ecmult_multi_pippenger_max_points(void) { int bucket_window = 0; for(; scratch_size < max_size; scratch_size+=256) { + size_t i; + size_t total_alloc; + size_t checkpoint; scratch = secp256k1_scratch_create(&ctx->error_callback, scratch_size); CHECK(scratch != NULL); - n_points_supported = secp256k1_pippenger_max_points(scratch); + checkpoint = secp256k1_scratch_checkpoint(&ctx->error_callback, scratch); + n_points_supported = secp256k1_pippenger_max_points(&ctx->error_callback, scratch); if (n_points_supported == 0) { - secp256k1_scratch_destroy(scratch); + secp256k1_scratch_destroy(&ctx->error_callback, scratch); continue; } bucket_window = secp256k1_pippenger_bucket_window(n_points_supported); - CHECK(secp256k1_scratch_allocate_frame(scratch, secp256k1_pippenger_scratch_size(n_points_supported, bucket_window), PIPPENGER_SCRATCH_OBJECTS)); - secp256k1_scratch_deallocate_frame(scratch); - secp256k1_scratch_destroy(scratch); + /* allocate `total_alloc` bytes over `PIPPENGER_SCRATCH_OBJECTS` many allocations */ + total_alloc = secp256k1_pippenger_scratch_size(n_points_supported, bucket_window); + for (i = 0; i < PIPPENGER_SCRATCH_OBJECTS - 1; i++) { + CHECK(secp256k1_scratch_alloc(&ctx->error_callback, scratch, 1)); + total_alloc--; + } + CHECK(secp256k1_scratch_alloc(&ctx->error_callback, scratch, total_alloc)); + secp256k1_scratch_apply_checkpoint(&ctx->error_callback, scratch, checkpoint); + secp256k1_scratch_destroy(&ctx->error_callback, scratch); } CHECK(bucket_window == PIPPENGER_MAX_BUCKET_WINDOW); } @@ -3019,19 +3074,25 @@ 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)); - secp256k1_scratch_destroy(scratch); + CHECK(secp256k1_ecmult_multi_var(&ctx->error_callback, &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(&ctx->error_callback, 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)); - secp256k1_scratch_destroy(scratch); + CHECK(secp256k1_ecmult_multi_var(&ctx->error_callback, &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(&ctx->error_callback, 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); @@ -3041,10 +3102,10 @@ void test_ecmult_multi_batching(void) { size_t scratch_size = secp256k1_strauss_scratch_size(i); scratch = secp256k1_scratch_create(&ctx->error_callback, scratch_size + STRAUSS_SCRATCH_OBJECTS*ALIGNMENT); } - CHECK(secp256k1_ecmult_multi_var(&ctx->ecmult_ctx, scratch, &r, &scG, ecmult_multi_callback, &data, n_points)); + CHECK(secp256k1_ecmult_multi_var(&ctx->error_callback, &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_scratch_destroy(&ctx->error_callback, scratch); } free(sc); free(pt); @@ -3059,13 +3120,15 @@ 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); - secp256k1_scratch_destroy(scratch); + test_ecmult_multi_batch_single(secp256k1_ecmult_strauss_batch_single); + secp256k1_scratch_destroy(&ctx->error_callback, scratch); /* Run test_ecmult_multi with space for exactly one point */ scratch = secp256k1_scratch_create(&ctx->error_callback, secp256k1_strauss_scratch_size(1) + STRAUSS_SCRATCH_OBJECTS*ALIGNMENT); test_ecmult_multi(scratch, secp256k1_ecmult_multi_var); - secp256k1_scratch_destroy(scratch); + secp256k1_scratch_destroy(&ctx->error_callback, scratch); test_ecmult_multi_batch_size_helper(); test_ecmult_multi_batching(); @@ -4402,7 +4465,7 @@ int test_ecdsa_der_parse(const unsigned char *sig, size_t siglen, int certainly_ if (valid_der) { ret |= (!roundtrips_der_lax) << 12; ret |= (len_der != len_der_lax) << 13; - ret |= (memcmp(roundtrip_der_lax, roundtrip_der, len_der) != 0) << 14; + ret |= ((len_der != len_der_lax) || (memcmp(roundtrip_der_lax, roundtrip_der, len_der) != 0)) << 14; } ret |= (roundtrips_der != roundtrips_der_lax) << 15; if (parsed_der) { @@ -4443,7 +4506,7 @@ int test_ecdsa_der_parse(const unsigned char *sig, size_t siglen, int certainly_ ret |= (roundtrips_der != roundtrips_openssl) << 7; if (roundtrips_openssl) { ret |= (len_der != (size_t)len_openssl) << 8; - ret |= (memcmp(roundtrip_der, roundtrip_openssl, len_der) != 0) << 9; + ret |= ((len_der != (size_t)len_openssl) || (memcmp(roundtrip_der, roundtrip_openssl, len_der) != 0)) << 9; } #endif return ret;