diff --git a/src/secp256k1/src/modules/recovery/Makefile.am.include b/src/secp256k1/src/modules/recovery/Makefile.am.include index bf23c26e7..e2d3f1248 100644 --- a/src/secp256k1/src/modules/recovery/Makefile.am.include +++ b/src/secp256k1/src/modules/recovery/Makefile.am.include @@ -1,8 +1,9 @@ include_HEADERS += include/secp256k1_recovery.h noinst_HEADERS += src/modules/recovery/main_impl.h noinst_HEADERS += src/modules/recovery/tests_impl.h +noinst_HEADERS += src/modules/recovery/tests_exhaustive_impl.h if USE_BENCHMARK noinst_PROGRAMS += bench_recover bench_recover_SOURCES = src/bench_recover.c bench_recover_LDADD = libsecp256k1.la $(SECP_LIBS) $(COMMON_LIB) endif diff --git a/src/secp256k1/src/modules/recovery/tests_exhaustive_impl.h b/src/secp256k1/src/modules/recovery/tests_exhaustive_impl.h new file mode 100644 index 000000000..9c75e6757 --- /dev/null +++ b/src/secp256k1/src/modules/recovery/tests_exhaustive_impl.h @@ -0,0 +1,140 @@ +/********************************************************************** + * Copyright (c) 2016 Andrew Poelstra * + * Distributed under the MIT software license, see the accompanying * + * file COPYING or http://www.opensource.org/licenses/mit-license.php.* + **********************************************************************/ + +#ifndef SECP256K1_MODULE_RECOVERY_EXHAUSTIVE_TESTS_H +#define SECP256K1_MODULE_RECOVERY_EXHAUSTIVE_TESTS_H + +#include "src/modules/recovery/main_impl.h" +#include "include/secp256k1_recovery.h" + +void test_exhaustive_recovery_sign(const secp256k1_context *ctx, const secp256k1_ge *group) { + int i, j, k; + + /* Loop */ + for (i = 1; i < EXHAUSTIVE_TEST_ORDER; i++) { /* message */ + for (j = 1; j < EXHAUSTIVE_TEST_ORDER; j++) { /* key */ + for (k = 1; k < EXHAUSTIVE_TEST_ORDER; k++) { /* nonce */ + const int starting_k = k; + secp256k1_fe r_dot_y_normalized; + secp256k1_ecdsa_recoverable_signature rsig; + secp256k1_ecdsa_signature sig; + secp256k1_scalar sk, msg, r, s, expected_r; + unsigned char sk32[32], msg32[32]; + int expected_recid; + int recid; + secp256k1_scalar_set_int(&msg, i); + secp256k1_scalar_set_int(&sk, j); + secp256k1_scalar_get_b32(sk32, &sk); + secp256k1_scalar_get_b32(msg32, &msg); + + secp256k1_ecdsa_sign_recoverable(ctx, &rsig, msg32, sk32, secp256k1_nonce_function_smallint, &k); + + /* Check directly */ + secp256k1_ecdsa_recoverable_signature_load(ctx, &r, &s, &recid, &rsig); + r_from_k(&expected_r, group, k); + CHECK(r == expected_r); + CHECK((k * s) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER || + (k * (EXHAUSTIVE_TEST_ORDER - s)) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER); + /* In computing the recid, there is an overflow condition that is disabled in + * scalar_low_impl.h `secp256k1_scalar_set_b32` because almost every r.y value + * will exceed the group order, and our signing code always holds out for r + * values that don't overflow, so with a proper overflow check the tests would + * loop indefinitely. */ + r_dot_y_normalized = group[k].y; + secp256k1_fe_normalize(&r_dot_y_normalized); + /* Also the recovery id is flipped depending if we hit the low-s branch */ + if ((k * s) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER) { + expected_recid = secp256k1_fe_is_odd(&r_dot_y_normalized) ? 1 : 0; + } else { + expected_recid = secp256k1_fe_is_odd(&r_dot_y_normalized) ? 0 : 1; + } + CHECK(recid == expected_recid); + + /* Convert to a standard sig then check */ + secp256k1_ecdsa_recoverable_signature_convert(ctx, &sig, &rsig); + secp256k1_ecdsa_signature_load(ctx, &r, &s, &sig); + /* Note that we compute expected_r *after* signing -- this is important + * because our nonce-computing function function might change k during + * signing. */ + r_from_k(&expected_r, group, k); + CHECK(r == expected_r); + CHECK((k * s) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER || + (k * (EXHAUSTIVE_TEST_ORDER - s)) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER); + + /* Overflow means we've tried every possible nonce */ + if (k < starting_k) { + break; + } + } + } + } +} + +void test_exhaustive_recovery_verify(const secp256k1_context *ctx, const secp256k1_ge *group) { + /* This is essentially a copy of test_exhaustive_verify, with recovery added */ + int s, r, msg, key; + for (s = 1; s < EXHAUSTIVE_TEST_ORDER; s++) { + for (r = 1; r < EXHAUSTIVE_TEST_ORDER; r++) { + for (msg = 1; msg < EXHAUSTIVE_TEST_ORDER; msg++) { + for (key = 1; key < EXHAUSTIVE_TEST_ORDER; key++) { + secp256k1_ge nonconst_ge; + secp256k1_ecdsa_recoverable_signature rsig; + secp256k1_ecdsa_signature sig; + secp256k1_pubkey pk; + secp256k1_scalar sk_s, msg_s, r_s, s_s; + secp256k1_scalar s_times_k_s, msg_plus_r_times_sk_s; + int recid = 0; + int k, should_verify; + unsigned char msg32[32]; + + secp256k1_scalar_set_int(&s_s, s); + secp256k1_scalar_set_int(&r_s, r); + secp256k1_scalar_set_int(&msg_s, msg); + secp256k1_scalar_set_int(&sk_s, key); + secp256k1_scalar_get_b32(msg32, &msg_s); + + /* Verify by hand */ + /* Run through every k value that gives us this r and check that *one* works. + * Note there could be none, there could be multiple, ECDSA is weird. */ + should_verify = 0; + for (k = 0; k < EXHAUSTIVE_TEST_ORDER; k++) { + secp256k1_scalar check_x_s; + r_from_k(&check_x_s, group, k); + if (r_s == check_x_s) { + secp256k1_scalar_set_int(&s_times_k_s, k); + secp256k1_scalar_mul(&s_times_k_s, &s_times_k_s, &s_s); + secp256k1_scalar_mul(&msg_plus_r_times_sk_s, &r_s, &sk_s); + secp256k1_scalar_add(&msg_plus_r_times_sk_s, &msg_plus_r_times_sk_s, &msg_s); + should_verify |= secp256k1_scalar_eq(&s_times_k_s, &msg_plus_r_times_sk_s); + } + } + /* nb we have a "high s" rule */ + should_verify &= !secp256k1_scalar_is_high(&s_s); + + /* We would like to try recovering the pubkey and checking that it matches, + * but pubkey recovery is impossible in the exhaustive tests (the reason + * being that there are 12 nonzero r values, 12 nonzero points, and no + * overlap between the sets, so there are no valid signatures). */ + + /* Verify by converting to a standard signature and calling verify */ + secp256k1_ecdsa_recoverable_signature_save(&rsig, &r_s, &s_s, recid); + secp256k1_ecdsa_recoverable_signature_convert(ctx, &sig, &rsig); + memcpy(&nonconst_ge, &group[sk_s], sizeof(nonconst_ge)); + secp256k1_pubkey_save(&pk, &nonconst_ge); + CHECK(should_verify == + secp256k1_ecdsa_verify(ctx, &sig, msg32, &pk)); + } + } + } + } +} + +static void test_exhaustive_recovery(const secp256k1_context *ctx, const secp256k1_ge *group) { + test_exhaustive_recovery_sign(ctx, group); + test_exhaustive_recovery_verify(ctx, group); +} + +#endif /* SECP256K1_MODULE_RECOVERY_EXHAUSTIVE_TESTS_H */ diff --git a/src/secp256k1/src/tests_exhaustive.c b/src/secp256k1/src/tests_exhaustive.c index de1da9f28..ab06bab97 100644 --- a/src/secp256k1/src/tests_exhaustive.c +++ b/src/secp256k1/src/tests_exhaustive.c @@ -1,509 +1,383 @@ /*********************************************************************** * Copyright (c) 2016 Andrew Poelstra * * Distributed under the MIT software license, see the accompanying * * file COPYING or http://www.opensource.org/licenses/mit-license.php.* **********************************************************************/ #if defined HAVE_CONFIG_H #include "libsecp256k1-config.h" #endif #include #include #include #undef USE_ECMULT_STATIC_PRECOMPUTATION #ifndef EXHAUSTIVE_TEST_ORDER /* see group_impl.h for allowable values */ #define EXHAUSTIVE_TEST_ORDER 13 #define EXHAUSTIVE_TEST_LAMBDA 9 /* cube root of 1 mod 13 */ #endif #include "include/secp256k1.h" #include "assumptions.h" #include "group.h" #include "secp256k1.c" #include "testrand_impl.h" -#ifdef ENABLE_MODULE_RECOVERY -#include "src/modules/recovery/main_impl.h" -#include "include/secp256k1_recovery.h" -#endif - /** stolen from tests.c */ void ge_equals_ge(const secp256k1_ge *a, const secp256k1_ge *b) { CHECK(a->infinity == b->infinity); if (a->infinity) { return; } CHECK(secp256k1_fe_equal_var(&a->x, &b->x)); CHECK(secp256k1_fe_equal_var(&a->y, &b->y)); } void ge_equals_gej(const secp256k1_ge *a, const secp256k1_gej *b) { secp256k1_fe z2s; secp256k1_fe u1, u2, s1, s2; CHECK(a->infinity == b->infinity); if (a->infinity) { return; } /* Check a.x * b.z^2 == b.x && a.y * b.z^3 == b.y, to avoid inverses. */ secp256k1_fe_sqr(&z2s, &b->z); secp256k1_fe_mul(&u1, &a->x, &z2s); u2 = b->x; secp256k1_fe_normalize_weak(&u2); secp256k1_fe_mul(&s1, &a->y, &z2s); secp256k1_fe_mul(&s1, &s1, &b->z); s2 = b->y; secp256k1_fe_normalize_weak(&s2); CHECK(secp256k1_fe_equal_var(&u1, &u2)); CHECK(secp256k1_fe_equal_var(&s1, &s2)); } void random_fe(secp256k1_fe *x) { unsigned char bin[32]; do { secp256k1_rand256(bin); if (secp256k1_fe_set_b32(x, bin)) { return; } } while(1); } /** END stolen from tests.c */ int secp256k1_nonce_function_smallint(unsigned char *nonce32, const unsigned char *msg32, const unsigned char *key32, const unsigned char *algo16, void *data, unsigned int attempt) { secp256k1_scalar s; int *idata = data; (void)msg32; (void)key32; (void)algo16; /* Some nonces cannot be used because they'd cause s and/or r to be zero. * The signing function has retry logic here that just re-calls the nonce * function with an increased `attempt`. So if attempt > 0 this means we * need to change the nonce to avoid an infinite loop. */ if (attempt > 0) { *idata = (*idata + 1) % EXHAUSTIVE_TEST_ORDER; } secp256k1_scalar_set_int(&s, *idata); secp256k1_scalar_get_b32(nonce32, &s); return 1; } #ifdef USE_ENDOMORPHISM void test_exhaustive_endomorphism(const secp256k1_ge *group) { int i; for (i = 0; i < EXHAUSTIVE_TEST_ORDER; i++) { secp256k1_ge res; secp256k1_ge_mul_lambda(&res, &group[i]); ge_equals_ge(&group[i * EXHAUSTIVE_TEST_LAMBDA % EXHAUSTIVE_TEST_ORDER], &res); } } #endif void test_exhaustive_addition(const secp256k1_ge *group, const secp256k1_gej *groupj) { int i, j; /* Sanity-check (and check infinity functions) */ CHECK(secp256k1_ge_is_infinity(&group[0])); CHECK(secp256k1_gej_is_infinity(&groupj[0])); for (i = 1; i < EXHAUSTIVE_TEST_ORDER; i++) { CHECK(!secp256k1_ge_is_infinity(&group[i])); CHECK(!secp256k1_gej_is_infinity(&groupj[i])); } /* Check all addition formulae */ for (j = 0; j < EXHAUSTIVE_TEST_ORDER; j++) { secp256k1_fe fe_inv; secp256k1_fe_inv(&fe_inv, &groupj[j].z); for (i = 0; i < EXHAUSTIVE_TEST_ORDER; i++) { secp256k1_ge zless_gej; secp256k1_gej tmp; /* add_var */ secp256k1_gej_add_var(&tmp, &groupj[i], &groupj[j], NULL); ge_equals_gej(&group[(i + j) % EXHAUSTIVE_TEST_ORDER], &tmp); /* add_ge */ if (j > 0) { secp256k1_gej_add_ge(&tmp, &groupj[i], &group[j]); ge_equals_gej(&group[(i + j) % EXHAUSTIVE_TEST_ORDER], &tmp); } /* add_ge_var */ secp256k1_gej_add_ge_var(&tmp, &groupj[i], &group[j], NULL); ge_equals_gej(&group[(i + j) % EXHAUSTIVE_TEST_ORDER], &tmp); /* add_zinv_var */ zless_gej.infinity = groupj[j].infinity; zless_gej.x = groupj[j].x; zless_gej.y = groupj[j].y; secp256k1_gej_add_zinv_var(&tmp, &groupj[i], &zless_gej, &fe_inv); ge_equals_gej(&group[(i + j) % EXHAUSTIVE_TEST_ORDER], &tmp); } } /* Check doubling */ for (i = 0; i < EXHAUSTIVE_TEST_ORDER; i++) { secp256k1_gej tmp; secp256k1_gej_double(&tmp, &groupj[i]); ge_equals_gej(&group[(2 * i) % EXHAUSTIVE_TEST_ORDER], &tmp); secp256k1_gej_double_var(&tmp, &groupj[i], NULL); ge_equals_gej(&group[(2 * i) % EXHAUSTIVE_TEST_ORDER], &tmp); } /* Check negation */ for (i = 1; i < EXHAUSTIVE_TEST_ORDER; i++) { secp256k1_ge tmp; secp256k1_gej tmpj; secp256k1_ge_neg(&tmp, &group[i]); ge_equals_ge(&group[EXHAUSTIVE_TEST_ORDER - i], &tmp); secp256k1_gej_neg(&tmpj, &groupj[i]); ge_equals_gej(&group[EXHAUSTIVE_TEST_ORDER - i], &tmpj); } } void test_exhaustive_ecmult(const secp256k1_context *ctx, const secp256k1_ge *group, const secp256k1_gej *groupj) { int i, j, r_log; for (r_log = 1; r_log < EXHAUSTIVE_TEST_ORDER; r_log++) { for (j = 0; j < EXHAUSTIVE_TEST_ORDER; j++) { for (i = 0; i < EXHAUSTIVE_TEST_ORDER; i++) { secp256k1_gej tmp; secp256k1_scalar na, ng; secp256k1_scalar_set_int(&na, i); secp256k1_scalar_set_int(&ng, j); secp256k1_ecmult(&ctx->ecmult_ctx, &tmp, &groupj[r_log], &na, &ng); ge_equals_gej(&group[(i * r_log + j) % EXHAUSTIVE_TEST_ORDER], &tmp); if (i > 0) { secp256k1_ecmult_const(&tmp, &group[i], &ng, 256); ge_equals_gej(&group[(i * j) % EXHAUSTIVE_TEST_ORDER], &tmp); } } } } } typedef struct { secp256k1_scalar sc[2]; secp256k1_ge pt[2]; } ecmult_multi_data; static int ecmult_multi_callback(secp256k1_scalar *sc, secp256k1_ge *pt, size_t idx, void *cbdata) { ecmult_multi_data *data = (ecmult_multi_data*) cbdata; *sc = data->sc[idx]; *pt = data->pt[idx]; return 1; } void test_exhaustive_ecmult_multi(const secp256k1_context *ctx, const secp256k1_ge *group) { int i, j, k, x, y; secp256k1_scratch *scratch = secp256k1_scratch_create(&ctx->error_callback, 4096); for (i = 0; i < EXHAUSTIVE_TEST_ORDER; i++) { for (j = 0; j < EXHAUSTIVE_TEST_ORDER; j++) { for (k = 0; k < EXHAUSTIVE_TEST_ORDER; k++) { for (x = 0; x < EXHAUSTIVE_TEST_ORDER; x++) { for (y = 0; y < EXHAUSTIVE_TEST_ORDER; y++) { secp256k1_gej tmp; secp256k1_scalar g_sc; ecmult_multi_data data; secp256k1_scalar_set_int(&data.sc[0], i); secp256k1_scalar_set_int(&data.sc[1], j); secp256k1_scalar_set_int(&g_sc, k); data.pt[0] = group[x]; data.pt[1] = group[y]; secp256k1_ecmult_multi_var(&ctx->error_callback, &ctx->ecmult_ctx, scratch, &tmp, &g_sc, ecmult_multi_callback, &data, 2); ge_equals_gej(&group[(i * x + j * y + k) % EXHAUSTIVE_TEST_ORDER], &tmp); } } } } } secp256k1_scratch_destroy(&ctx->error_callback, scratch); } void r_from_k(secp256k1_scalar *r, const secp256k1_ge *group, int k) { secp256k1_fe x; unsigned char x_bin[32]; k %= EXHAUSTIVE_TEST_ORDER; x = group[k].x; secp256k1_fe_normalize(&x); secp256k1_fe_get_b32(x_bin, &x); secp256k1_scalar_set_b32(r, x_bin, NULL); } void test_exhaustive_verify(const secp256k1_context *ctx, const secp256k1_ge *group) { int s, r, msg, key; for (s = 1; s < EXHAUSTIVE_TEST_ORDER; s++) { for (r = 1; r < EXHAUSTIVE_TEST_ORDER; r++) { for (msg = 1; msg < EXHAUSTIVE_TEST_ORDER; msg++) { for (key = 1; key < EXHAUSTIVE_TEST_ORDER; key++) { secp256k1_ge nonconst_ge; secp256k1_ecdsa_signature sig; secp256k1_pubkey pk; secp256k1_scalar sk_s, msg_s, r_s, s_s; secp256k1_scalar s_times_k_s, msg_plus_r_times_sk_s; int k, should_verify; unsigned char msg32[32]; secp256k1_scalar_set_int(&s_s, s); secp256k1_scalar_set_int(&r_s, r); secp256k1_scalar_set_int(&msg_s, msg); secp256k1_scalar_set_int(&sk_s, key); /* Verify by hand */ /* Run through every k value that gives us this r and check that *one* works. * Note there could be none, there could be multiple, ECDSA is weird. */ should_verify = 0; for (k = 0; k < EXHAUSTIVE_TEST_ORDER; k++) { secp256k1_scalar check_x_s; r_from_k(&check_x_s, group, k); if (r_s == check_x_s) { secp256k1_scalar_set_int(&s_times_k_s, k); secp256k1_scalar_mul(&s_times_k_s, &s_times_k_s, &s_s); secp256k1_scalar_mul(&msg_plus_r_times_sk_s, &r_s, &sk_s); secp256k1_scalar_add(&msg_plus_r_times_sk_s, &msg_plus_r_times_sk_s, &msg_s); should_verify |= secp256k1_scalar_eq(&s_times_k_s, &msg_plus_r_times_sk_s); } } /* nb we have a "high s" rule */ should_verify &= !secp256k1_scalar_is_high(&s_s); /* Verify by calling verify */ secp256k1_ecdsa_signature_save(&sig, &r_s, &s_s); memcpy(&nonconst_ge, &group[sk_s], sizeof(nonconst_ge)); secp256k1_pubkey_save(&pk, &nonconst_ge); secp256k1_scalar_get_b32(msg32, &msg_s); CHECK(should_verify == secp256k1_ecdsa_verify(ctx, &sig, msg32, &pk)); } } } } } void test_exhaustive_sign(const secp256k1_context *ctx, const secp256k1_ge *group) { int i, j, k; /* Loop */ for (i = 1; i < EXHAUSTIVE_TEST_ORDER; i++) { /* message */ for (j = 1; j < EXHAUSTIVE_TEST_ORDER; j++) { /* key */ for (k = 1; k < EXHAUSTIVE_TEST_ORDER; k++) { /* nonce */ const int starting_k = k; secp256k1_ecdsa_signature sig; secp256k1_scalar sk, msg, r, s, expected_r; unsigned char sk32[32], msg32[32]; secp256k1_scalar_set_int(&msg, i); secp256k1_scalar_set_int(&sk, j); secp256k1_scalar_get_b32(sk32, &sk); secp256k1_scalar_get_b32(msg32, &msg); secp256k1_ecdsa_sign(ctx, &sig, msg32, sk32, secp256k1_nonce_function_smallint, &k); secp256k1_ecdsa_signature_load(ctx, &r, &s, &sig); /* Note that we compute expected_r *after* signing -- this is important * because our nonce-computing function function might change k during * signing. */ r_from_k(&expected_r, group, k); CHECK(r == expected_r); CHECK((k * s) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER || (k * (EXHAUSTIVE_TEST_ORDER - s)) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER); /* Overflow means we've tried every possible nonce */ if (k < starting_k) { break; } } } } /* We would like to verify zero-knowledge here by counting how often every * possible (s, r) tuple appears, but because the group order is larger * than the field order, when coercing the x-values to scalar values, some * appear more often than others, so we are actually not zero-knowledge. * (This effect also appears in the real code, but the difference is on the * order of 1/2^128th the field order, so the deviation is not useful to a * computationally bounded attacker.) */ } #ifdef ENABLE_MODULE_RECOVERY -void test_exhaustive_recovery_sign(const secp256k1_context *ctx, const secp256k1_ge *group) { - int i, j, k; - - /* Loop */ - for (i = 1; i < EXHAUSTIVE_TEST_ORDER; i++) { /* message */ - for (j = 1; j < EXHAUSTIVE_TEST_ORDER; j++) { /* key */ - for (k = 1; k < EXHAUSTIVE_TEST_ORDER; k++) { /* nonce */ - const int starting_k = k; - secp256k1_fe r_dot_y_normalized; - secp256k1_ecdsa_recoverable_signature rsig; - secp256k1_ecdsa_signature sig; - secp256k1_scalar sk, msg, r, s, expected_r; - unsigned char sk32[32], msg32[32]; - int expected_recid; - int recid; - secp256k1_scalar_set_int(&msg, i); - secp256k1_scalar_set_int(&sk, j); - secp256k1_scalar_get_b32(sk32, &sk); - secp256k1_scalar_get_b32(msg32, &msg); - - secp256k1_ecdsa_sign_recoverable(ctx, &rsig, msg32, sk32, secp256k1_nonce_function_smallint, &k); - - /* Check directly */ - secp256k1_ecdsa_recoverable_signature_load(ctx, &r, &s, &recid, &rsig); - r_from_k(&expected_r, group, k); - CHECK(r == expected_r); - CHECK((k * s) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER || - (k * (EXHAUSTIVE_TEST_ORDER - s)) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER); - /* In computing the recid, there is an overflow condition that is disabled in - * scalar_low_impl.h `secp256k1_scalar_set_b32` because almost every r.y value - * will exceed the group order, and our signing code always holds out for r - * values that don't overflow, so with a proper overflow check the tests would - * loop indefinitely. */ - r_dot_y_normalized = group[k].y; - secp256k1_fe_normalize(&r_dot_y_normalized); - /* Also the recovery id is flipped depending if we hit the low-s branch */ - if ((k * s) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER) { - expected_recid = secp256k1_fe_is_odd(&r_dot_y_normalized) ? 1 : 0; - } else { - expected_recid = secp256k1_fe_is_odd(&r_dot_y_normalized) ? 0 : 1; - } - CHECK(recid == expected_recid); - - /* Convert to a standard sig then check */ - secp256k1_ecdsa_recoverable_signature_convert(ctx, &sig, &rsig); - secp256k1_ecdsa_signature_load(ctx, &r, &s, &sig); - /* Note that we compute expected_r *after* signing -- this is important - * because our nonce-computing function function might change k during - * signing. */ - r_from_k(&expected_r, group, k); - CHECK(r == expected_r); - CHECK((k * s) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER || - (k * (EXHAUSTIVE_TEST_ORDER - s)) % EXHAUSTIVE_TEST_ORDER == (i + r * j) % EXHAUSTIVE_TEST_ORDER); - - /* Overflow means we've tried every possible nonce */ - if (k < starting_k) { - break; - } - } - } - } -} - -void test_exhaustive_recovery_verify(const secp256k1_context *ctx, const secp256k1_ge *group) { - /* This is essentially a copy of test_exhaustive_verify, with recovery added */ - int s, r, msg, key; - for (s = 1; s < EXHAUSTIVE_TEST_ORDER; s++) { - for (r = 1; r < EXHAUSTIVE_TEST_ORDER; r++) { - for (msg = 1; msg < EXHAUSTIVE_TEST_ORDER; msg++) { - for (key = 1; key < EXHAUSTIVE_TEST_ORDER; key++) { - secp256k1_ge nonconst_ge; - secp256k1_ecdsa_recoverable_signature rsig; - secp256k1_ecdsa_signature sig; - secp256k1_pubkey pk; - secp256k1_scalar sk_s, msg_s, r_s, s_s; - secp256k1_scalar s_times_k_s, msg_plus_r_times_sk_s; - int recid = 0; - int k, should_verify; - unsigned char msg32[32]; - - secp256k1_scalar_set_int(&s_s, s); - secp256k1_scalar_set_int(&r_s, r); - secp256k1_scalar_set_int(&msg_s, msg); - secp256k1_scalar_set_int(&sk_s, key); - secp256k1_scalar_get_b32(msg32, &msg_s); - - /* Verify by hand */ - /* Run through every k value that gives us this r and check that *one* works. - * Note there could be none, there could be multiple, ECDSA is weird. */ - should_verify = 0; - for (k = 0; k < EXHAUSTIVE_TEST_ORDER; k++) { - secp256k1_scalar check_x_s; - r_from_k(&check_x_s, group, k); - if (r_s == check_x_s) { - secp256k1_scalar_set_int(&s_times_k_s, k); - secp256k1_scalar_mul(&s_times_k_s, &s_times_k_s, &s_s); - secp256k1_scalar_mul(&msg_plus_r_times_sk_s, &r_s, &sk_s); - secp256k1_scalar_add(&msg_plus_r_times_sk_s, &msg_plus_r_times_sk_s, &msg_s); - should_verify |= secp256k1_scalar_eq(&s_times_k_s, &msg_plus_r_times_sk_s); - } - } - /* nb we have a "high s" rule */ - should_verify &= !secp256k1_scalar_is_high(&s_s); - - /* We would like to try recovering the pubkey and checking that it matches, - * but pubkey recovery is impossible in the exhaustive tests (the reason - * being that there are 12 nonzero r values, 12 nonzero points, and no - * overlap between the sets, so there are no valid signatures). */ - - /* Verify by converting to a standard signature and calling verify */ - secp256k1_ecdsa_recoverable_signature_save(&rsig, &r_s, &s_s, recid); - secp256k1_ecdsa_recoverable_signature_convert(ctx, &sig, &rsig); - memcpy(&nonconst_ge, &group[sk_s], sizeof(nonconst_ge)); - secp256k1_pubkey_save(&pk, &nonconst_ge); - CHECK(should_verify == - secp256k1_ecdsa_verify(ctx, &sig, msg32, &pk)); - } - } - } - } -} +#include "src/modules/recovery/tests_exhaustive_impl.h" #endif int main(void) { int i; secp256k1_gej groupj[EXHAUSTIVE_TEST_ORDER]; secp256k1_ge group[EXHAUSTIVE_TEST_ORDER]; /* Build context */ secp256k1_context *ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY); /* TODO set z = 1, then do num_tests runs with random z values */ /* Generate the entire group */ secp256k1_gej_set_infinity(&groupj[0]); secp256k1_ge_set_gej(&group[0], &groupj[0]); for (i = 1; i < EXHAUSTIVE_TEST_ORDER; i++) { /* Set a different random z-value for each Jacobian point */ secp256k1_fe z; random_fe(&z); secp256k1_gej_add_ge(&groupj[i], &groupj[i - 1], &secp256k1_ge_const_g); secp256k1_ge_set_gej(&group[i], &groupj[i]); secp256k1_gej_rescale(&groupj[i], &z); /* Verify against ecmult_gen */ { secp256k1_scalar scalar_i; secp256k1_gej generatedj; secp256k1_ge generated; secp256k1_scalar_set_int(&scalar_i, i); secp256k1_ecmult_gen(&ctx->ecmult_gen_ctx, &generatedj, &scalar_i); secp256k1_ge_set_gej(&generated, &generatedj); CHECK(group[i].infinity == 0); CHECK(generated.infinity == 0); CHECK(secp256k1_fe_equal_var(&generated.x, &group[i].x)); CHECK(secp256k1_fe_equal_var(&generated.y, &group[i].y)); } } /* Run the tests */ #ifdef USE_ENDOMORPHISM test_exhaustive_endomorphism(group); #endif test_exhaustive_addition(group, groupj); test_exhaustive_ecmult(ctx, group, groupj); test_exhaustive_ecmult_multi(ctx, group); test_exhaustive_sign(ctx, group); test_exhaustive_verify(ctx, group); #ifdef ENABLE_MODULE_RECOVERY - test_exhaustive_recovery_sign(ctx, group); - test_exhaustive_recovery_verify(ctx, group); + test_exhaustive_recovery(ctx, group); #endif secp256k1_context_destroy(ctx); return 0; }