diff --git a/Makefile.am b/Makefile.am index e5657f7f313..c071fbe2753 100644 --- a/Makefile.am +++ b/Makefile.am @@ -93,7 +93,10 @@ TESTS = if USE_TESTS noinst_PROGRAMS += tests tests_SOURCES = src/tests.c -tests_CPPFLAGS = -DSECP256K1_BUILD -DVERIFY -I$(top_srcdir)/src -I$(top_srcdir)/include $(SECP_INCLUDES) $(SECP_TEST_INCLUDES) +tests_CPPFLAGS = -DSECP256K1_BUILD -I$(top_srcdir)/src -I$(top_srcdir)/include $(SECP_INCLUDES) $(SECP_TEST_INCLUDES) +if !ENABLE_COVERAGE +tests_CPPFLAGS += -DVERIFY +endif tests_LDADD = $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB) tests_LDFLAGS = -static TESTS += tests @@ -102,7 +105,10 @@ endif if USE_EXHAUSTIVE_TESTS noinst_PROGRAMS += exhaustive_tests exhaustive_tests_SOURCES = src/tests_exhaustive.c -exhaustive_tests_CPPFLAGS = -DSECP256K1_BUILD -DVERIFY -I$(top_srcdir)/src $(SECP_INCLUDES) +exhaustive_tests_CPPFLAGS = -DSECP256K1_BUILD -I$(top_srcdir)/src $(SECP_INCLUDES) +if !ENABLE_COVERAGE +exhaustive_tests_CPPFLAGS += -DVERIFY +endif exhaustive_tests_LDADD = $(SECP_LIBS) exhaustive_tests_LDFLAGS = -static TESTS += exhaustive_tests diff --git a/configure.ac b/configure.ac index ec50ffe3a25..e5fcbcb4edf 100644 --- a/configure.ac +++ b/configure.ac @@ -20,7 +20,7 @@ AC_PATH_TOOL(STRIP, strip) AX_PROG_CC_FOR_BUILD if test "x$CFLAGS" = "x"; then - CFLAGS="-O3 -g" + CFLAGS="-g" fi AM_PROG_CC_C_O @@ -89,6 +89,11 @@ AC_ARG_ENABLE(benchmark, [use_benchmark=$enableval], [use_benchmark=no]) +AC_ARG_ENABLE(coverage, + AS_HELP_STRING([--enable-coverage],[enable compiler flags to support kcov coverage analysis]), + [enable_coverage=$enableval], + [enable_coverage=no]) + AC_ARG_ENABLE(tests, AS_HELP_STRING([--enable-tests],[compile tests (default is yes)]), [use_tests=$enableval], @@ -154,6 +159,14 @@ AC_COMPILE_IFELSE([AC_LANG_SOURCE([[void myfunc() {__builtin_expect(0,0);}]])], [ AC_MSG_RESULT([no]) ]) +if test x"$enable_coverage" = x"yes"; then + AC_DEFINE(COVERAGE, 1, [Define this symbol to compile out all VERIFY code]) + CFLAGS="$CFLAGS -O0 --coverage" + LDFLAGS="--coverage" +else + CFLAGS="$CFLAGS -O3" +fi + if test x"$use_ecmult_static_precomputation" != x"no"; then save_cross_compiling=$cross_compiling cross_compiling=no @@ -434,6 +447,7 @@ AC_MSG_NOTICE([Using field implementation: $set_field]) AC_MSG_NOTICE([Using bignum implementation: $set_bignum]) AC_MSG_NOTICE([Using scalar implementation: $set_scalar]) AC_MSG_NOTICE([Using endomorphism optimizations: $use_endomorphism]) +AC_MSG_NOTICE([Building for coverage analysis: $enable_coverage]) AC_MSG_NOTICE([Building ECDH module: $enable_module_ecdh]) AC_MSG_NOTICE([Building ECDSA pubkey recovery module: $enable_module_recovery]) AC_MSG_NOTICE([Using jni: $use_jni]) @@ -460,6 +474,7 @@ AC_SUBST(SECP_INCLUDES) AC_SUBST(SECP_LIBS) AC_SUBST(SECP_TEST_LIBS) AC_SUBST(SECP_TEST_INCLUDES) +AM_CONDITIONAL([ENABLE_COVERAGE], [test x"$enable_coverage" = x"yes"]) AM_CONDITIONAL([USE_TESTS], [test x"$use_tests" != x"no"]) AM_CONDITIONAL([USE_EXHAUSTIVE_TESTS], [test x"$use_exhaustive_tests" != x"no"]) AM_CONDITIONAL([USE_BENCHMARK], [test x"$use_benchmark" = x"yes"]) diff --git a/src/ecdsa_impl.h b/src/ecdsa_impl.h index 9a42e519bd5..453bb118806 100644 --- a/src/ecdsa_impl.h +++ b/src/ecdsa_impl.h @@ -225,14 +225,12 @@ static int secp256k1_ecdsa_sig_verify(const secp256k1_ecmult_context *ctx, const #if defined(EXHAUSTIVE_TEST_ORDER) { secp256k1_scalar computed_r; - int overflow = 0; secp256k1_ge pr_ge; secp256k1_ge_set_gej(&pr_ge, &pr); secp256k1_fe_normalize(&pr_ge.x); secp256k1_fe_get_b32(c, &pr_ge.x); - secp256k1_scalar_set_b32(&computed_r, c, &overflow); - /* we fully expect overflow */ + secp256k1_scalar_set_b32(&computed_r, c, NULL); return secp256k1_scalar_eq(sigr, &computed_r); } #else @@ -285,14 +283,10 @@ static int secp256k1_ecdsa_sig_sign(const secp256k1_ecmult_gen_context *ctx, sec secp256k1_fe_normalize(&r.y); secp256k1_fe_get_b32(b, &r.x); secp256k1_scalar_set_b32(sigr, b, &overflow); - if (secp256k1_scalar_is_zero(sigr)) { - /* P.x = order is on the curve, so technically sig->r could end up zero, which would be an invalid signature. - * This branch is cryptographically unreachable as hitting it requires finding the discrete log of P.x = N. - */ - secp256k1_gej_clear(&rp); - secp256k1_ge_clear(&r); - return 0; - } + /* These two conditions should be checked before calling */ + VERIFY_CHECK(!secp256k1_scalar_is_zero(sigr)); + VERIFY_CHECK(overflow == 0); + if (recid) { /* The overflow condition is cryptographically unreachable as hitting it requires finding the discrete log * of some P where P.x >= order, and only 1 in about 2^127 points meet this criteria. diff --git a/src/field_10x26_impl.h b/src/field_10x26_impl.h index 7b8c0796084..5fb092f1beb 100644 --- a/src/field_10x26_impl.h +++ b/src/field_10x26_impl.h @@ -38,10 +38,6 @@ static void secp256k1_fe_verify(const secp256k1_fe *a) { } VERIFY_CHECK(r == 1); } -#else -static void secp256k1_fe_verify(const secp256k1_fe *a) { - (void)a; -} #endif static void secp256k1_fe_normalize(secp256k1_fe *r) { diff --git a/src/field_5x52_impl.h b/src/field_5x52_impl.h index 7a99eb21ecc..dd88f38c77b 100644 --- a/src/field_5x52_impl.h +++ b/src/field_5x52_impl.h @@ -49,10 +49,6 @@ static void secp256k1_fe_verify(const secp256k1_fe *a) { } VERIFY_CHECK(r == 1); } -#else -static void secp256k1_fe_verify(const secp256k1_fe *a) { - (void)a; -} #endif static void secp256k1_fe_normalize(secp256k1_fe *r) { diff --git a/src/group_impl.h b/src/group_impl.h index 2e192b62fd2..7d723532ff3 100644 --- a/src/group_impl.h +++ b/src/group_impl.h @@ -200,12 +200,6 @@ static void secp256k1_gej_set_infinity(secp256k1_gej *r) { secp256k1_fe_clear(&r->z); } -static void secp256k1_ge_set_infinity(secp256k1_ge *r) { - r->infinity = 1; - secp256k1_fe_clear(&r->x); - secp256k1_fe_clear(&r->y); -} - static void secp256k1_gej_clear(secp256k1_gej *r) { r->infinity = 0; secp256k1_fe_clear(&r->x); diff --git a/src/modules/ecdh/main_impl.h b/src/modules/ecdh/main_impl.h index c23e4f82f7f..9e30fb73dd7 100644 --- a/src/modules/ecdh/main_impl.h +++ b/src/modules/ecdh/main_impl.h @@ -16,10 +16,10 @@ int secp256k1_ecdh(const secp256k1_context* ctx, unsigned char *result, const se secp256k1_gej res; secp256k1_ge pt; secp256k1_scalar s; + VERIFY_CHECK(ctx != NULL); ARG_CHECK(result != NULL); ARG_CHECK(point != NULL); ARG_CHECK(scalar != NULL); - (void)ctx; secp256k1_pubkey_load(ctx, &pt, point); secp256k1_scalar_set_b32(&s, scalar, &overflow); diff --git a/src/modules/ecdh/tests_impl.h b/src/modules/ecdh/tests_impl.h index 7badc9033f7..85a5d0a9a69 100644 --- a/src/modules/ecdh/tests_impl.h +++ b/src/modules/ecdh/tests_impl.h @@ -7,6 +7,35 @@ #ifndef _SECP256K1_MODULE_ECDH_TESTS_ #define _SECP256K1_MODULE_ECDH_TESTS_ +void test_ecdh_api(void) { + /* Setup context that just counts errors */ + secp256k1_context *tctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN); + secp256k1_pubkey point; + unsigned char res[32]; + unsigned char s_one[32] = { 0 }; + int32_t ecount = 0; + s_one[31] = 1; + + secp256k1_context_set_error_callback(tctx, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_illegal_callback(tctx, counting_illegal_callback_fn, &ecount); + CHECK(secp256k1_ec_pubkey_create(tctx, &point, s_one) == 1); + + /* Check all NULLs are detected */ + CHECK(secp256k1_ecdh(tctx, res, &point, s_one) == 1); + CHECK(ecount == 0); + CHECK(secp256k1_ecdh(tctx, NULL, &point, s_one) == 0); + CHECK(ecount == 1); + CHECK(secp256k1_ecdh(tctx, res, NULL, s_one) == 0); + CHECK(ecount == 2); + CHECK(secp256k1_ecdh(tctx, res, &point, NULL) == 0); + CHECK(ecount == 3); + CHECK(secp256k1_ecdh(tctx, res, &point, s_one) == 1); + CHECK(ecount == 3); + + /* Cleanup */ + secp256k1_context_destroy(tctx); +} + void test_ecdh_generator_basepoint(void) { unsigned char s_one[32] = { 0 }; secp256k1_pubkey point[2]; @@ -68,6 +97,7 @@ void test_bad_scalar(void) { } void run_ecdh_tests(void) { + test_ecdh_api(); test_ecdh_generator_basepoint(); test_bad_scalar(); } diff --git a/src/modules/recovery/main_impl.h b/src/modules/recovery/main_impl.h index 86f2f0cb2b5..c6fbe239813 100755 --- a/src/modules/recovery/main_impl.h +++ b/src/modules/recovery/main_impl.h @@ -179,7 +179,7 @@ int secp256k1_ecdsa_recover(const secp256k1_context* ctx, secp256k1_pubkey *pubk ARG_CHECK(pubkey != NULL); secp256k1_ecdsa_recoverable_signature_load(ctx, &r, &s, &recid, signature); - ARG_CHECK(recid >= 0 && recid < 4); + VERIFY_CHECK(recid >= 0 && recid < 4); /* should have been caught in parse_compact */ secp256k1_scalar_set_b32(&m, msg32, NULL); if (secp256k1_ecdsa_sig_recover(&ctx->ecmult_ctx, &r, &s, &q, &m, recid)) { secp256k1_pubkey_save(pubkey, &q); diff --git a/src/modules/recovery/tests_impl.h b/src/modules/recovery/tests_impl.h index 8932d5f0afc..765c7dd81e9 100644 --- a/src/modules/recovery/tests_impl.h +++ b/src/modules/recovery/tests_impl.h @@ -7,6 +7,146 @@ #ifndef _SECP256K1_MODULE_RECOVERY_TESTS_ #define _SECP256K1_MODULE_RECOVERY_TESTS_ +static int recovery_test_nonce_function(unsigned char *nonce32, const unsigned char *msg32, const unsigned char *key32, const unsigned char *algo16, void *data, unsigned int counter) { + (void) msg32; + (void) key32; + (void) algo16; + (void) data; + + /* On the first run, return 0 to force a second run */ + if (counter == 0) { + memset(nonce32, 0, 32); + return 1; + } + /* On the second run, return an overflow to force a third run */ + if (counter == 1) { + memset(nonce32, 0xff, 32); + return 1; + } + /* On the next run, return a valid nonce, but flip a coin as to whether or not to fail signing. */ + memset(nonce32, 1, 32); + return secp256k1_rand_bits(1); +} + +void test_ecdsa_recovery_api(void) { + /* Setup contexts that just count errors */ + secp256k1_context *none = secp256k1_context_create(SECP256K1_CONTEXT_NONE); + secp256k1_context *sign = secp256k1_context_create(SECP256K1_CONTEXT_SIGN); + secp256k1_context *vrfy = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY); + secp256k1_context *both = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY); + secp256k1_pubkey pubkey; + secp256k1_pubkey recpubkey; + secp256k1_ecdsa_signature normal_sig; + secp256k1_ecdsa_recoverable_signature recsig; + unsigned char privkey[32] = { 1 }; + unsigned char message[32] = { 2 }; + int32_t ecount = 0; + int recid = 0; + unsigned char sig[74]; + unsigned char zero_privkey[32] = { 0 }; + unsigned char over_privkey[32] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; + + secp256k1_context_set_error_callback(none, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_error_callback(sign, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_error_callback(vrfy, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_error_callback(both, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_illegal_callback(none, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_illegal_callback(sign, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_illegal_callback(vrfy, counting_illegal_callback_fn, &ecount); + secp256k1_context_set_illegal_callback(both, counting_illegal_callback_fn, &ecount); + + /* Construct and verify corresponding public key. */ + CHECK(secp256k1_ec_seckey_verify(ctx, privkey) == 1); + CHECK(secp256k1_ec_pubkey_create(ctx, &pubkey, privkey) == 1); + + /* Check bad contexts and NULLs for signing */ + ecount = 0; + CHECK(secp256k1_ecdsa_sign_recoverable(none, &recsig, message, privkey, NULL, NULL) == 0); + CHECK(ecount == 1); + CHECK(secp256k1_ecdsa_sign_recoverable(sign, &recsig, message, privkey, NULL, NULL) == 1); + CHECK(ecount == 1); + CHECK(secp256k1_ecdsa_sign_recoverable(vrfy, &recsig, message, privkey, NULL, NULL) == 0); + CHECK(ecount == 2); + CHECK(secp256k1_ecdsa_sign_recoverable(both, &recsig, message, privkey, NULL, NULL) == 1); + CHECK(ecount == 2); + CHECK(secp256k1_ecdsa_sign_recoverable(both, NULL, message, privkey, NULL, NULL) == 0); + CHECK(ecount == 3); + CHECK(secp256k1_ecdsa_sign_recoverable(both, &recsig, NULL, privkey, NULL, NULL) == 0); + CHECK(ecount == 4); + CHECK(secp256k1_ecdsa_sign_recoverable(both, &recsig, message, NULL, NULL, NULL) == 0); + CHECK(ecount == 5); + /* This will fail or succeed randomly, and in either case will not ARG_CHECK failure */ + secp256k1_ecdsa_sign_recoverable(both, &recsig, message, privkey, recovery_test_nonce_function, NULL); + CHECK(ecount == 5); + /* These will all fail, but not in ARG_CHECK way */ + CHECK(secp256k1_ecdsa_sign_recoverable(both, &recsig, message, zero_privkey, NULL, NULL) == 0); + CHECK(secp256k1_ecdsa_sign_recoverable(both, &recsig, message, over_privkey, NULL, NULL) == 0); + /* This one will succeed. */ + CHECK(secp256k1_ecdsa_sign_recoverable(both, &recsig, message, privkey, NULL, NULL) == 1); + CHECK(ecount == 5); + + /* Check signing with a goofy nonce function */ + + /* Check bad contexts and NULLs for recovery */ + ecount = 0; + CHECK(secp256k1_ecdsa_recover(none, &recpubkey, &recsig, message) == 0); + CHECK(ecount == 1); + CHECK(secp256k1_ecdsa_recover(sign, &recpubkey, &recsig, message) == 0); + CHECK(ecount == 2); + CHECK(secp256k1_ecdsa_recover(vrfy, &recpubkey, &recsig, message) == 1); + CHECK(ecount == 2); + CHECK(secp256k1_ecdsa_recover(both, &recpubkey, &recsig, message) == 1); + CHECK(ecount == 2); + CHECK(secp256k1_ecdsa_recover(both, NULL, &recsig, message) == 0); + CHECK(ecount == 3); + CHECK(secp256k1_ecdsa_recover(both, &recpubkey, NULL, message) == 0); + CHECK(ecount == 4); + CHECK(secp256k1_ecdsa_recover(both, &recpubkey, &recsig, NULL) == 0); + CHECK(ecount == 5); + + /* Check NULLs for conversion */ + CHECK(secp256k1_ecdsa_sign(both, &normal_sig, message, privkey, NULL, NULL) == 1); + ecount = 0; + CHECK(secp256k1_ecdsa_recoverable_signature_convert(both, NULL, &recsig) == 0); + CHECK(ecount == 1); + CHECK(secp256k1_ecdsa_recoverable_signature_convert(both, &normal_sig, NULL) == 0); + CHECK(ecount == 2); + CHECK(secp256k1_ecdsa_recoverable_signature_convert(both, &normal_sig, &recsig) == 1); + + /* Check NULLs for de/serialization */ + CHECK(secp256k1_ecdsa_sign_recoverable(both, &recsig, message, privkey, NULL, NULL) == 1); + ecount = 0; + CHECK(secp256k1_ecdsa_recoverable_signature_serialize_compact(both, NULL, &recid, &recsig) == 0); + CHECK(ecount == 1); + CHECK(secp256k1_ecdsa_recoverable_signature_serialize_compact(both, sig, NULL, &recsig) == 0); + CHECK(ecount == 2); + CHECK(secp256k1_ecdsa_recoverable_signature_serialize_compact(both, sig, &recid, NULL) == 0); + CHECK(ecount == 3); + CHECK(secp256k1_ecdsa_recoverable_signature_serialize_compact(both, sig, &recid, &recsig) == 1); + + CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(both, NULL, sig, recid) == 0); + CHECK(ecount == 4); + CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(both, &recsig, NULL, recid) == 0); + CHECK(ecount == 5); + CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(both, &recsig, sig, -1) == 0); + CHECK(ecount == 6); + CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(both, &recsig, sig, 5) == 0); + CHECK(ecount == 7); + /* overflow in signature will fail but not affect ecount */ + memcpy(sig, over_privkey, 32); + CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(both, &recsig, sig, recid) == 0); + CHECK(ecount == 7); + + /* cleanup */ + secp256k1_context_destroy(none); + secp256k1_context_destroy(sign); + secp256k1_context_destroy(vrfy); + secp256k1_context_destroy(both); +} + void test_ecdsa_recovery_end_to_end(void) { unsigned char extra[32] = {0x00}; unsigned char privkey[32]; @@ -241,6 +381,9 @@ void test_ecdsa_recovery_edge_cases(void) { void run_recovery_tests(void) { int i; + for (i = 0; i < count; i++) { + test_ecdsa_recovery_api(); + } for (i = 0; i < 64*count; i++) { test_ecdsa_recovery_end_to_end(); } diff --git a/src/tests_exhaustive.c b/src/tests_exhaustive.c index bda6ee475c9..b040bb0733d 100644 --- a/src/tests_exhaustive.c +++ b/src/tests_exhaustive.c @@ -26,6 +26,11 @@ #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); @@ -77,7 +82,7 @@ int secp256k1_nonce_function_smallint(unsigned char *nonce32, const unsigned cha * 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 = (*idata + 1) % EXHAUSTIVE_TEST_ORDER; } secp256k1_scalar_set_int(&s, *idata); secp256k1_scalar_get_b32(nonce32, &s); @@ -244,6 +249,7 @@ void test_exhaustive_sign(const secp256k1_context *ctx, const secp256k1_ge *grou for (i = 1; i < order; i++) { /* message */ for (j = 1; j < order; j++) { /* key */ for (k = 1; k < 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]; @@ -262,6 +268,11 @@ void test_exhaustive_sign(const secp256k1_context *ctx, const secp256k1_ge *grou CHECK(r == expected_r); CHECK((k * s) % order == (i + r * j) % order || (k * (EXHAUSTIVE_TEST_ORDER - s)) % order == (i + r * j) % order); + + /* Overflow means we've tried every possible nonce */ + if (k < starting_k) { + break; + } } } } @@ -276,6 +287,130 @@ void test_exhaustive_sign(const secp256k1_context *ctx, const secp256k1_ge *grou */ } +#ifdef ENABLE_MODULE_RECOVERY +void test_exhaustive_recovery_sign(const secp256k1_context *ctx, const secp256k1_ge *group, int order) { + int i, j, k; + + /* Loop */ + for (i = 1; i < order; i++) { /* message */ + for (j = 1; j < order; j++) { /* key */ + for (k = 1; k < 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) % order == (i + r * j) % order || + (k * (EXHAUSTIVE_TEST_ORDER - s)) % order == (i + r * j) % 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) % order == (i + r * j) % 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) % order == (i + r * j) % order || + (k * (EXHAUSTIVE_TEST_ORDER - s)) % order == (i + r * j) % 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, int order) { + /* This is essentially a copy of test_exhaustive_verify, with recovery added */ + int s, r, msg, key; + for (s = 1; s < order; s++) { + for (r = 1; r < order; r++) { + for (msg = 1; msg < order; msg++) { + for (key = 1; key < 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 < 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)); + } + } + } + } +} +#endif + int main(void) { int i; secp256k1_gej groupj[EXHAUSTIVE_TEST_ORDER]; @@ -324,6 +459,12 @@ int main(void) { test_exhaustive_sign(ctx, group, EXHAUSTIVE_TEST_ORDER); test_exhaustive_verify(ctx, group, EXHAUSTIVE_TEST_ORDER); +#ifdef ENABLE_MODULE_RECOVERY + test_exhaustive_recovery_sign(ctx, group, EXHAUSTIVE_TEST_ORDER); + test_exhaustive_recovery_verify(ctx, group, EXHAUSTIVE_TEST_ORDER); +#endif + + secp256k1_context_destroy(ctx); return 0; } diff --git a/src/util.h b/src/util.h index 4eef4ded47f..4092a86c917 100644 --- a/src/util.h +++ b/src/util.h @@ -57,7 +57,10 @@ static SECP256K1_INLINE void secp256k1_callback_call(const secp256k1_callback * #endif /* Like assert(), but when VERIFY is defined, and side-effect safe. */ -#ifdef VERIFY +#if defined(COVERAGE) +#define VERIFY_CHECK(check) +#define VERIFY_SETUP(stmt) +#elif defined(VERIFY) #define VERIFY_CHECK CHECK #define VERIFY_SETUP(stmt) do { stmt; } while(0) #else