diff --git a/.gitignore b/.gitignore index efb277d3470..87fea161ba5 100644 --- a/.gitignore +++ b/.gitignore @@ -6,6 +6,7 @@ bench_schnorr_verify bench_recover bench_internal tests +exhaustive_tests gen_context *.exe *.so diff --git a/Makefile.am b/Makefile.am index 7461ff328b4..df2017a7958 100644 --- a/Makefile.am +++ b/Makefile.am @@ -87,13 +87,23 @@ bench_internal_LDADD = $(SECP_LIBS) $(COMMON_LIB) bench_internal_CPPFLAGS = -DSECP256K1_BUILD $(SECP_INCLUDES) endif +TESTS = if USE_TESTS noinst_PROGRAMS += tests tests_SOURCES = src/tests.c tests_CPPFLAGS = -DSECP256K1_BUILD -DVERIFY -I$(top_srcdir)/src -I$(top_srcdir)/include $(SECP_INCLUDES) $(SECP_TEST_INCLUDES) tests_LDADD = $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB) tests_LDFLAGS = -static -TESTS = tests +TESTS += tests +endif + +if USE_EXHAUSTIVE_TESTS +noinst_PROGRAMS += exhaustive_tests +exhaustive_tests_SOURCES = src/tests_exhaustive.c +exhaustive_tests_CPPFLAGS = -DSECP256K1_BUILD -DVERIFY -I$(top_srcdir)/src $(SECP_INCLUDES) +exhaustive_tests_LDADD = $(SECP_LIBS) +exhaustive_tests_LDFLAGS = -static +TESTS += exhaustive_tests endif JAVAROOT=src/java @@ -140,6 +150,7 @@ $(gen_context_BIN): $(gen_context_OBJECTS) $(libsecp256k1_la_OBJECTS): src/ecmult_static_context.h $(tests_OBJECTS): src/ecmult_static_context.h +$(exhaustive_tests_OBJECTS): src/ecmult_static_context.h $(bench_internal_OBJECTS): src/ecmult_static_context.h src/ecmult_static_context.h: $(gen_context_BIN) diff --git a/configure.ac b/configure.ac index 1933f7169fe..ec50ffe3a25 100644 --- a/configure.ac +++ b/configure.ac @@ -104,6 +104,11 @@ AC_ARG_ENABLE(experimental, [use_experimental=$enableval], [use_experimental=no]) +AC_ARG_ENABLE(exhaustive_tests, + AS_HELP_STRING([--enable-exhaustive-tests],[compile exhaustive tests (default is yes)]), + [use_exhaustive_tests=$enableval], + [use_exhaustive_tests=yes]) + AC_ARG_ENABLE(endomorphism, AS_HELP_STRING([--enable-endomorphism],[enable endomorphism (default is no)]), [use_endomorphism=$enableval], @@ -456,6 +461,7 @@ AC_SUBST(SECP_LIBS) AC_SUBST(SECP_TEST_LIBS) AC_SUBST(SECP_TEST_INCLUDES) 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"$use_benchmark" = x"yes"]) AM_CONDITIONAL([USE_ECMULT_STATIC_PRECOMPUTATION], [test x"$set_precomp" = x"yes"]) AM_CONDITIONAL([ENABLE_MODULE_ECDH], [test x"$enable_module_ecdh" = x"yes"]) diff --git a/src/ecmult_impl.h b/src/ecmult_impl.h index d1e83bd6dd4..8ed19b7a532 100644 --- a/src/ecmult_impl.h +++ b/src/ecmult_impl.h @@ -7,6 +7,8 @@ #ifndef _SECP256K1_ECMULT_IMPL_H_ #define _SECP256K1_ECMULT_IMPL_H_ +#include + #include "group.h" #include "scalar.h" #include "ecmult.h" @@ -16,6 +18,15 @@ /* optimal for 128-bit and 256-bit exponents. */ #define WINDOW_A 5 +#if defined(EXHAUSTIVE_TEST_ORDER) +# if EXHAUSTIVE_TEST_ORDER > 128 +# define WINDOW_G 8 +# elif EXHAUSTIVE_TEST_ORDER > 8 +# define WINDOW_G 4 +# else +# define WINDOW_G 2 +# endif +#else /** larger numbers may result in slightly better performance, at the cost of exponentially larger precomputed tables. */ #ifdef USE_ENDOMORPHISM @@ -25,6 +36,7 @@ /** One table for window size 16: 1.375 MiB. */ #define WINDOW_G 16 #endif +#endif /** The number of entries a table with precomputed multiples needs to have. */ #define ECMULT_TABLE_SIZE(w) (1 << ((w)-2)) diff --git a/src/field.h b/src/field.h index 4daefc43a0a..bbb1ee866cc 100644 --- a/src/field.h +++ b/src/field.h @@ -30,6 +30,8 @@ #error "Please select field implementation" #endif +#include "util.h" + /** Normalize a field element. */ static void secp256k1_fe_normalize(secp256k1_fe *r); @@ -50,6 +52,9 @@ static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe *r); /** Set a field element equal to a small integer. Resulting field element is normalized. */ static void secp256k1_fe_set_int(secp256k1_fe *r, int a); +/** Sets a field element equal to zero, initializing all fields. */ +static void secp256k1_fe_clear(secp256k1_fe *a); + /** Verify whether a field element is zero. Requires the input to be normalized. */ static int secp256k1_fe_is_zero(const secp256k1_fe *a); diff --git a/src/group_impl.h b/src/group_impl.h index 18f2b37353f..97d5118356f 100644 --- a/src/group_impl.h +++ b/src/group_impl.h @@ -11,6 +11,18 @@ #include "field.h" #include "group.h" +#if defined(EXHAUSTIVE_TEST_ORDER) +# if EXHAUSTIVE_TEST_ORDER == 199 +const secp256k1_ge secp256k1_ge_const_g = SECP256K1_GE_CONST( + 0xFA7CC9A7, 0x0737F2DB, 0xA749DD39, 0x2B4FB069, + 0x3B017A7D, 0xA808C2F1, 0xFB12940C, 0x9EA66C18, + 0x78AC123A, 0x5ED8AEF3, 0x8732BC91, 0x1F3A2868, + 0x48DF246C, 0x808DAE72, 0xCFE52572, 0x7F0501ED +); +# else +# error No known generator for the specified exhaustive test group order. +# endif +#else /** Generator for secp256k1, value 'g' defined in * "Standards for Efficient Cryptography" (SEC2) 2.7.1. */ @@ -20,6 +32,7 @@ static const secp256k1_ge secp256k1_ge_const_g = SECP256K1_GE_CONST( 0x483ADA77UL, 0x26A3C465UL, 0x5DA4FBFCUL, 0x0E1108A8UL, 0xFD17B448UL, 0xA6855419UL, 0x9C47D08FUL, 0xFB10D4B8UL ); +#endif static void secp256k1_ge_set_gej_zinv(secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_fe *zi) { secp256k1_fe zi2; @@ -145,9 +158,15 @@ static void secp256k1_ge_globalz_set_table_gej(size_t len, secp256k1_ge *r, secp static void secp256k1_gej_set_infinity(secp256k1_gej *r) { r->infinity = 1; - secp256k1_fe_set_int(&r->x, 0); - secp256k1_fe_set_int(&r->y, 0); - secp256k1_fe_set_int(&r->z, 0); + secp256k1_fe_clear(&r->x); + secp256k1_fe_clear(&r->y); + 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) { diff --git a/src/tests_exhaustive.c b/src/tests_exhaustive.c new file mode 100644 index 00000000000..7a916e917dd --- /dev/null +++ b/src/tests_exhaustive.c @@ -0,0 +1,171 @@ +/********************************************************************** + * Copyright (c) 2015 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 + +#ifndef EXHAUSTIVE_TEST_ORDER +#define EXHAUSTIVE_TEST_ORDER 199 +#endif + +#include "include/secp256k1.h" +#include "group.h" +#include "secp256k1.c" +#include "testrand_impl.h" + +/** 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 */ + +void test_exhaustive_addition(const secp256k1_ge *group, const secp256k1_gej *groupj, int order) { + 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 < order; i++) { + CHECK(!secp256k1_ge_is_infinity(&group[i])); + CHECK(!secp256k1_gej_is_infinity(&groupj[i])); + } + + /* Check all addition formulae */ + for (j = 0; j < order; j++) { + secp256k1_fe fe_inv; + secp256k1_fe_inv(&fe_inv, &groupj[j].z); + for (i = 0; i < 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) % order], &tmp); + /* add_ge */ + if (j > 0) { + secp256k1_gej_add_ge(&tmp, &groupj[i], &group[j]); + ge_equals_gej(&group[(i + j) % order], &tmp); + } + /* add_ge_var */ + secp256k1_gej_add_ge_var(&tmp, &groupj[i], &group[j], NULL); + ge_equals_gej(&group[(i + j) % 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) % order], &tmp); + } + } + + /* Check doubling */ + for (i = 0; i < order; i++) { + secp256k1_gej tmp; + if (i > 0) { + secp256k1_gej_double_nonzero(&tmp, &groupj[i], NULL); + ge_equals_gej(&group[(2 * i) % order], &tmp); + } + secp256k1_gej_double_var(&tmp, &groupj[i], NULL); + ge_equals_gej(&group[(2 * i) % order], &tmp); + } + + /* Check negation */ + for (i = 1; i < order; i++) { + secp256k1_ge tmp; + secp256k1_gej tmpj; + secp256k1_ge_neg(&tmp, &group[i]); + ge_equals_ge(&group[order - i], &tmp); + secp256k1_gej_neg(&tmpj, &groupj[i]); + ge_equals_gej(&group[order - i], &tmpj); + } +} + +void test_exhaustive_ecmult(secp256k1_context *ctx, secp256k1_ge *group, secp256k1_gej *groupj, int order) { + int i, j; + const int r_log = secp256k1_rand32() % order; /* TODO be less biased */ + for (j = 0; j < order; j++) { + for (i = 0; i < 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) % order], &tmp); + + /* TODO we cannot exhaustively test ecmult_const as it does a scalar + * negation for even numbers, and our code is not designed to handle + * such a small scalar modulus. */ + } + } +} + +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_ge_set_infinity(&group[0]); + secp256k1_gej_set_infinity(&groupj[0]); + for (i = 1; i < EXHAUSTIVE_TEST_ORDER; i++) { + 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); + } + + /* Run the tests */ + test_exhaustive_addition(group, groupj, EXHAUSTIVE_TEST_ORDER); + test_exhaustive_ecmult(ctx, group, groupj, EXHAUSTIVE_TEST_ORDER); + + return 0; +} +