diff --git a/src/bench_inv.c b/src/bench_inv.c index 3bdedea30e4..9cf12cff649 100644 --- a/src/bench_inv.c +++ b/src/bench_inv.c @@ -42,11 +42,7 @@ void bench_inv(void* arg) { } int main(void) { - secp256k1_ge_start(); - bench_inv_t data; run_benchmark(bench_inv, bench_inv_setup, NULL, &data, 10, 20000); - - secp256k1_ge_stop(); return 0; } diff --git a/src/ecdsa_impl.h b/src/ecdsa_impl.h index 674650c1e9f..1c1bc8216aa 100644 --- a/src/ecdsa_impl.h +++ b/src/ecdsa_impl.h @@ -15,43 +15,14 @@ #include "ecmult_gen.h" #include "ecdsa.h" -typedef struct { - secp256k1_fe_t order_as_fe; - secp256k1_fe_t p_minus_order; -} secp256k1_ecdsa_consts_t; +static const secp256k1_fe_t secp256k1_ecdsa_const_order_as_fe = SECP256K1_FE_CONST( + 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFEUL, + 0xBAAEDCE6UL, 0xAF48A03BUL, 0xBFD25E8CUL, 0xD0364141UL +); -static const secp256k1_ecdsa_consts_t *secp256k1_ecdsa_consts = NULL; - -static void secp256k1_ecdsa_start(void) { - if (secp256k1_ecdsa_consts != NULL) - return; - - /* Allocate. */ - secp256k1_ecdsa_consts_t *ret = (secp256k1_ecdsa_consts_t*)checked_malloc(sizeof(secp256k1_ecdsa_consts_t)); - - static const unsigned char order[] = { - 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, - 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE, - 0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B, - 0xBF,0xD2,0x5E,0x8C,0xD0,0x36,0x41,0x41 - }; - - secp256k1_fe_set_b32(&ret->order_as_fe, order); - secp256k1_fe_negate(&ret->p_minus_order, &ret->order_as_fe, 1); - secp256k1_fe_normalize_var(&ret->p_minus_order); - - /* Set the global pointer. */ - secp256k1_ecdsa_consts = ret; -} - -static void secp256k1_ecdsa_stop(void) { - if (secp256k1_ecdsa_consts == NULL) - return; - - secp256k1_ecdsa_consts_t *c = (secp256k1_ecdsa_consts_t*)secp256k1_ecdsa_consts; - secp256k1_ecdsa_consts = NULL; - free(c); -} +static const secp256k1_fe_t secp256k1_ecdsa_const_p_minus_order = SECP256K1_FE_CONST( + 0, 0, 0, 1, 0x45512319UL, 0x50B75FC4UL, 0x402DA172UL, 0x2FC9BAEEUL +); static int secp256k1_ecdsa_sig_parse(secp256k1_ecdsa_sig_t *r, const unsigned char *sig, int size) { if (sig[0] != 0x30) return 0; @@ -146,11 +117,11 @@ static int secp256k1_ecdsa_sig_verify(const secp256k1_ecdsa_sig_t *sig, const se // xr.x == xr * xr.z^2 mod p, so the signature is valid. return 1; } - if (secp256k1_fe_cmp_var(&xr, &secp256k1_ecdsa_consts->p_minus_order) >= 0) { + if (secp256k1_fe_cmp_var(&xr, &secp256k1_ecdsa_const_p_minus_order) >= 0) { // xr + p >= n, so we can skip testing the second case. return 0; } - secp256k1_fe_add(&xr, &secp256k1_ecdsa_consts->order_as_fe); + secp256k1_fe_add(&xr, &secp256k1_ecdsa_const_order_as_fe); if (secp256k1_gej_eq_x_var(&xr, &pr)) { // (xr + n) * pr.z^2 mod p == pr.x, so the signature is valid. return 1; @@ -167,9 +138,9 @@ static int secp256k1_ecdsa_sig_recover(const secp256k1_ecdsa_sig_t *sig, secp256 secp256k1_fe_t fx; VERIFY_CHECK(secp256k1_fe_set_b32(&fx, brx)); /* brx comes from a scalar, so is less than the order; certainly less than p */ if (recid & 2) { - if (secp256k1_fe_cmp_var(&fx, &secp256k1_ecdsa_consts->p_minus_order) >= 0) + if (secp256k1_fe_cmp_var(&fx, &secp256k1_ecdsa_const_p_minus_order) >= 0) return 0; - secp256k1_fe_add(&fx, &secp256k1_ecdsa_consts->order_as_fe); + secp256k1_fe_add(&fx, &secp256k1_ecdsa_const_order_as_fe); } secp256k1_ge_t x; if (!secp256k1_ge_set_xo_var(&x, &fx, recid & 1)) diff --git a/src/ecmult_gen_impl.h b/src/ecmult_gen_impl.h index 48436316e12..94804de7e13 100644 --- a/src/ecmult_gen_impl.h +++ b/src/ecmult_gen_impl.h @@ -37,8 +37,7 @@ static void secp256k1_ecmult_gen_start(void) { secp256k1_ecmult_gen_consts_t *ret = (secp256k1_ecmult_gen_consts_t*)checked_malloc(sizeof(secp256k1_ecmult_gen_consts_t)); /* get the generator */ - const secp256k1_ge_t *g = &secp256k1_ge_consts->g; - secp256k1_gej_t gj; secp256k1_gej_set_ge(&gj, g); + secp256k1_gej_t gj; secp256k1_gej_set_ge(&gj, &secp256k1_ge_const_g); /* Construct a group element with no known corresponding scalar (nothing up my sleeve). */ secp256k1_gej_t nums_gej; @@ -50,7 +49,7 @@ static void secp256k1_ecmult_gen_start(void) { VERIFY_CHECK(secp256k1_ge_set_xo_var(&nums_ge, &nums_x, 0)); secp256k1_gej_set_ge(&nums_gej, &nums_ge); /* Add G to make the bits in x uniformly distributed. */ - secp256k1_gej_add_ge_var(&nums_gej, &nums_gej, g); + secp256k1_gej_add_ge_var(&nums_gej, &nums_gej, &secp256k1_ge_const_g); } /* compute prec. */ diff --git a/src/ecmult_impl.h b/src/ecmult_impl.h index 345cfae7332..58bede72853 100644 --- a/src/ecmult_impl.h +++ b/src/ecmult_impl.h @@ -91,8 +91,7 @@ static void secp256k1_ecmult_start(void) { secp256k1_ecmult_consts_t *ret = (secp256k1_ecmult_consts_t*)checked_malloc(sizeof(secp256k1_ecmult_consts_t)); /* get the generator */ - const secp256k1_ge_t *g = &secp256k1_ge_consts->g; - secp256k1_gej_t gj; secp256k1_gej_set_ge(&gj, g); + secp256k1_gej_t gj; secp256k1_gej_set_ge(&gj, &secp256k1_ge_const_g); #ifdef USE_ENDOMORPHISM /* calculate 2^128*generator */ diff --git a/src/field.h b/src/field.h index 14e2b813c17..7efd708fc4c 100644 --- a/src/field.h +++ b/src/field.h @@ -30,21 +30,6 @@ #error "Please select field implementation" #endif -typedef struct { -#ifndef USE_NUM_NONE - secp256k1_num_t p; -#endif - secp256k1_fe_t order; -} secp256k1_fe_consts_t; - -static const secp256k1_fe_consts_t *secp256k1_fe_consts = NULL; - -/** Initialize field element precomputation data. */ -static void secp256k1_fe_start(void); - -/** Unload field element precomputation data. */ -static void secp256k1_fe_stop(void); - /** Normalize a field element. */ static void secp256k1_fe_normalize(secp256k1_fe_t *r); diff --git a/src/field_10x26.h b/src/field_10x26.h index 66fb3f2563a..e3c243649fa 100644 --- a/src/field_10x26.h +++ b/src/field_10x26.h @@ -18,4 +18,23 @@ typedef struct { #endif } secp256k1_fe_t; +#define SECP256K1_FE_CONST_INNER(d7, d6, d5, d4, d3, d2, d1, d0) { \ + (d0) & 0x3FFFFFFUL, \ + ((d0) >> 26) | ((d1) & 0xFFFFFUL) << 6, \ + ((d1) >> 20) | ((d2) & 0x3FFFUL) << 12, \ + ((d2) >> 14) | ((d3) & 0xFFUL) << 18, \ + ((d3) >> 8) | ((d4) & 0x3) << 24, \ + ((d4) >> 2) & 0x3FFFFFFUL, \ + ((d4) >> 28) | ((d5) & 0x3FFFFFUL) << 4, \ + ((d5) >> 22) | ((d6) & 0xFFFF) << 10, \ + ((d6) >> 16) | ((d7) & 0x3FF) << 16, \ + ((d7) >> 10) \ +} + +#ifdef VERIFY +#define SECP256K1_FE_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {SECP256K1_FE_CONST_INNER((d7), (d6), (d5), (d4), (d3), (d2), (d1), (d0)), 1, 1} +#else +#define SECP256K1_FE_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {SECP256K1_FE_CONST_INNER((d7), (d6), (d5), (d4), (d3), (d2), (d1), (d0))} +#endif + #endif diff --git a/src/field_10x26_impl.h b/src/field_10x26_impl.h index 9ef60a807ac..ed7e3d2c57f 100644 --- a/src/field_10x26_impl.h +++ b/src/field_10x26_impl.h @@ -13,9 +13,6 @@ #include "num.h" #include "field.h" -static void secp256k1_fe_inner_start(void) {} -static void secp256k1_fe_inner_stop(void) {} - #ifdef VERIFY static void secp256k1_fe_verify(const secp256k1_fe_t *a) { const uint32_t *d = a->n; diff --git a/src/field_5x52.h b/src/field_5x52.h index aeb0a6a1e86..13934d0b2de 100644 --- a/src/field_5x52.h +++ b/src/field_5x52.h @@ -18,4 +18,18 @@ typedef struct { #endif } secp256k1_fe_t; +#define SECP256K1_FE_CONST_INNER(d7, d6, d5, d4, d3, d2, d1, d0) { \ + (d0) | ((uint64_t)(d1) & 0xFFFFFUL) << 32, \ + ((d1) >> 20) | ((uint64_t)(d2)) << 12 | ((uint64_t)(d3) & 0xFFUL) << 44, \ + ((d3) >> 8) | ((uint64_t)(d4) & 0xFFFFFFFUL) << 24, \ + ((d4) >> 28) | ((uint64_t)(d5)) << 4 | ((uint64_t)(d6) & 0xFFFFUL) << 36, \ + ((d6) >> 16) | ((uint64_t)(d7)) << 16 \ +} + +#ifdef VERIFY +#define SECP256K1_FE_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {SECP256K1_FE_CONST_INNER((d7), (d6), (d5), (d4), (d3), (d2), (d1), (d0)), 1, 1} +#else +#define SECP256K1_FE_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {SECP256K1_FE_CONST_INNER((d7), (d6), (d5), (d4), (d3), (d2), (d1), (d0))} +#endif + #endif diff --git a/src/field_5x52_impl.h b/src/field_5x52_impl.h index 4db9e6f5ff5..748c0c07a5b 100644 --- a/src/field_5x52_impl.h +++ b/src/field_5x52_impl.h @@ -30,9 +30,6 @@ * output. */ -static void secp256k1_fe_inner_start(void) {} -static void secp256k1_fe_inner_stop(void) {} - #ifdef VERIFY static void secp256k1_fe_verify(const secp256k1_fe_t *a) { const uint64_t *d = a->n; diff --git a/src/field_impl.h b/src/field_impl.h index 4e2c24aa153..c6828d121c0 100644 --- a/src/field_impl.h +++ b/src/field_impl.h @@ -206,13 +206,20 @@ static void secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) { #if defined(USE_FIELD_INV_BUILTIN) secp256k1_fe_inv(r, a); #elif defined(USE_FIELD_INV_NUM) + static const unsigned char prime[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,0xFE,0xFF,0xFF,0xFC,0x2F + }; unsigned char b[32]; secp256k1_fe_t c = *a; secp256k1_fe_normalize_var(&c); secp256k1_fe_get_b32(b, &c); - secp256k1_num_t n; + secp256k1_num_t n, m; secp256k1_num_set_bin(&n, b, 32); - secp256k1_num_mod_inverse(&n, &n, &secp256k1_fe_consts->p); + secp256k1_num_set_bin(&m, prime, 32); + secp256k1_num_mod_inverse(&n, &n, &m); secp256k1_num_get_bin(b, 32, &n); VERIFY_CHECK(secp256k1_fe_set_b32(r, b)); #else @@ -244,32 +251,4 @@ static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t r[len], const se r[0] = u; } -static void secp256k1_fe_start(void) { -#ifndef USE_NUM_NONE - static const unsigned char secp256k1_fe_consts_p[] = { - 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,0xFE,0xFF,0xFF,0xFC,0x2F - }; -#endif - if (secp256k1_fe_consts == NULL) { - secp256k1_fe_inner_start(); - secp256k1_fe_consts_t *ret = (secp256k1_fe_consts_t*)checked_malloc(sizeof(secp256k1_fe_consts_t)); -#ifndef USE_NUM_NONE - secp256k1_num_set_bin(&ret->p, secp256k1_fe_consts_p, sizeof(secp256k1_fe_consts_p)); -#endif - secp256k1_fe_consts = ret; - } -} - -static void secp256k1_fe_stop(void) { - if (secp256k1_fe_consts != NULL) { - secp256k1_fe_consts_t *c = (secp256k1_fe_consts_t*)secp256k1_fe_consts; - free((void*)c); - secp256k1_fe_consts = NULL; - secp256k1_fe_inner_stop(); - } -} - #endif diff --git a/src/group.h b/src/group.h index 6dea6bb5acb..d9555f0a22e 100644 --- a/src/group.h +++ b/src/group.h @@ -25,24 +25,6 @@ typedef struct { int infinity; /* whether this represents the point at infinity */ } secp256k1_gej_t; -/** Global constants related to the group */ -typedef struct { - secp256k1_ge_t g; /* the generator point */ - -#ifdef USE_ENDOMORPHISM - /* constants related to secp256k1's efficiently computable endomorphism */ - secp256k1_fe_t beta; -#endif -} secp256k1_ge_consts_t; - -static const secp256k1_ge_consts_t *secp256k1_ge_consts = NULL; - -/** Initialize the group module. */ -static void secp256k1_ge_start(void); - -/** De-initialize the group module. */ -static void secp256k1_ge_stop(void); - /** Set a group element equal to the point at infinity */ static void secp256k1_ge_set_infinity(secp256k1_ge_t *r); diff --git a/src/group_impl.h b/src/group_impl.h index fef06df2892..8fb17175da0 100644 --- a/src/group_impl.h +++ b/src/group_impl.h @@ -13,6 +13,18 @@ #include "field.h" #include "group.h" +static const secp256k1_ge_t secp256k1_ge_const_g = { + SECP256K1_FE_CONST( + 0x79BE667EUL, 0xF9DCBBACUL, 0x55A06295UL, 0xCE870B07UL, + 0x029BFCDBUL, 0x2DCE28D9UL, 0x59F2815BUL, 0x16F81798UL + ), + SECP256K1_FE_CONST( + 0x483ADA77UL, 0x26A3C465UL, 0x5DA4FBFCUL, 0x0E1108A8UL, + 0xFD17B448UL, 0xA6855419UL, 0x9C47D08FUL, 0xFB10D4B8UL + ), + 0 +}; + static void secp256k1_ge_set_infinity(secp256k1_ge_t *r) { r->infinity = 1; } @@ -396,53 +408,13 @@ static void secp256k1_gej_get_hex(char *r, int *rlen, const secp256k1_gej_t *a) #ifdef USE_ENDOMORPHISM static void secp256k1_gej_mul_lambda(secp256k1_gej_t *r, const secp256k1_gej_t *a) { - const secp256k1_fe_t *beta = &secp256k1_ge_consts->beta; + static const secp256k1_fe_t beta = SECP256K1_FE_CONST( + 0x7ae96a2bul, 0x657c0710ul, 0x6e64479eul, 0xac3434e9ul, + 0x9cf04975ul, 0x12f58995ul, 0xc1396c28ul, 0x719501eeul + ); *r = *a; - secp256k1_fe_mul(&r->x, &r->x, beta); + secp256k1_fe_mul(&r->x, &r->x, &beta); } #endif -static void secp256k1_ge_start(void) { - static const unsigned char secp256k1_ge_consts_g_x[] = { - 0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC, - 0x55,0xA0,0x62,0x95,0xCE,0x87,0x0B,0x07, - 0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9, - 0x59,0xF2,0x81,0x5B,0x16,0xF8,0x17,0x98 - }; - static const unsigned char secp256k1_ge_consts_g_y[] = { - 0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65, - 0x5D,0xA4,0xFB,0xFC,0x0E,0x11,0x08,0xA8, - 0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19, - 0x9C,0x47,0xD0,0x8F,0xFB,0x10,0xD4,0xB8 - }; -#ifdef USE_ENDOMORPHISM - /* properties of secp256k1's efficiently computable endomorphism */ - static const unsigned char secp256k1_ge_consts_beta[] = { - 0x7a,0xe9,0x6a,0x2b,0x65,0x7c,0x07,0x10, - 0x6e,0x64,0x47,0x9e,0xac,0x34,0x34,0xe9, - 0x9c,0xf0,0x49,0x75,0x12,0xf5,0x89,0x95, - 0xc1,0x39,0x6c,0x28,0x71,0x95,0x01,0xee - }; -#endif - if (secp256k1_ge_consts == NULL) { - secp256k1_ge_consts_t *ret = (secp256k1_ge_consts_t*)checked_malloc(sizeof(secp256k1_ge_consts_t)); -#ifdef USE_ENDOMORPHISM - VERIFY_CHECK(secp256k1_fe_set_b32(&ret->beta, secp256k1_ge_consts_beta)); -#endif - secp256k1_fe_t g_x, g_y; - VERIFY_CHECK(secp256k1_fe_set_b32(&g_x, secp256k1_ge_consts_g_x)); - VERIFY_CHECK(secp256k1_fe_set_b32(&g_y, secp256k1_ge_consts_g_y)); - secp256k1_ge_set_xy(&ret->g, &g_x, &g_y); - secp256k1_ge_consts = ret; - } -} - -static void secp256k1_ge_stop(void) { - if (secp256k1_ge_consts != NULL) { - secp256k1_ge_consts_t *c = (secp256k1_ge_consts_t*)secp256k1_ge_consts; - free((void*)c); - secp256k1_ge_consts = NULL; - } -} - #endif diff --git a/src/scalar.h b/src/scalar.h index 2f5ba0d447a..f524eef2698 100644 --- a/src/scalar.h +++ b/src/scalar.h @@ -21,9 +21,6 @@ #error "Please select scalar implementation" #endif -static void secp256k1_scalar_start(void); -static void secp256k1_scalar_stop(void); - /** Clear a scalar to prevent the leak of sensitive data. */ static void secp256k1_scalar_clear(secp256k1_scalar_t *r); diff --git a/src/scalar_4x64.h b/src/scalar_4x64.h index 5a751c68622..82899aa7b04 100644 --- a/src/scalar_4x64.h +++ b/src/scalar_4x64.h @@ -14,4 +14,6 @@ typedef struct { uint64_t d[4]; } secp256k1_scalar_t; +#define SECP256K1_SCALAR_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {{((uint64_t)(d1)) << 32 | (d0), ((uint64_t)(d3)) << 32 | (d2), ((uint64_t)(d5)) << 32 | (d4), ((uint64_t)(d7)) << 32 | (d6)}} + #endif diff --git a/src/scalar_8x32.h b/src/scalar_8x32.h index f70328cfc93..f17017e24e2 100644 --- a/src/scalar_8x32.h +++ b/src/scalar_8x32.h @@ -14,4 +14,6 @@ typedef struct { uint32_t d[8]; } secp256k1_scalar_t; +#define SECP256K1_SCALAR_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {{(d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7)}} + #endif diff --git a/src/scalar_impl.h b/src/scalar_impl.h index 4408cce2d88..7c00b50abf2 100644 --- a/src/scalar_impl.h +++ b/src/scalar_impl.h @@ -24,121 +24,6 @@ #error "Please select scalar implementation" #endif -typedef struct { -#ifndef USE_NUM_NONE - secp256k1_num_t order; -#endif -#ifdef USE_ENDOMORPHISM - secp256k1_scalar_t minus_lambda, minus_b1, minus_b2, g1, g2; -#endif -} secp256k1_scalar_consts_t; - -static const secp256k1_scalar_consts_t *secp256k1_scalar_consts = NULL; - -static void secp256k1_scalar_start(void) { - if (secp256k1_scalar_consts != NULL) - return; - - /* Allocate. */ - secp256k1_scalar_consts_t *ret = (secp256k1_scalar_consts_t*)checked_malloc(sizeof(secp256k1_scalar_consts_t)); - -#ifndef USE_NUM_NONE - static const unsigned char secp256k1_scalar_consts_order[] = { - 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, - 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE, - 0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B, - 0xBF,0xD2,0x5E,0x8C,0xD0,0x36,0x41,0x41 - }; - secp256k1_num_set_bin(&ret->order, secp256k1_scalar_consts_order, sizeof(secp256k1_scalar_consts_order)); -#endif -#ifdef USE_ENDOMORPHISM - /** - * Lambda is a scalar which has the property for secp256k1 that point multiplication by - * it is efficiently computable (see secp256k1_gej_mul_lambda). */ - static const unsigned char secp256k1_scalar_consts_lambda[32] = { - 0x53,0x63,0xad,0x4c,0xc0,0x5c,0x30,0xe0, - 0xa5,0x26,0x1c,0x02,0x88,0x12,0x64,0x5a, - 0x12,0x2e,0x22,0xea,0x20,0x81,0x66,0x78, - 0xdf,0x02,0x96,0x7c,0x1b,0x23,0xbd,0x72 - }; - /** - * "Guide to Elliptic Curve Cryptography" (Hankerson, Menezes, Vanstone) gives an algorithm - * (algorithm 3.74) to find k1 and k2 given k, such that k1 + k2 * lambda == k mod n, and k1 - * and k2 have a small size. - * It relies on constants a1, b1, a2, b2. These constants for the value of lambda above are: - * - * - a1 = {0x30,0x86,0xd2,0x21,0xa7,0xd4,0x6b,0xcd,0xe8,0x6c,0x90,0xe4,0x92,0x84,0xeb,0x15} - * - b1 = -{0xe4,0x43,0x7e,0xd6,0x01,0x0e,0x88,0x28,0x6f,0x54,0x7f,0xa9,0x0a,0xbf,0xe4,0xc3} - * - a2 = {0x01,0x14,0xca,0x50,0xf7,0xa8,0xe2,0xf3,0xf6,0x57,0xc1,0x10,0x8d,0x9d,0x44,0xcf,0xd8} - * - b2 = {0x30,0x86,0xd2,0x21,0xa7,0xd4,0x6b,0xcd,0xe8,0x6c,0x90,0xe4,0x92,0x84,0xeb,0x15} - * - * The algorithm then computes c1 = round(b1 * k / n) and c2 = round(b2 * k / n), and gives - * k1 = k - (c1*a1 + c2*a2) and k2 = -(c1*b1 + c2*b2). Instead, we use modular arithmetic, and - * compute k1 as k - k2 * lambda, avoiding the need for constants a1 and a2. - * - * g1, g2 are precomputed constants used to replace division with a rounded multiplication - * when decomposing the scalar for an endomorphism-based point multiplication. - * - * The possibility of using precomputed estimates is mentioned in "Guide to Elliptic Curve - * Cryptography" (Hankerson, Menezes, Vanstone) in section 3.5. - * - * The derivation is described in the paper "Efficient Software Implementation of Public-Key - * Cryptography on Sensor Networks Using the MSP430X Microcontroller" (Gouvea, Oliveira, Lopez), - * Section 4.3 (here we use a somewhat higher-precision estimate): - * d = a1*b2 - b1*a2 - * g1 = round((2^272)*b2/d) - * g2 = round((2^272)*b1/d) - * - * (Note that 'd' is also equal to the curve order here because [a1,b1] and [a2,b2] are found - * as outputs of the Extended Euclidean Algorithm on inputs 'order' and 'lambda'). - */ - static const unsigned char secp256k1_scalar_consts_minus_b1[32] = { - 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, - 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, - 0xe4,0x43,0x7e,0xd6,0x01,0x0e,0x88,0x28, - 0x6f,0x54,0x7f,0xa9,0x0a,0xbf,0xe4,0xc3 - }; - static const unsigned char secp256k1_scalar_consts_b2[32] = { - 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, - 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, - 0x30,0x86,0xd2,0x21,0xa7,0xd4,0x6b,0xcd, - 0xe8,0x6c,0x90,0xe4,0x92,0x84,0xeb,0x15 - }; - static const unsigned char secp256k1_scalar_consts_g1[32] = { - 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, - 0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x86, - 0xd2,0x21,0xa7,0xd4,0x6b,0xcd,0xe8,0x6c, - 0x90,0xe4,0x92,0x84,0xeb,0x15,0x3d,0xab - }; - static const unsigned char secp256k1_scalar_consts_g2[32] = { - 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, - 0x00,0x00,0x00,0x00,0x00,0x00,0xe4,0x43, - 0x7e,0xd6,0x01,0x0e,0x88,0x28,0x6f,0x54, - 0x7f,0xa9,0x0a,0xbf,0xe4,0xc4,0x22,0x12 - }; - - secp256k1_scalar_set_b32(&ret->minus_lambda, secp256k1_scalar_consts_lambda, NULL); - secp256k1_scalar_negate(&ret->minus_lambda, &ret->minus_lambda); - secp256k1_scalar_set_b32(&ret->minus_b1, secp256k1_scalar_consts_minus_b1, NULL); - secp256k1_scalar_set_b32(&ret->minus_b2, secp256k1_scalar_consts_b2, NULL); - secp256k1_scalar_negate(&ret->minus_b2, &ret->minus_b2); - secp256k1_scalar_set_b32(&ret->g1, secp256k1_scalar_consts_g1, NULL); - secp256k1_scalar_set_b32(&ret->g2, secp256k1_scalar_consts_g2, NULL); -#endif - - /* Set the global pointer. */ - secp256k1_scalar_consts = ret; -} - -static void secp256k1_scalar_stop(void) { - if (secp256k1_scalar_consts == NULL) - return; - - secp256k1_scalar_consts_t *c = (secp256k1_scalar_consts_t*)secp256k1_scalar_consts; - secp256k1_scalar_consts = NULL; - free(c); -} - #ifndef USE_NUM_NONE static void secp256k1_scalar_get_num(secp256k1_num_t *r, const secp256k1_scalar_t *a) { unsigned char c[32]; @@ -147,7 +32,13 @@ static void secp256k1_scalar_get_num(secp256k1_num_t *r, const secp256k1_scalar_ } static void secp256k1_scalar_order_get_num(secp256k1_num_t *r) { - *r = secp256k1_scalar_consts->order; + static const unsigned char order[32] = { + 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, + 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE, + 0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B, + 0xBF,0xD2,0x5E,0x8C,0xD0,0x36,0x41,0x41 + }; + secp256k1_num_set_bin(r, order, 32); } #endif @@ -308,9 +199,10 @@ static void secp256k1_scalar_inverse_var(secp256k1_scalar_t *r, const secp256k1_ #elif defined(USE_SCALAR_INV_NUM) unsigned char b[32]; secp256k1_scalar_get_b32(b, x); - secp256k1_num_t n; + secp256k1_num_t n, m; secp256k1_num_set_bin(&n, b, 32); - secp256k1_num_mod_inverse(&n, &n, &secp256k1_scalar_consts->order); + secp256k1_scalar_order_get_num(&m); + secp256k1_num_mod_inverse(&n, &n, &m); secp256k1_num_get_bin(b, 32, &n); secp256k1_scalar_set_b32(r, b, NULL); #else @@ -319,16 +211,74 @@ static void secp256k1_scalar_inverse_var(secp256k1_scalar_t *r, const secp256k1_ } #ifdef USE_ENDOMORPHISM +/** + * The Secp256k1 curve has an endomorphism, where lambda * (x, y) = (beta * x, y), where + * lambda is {0x53,0x63,0xad,0x4c,0xc0,0x5c,0x30,0xe0,0xa5,0x26,0x1c,0x02,0x88,0x12,0x64,0x5a, + * 0x12,0x2e,0x22,0xea,0x20,0x81,0x66,0x78,0xdf,0x02,0x96,0x7c,0x1b,0x23,0xbd,0x72} + * + * "Guide to Elliptic Curve Cryptography" (Hankerson, Menezes, Vanstone) gives an algorithm + * (algorithm 3.74) to find k1 and k2 given k, such that k1 + k2 * lambda == k mod n, and k1 + * and k2 have a small size. + * It relies on constants a1, b1, a2, b2. These constants for the value of lambda above are: + * + * - a1 = {0x30,0x86,0xd2,0x21,0xa7,0xd4,0x6b,0xcd,0xe8,0x6c,0x90,0xe4,0x92,0x84,0xeb,0x15} + * - b1 = -{0xe4,0x43,0x7e,0xd6,0x01,0x0e,0x88,0x28,0x6f,0x54,0x7f,0xa9,0x0a,0xbf,0xe4,0xc3} + * - a2 = {0x01,0x14,0xca,0x50,0xf7,0xa8,0xe2,0xf3,0xf6,0x57,0xc1,0x10,0x8d,0x9d,0x44,0xcf,0xd8} + * - b2 = {0x30,0x86,0xd2,0x21,0xa7,0xd4,0x6b,0xcd,0xe8,0x6c,0x90,0xe4,0x92,0x84,0xeb,0x15} + * + * The algorithm then computes c1 = round(b1 * k / n) and c2 = round(b2 * k / n), and gives + * k1 = k - (c1*a1 + c2*a2) and k2 = -(c1*b1 + c2*b2). Instead, we use modular arithmetic, and + * compute k1 as k - k2 * lambda, avoiding the need for constants a1 and a2. + * + * g1, g2 are precomputed constants used to replace division with a rounded multiplication + * when decomposing the scalar for an endomorphism-based point multiplication. + * + * The possibility of using precomputed estimates is mentioned in "Guide to Elliptic Curve + * Cryptography" (Hankerson, Menezes, Vanstone) in section 3.5. + * + * The derivation is described in the paper "Efficient Software Implementation of Public-Key + * Cryptography on Sensor Networks Using the MSP430X Microcontroller" (Gouvea, Oliveira, Lopez), + * Section 4.3 (here we use a somewhat higher-precision estimate): + * d = a1*b2 - b1*a2 + * g1 = round((2^272)*b2/d) + * g2 = round((2^272)*b1/d) + * + * (Note that 'd' is also equal to the curve order here because [a1,b1] and [a2,b2] are found + * as outputs of the Extended Euclidean Algorithm on inputs 'order' and 'lambda'). + * + * The function below splits a in r1 and r2, such that r1 + lambda * r2 == a (mod order). + */ + static void secp256k1_scalar_split_lambda_var(secp256k1_scalar_t *r1, secp256k1_scalar_t *r2, const secp256k1_scalar_t *a) { + static const secp256k1_scalar_t minus_lambda = SECP256K1_SCALAR_CONST( + 0xAC9C52B3UL, 0x3FA3CF1FUL, 0x5AD9E3FDUL, 0x77ED9BA4UL, + 0xA880B9FCUL, 0x8EC739C2UL, 0xE0CFC810UL, 0xB51283CFUL + ); + static const secp256k1_scalar_t minus_b1 = SECP256K1_SCALAR_CONST( + 0x00000000UL, 0x00000000UL, 0x00000000UL, 0x00000000UL, + 0xE4437ED6UL, 0x010E8828UL, 0x6F547FA9UL, 0x0ABFE4C3UL + ); + static const secp256k1_scalar_t minus_b2 = SECP256K1_SCALAR_CONST( + 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFEUL, + 0x8A280AC5UL, 0x0774346DUL, 0xD765CDA8UL, 0x3DB1562CUL + ); + static const secp256k1_scalar_t g1 = SECP256K1_SCALAR_CONST( + 0x00000000UL, 0x00000000UL, 0x00000000UL, 0x00003086UL, + 0xD221A7D4UL, 0x6BCDE86CUL, 0x90E49284UL, 0xEB153DABUL + ); + static const secp256k1_scalar_t g2 = SECP256K1_SCALAR_CONST( + 0x00000000UL, 0x00000000UL, 0x00000000UL, 0x0000E443UL, + 0x7ED6010EUL, 0x88286F54UL, 0x7FA90ABFUL, 0xE4C42212UL + ); VERIFY_CHECK(r1 != a); VERIFY_CHECK(r2 != a); secp256k1_scalar_t c1, c2; - secp256k1_scalar_mul_shift_var(&c1, a, &secp256k1_scalar_consts->g1, 272); - secp256k1_scalar_mul_shift_var(&c2, a, &secp256k1_scalar_consts->g2, 272); - secp256k1_scalar_mul(&c1, &c1, &secp256k1_scalar_consts->minus_b1); - secp256k1_scalar_mul(&c2, &c2, &secp256k1_scalar_consts->minus_b2); + secp256k1_scalar_mul_shift_var(&c1, a, &g1, 272); + secp256k1_scalar_mul_shift_var(&c2, a, &g2, 272); + secp256k1_scalar_mul(&c1, &c1, &minus_b1); + secp256k1_scalar_mul(&c2, &c2, &minus_b2); secp256k1_scalar_add(r2, &c1, &c2); - secp256k1_scalar_mul(r1, r2, &secp256k1_scalar_consts->minus_lambda); + secp256k1_scalar_mul(r1, r2, &minus_lambda); secp256k1_scalar_add(r1, r1, a); } #endif diff --git a/src/secp256k1.c b/src/secp256k1.c index 58bcd8d009e..26973940732 100644 --- a/src/secp256k1.c +++ b/src/secp256k1.c @@ -20,10 +20,6 @@ #include "hash_impl.h" void secp256k1_start(unsigned int flags) { - secp256k1_fe_start(); - secp256k1_ge_start(); - secp256k1_scalar_start(); - secp256k1_ecdsa_start(); if (flags & SECP256K1_START_SIGN) { secp256k1_ecmult_gen_start(); } @@ -35,10 +31,6 @@ void secp256k1_start(unsigned int flags) { void secp256k1_stop(void) { secp256k1_ecmult_stop(); secp256k1_ecmult_gen_stop(); - secp256k1_ecdsa_stop(); - secp256k1_scalar_stop(); - secp256k1_ge_stop(); - secp256k1_fe_stop(); } int secp256k1_ecdsa_verify(const unsigned char *msg32, const unsigned char *sig, int siglen, const unsigned char *pubkey, int pubkeylen) { diff --git a/src/tests.c b/src/tests.c index cff32f1d068..54707e0f51b 100644 --- a/src/tests.c +++ b/src/tests.c @@ -1657,12 +1657,6 @@ int main(int argc, char **argv) { /* initializing a second time shouldn't cause any harm or memory leaks. */ secp256k1_start(SECP256K1_START_SIGN | SECP256K1_START_VERIFY); - /* Likewise, re-running the internal init functions should be harmless. */ - secp256k1_fe_start(); - secp256k1_ge_start(); - secp256k1_scalar_start(); - secp256k1_ecdsa_start(); - run_sha256_tests(); run_hmac_sha256_tests(); run_rfc6979_hmac_sha256_tests(); @@ -1707,11 +1701,5 @@ int main(int argc, char **argv) { /* shutting down twice shouldn't cause any double frees. */ secp256k1_stop(); - - /* Same for the internal shutdown functions. */ - secp256k1_fe_stop(); - secp256k1_ge_stop(); - secp256k1_scalar_stop(); - secp256k1_ecdsa_stop(); return 0; }