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Make constant initializers independent from num

This commit is contained in:
Pieter Wuille 2014-11-27 19:12:13 +01:00
parent 0af5b47133
commit 659b554d7b
6 changed files with 92 additions and 94 deletions
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10
src/ecdsa_impl.h
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@ -29,10 +29,14 @@ static void secp256k1_ecdsa_start(void) {
/* Allocate. */
secp256k1_ecdsa_consts_t *ret = (secp256k1_ecdsa_consts_t*)malloc(sizeof(secp256k1_ecdsa_consts_t));
unsigned char p[32];
secp256k1_num_get_bin(p, 32, &secp256k1_ge_consts->order);
secp256k1_fe_set_b32(&ret->order_as_fe, p);
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(&ret->p_minus_order);

2
src/group.h
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@ -27,8 +27,6 @@ typedef struct {
/** Global constants related to the group */
typedef struct {
secp256k1_num_t order; /* the order of the curve (= order of its generator) */
secp256k1_num_t half_order; /* half the order of the curve (= order of its generator) */
secp256k1_ge_t g; /* the generator point */
#ifdef USE_ENDOMORPHISM

9
src/group_impl.h
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@ -413,12 +413,6 @@ static void secp256k1_gej_mul_lambda(secp256k1_gej_t *r, const secp256k1_gej_t *
static void secp256k1_ge_start(void) {
static const unsigned char secp256k1_ge_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
};
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,
@ -442,9 +436,6 @@ static void secp256k1_ge_start(void) {
#endif
if (secp256k1_ge_consts == NULL) {
secp256k1_ge_consts_t *ret = (secp256k1_ge_consts_t*)malloc(sizeof(secp256k1_ge_consts_t));
secp256k1_num_set_bin(&ret->order, secp256k1_ge_consts_order, sizeof(secp256k1_ge_consts_order));
secp256k1_num_copy(&ret->half_order, &ret->order);
secp256k1_num_shift(&ret->half_order, 1);
#ifdef USE_ENDOMORPHISM
VERIFY_CHECK(secp256k1_fe_set_b32(&ret->beta, secp256k1_ge_consts_beta));
#endif

3
src/scalar.h
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@ -75,6 +75,9 @@ static int secp256k1_scalar_is_high(const secp256k1_scalar_t *a);
/** Convert a scalar to a number. */
static void secp256k1_scalar_get_num(secp256k1_num_t *r, const secp256k1_scalar_t *a);
/** Get the order of the group as a number. */
static void secp256k1_scalar_order_get_num(secp256k1_num_t *r);
/** Compare two scalars. */
static int secp256k1_scalar_eq(const secp256k1_scalar_t *a, const secp256k1_scalar_t *b);

20
src/scalar_impl.h
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@ -25,6 +25,7 @@
#endif
typedef struct {
secp256k1_num_t order;
#ifdef USE_ENDOMORPHISM
secp256k1_num_t a1b2, b1, a2;
#endif
@ -39,6 +40,13 @@ static void secp256k1_scalar_start(void) {
/* Allocate. */
secp256k1_scalar_consts_t *ret = (secp256k1_scalar_consts_t*)malloc(sizeof(secp256k1_scalar_consts_t));
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));
#ifdef USE_ENDOMORPHISM
static const unsigned char secp256k1_scalar_consts_a1b2[] = {
0x30,0x86,0xd2,0x21,0xa7,0xd4,0x6b,0xcd,
@ -78,6 +86,9 @@ static void secp256k1_scalar_get_num(secp256k1_num_t *r, const secp256k1_scalar_
secp256k1_num_set_bin(r, c, 32);
}
static void secp256k1_scalar_order_get_num(secp256k1_num_t *r) {
*r = secp256k1_scalar_consts->order;
}
static void secp256k1_scalar_inverse(secp256k1_scalar_t *r, const secp256k1_scalar_t *x) {
/* First compute x ^ (2^N - 1) for some values of N. */
@ -238,7 +249,7 @@ static void secp256k1_scalar_inverse_var(secp256k1_scalar_t *r, const secp256k1_
secp256k1_scalar_get_b32(b, x);
secp256k1_num_t n;
secp256k1_num_set_bin(&n, b, 32);
secp256k1_num_mod_inverse(&n, &n, &secp256k1_ge_consts->order);
secp256k1_num_mod_inverse(&n, &n, &secp256k1_scalar_consts->order);
secp256k1_num_get_bin(b, 32, &n);
secp256k1_scalar_set_b32(r, b, NULL);
#else
@ -256,19 +267,18 @@ static void secp256k1_scalar_split_lambda_var(secp256k1_scalar_t *r1, secp256k1_
secp256k1_num_t rn1, rn2;
const secp256k1_scalar_consts_t *c = secp256k1_scalar_consts;
const secp256k1_num_t *order = &secp256k1_ge_consts->order;
secp256k1_num_t bnc1, bnc2, bnt1, bnt2, bnn2;
secp256k1_num_copy(&bnn2, order);
secp256k1_num_copy(&bnn2, &c->order);
secp256k1_num_shift(&bnn2, 1);
secp256k1_num_mul(&bnc1, &na, &c->a1b2);
secp256k1_num_add(&bnc1, &bnc1, &bnn2);
secp256k1_num_div(&bnc1, &bnc1, order);
secp256k1_num_div(&bnc1, &bnc1, &c->order);
secp256k1_num_mul(&bnc2, &na, &c->b1);
secp256k1_num_add(&bnc2, &bnc2, &bnn2);
secp256k1_num_div(&bnc2, &bnc2, order);
secp256k1_num_div(&bnc2, &bnc2, &c->order);
secp256k1_num_mul(&bnt1, &bnc1, &c->a1b2);
secp256k1_num_mul(&bnt2, &bnc2, &c->a2);

142
src/tests.c
View File

@ -23,23 +23,13 @@
static int count = 64;
/***** NUM TESTS *****/
void random_num_negate(secp256k1_num_t *num) {
if (secp256k1_rand32() & 1)
secp256k1_num_negate(num);
}
void random_field_element_test(secp256k1_fe_t *fe) {
do {
unsigned char b32[32];
secp256k1_rand256_test(b32);
secp256k1_num_t num;
secp256k1_num_set_bin(&num, b32, 32);
if (secp256k1_num_cmp(&num, &secp256k1_fe_consts->p) >= 0)
continue;
VERIFY_CHECK(secp256k1_fe_set_b32(fe, b32));
break;
if (secp256k1_fe_set_b32(fe, b32)) {
break;
}
} while(1);
}
@ -75,19 +65,6 @@ void random_group_element_jacobian_test(secp256k1_gej_t *gej, const secp256k1_ge
gej->infinity = ge->infinity;
}
void random_num_order_test(secp256k1_num_t *num) {
do {
unsigned char b32[32];
secp256k1_rand256_test(b32);
secp256k1_num_set_bin(num, b32, 32);
if (secp256k1_num_is_zero(num))
continue;
if (secp256k1_num_cmp(num, &secp256k1_ge_consts->order) >= 0)
continue;
break;
} while(1);
}
void random_scalar_order_test(secp256k1_scalar_t *num) {
do {
unsigned char b32[32];
@ -112,17 +89,23 @@ void random_scalar_order(secp256k1_scalar_t *num) {
} while(1);
}
/***** NUM TESTS *****/
void random_num_negate(secp256k1_num_t *num) {
if (secp256k1_rand32() & 1)
secp256k1_num_negate(num);
}
void random_num_order_test(secp256k1_num_t *num) {
secp256k1_scalar_t sc;
random_scalar_order_test(&sc);
secp256k1_scalar_get_num(num, &sc);
}
void random_num_order(secp256k1_num_t *num) {
do {
unsigned char b32[32];
secp256k1_rand256(b32);
secp256k1_num_set_bin(num, b32, 32);
if (secp256k1_num_is_zero(num))
continue;
if (secp256k1_num_cmp(num, &secp256k1_ge_consts->order) >= 0)
continue;
break;
} while(1);
secp256k1_scalar_t sc;
random_scalar_order(&sc);
secp256k1_scalar_get_num(num, &sc);
}
void test_num_get_set_bin(void) {
@ -208,29 +191,27 @@ void scalar_test(void) {
unsigned char c[32];
/* Set 's' to a random scalar, with value 'snum'. */
secp256k1_rand256_test(c);
secp256k1_scalar_t s;
secp256k1_scalar_set_b32(&s, c, NULL);
secp256k1_num_t snum;
secp256k1_num_set_bin(&snum, c, 32);
secp256k1_num_mod(&snum, &secp256k1_ge_consts->order);
random_scalar_order_test(&s);
/* Set 's1' to a random scalar, with value 's1num'. */
secp256k1_rand256_test(c);
secp256k1_scalar_t s1;
secp256k1_scalar_set_b32(&s1, c, NULL);
secp256k1_num_t s1num;
secp256k1_num_set_bin(&s1num, c, 32);
secp256k1_num_mod(&s1num, &secp256k1_ge_consts->order);
random_scalar_order_test(&s1);
/* Set 's2' to a random scalar, with value 'snum2', and byte array representation 'c'. */
secp256k1_rand256_test(c);
secp256k1_scalar_t s2;
int overflow = 0;
secp256k1_scalar_set_b32(&s2, c, &overflow);
secp256k1_num_t s2num;
secp256k1_num_set_bin(&s2num, c, 32);
secp256k1_num_mod(&s2num, &secp256k1_ge_consts->order);
random_scalar_order_test(&s2);
secp256k1_scalar_get_b32(c, &s2);
secp256k1_num_t snum, s1num, s2num;
secp256k1_scalar_get_num(&snum, &s);
secp256k1_scalar_get_num(&s1num, &s1);
secp256k1_scalar_get_num(&s2num, &s2);
secp256k1_num_t order;
secp256k1_scalar_order_get_num(&order);
secp256k1_num_t half_order = order;
secp256k1_num_shift(&half_order, 1);
{
/* Test that fetching groups of 4 bits from a scalar and recursing n(i)=16*n(i-1)+p(i) reconstructs it. */
@ -268,22 +249,11 @@ void scalar_test(void) {
CHECK(secp256k1_scalar_eq(&n, &s));
}
{
/* Test that get_b32 returns the same as get_bin on the number. */
unsigned char r1[32];
secp256k1_scalar_get_b32(r1, &s2);
unsigned char r2[32];
secp256k1_num_get_bin(r2, 32, &s2num);
CHECK(memcmp(r1, r2, 32) == 0);
/* If no overflow occurred when assigning, it should also be equal to the original byte array. */
CHECK((memcmp(r1, c, 32) == 0) == (overflow == 0));
}
{
/* Test that adding the scalars together is equal to adding their numbers together modulo the order. */
secp256k1_num_t rnum;
secp256k1_num_add(&rnum, &snum, &s2num);
secp256k1_num_mod(&rnum, &secp256k1_ge_consts->order);
secp256k1_num_mod(&rnum, &order);
secp256k1_scalar_t r;
secp256k1_scalar_add(&r, &s, &s2);
secp256k1_num_t r2num;
@ -295,7 +265,7 @@ void scalar_test(void) {
/* Test that multipying the scalars is equal to multiplying their numbers modulo the order. */
secp256k1_num_t rnum;
secp256k1_num_mul(&rnum, &snum, &s2num);
secp256k1_num_mod(&rnum, &secp256k1_ge_consts->order);
secp256k1_num_mod(&rnum, &order);
secp256k1_scalar_t r;
secp256k1_scalar_mul(&r, &s, &s2);
secp256k1_num_t r2num;
@ -312,14 +282,14 @@ void scalar_test(void) {
/* Check that comparison with zero matches comparison with zero on the number. */
CHECK(secp256k1_num_is_zero(&snum) == secp256k1_scalar_is_zero(&s));
/* Check that comparison with the half order is equal to testing for high scalar. */
CHECK(secp256k1_scalar_is_high(&s) == (secp256k1_num_cmp(&snum, &secp256k1_ge_consts->half_order) > 0));
CHECK(secp256k1_scalar_is_high(&s) == (secp256k1_num_cmp(&snum, &half_order) > 0));
secp256k1_scalar_t neg;
secp256k1_scalar_negate(&neg, &s);
secp256k1_num_t negnum;
secp256k1_num_sub(&negnum, &secp256k1_ge_consts->order, &snum);
secp256k1_num_mod(&negnum, &secp256k1_ge_consts->order);
secp256k1_num_sub(&negnum, &order, &snum);
secp256k1_num_mod(&negnum, &order);
/* Check that comparison with the half order is equal to testing for high scalar after negation. */
CHECK(secp256k1_scalar_is_high(&neg) == (secp256k1_num_cmp(&negnum, &secp256k1_ge_consts->half_order) > 0));
CHECK(secp256k1_scalar_is_high(&neg) == (secp256k1_num_cmp(&negnum, &half_order) > 0));
/* Negating should change the high property, unless the value was already zero. */
CHECK((secp256k1_scalar_is_high(&s) == secp256k1_scalar_is_high(&neg)) == secp256k1_scalar_is_zero(&s));
secp256k1_num_t negnum2;
@ -340,7 +310,7 @@ void scalar_test(void) {
secp256k1_scalar_t inv;
secp256k1_scalar_inverse(&inv, &s);
secp256k1_num_t invnum;
secp256k1_num_mod_inverse(&invnum, &snum, &secp256k1_ge_consts->order);
secp256k1_num_mod_inverse(&invnum, &snum, &order);
secp256k1_num_t invnum2;
secp256k1_scalar_get_num(&invnum2, &inv);
CHECK(secp256k1_num_eq(&invnum, &invnum2));
@ -431,6 +401,28 @@ void run_scalar_tests(void) {
for (int i = 0; i < 128 * count; i++) {
scalar_test();
}
{
// (-1)+1 should be zero.
secp256k1_scalar_t s, o;
secp256k1_scalar_set_int(&s, 1);
secp256k1_scalar_negate(&o, &s);
secp256k1_scalar_add(&o, &o, &s);
CHECK(secp256k1_scalar_is_zero(&o));
}
{
// A scalar with value of the curve order should be 0.
secp256k1_num_t order;
secp256k1_scalar_order_get_num(&order);
unsigned char bin[32];
secp256k1_num_get_bin(bin, 32, &order);
secp256k1_scalar_t zero;
int overflow = 0;
secp256k1_scalar_set_b32(&zero, bin, &overflow);
CHECK(overflow == 1);
CHECK(secp256k1_scalar_is_zero(&zero));
}
}
/***** FIELD TESTS *****/
@ -868,11 +860,11 @@ void test_ecdsa_end_to_end(void) {
/* Generate a random key and message. */
{
secp256k1_num_t msg, key;
random_num_order_test(&msg);
random_num_order_test(&key);
secp256k1_num_get_bin(privkey, 32, &key);
secp256k1_num_get_bin(message, 32, &msg);
secp256k1_scalar_t msg, key;
random_scalar_order_test(&msg);
random_scalar_order_test(&key);
secp256k1_scalar_get_b32(privkey, &key);
secp256k1_scalar_get_b32(message, &msg);
}
/* Construct and verify corresponding public key. */