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Convert the field/group/ecdsa constant initialization to static consts

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This commit is contained in:
Pieter Wuille
2015-01-21 17:38:17 -05:00
parent 19f3e76002
commit 4732d26069
12 changed files with 73 additions and 173 deletions
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51
src/ecdsa_impl.h
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@@ -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))