-// Copyright (c) 2013 Pieter Wuille
-// Distributed under the MIT/X11 software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+/**********************************************************************
+ * Copyright (c) 2013, 2014 Pieter Wuille *
+ * Distributed under the MIT software license, see the accompanying *
+ * file COPYING or http://www.opensource.org/licenses/mit-license.php.*
+ **********************************************************************/
#ifndef _SECP256K1_FIELD_IMPL_H_
#define _SECP256K1_FIELD_IMPL_H_
#include "util.h"
-#if defined(USE_FIELD_GMP)
-#include "field_gmp_impl.h"
-#elif defined(USE_FIELD_10X26)
+#if defined(USE_FIELD_10X26)
#include "field_10x26_impl.h"
#elif defined(USE_FIELD_5X52)
#include "field_5x52_impl.h"
#error "Please select field implementation"
#endif
-static void secp256k1_fe_get_hex(char *r, int *rlen, const secp256k1_fe_t *a) {
- if (*rlen < 65) {
- *rlen = 65;
- return;
- }
- *rlen = 65;
+static void secp256k1_fe_get_hex(char *r64, const secp256k1_fe_t *a) {
+ secp256k1_fe_t b;
+ int i;
unsigned char tmp[32];
- secp256k1_fe_t b = *a;
+ b = *a;
secp256k1_fe_normalize(&b);
secp256k1_fe_get_b32(tmp, &b);
- for (int i=0; i<32; i++) {
+ for (i=0; i<32; i++) {
static const char *c = "0123456789ABCDEF";
- r[2*i] = c[(tmp[i] >> 4) & 0xF];
- r[2*i+1] = c[(tmp[i]) & 0xF];
+ r64[2*i] = c[(tmp[i] >> 4) & 0xF];
+ r64[2*i+1] = c[(tmp[i]) & 0xF];
}
- r[64] = 0x00;
}
-static void secp256k1_fe_set_hex(secp256k1_fe_t *r, const char *a, int alen) {
- unsigned char tmp[32] = {};
+static int secp256k1_fe_set_hex(secp256k1_fe_t *r, const char *a64) {
+ int i;
+ unsigned char tmp[32];
static const int cvt[256] = {0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0};
- for (int i=0; i<32; i++) {
- if (alen > i*2)
- tmp[32 - alen/2 + i] = (cvt[(unsigned char)a[2*i]] << 4) + cvt[(unsigned char)a[2*i+1]];
+ for (i=0; i<32; i++) {
+ tmp[i] = (cvt[(unsigned char)a64[2*i]] << 4) + cvt[(unsigned char)a64[2*i+1]];
}
- secp256k1_fe_set_b32(r, tmp);
+ return secp256k1_fe_set_b32(r, tmp);
}
-static int secp256k1_fe_sqrt(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+SECP256K1_INLINE static int secp256k1_fe_equal_var(const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
+ secp256k1_fe_t na;
+ secp256k1_fe_negate(&na, a, 1);
+ secp256k1_fe_add(&na, b);
+ return secp256k1_fe_normalizes_to_zero_var(&na);
+}
+
+static int secp256k1_fe_sqrt_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+ secp256k1_fe_t x2, x3, x6, x9, x11, x22, x44, x88, x176, x220, x223, t1;
+ int j;
- // The binary representation of (p + 1)/4 has 3 blocks of 1s, with lengths in
- // { 2, 22, 223 }. Use an addition chain to calculate 2^n - 1 for each block:
- // 1, [2], 3, 6, 9, 11, [22], 44, 88, 176, 220, [223]
+ /** The binary representation of (p + 1)/4 has 3 blocks of 1s, with lengths in
+ * { 2, 22, 223 }. Use an addition chain to calculate 2^n - 1 for each block:
+ * 1, [2], 3, 6, 9, 11, [22], 44, 88, 176, 220, [223]
+ */
- secp256k1_fe_t x2;
secp256k1_fe_sqr(&x2, a);
secp256k1_fe_mul(&x2, &x2, a);
- secp256k1_fe_t x3;
secp256k1_fe_sqr(&x3, &x2);
secp256k1_fe_mul(&x3, &x3, a);
- secp256k1_fe_t x6 = x3;
- for (int j=0; j<3; j++) secp256k1_fe_sqr(&x6, &x6);
+ x6 = x3;
+ for (j=0; j<3; j++) secp256k1_fe_sqr(&x6, &x6);
secp256k1_fe_mul(&x6, &x6, &x3);
- secp256k1_fe_t x9 = x6;
- for (int j=0; j<3; j++) secp256k1_fe_sqr(&x9, &x9);
+ x9 = x6;
+ for (j=0; j<3; j++) secp256k1_fe_sqr(&x9, &x9);
secp256k1_fe_mul(&x9, &x9, &x3);
- secp256k1_fe_t x11 = x9;
- for (int j=0; j<2; j++) secp256k1_fe_sqr(&x11, &x11);
+ x11 = x9;
+ for (j=0; j<2; j++) secp256k1_fe_sqr(&x11, &x11);
secp256k1_fe_mul(&x11, &x11, &x2);
- secp256k1_fe_t x22 = x11;
- for (int j=0; j<11; j++) secp256k1_fe_sqr(&x22, &x22);
+ x22 = x11;
+ for (j=0; j<11; j++) secp256k1_fe_sqr(&x22, &x22);
secp256k1_fe_mul(&x22, &x22, &x11);
- secp256k1_fe_t x44 = x22;
- for (int j=0; j<22; j++) secp256k1_fe_sqr(&x44, &x44);
+ x44 = x22;
+ for (j=0; j<22; j++) secp256k1_fe_sqr(&x44, &x44);
secp256k1_fe_mul(&x44, &x44, &x22);
- secp256k1_fe_t x88 = x44;
- for (int j=0; j<44; j++) secp256k1_fe_sqr(&x88, &x88);
+ x88 = x44;
+ for (j=0; j<44; j++) secp256k1_fe_sqr(&x88, &x88);
secp256k1_fe_mul(&x88, &x88, &x44);
- secp256k1_fe_t x176 = x88;
- for (int j=0; j<88; j++) secp256k1_fe_sqr(&x176, &x176);
+ x176 = x88;
+ for (j=0; j<88; j++) secp256k1_fe_sqr(&x176, &x176);
secp256k1_fe_mul(&x176, &x176, &x88);
- secp256k1_fe_t x220 = x176;
- for (int j=0; j<44; j++) secp256k1_fe_sqr(&x220, &x220);
+ x220 = x176;
+ for (j=0; j<44; j++) secp256k1_fe_sqr(&x220, &x220);
secp256k1_fe_mul(&x220, &x220, &x44);
- secp256k1_fe_t x223 = x220;
- for (int j=0; j<3; j++) secp256k1_fe_sqr(&x223, &x223);
+ x223 = x220;
+ for (j=0; j<3; j++) secp256k1_fe_sqr(&x223, &x223);
secp256k1_fe_mul(&x223, &x223, &x3);
- // The final result is then assembled using a sliding window over the blocks.
+ /* The final result is then assembled using a sliding window over the blocks. */
- secp256k1_fe_t t1 = x223;
- for (int j=0; j<23; j++) secp256k1_fe_sqr(&t1, &t1);
+ t1 = x223;
+ for (j=0; j<23; j++) secp256k1_fe_sqr(&t1, &t1);
secp256k1_fe_mul(&t1, &t1, &x22);
- for (int j=0; j<6; j++) secp256k1_fe_sqr(&t1, &t1);
+ for (j=0; j<6; j++) secp256k1_fe_sqr(&t1, &t1);
secp256k1_fe_mul(&t1, &t1, &x2);
secp256k1_fe_sqr(&t1, &t1);
secp256k1_fe_sqr(r, &t1);
- // Check that a square root was actually calculated
+ /* Check that a square root was actually calculated */
secp256k1_fe_sqr(&t1, r);
- secp256k1_fe_negate(&t1, &t1, 1);
- secp256k1_fe_add(&t1, a);
- secp256k1_fe_normalize(&t1);
- return secp256k1_fe_is_zero(&t1);
+ return secp256k1_fe_equal_var(&t1, a);
}
static void secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+ secp256k1_fe_t x2, x3, x6, x9, x11, x22, x44, x88, x176, x220, x223, t1;
+ int j;
- // The binary representation of (p - 2) has 5 blocks of 1s, with lengths in
- // { 1, 2, 22, 223 }. Use an addition chain to calculate 2^n - 1 for each block:
- // [1], [2], 3, 6, 9, 11, [22], 44, 88, 176, 220, [223]
+ /** The binary representation of (p - 2) has 5 blocks of 1s, with lengths in
+ * { 1, 2, 22, 223 }. Use an addition chain to calculate 2^n - 1 for each block:
+ * [1], [2], 3, 6, 9, 11, [22], 44, 88, 176, 220, [223]
+ */
- secp256k1_fe_t x2;
secp256k1_fe_sqr(&x2, a);
secp256k1_fe_mul(&x2, &x2, a);
- secp256k1_fe_t x3;
secp256k1_fe_sqr(&x3, &x2);
secp256k1_fe_mul(&x3, &x3, a);
- secp256k1_fe_t x6 = x3;
- for (int j=0; j<3; j++) secp256k1_fe_sqr(&x6, &x6);
+ x6 = x3;
+ for (j=0; j<3; j++) secp256k1_fe_sqr(&x6, &x6);
secp256k1_fe_mul(&x6, &x6, &x3);
- secp256k1_fe_t x9 = x6;
- for (int j=0; j<3; j++) secp256k1_fe_sqr(&x9, &x9);
+ x9 = x6;
+ for (j=0; j<3; j++) secp256k1_fe_sqr(&x9, &x9);
secp256k1_fe_mul(&x9, &x9, &x3);
- secp256k1_fe_t x11 = x9;
- for (int j=0; j<2; j++) secp256k1_fe_sqr(&x11, &x11);
+ x11 = x9;
+ for (j=0; j<2; j++) secp256k1_fe_sqr(&x11, &x11);
secp256k1_fe_mul(&x11, &x11, &x2);
- secp256k1_fe_t x22 = x11;
- for (int j=0; j<11; j++) secp256k1_fe_sqr(&x22, &x22);
+ x22 = x11;
+ for (j=0; j<11; j++) secp256k1_fe_sqr(&x22, &x22);
secp256k1_fe_mul(&x22, &x22, &x11);
- secp256k1_fe_t x44 = x22;
- for (int j=0; j<22; j++) secp256k1_fe_sqr(&x44, &x44);
+ x44 = x22;
+ for (j=0; j<22; j++) secp256k1_fe_sqr(&x44, &x44);
secp256k1_fe_mul(&x44, &x44, &x22);
- secp256k1_fe_t x88 = x44;
- for (int j=0; j<44; j++) secp256k1_fe_sqr(&x88, &x88);
+ x88 = x44;
+ for (j=0; j<44; j++) secp256k1_fe_sqr(&x88, &x88);
secp256k1_fe_mul(&x88, &x88, &x44);
- secp256k1_fe_t x176 = x88;
- for (int j=0; j<88; j++) secp256k1_fe_sqr(&x176, &x176);
+ x176 = x88;
+ for (j=0; j<88; j++) secp256k1_fe_sqr(&x176, &x176);
secp256k1_fe_mul(&x176, &x176, &x88);
- secp256k1_fe_t x220 = x176;
- for (int j=0; j<44; j++) secp256k1_fe_sqr(&x220, &x220);
+ x220 = x176;
+ for (j=0; j<44; j++) secp256k1_fe_sqr(&x220, &x220);
secp256k1_fe_mul(&x220, &x220, &x44);
- secp256k1_fe_t x223 = x220;
- for (int j=0; j<3; j++) secp256k1_fe_sqr(&x223, &x223);
+ x223 = x220;
+ for (j=0; j<3; j++) secp256k1_fe_sqr(&x223, &x223);
secp256k1_fe_mul(&x223, &x223, &x3);
- // The final result is then assembled using a sliding window over the blocks.
+ /* The final result is then assembled using a sliding window over the blocks. */
- secp256k1_fe_t t1 = x223;
- for (int j=0; j<23; j++) secp256k1_fe_sqr(&t1, &t1);
+ t1 = x223;
+ for (j=0; j<23; j++) secp256k1_fe_sqr(&t1, &t1);
secp256k1_fe_mul(&t1, &t1, &x22);
- for (int j=0; j<5; j++) secp256k1_fe_sqr(&t1, &t1);
+ for (j=0; j<5; j++) secp256k1_fe_sqr(&t1, &t1);
secp256k1_fe_mul(&t1, &t1, a);
- for (int j=0; j<3; j++) secp256k1_fe_sqr(&t1, &t1);
+ for (j=0; j<3; j++) secp256k1_fe_sqr(&t1, &t1);
secp256k1_fe_mul(&t1, &t1, &x2);
- for (int j=0; j<2; j++) secp256k1_fe_sqr(&t1, &t1);
- secp256k1_fe_mul(r, &t1, a);
+ for (j=0; j<2; j++) secp256k1_fe_sqr(&t1, &t1);
+ secp256k1_fe_mul(r, a, &t1);
}
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(&c);
+ 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);
- secp256k1_fe_set_b32(r, b);
+ VERIFY_CHECK(secp256k1_fe_set_b32(r, b));
#else
#error "Please select field inverse implementation"
#endif
}
-static void secp256k1_fe_inv_all(size_t len, secp256k1_fe_t r[len], const secp256k1_fe_t a[len]) {
- if (len < 1)
- return;
-
- VERIFY_CHECK((r + len <= a) || (a + len <= r));
-
- r[0] = a[0];
-
- size_t i = 0;
- while (++i < len) {
- secp256k1_fe_mul(&r[i], &r[i - 1], &a[i]);
- }
-
- secp256k1_fe_t u; secp256k1_fe_inv(&u, &r[--i]);
-
- while (i > 0) {
- int j = i--;
- secp256k1_fe_mul(&r[j], &r[i], &u);
- secp256k1_fe_mul(&u, &u, &a[j]);
- }
-
- r[0] = u;
-}
-
-static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t r[len], const secp256k1_fe_t a[len]) {
+static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+ secp256k1_fe_t u;
+ size_t i;
if (len < 1)
return;
r[0] = a[0];
- size_t i = 0;
+ i = 0;
while (++i < len) {
secp256k1_fe_mul(&r[i], &r[i - 1], &a[i]);
}
- secp256k1_fe_t u; secp256k1_fe_inv_var(&u, &r[--i]);
+ secp256k1_fe_inv_var(&u, &r[--i]);
while (i > 0) {
int j = i--;
r[0] = u;
}
-static void secp256k1_fe_start(void) {
- 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
- };
- if (secp256k1_fe_consts == NULL) {
- secp256k1_fe_inner_start();
- secp256k1_fe_consts_t *ret = (secp256k1_fe_consts_t*)malloc(sizeof(secp256k1_fe_consts_t));
- secp256k1_num_set_bin(&ret->p, secp256k1_fe_consts_p, sizeof(secp256k1_fe_consts_p));
- 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
projects / secp256k1.git / blobdiff