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Merge pull request #124

4d4eeea Make secp256k1_fe_mul_inner use the r != property (Pieter Wuille)
be82e92 Require that r and b are different for field multiplication. (Pieter Wuille)
master
Pieter Wuille 8 years ago
parent
commit
276f987d70
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GPG Key ID: 57896D2FF8F0B657
  1. 12
      include/secp256k1.h
  2. 2
      src/field.h
  3. 5
      src/field_10x26_impl.h
  4. 3
      src/field_5x52_impl.h
  5. 84
      src/field_5x52_int128_impl.h
  6. 3
      src/field_gmp_impl.h
  7. 2
      src/field_impl.h
  8. 4
      src/group_impl.h
  9. 17
      src/util.h

12
include/secp256k1.h

@ -14,18 +14,6 @@ extern "C" { @@ -14,18 +14,6 @@ extern "C" {
# endif
# endif
# if (!defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L) )
# if SECP256K1_GNUC_PREREQ(3,0)
# define SECP256K1_RESTRICT __restrict__
# elif (defined(_MSC_VER) && _MSC_VER >= 1400)
# define SECP256K1_RESTRICT __restrict
# else
# define SECP256K1_RESTRICT
# endif
# else
# define SECP256K1_RESTRICT restrict
# endif
# if (!defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L) )
# if SECP256K1_GNUC_PREREQ(2,7)
# define SECP256K1_INLINE __inline__

2
src/field.h

@ -82,7 +82,7 @@ static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a); @@ -82,7 +82,7 @@ static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a);
/** Sets a field element to be the product of two others. Requires the inputs' magnitudes to be at most 8.
* The output magnitude is 1 (but not guaranteed to be normalized). */
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t *b);
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t * SECP256K1_RESTRICT b);
/** Sets a field element to be the square of another. Requires the input's magnitude to be at most 8.
* The output magnitude is 1 (but not guaranteed to be normalized). */

5
src/field_10x26_impl.h

@ -271,7 +271,7 @@ SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1 @@ -271,7 +271,7 @@ SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1
#define VERIFY_BITS(x, n) do { } while(0)
#endif
SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint32_t *a, const uint32_t *b, uint32_t *r) {
SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint32_t *a, const uint32_t * SECP256K1_RESTRICT b, uint32_t *r) {
VERIFY_BITS(a[0], 30);
VERIFY_BITS(a[1], 30);
VERIFY_BITS(a[2], 30);
@ -871,12 +871,13 @@ SECP256K1_INLINE static void secp256k1_fe_sqr_inner(const uint32_t *a, uint32_t @@ -871,12 +871,13 @@ SECP256K1_INLINE static void secp256k1_fe_sqr_inner(const uint32_t *a, uint32_t
}
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t * SECP256K1_RESTRICT b) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
VERIFY_CHECK(b->magnitude <= 8);
secp256k1_fe_verify(a);
secp256k1_fe_verify(b);
VERIFY_CHECK(r != b);
#endif
secp256k1_fe_mul_inner(a->n, b->n, r->n);
#ifdef VERIFY

3
src/field_5x52_impl.h

@ -247,12 +247,13 @@ SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1 @@ -247,12 +247,13 @@ SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1
#endif
}
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t * SECP256K1_RESTRICT b) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
VERIFY_CHECK(b->magnitude <= 8);
secp256k1_fe_verify(a);
secp256k1_fe_verify(b);
VERIFY_CHECK(r != b);
#endif
secp256k1_fe_mul_inner(a->n, b->n, r->n);
#ifdef VERIFY

84
src/field_5x52_int128_impl.h

@ -15,7 +15,7 @@ @@ -15,7 +15,7 @@
#define VERIFY_BITS(x, n) do { } while(0)
#endif
SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uint64_t *b, uint64_t *r) {
SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uint64_t *b, uint64_t * SECP256K1_RESTRICT r) {
VERIFY_BITS(a[0], 56);
VERIFY_BITS(a[1], 56);
VERIFY_BITS(a[2], 56);
@ -26,6 +26,7 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin @@ -26,6 +26,7 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin
VERIFY_BITS(b[2], 56);
VERIFY_BITS(b[3], 56);
VERIFY_BITS(b[4], 52);
VERIFY_CHECK(r != b);
const uint64_t M = 0xFFFFFFFFFFFFFULL, R = 0x1000003D10ULL;
/* [... a b c] is a shorthand for ... + a<<104 + b<<52 + c<<0 mod n.
@ -33,15 +34,17 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin @@ -33,15 +34,17 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin
* Note that [x 0 0 0 0 0] = [x*R].
*/
uint64_t a0 = a[0], a1 = a[1], a2 = a[2], a3 = a[3], a4 = a[4];
__int128 c, d;
d = (__int128)a[0] * b[3]
+ (__int128)a[1] * b[2]
+ (__int128)a[2] * b[1]
+ (__int128)a[3] * b[0];
d = (__int128)a0 * b[3]
+ (__int128)a1 * b[2]
+ (__int128)a2 * b[1]
+ (__int128)a3 * b[0];
VERIFY_BITS(d, 114);
/* [d 0 0 0] = [p3 0 0 0] */
c = (__int128)a[4] * b[4];
c = (__int128)a4 * b[4];
VERIFY_BITS(c, 112);
/* [c 0 0 0 0 d 0 0 0] = [p8 0 0 0 0 p3 0 0 0] */
d += (c & M) * R; c >>= 52;
@ -53,11 +56,11 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin @@ -53,11 +56,11 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin
VERIFY_BITS(d, 63);
/* [c 0 0 0 0 d t3 0 0 0] = [p8 0 0 0 0 p3 0 0 0] */
d += (__int128)a[0] * b[4]
+ (__int128)a[1] * b[3]
+ (__int128)a[2] * b[2]
+ (__int128)a[3] * b[1]
+ (__int128)a[4] * b[0];
d += (__int128)a0 * b[4]
+ (__int128)a1 * b[3]
+ (__int128)a2 * b[2]
+ (__int128)a3 * b[1]
+ (__int128)a4 * b[0];
VERIFY_BITS(d, 115);
/* [c 0 0 0 0 d t3 0 0 0] = [p8 0 0 0 p4 p3 0 0 0] */
d += c * R;
@ -72,13 +75,13 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin @@ -72,13 +75,13 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin
VERIFY_BITS(t4, 48);
/* [d t4+(tx<<48) t3 0 0 0] = [p8 0 0 0 p4 p3 0 0 0] */
c = (__int128)a[0] * b[0];
c = (__int128)a0 * b[0];
VERIFY_BITS(c, 112);
/* [d t4+(tx<<48) t3 0 0 c] = [p8 0 0 0 p4 p3 0 0 p0] */
d += (__int128)a[1] * b[4]
+ (__int128)a[2] * b[3]
+ (__int128)a[3] * b[2]
+ (__int128)a[4] * b[1];
d += (__int128)a1 * b[4]
+ (__int128)a2 * b[3]
+ (__int128)a3 * b[2]
+ (__int128)a4 * b[1];
VERIFY_BITS(d, 115);
/* [d t4+(tx<<48) t3 0 0 c] = [p8 0 0 p5 p4 p3 0 0 p0] */
uint64_t u0 = d & M; d >>= 52;
@ -92,48 +95,43 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin @@ -92,48 +95,43 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin
c += (__int128)u0 * (R >> 4);
VERIFY_BITS(c, 115);
/* [d 0 t4 t3 0 0 c] = [p8 0 0 p5 p4 p3 0 0 p0] */
uint64_t t0 = c & M; c >>= 52;
VERIFY_BITS(t0, 52);
r[0] = c & M; c >>= 52;
VERIFY_BITS(r[0], 52);
VERIFY_BITS(c, 61);
/* [d 0 t4 t3 0 c t0] = [p8 0 0 p5 p4 p3 0 0 p0] */
/* [d 0 t4 t3 0 c r0] = [p8 0 0 p5 p4 p3 0 0 p0] */
c += (__int128)a[0] * b[1]
+ (__int128)a[1] * b[0];
c += (__int128)a0 * b[1]
+ (__int128)a1 * b[0];
VERIFY_BITS(c, 114);
/* [d 0 t4 t3 0 c t0] = [p8 0 0 p5 p4 p3 0 p1 p0] */
d += (__int128)a[2] * b[4]
+ (__int128)a[3] * b[3]
+ (__int128)a[4] * b[2];
/* [d 0 t4 t3 0 c r0] = [p8 0 0 p5 p4 p3 0 p1 p0] */
d += (__int128)a2 * b[4]
+ (__int128)a3 * b[3]
+ (__int128)a4 * b[2];
VERIFY_BITS(d, 114);
/* [d 0 t4 t3 0 c t0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */
/* [d 0 t4 t3 0 c r0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */
c += (d & M) * R; d >>= 52;
VERIFY_BITS(c, 115);
VERIFY_BITS(d, 62);
/* [d 0 0 t4 t3 0 c t0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */
uint64_t t1 = c & M; c >>= 52;
VERIFY_BITS(t1, 52);
/* [d 0 0 t4 t3 0 c r0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */
r[1] = c & M; c >>= 52;
VERIFY_BITS(r[1], 52);
VERIFY_BITS(c, 63);
/* [d 0 0 t4 t3 c t1 t0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */
/* [d 0 0 t4 t3 c r1 r0] = [p8 0 p6 p5 p4 p3 0 p1 p0] */
c += (__int128)a[0] * b[2]
+ (__int128)a[1] * b[1]
+ (__int128)a[2] * b[0];
c += (__int128)a0 * b[2]
+ (__int128)a1 * b[1]
+ (__int128)a2 * b[0];
VERIFY_BITS(c, 114);
/* [d 0 0 t4 t3 c t1 t0] = [p8 0 p6 p5 p4 p3 p2 p1 p0] */
d += (__int128)a[3] * b[4]
+ (__int128)a[4] * b[3];
/* [d 0 0 t4 t3 c r1 r0] = [p8 0 p6 p5 p4 p3 p2 p1 p0] */
d += (__int128)a3 * b[4]
+ (__int128)a4 * b[3];
VERIFY_BITS(d, 114);
/* [d 0 0 t4 t3 c t1 t0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */
/* [d 0 0 t4 t3 c t1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */
c += (d & M) * R; d >>= 52;
VERIFY_BITS(c, 115);
VERIFY_BITS(d, 62);
/* [d 0 0 0 t4 t3 c t1 t0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */
/* [d 0 0 0 t4 t3 c r1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */
r[0] = t0;
VERIFY_BITS(r[0], 52);
/* [d 0 0 0 t4 t3 c t1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */
r[1] = t1;
VERIFY_BITS(r[1], 52);
/* [d 0 0 0 t4 t3 c r1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */
r[2] = c & M; c >>= 52;
VERIFY_BITS(r[2], 52);

3
src/field_gmp_impl.h

@ -151,7 +151,8 @@ static void secp256k1_fe_reduce(secp256k1_fe_t *r, mp_limb_t *tmp) { @@ -151,7 +151,8 @@ static void secp256k1_fe_reduce(secp256k1_fe_t *r, mp_limb_t *tmp) {
r->n[FIELD_LIMBS] = mpn_add(r->n, tmp, FIELD_LIMBS, q, 1+(33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS);
}
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t * SECP256K1_RESTRICT b) {
VERIFY_CHECK(r != b);
secp256k1_fe_t ac = *a;
secp256k1_fe_t bc = *b;
secp256k1_fe_normalize(&ac);

2
src/field_impl.h

@ -197,7 +197,7 @@ static void secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a) { @@ -197,7 +197,7 @@ static void secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
for (int 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);
secp256k1_fe_mul(r, a, &t1);
}
static void secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {

4
src/group_impl.h

@ -217,7 +217,7 @@ static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t * @@ -217,7 +217,7 @@ static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t *
}
secp256k1_fe_t t1,t2,t3,t4;
secp256k1_fe_mul(&r->z, &a->y, &a->z);
secp256k1_fe_mul(&r->z, &a->z, &a->y);
secp256k1_fe_mul_int(&r->z, 2); /* Z' = 2*Y*Z (2) */
secp256k1_fe_sqr(&t1, &a->x);
secp256k1_fe_mul_int(&t1, 3); /* T1 = 3*X^2 (3) */
@ -226,7 +226,7 @@ static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t * @@ -226,7 +226,7 @@ static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t *
secp256k1_fe_mul_int(&t3, 2); /* T3 = 2*Y^2 (2) */
secp256k1_fe_sqr(&t4, &t3);
secp256k1_fe_mul_int(&t4, 2); /* T4 = 8*Y^4 (2) */
secp256k1_fe_mul(&t3, &a->x, &t3); /* T3 = 2*X*Y^2 (1) */
secp256k1_fe_mul(&t3, &t3, &a->x); /* T3 = 2*X*Y^2 (1) */
r->x = t3;
secp256k1_fe_mul_int(&r->x, 4); /* X' = 8*X*Y^2 (4) */
secp256k1_fe_negate(&r->x, &r->x, 4); /* X' = -8*X*Y^2 (5) */

17
src/util.h

@ -61,4 +61,21 @@ @@ -61,4 +61,21 @@
#define VERIFY_CHECK(cond) do { (void)(cond); } while(0)
#endif
/* Macro for restrict, when available and not in a VERIFY build. */
#if defined(SECP256K1_BUILD) && defined(VERIFY)
# define SECP256K1_RESTRICT
#else
# if (!defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L) )
# if SECP256K1_GNUC_PREREQ(3,0)
# define SECP256K1_RESTRICT __restrict__
# elif (defined(_MSC_VER) && _MSC_VER >= 1400)
# define SECP256K1_RESTRICT __restrict
# else
# define SECP256K1_RESTRICT
# endif
# else
# define SECP256K1_RESTRICT restrict
# endif
#endif
#endif

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