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-rw-r--r--src/modinv64_impl.h44
1 files changed, 16 insertions, 28 deletions
diff --git a/src/modinv64_impl.h b/src/modinv64_impl.h
index c7cef872a4..0dc1e80696 100644
--- a/src/modinv64_impl.h
+++ b/src/modinv64_impl.h
@@ -144,7 +144,6 @@ static void secp256k1_modinv64_normalize_62(secp256k1_modinv64_signed62 *r, int6
r->v[3] = r3;
r->v[4] = r4;
-#ifdef VERIFY
VERIFY_CHECK(r0 >> 62 == 0);
VERIFY_CHECK(r1 >> 62 == 0);
VERIFY_CHECK(r2 >> 62 == 0);
@@ -152,7 +151,6 @@ static void secp256k1_modinv64_normalize_62(secp256k1_modinv64_signed62 *r, int6
VERIFY_CHECK(r4 >> 62 == 0);
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(r, 5, &modinfo->modulus, 0) >= 0); /* r >= 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(r, 5, &modinfo->modulus, 1) < 0); /* r < modulus */
-#endif
}
/* Compute the transition matrix and eta for 59 divsteps (where zeta=-(delta+1/2)).
@@ -216,7 +214,7 @@ static int64_t secp256k1_modinv64_divsteps_59(int64_t zeta, uint64_t f0, uint64_
t->v = (int64_t)v;
t->q = (int64_t)q;
t->r = (int64_t)r;
-#ifdef VERIFY
+
/* The determinant of t must be a power of two. This guarantees that multiplication with t
* does not change the gcd of f and g, apart from adding a power-of-2 factor to it (which
* will be divided out again). As each divstep's individual matrix has determinant 2, the
@@ -224,7 +222,7 @@ static int64_t secp256k1_modinv64_divsteps_59(int64_t zeta, uint64_t f0, uint64_
* 8*identity (which has determinant 2^6) means the overall outputs has determinant
* 2^65. */
VERIFY_CHECK(secp256k1_modinv64_det_check_pow2(t, 65, 0));
-#endif
+
return zeta;
}
@@ -301,13 +299,13 @@ static int64_t secp256k1_modinv64_divsteps_62_var(int64_t eta, uint64_t f0, uint
t->v = (int64_t)v;
t->q = (int64_t)q;
t->r = (int64_t)r;
-#ifdef VERIFY
+
/* The determinant of t must be a power of two. This guarantees that multiplication with t
* does not change the gcd of f and g, apart from adding a power-of-2 factor to it (which
* will be divided out again). As each divstep's individual matrix has determinant 2, the
* aggregate of 62 of them will have determinant 2^62. */
VERIFY_CHECK(secp256k1_modinv64_det_check_pow2(t, 62, 0));
-#endif
+
return eta;
}
@@ -392,13 +390,13 @@ static int64_t secp256k1_modinv64_posdivsteps_62_var(int64_t eta, uint64_t f0, u
t->v = (int64_t)v;
t->q = (int64_t)q;
t->r = (int64_t)r;
-#ifdef VERIFY
+
/* The determinant of t must be a power of two. This guarantees that multiplication with t
* does not change the gcd of f and g, apart from adding a power-of-2 factor to it (which
* will be divided out again). As each divstep's individual matrix has determinant 2 or -2,
* the aggregate of 62 of them will have determinant 2^62 or -2^62. */
VERIFY_CHECK(secp256k1_modinv64_det_check_pow2(t, 62, 1));
-#endif
+
*jacp = jac;
return eta;
}
@@ -417,14 +415,13 @@ static void secp256k1_modinv64_update_de_62(secp256k1_modinv64_signed62 *d, secp
const int64_t u = t->u, v = t->v, q = t->q, r = t->r;
int64_t md, me, sd, se;
secp256k1_int128 cd, ce;
-#ifdef VERIFY
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(d, 5, &modinfo->modulus, -2) > 0); /* d > -2*modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(d, 5, &modinfo->modulus, 1) < 0); /* d < modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(e, 5, &modinfo->modulus, -2) > 0); /* e > -2*modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(e, 5, &modinfo->modulus, 1) < 0); /* e < modulus */
VERIFY_CHECK(secp256k1_modinv64_abs(u) <= (((int64_t)1 << 62) - secp256k1_modinv64_abs(v))); /* |u|+|v| <= 2^62 */
VERIFY_CHECK(secp256k1_modinv64_abs(q) <= (((int64_t)1 << 62) - secp256k1_modinv64_abs(r))); /* |q|+|r| <= 2^62 */
-#endif
+
/* [md,me] start as zero; plus [u,q] if d is negative; plus [v,r] if e is negative. */
sd = d4 >> 63;
se = e4 >> 63;
@@ -489,12 +486,11 @@ static void secp256k1_modinv64_update_de_62(secp256k1_modinv64_signed62 *d, secp
/* What remains is limb 5 of t*[d,e]+modulus*[md,me]; store it as output limb 4. */
d->v[4] = secp256k1_i128_to_i64(&cd);
e->v[4] = secp256k1_i128_to_i64(&ce);
-#ifdef VERIFY
+
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(d, 5, &modinfo->modulus, -2) > 0); /* d > -2*modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(d, 5, &modinfo->modulus, 1) < 0); /* d < modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(e, 5, &modinfo->modulus, -2) > 0); /* e > -2*modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(e, 5, &modinfo->modulus, 1) < 0); /* e < modulus */
-#endif
}
/* Compute (t/2^62) * [f, g], where t is a transition matrix scaled by 2^62.
@@ -606,25 +602,23 @@ static void secp256k1_modinv64(secp256k1_modinv64_signed62 *x, const secp256k1_m
/* Update d,e using that transition matrix. */
secp256k1_modinv64_update_de_62(&d, &e, &t, modinfo);
/* Update f,g using that transition matrix. */
-#ifdef VERIFY
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, -1) > 0); /* f > -modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, 1) <= 0); /* f <= modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, 5, &modinfo->modulus, -1) > 0); /* g > -modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, 5, &modinfo->modulus, 1) < 0); /* g < modulus */
-#endif
+
secp256k1_modinv64_update_fg_62(&f, &g, &t);
-#ifdef VERIFY
+
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, -1) > 0); /* f > -modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, 1) <= 0); /* f <= modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, 5, &modinfo->modulus, -1) > 0); /* g > -modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, 5, &modinfo->modulus, 1) < 0); /* g < modulus */
-#endif
}
/* At this point sufficient iterations have been performed that g must have reached 0
* and (if g was not originally 0) f must now equal +/- GCD of the initial f, g
* values i.e. +/- 1, and d now contains +/- the modular inverse. */
-#ifdef VERIFY
+
/* g == 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, 5, &SECP256K1_SIGNED62_ONE, 0) == 0);
/* |f| == 1, or (x == 0 and d == 0 and |f|=modulus) */
@@ -634,7 +628,6 @@ static void secp256k1_modinv64(secp256k1_modinv64_signed62 *x, const secp256k1_m
secp256k1_modinv64_mul_cmp_62(&d, 5, &SECP256K1_SIGNED62_ONE, 0) == 0 &&
(secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, 1) == 0 ||
secp256k1_modinv64_mul_cmp_62(&f, 5, &modinfo->modulus, -1) == 0)));
-#endif
/* Optionally negate d, normalize to [0,modulus), and return it. */
secp256k1_modinv64_normalize_62(&d, f.v[4], modinfo);
@@ -663,12 +656,11 @@ static void secp256k1_modinv64_var(secp256k1_modinv64_signed62 *x, const secp256
/* Update d,e using that transition matrix. */
secp256k1_modinv64_update_de_62(&d, &e, &t, modinfo);
/* Update f,g using that transition matrix. */
-#ifdef VERIFY
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, -1) > 0); /* f > -modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 1) <= 0); /* f <= modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &modinfo->modulus, -1) > 0); /* g > -modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &modinfo->modulus, 1) < 0); /* g < modulus */
-#endif
+
secp256k1_modinv64_update_fg_62_var(len, &f, &g, &t);
/* If the bottom limb of g is zero, there is a chance that g=0. */
if (g.v[0] == 0) {
@@ -693,18 +685,17 @@ static void secp256k1_modinv64_var(secp256k1_modinv64_signed62 *x, const secp256
g.v[len - 2] |= (uint64_t)gn << 62;
--len;
}
-#ifdef VERIFY
+
VERIFY_CHECK(++i < 12); /* We should never need more than 12*62 = 744 divsteps */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, -1) > 0); /* f > -modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 1) <= 0); /* f <= modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &modinfo->modulus, -1) > 0); /* g > -modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &modinfo->modulus, 1) < 0); /* g < modulus */
-#endif
}
/* At this point g is 0 and (if g was not originally 0) f must now equal +/- GCD of
* the initial f, g values i.e. +/- 1, and d now contains +/- the modular inverse. */
-#ifdef VERIFY
+
/* g == 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &SECP256K1_SIGNED62_ONE, 0) == 0);
/* |f| == 1, or (x == 0 and d == 0 and |f|=modulus) */
@@ -714,7 +705,6 @@ static void secp256k1_modinv64_var(secp256k1_modinv64_signed62 *x, const secp256
secp256k1_modinv64_mul_cmp_62(&d, 5, &SECP256K1_SIGNED62_ONE, 0) == 0 &&
(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 1) == 0 ||
secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, -1) == 0)));
-#endif
/* Optionally negate d, normalize to [0,modulus), and return it. */
secp256k1_modinv64_normalize_62(&d, f.v[len - 1], modinfo);
@@ -753,12 +743,11 @@ static int secp256k1_jacobi64_maybe_var(const secp256k1_modinv64_signed62 *x, co
secp256k1_modinv64_trans2x2 t;
eta = secp256k1_modinv64_posdivsteps_62_var(eta, f.v[0] | ((uint64_t)f.v[1] << 62), g.v[0] | ((uint64_t)g.v[1] << 62), &t, &jac);
/* Update f,g using that transition matrix. */
-#ifdef VERIFY
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 0) > 0); /* f > 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 1) <= 0); /* f <= modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &modinfo->modulus, 0) > 0); /* g > 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &modinfo->modulus, 1) < 0); /* g < modulus */
-#endif
+
secp256k1_modinv64_update_fg_62_var(len, &f, &g, &t);
/* If the bottom limb of f is 1, there is a chance that f=1. */
if (f.v[0] == 1) {
@@ -779,12 +768,11 @@ static int secp256k1_jacobi64_maybe_var(const secp256k1_modinv64_signed62 *x, co
cond |= gn;
/* If so, reduce length. */
if (cond == 0) --len;
-#ifdef VERIFY
+
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 0) > 0); /* f > 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&f, len, &modinfo->modulus, 1) <= 0); /* f <= modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &modinfo->modulus, 0) > 0); /* g > 0 */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(&g, len, &modinfo->modulus, 1) < 0); /* g < modulus */
-#endif
}
/* The loop failed to converge to f=g after 1550 iterations. Return 0, indicating unknown result. */
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-28 00:54:54 +0000