diff options
Diffstat (limited to 'src/modinv32_impl.h')
-rw-r--r-- | src/modinv32_impl.h | 33 |
1 files changed, 11 insertions, 22 deletions
diff --git a/src/modinv32_impl.h b/src/modinv32_impl.h index 0ea2699863..75eb354ff0 100644 --- a/src/modinv32_impl.h +++ b/src/modinv32_impl.h @@ -144,7 +144,6 @@ static void secp256k1_modinv32_normalize_30(secp256k1_modinv32_signed30 *r, int3 r->v[7] = r7; r->v[8] = r8; -#ifdef VERIFY VERIFY_CHECK(r0 >> 30 == 0); VERIFY_CHECK(r1 >> 30 == 0); VERIFY_CHECK(r2 >> 30 == 0); @@ -156,7 +155,6 @@ static void secp256k1_modinv32_normalize_30(secp256k1_modinv32_signed30 *r, int3 VERIFY_CHECK(r8 >> 30 == 0); VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(r, 9, &modinfo->modulus, 0) >= 0); /* r >= 0 */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(r, 9, &modinfo->modulus, 1) < 0); /* r < modulus */ -#endif } /* Data type for transition matrices (see section 3 of explanation). @@ -413,14 +411,13 @@ static void secp256k1_modinv32_update_de_30(secp256k1_modinv32_signed30 *d, secp int32_t di, ei, md, me, sd, se; int64_t cd, ce; int i; -#ifdef VERIFY VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(d, 9, &modinfo->modulus, -2) > 0); /* d > -2*modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(d, 9, &modinfo->modulus, 1) < 0); /* d < modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(e, 9, &modinfo->modulus, -2) > 0); /* e > -2*modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(e, 9, &modinfo->modulus, 1) < 0); /* e < modulus */ VERIFY_CHECK(labs(u) <= (M30 + 1 - labs(v))); /* |u|+|v| <= 2^30 */ VERIFY_CHECK(labs(q) <= (M30 + 1 - labs(r))); /* |q|+|r| <= 2^30 */ -#endif + /* [md,me] start as zero; plus [u,q] if d is negative; plus [v,r] if e is negative. */ sd = d->v[8] >> 31; se = e->v[8] >> 31; @@ -455,12 +452,11 @@ static void secp256k1_modinv32_update_de_30(secp256k1_modinv32_signed30 *d, secp /* What remains is limb 9 of t*[d,e]+modulus*[md,me]; store it as output limb 8. */ d->v[8] = (int32_t)cd; e->v[8] = (int32_t)ce; -#ifdef VERIFY + VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(d, 9, &modinfo->modulus, -2) > 0); /* d > -2*modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(d, 9, &modinfo->modulus, 1) < 0); /* d < modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(e, 9, &modinfo->modulus, -2) > 0); /* e > -2*modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(e, 9, &modinfo->modulus, 1) < 0); /* e < modulus */ -#endif } /* Compute (t/2^30) * [f, g], where t is a transition matrix for 30 divsteps. @@ -550,25 +546,23 @@ static void secp256k1_modinv32(secp256k1_modinv32_signed30 *x, const secp256k1_m /* Update d,e using that transition matrix. */ secp256k1_modinv32_update_de_30(&d, &e, &t, modinfo); /* Update f,g using that transition matrix. */ -#ifdef VERIFY VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, -1) > 0); /* f > -modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, 1) <= 0); /* f <= modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, 9, &modinfo->modulus, -1) > 0); /* g > -modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, 9, &modinfo->modulus, 1) < 0); /* g < modulus */ -#endif + secp256k1_modinv32_update_fg_30(&f, &g, &t); -#ifdef VERIFY + VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, -1) > 0); /* f > -modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, 1) <= 0); /* f <= modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, 9, &modinfo->modulus, -1) > 0); /* g > -modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, 9, &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_modinv32_mul_cmp_30(&g, 9, &SECP256K1_SIGNED30_ONE, 0) == 0); /* |f| == 1, or (x == 0 and d == 0 and |f|=modulus) */ @@ -578,7 +572,6 @@ static void secp256k1_modinv32(secp256k1_modinv32_signed30 *x, const secp256k1_m secp256k1_modinv32_mul_cmp_30(&d, 9, &SECP256K1_SIGNED30_ONE, 0) == 0 && (secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, 1) == 0 || secp256k1_modinv32_mul_cmp_30(&f, 9, &modinfo->modulus, -1) == 0))); -#endif /* Optionally negate d, normalize to [0,modulus), and return it. */ secp256k1_modinv32_normalize_30(&d, f.v[8], modinfo); @@ -607,12 +600,12 @@ static void secp256k1_modinv32_var(secp256k1_modinv32_signed30 *x, const secp256 /* Update d,e using that transition matrix. */ secp256k1_modinv32_update_de_30(&d, &e, &t, modinfo); /* Update f,g using that transition matrix. */ -#ifdef VERIFY + VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, -1) > 0); /* f > -modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 1) <= 0); /* f <= modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, len, &modinfo->modulus, -1) > 0); /* g > -modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, len, &modinfo->modulus, 1) < 0); /* g < modulus */ -#endif + secp256k1_modinv32_update_fg_30_var(len, &f, &g, &t); /* If the bottom limb of g is 0, there is a chance g=0. */ if (g.v[0] == 0) { @@ -637,18 +630,17 @@ static void secp256k1_modinv32_var(secp256k1_modinv32_signed30 *x, const secp256 g.v[len - 2] |= (uint32_t)gn << 30; --len; } -#ifdef VERIFY + VERIFY_CHECK(++i < 25); /* We should never need more than 25*30 = 750 divsteps */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, -1) > 0); /* f > -modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 1) <= 0); /* f <= modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, len, &modinfo->modulus, -1) > 0); /* g > -modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&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_modinv32_mul_cmp_30(&g, len, &SECP256K1_SIGNED30_ONE, 0) == 0); /* |f| == 1, or (x == 0 and d == 0 and |f|=modulus) */ @@ -658,7 +650,6 @@ static void secp256k1_modinv32_var(secp256k1_modinv32_signed30 *x, const secp256 secp256k1_modinv32_mul_cmp_30(&d, 9, &SECP256K1_SIGNED30_ONE, 0) == 0 && (secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 1) == 0 || secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, -1) == 0))); -#endif /* Optionally negate d, normalize to [0,modulus), and return it. */ secp256k1_modinv32_normalize_30(&d, f.v[len - 1], modinfo); @@ -697,12 +688,11 @@ static int secp256k1_jacobi32_maybe_var(const secp256k1_modinv32_signed30 *x, co secp256k1_modinv32_trans2x2 t; eta = secp256k1_modinv32_posdivsteps_30_var(eta, f.v[0] | ((uint32_t)f.v[1] << 30), g.v[0] | ((uint32_t)g.v[1] << 30), &t, &jac); /* Update f,g using that transition matrix. */ -#ifdef VERIFY VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 0) > 0); /* f > 0 */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 1) <= 0); /* f <= modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, len, &modinfo->modulus, 0) > 0); /* g > 0 */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, len, &modinfo->modulus, 1) < 0); /* g < modulus */ -#endif + secp256k1_modinv32_update_fg_30_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) { @@ -723,12 +713,11 @@ static int secp256k1_jacobi32_maybe_var(const secp256k1_modinv32_signed30 *x, co cond |= gn; /* If so, reduce length. */ if (cond == 0) --len; -#ifdef VERIFY + VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 0) > 0); /* f > 0 */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&f, len, &modinfo->modulus, 1) <= 0); /* f <= modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, len, &modinfo->modulus, 0) > 0); /* g > 0 */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(&g, len, &modinfo->modulus, 1) < 0); /* g < modulus */ -#endif } /* The loop failed to converge to f=g after 1500 iterations. Return 0, indicating unknown result. */ |