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tls: shrink sp_256_proj_point_dbl_10

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function                                             old     new   delta
sp_256_ecc_mulmod_10                                1329    1300     -29

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-04-26 17:25:27 +02:00
parent b3b1713a58
commit 772e18775e
1 changed files with 23 additions and 36 deletions
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59
networking/tls_sp_c32.c
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@ -681,18 +681,11 @@ static void sp_256_proj_point_dbl_10(sp_point* r, sp_point* p, sp_digit* t)
static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q,
sp_digit* t)
{
sp_point *ap[2];
sp_point *rp[2];
sp_point tp;
sp_digit* t1 = t;
sp_digit* t2 = t + 2*10;
sp_digit* t3 = t + 4*10;
sp_digit* t4 = t + 6*10;
sp_digit* t5 = t + 8*10;
sp_digit* x;
sp_digit* y;
sp_digit* z;
int i;
/* Ensure only the first point is the same as the result. */
if (q == r) {
@ -711,33 +704,27 @@ static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q,
sp_256_proj_point_dbl_10(r, p, t);
}
else {
rp[0] = r;
rp[1] = &tp;
memset(&tp, 0, sizeof(tp));
x = rp[p->infinity | q->infinity]->x;
y = rp[p->infinity | q->infinity]->y;
z = rp[p->infinity | q->infinity]->z;
sp_point tp;
sp_point *v;
ap[0] = p;
ap[1] = q;
for (i=0; i<10; i++)
r->x[i] = ap[p->infinity]->x[i];
for (i=0; i<10; i++)
r->y[i] = ap[p->infinity]->y[i];
for (i=0; i<10; i++)
r->z[i] = ap[p->infinity]->z[i];
r->infinity = ap[p->infinity]->infinity;
v = r;
if (p->infinity | q->infinity) {
memset(&tp, 0, sizeof(tp));
v = &tp;
}
*r = p->infinity ? *q : *p; /* struct copy */
/* U1 = X1*Z2^2 */
sp_256_mont_sqr_10(t1, q->z, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t3, t1, q->z, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t1, t1, x, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t1, t1, v->x, p256_mod, p256_mp_mod);
/* U2 = X2*Z1^2 */
sp_256_mont_sqr_10(t2, z, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t4, t2, z, p256_mod, p256_mp_mod);
sp_256_mont_sqr_10(t2, v->z, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t4, t2, v->z, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t2, t2, q->x, p256_mod, p256_mp_mod);
/* S1 = Y1*Z2^3 */
sp_256_mont_mul_10(t3, t3, y, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t3, t3, v->y, p256_mod, p256_mp_mod);
/* S2 = Y2*Z1^3 */
sp_256_mont_mul_10(t4, t4, q->y, p256_mod, p256_mp_mod);
/* H = U2 - U1 */
@ -745,21 +732,21 @@ static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q,
/* R = S2 - S1 */
sp_256_mont_sub_10(t4, t4, t3, p256_mod);
/* Z3 = H*Z1*Z2 */
sp_256_mont_mul_10(z, z, q->z, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(z, z, t2, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(v->z, v->z, q->z, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(v->z, v->z, t2, p256_mod, p256_mp_mod);
/* X3 = R^2 - H^3 - 2*U1*H^2 */
sp_256_mont_sqr_10(x, t4, p256_mod, p256_mp_mod);
sp_256_mont_sqr_10(v->x, t4, p256_mod, p256_mp_mod);
sp_256_mont_sqr_10(t5, t2, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(y, t1, t5, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(v->y, t1, t5, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t5, t5, t2, p256_mod, p256_mp_mod);
sp_256_mont_sub_10(x, x, t5, p256_mod);
sp_256_mont_dbl_10(t1, y, p256_mod);
sp_256_mont_sub_10(x, x, t1, p256_mod);
sp_256_mont_sub_10(v->x, v->x, t5, p256_mod);
sp_256_mont_dbl_10(t1, v->y, p256_mod);
sp_256_mont_sub_10(v->x, v->x, t1, p256_mod);
/* Y3 = R*(U1*H^2 - X3) - S1*H^3 */
sp_256_mont_sub_10(y, y, x, p256_mod);
sp_256_mont_mul_10(y, y, t4, p256_mod, p256_mp_mod);
sp_256_mont_sub_10(v->y, v->y, v->x, p256_mod);
sp_256_mont_mul_10(v->y, v->y, t4, p256_mod, p256_mp_mod);
sp_256_mont_mul_10(t5, t5, t3, p256_mod, p256_mp_mod);
sp_256_mont_sub_10(y, y, t5, p256_mod);
sp_256_mont_sub_10(v->y, v->y, t5, p256_mod);
}
}