Function fxBigInt_ec_norm

modules/crypt/arith/xsBigIntEx.c:908–941

}

void fxBigInt_ec_norm(xsMachine *the, txECPoint *r, txECPoint *a, txECParam *ec)
{
	txBigInt *inv, *inv2, *inv3;
	pool_t pool;
	
	if (r->z == NULL)
		r->z = fxBigInt_alloc(the, ec->m->size);
	if (r->y == NULL)
		r->y = fxBigInt_alloc(the, ec->m->size);
	if (r->x == NULL)
		r->x = fxBigInt_alloc(the, ec->m->size);

	if (fxBigInt_iszero(a->z) || fxBigInt_ucomp(a->z, ec->one) == 0) {
		fxBigInt_copy(r->x, a->x);
		fxBigInt_copy(r->y, a->y);
		fxBigInt_copy(r->z, a->z);
		return;
	}
	
	pool_init(&pool);
	inv = pool_get(the, ec->m->size, &pool);
	inv2 = pool_get(the, ec->m->size, &pool);
	inv3 = pool_get(the, ec->m->size, &pool);
	inv = mont_out(the, inv, a->z, ec->m, ec->u);
	inv = fxBigInt_mod_mulinv(the, inv, inv, ec->m);
	inv = mont_in(the, inv, inv, ec->m);
	inv2 = fxBigInt_mont_square(the, inv2, inv, ec->m, ec->u, &pool);
	inv3 = fxBigInt_mont_mul(the, inv3, inv2, inv, ec->m, ec->u, &pool);
	
	fxBigInt_mont_mul(the, r->x, a->x, inv2, ec->m, ec->u, &pool);
	fxBigInt_mont_mul(the, r->y, a->y, inv3, ec->m, ec->u, &pool);
	fxBigInt_copy(r->z, ec->one);
	pool_dispose(the, &pool);
}