#define COFACTOR 4
-/* Comb config: number of combs, n, t, s. */
-#define COMBS_N 5
-#define COMBS_T 5
-#define COMBS_S 18
#define C448_WNAF_FIXED_TABLE_BITS 5
#define C448_WNAF_VAR_TABLE_BITS 3
-static const int EDWARDS_D = -39081;
+#define EDWARDS_D (-39081)
+
static const curve448_scalar_t precomputed_scalarmul_adjustment = {
{
{
#define WBITS C448_WORD_BITS /* NB this may be different from ARCH_WORD_BITS */
-/* Projective Niels coordinates */
-typedef struct {
- gf a, b, c;
-} niels_s, niels_t[1];
-typedef struct {
- niels_t n;
- gf z;
-} VECTOR_ALIGNED pniels_t[1];
-
-/* Precomputed base */
-struct curve448_precomputed_s {
- niels_t table[COMBS_N << (COMBS_T - 1)];
-};
-
-extern const gf curve448_precomputed_base_as_fe[];
-const curve448_precomputed_s *curve448_precomputed_base =
- (const curve448_precomputed_s *)&curve448_precomputed_base_as_fe;
-
/* Inverse. */
static void gf_invert(gf y, const gf x, int assert_nonzero)
{
mask_t ret;
-
gf t1, t2;
+
gf_sqr(t1, x); /* o^2 */
ret = gf_isr(t2, t1); /* +-1/sqrt(o^2) = +-1/o */
(void)ret;
int before_double)
{
gf a, b, c;
+
gf_sub_nr(b, d->y, d->x); /* 3+e */
gf_mul(a, e->b, b);
gf_add_nr(b, d->x, d->y); /* 2+e */
const curve448_point_t q)
{
mask_t succ;
+ gf a, b;
/* equality mod 2-torsion compares x/y */
- gf a, b;
gf_mul(a, p->y, q->x);
gf_mul(b, q->y, p->x);
succ = gf_eq(a, b);
c448_bool_t curve448_point_valid(const curve448_point_t p)
{
mask_t out;
-
gf a, b, c;
+
gf_mul(a, p->x, p->y);
gf_mul(b, p->z, p->t);
out = gf_eq(a, b);
const curve448_precomputed_s * table,
const curve448_scalar_t scalar)
{
- int i;
- unsigned j, k;
+ unsigned int i, j, k;
const unsigned int n = COMBS_N, t = COMBS_T, s = COMBS_S;
niels_t ni;
-
curve448_scalar_t scalar1x;
+
curve448_scalar_add(scalar1x, scalar, precomputed_scalarmul_adjustment);
curve448_scalar_halve(scalar1x, scalar1x);
- for (i = s - 1; i >= 0; i--) {
- if (i != (int)s - 1)
+ for (i = s; i > 0; i--) {
+ if (i != s)
point_double_internal(out, out, 0);
for (j = 0; j < n; j++) {
mask_t invert;
for (k = 0; k < t; k++) {
- unsigned int bit = i + s * (k + j * t);
- if (bit < C448_SCALAR_BITS) {
+ unsigned int bit = (i - 1) + s * (k + j * t);
+
+ if (bit < C448_SCALAR_BITS)
tab |=
(scalar1x->limb[bit / WBITS] >> (bit % WBITS) & 1) << k;
- }
}
invert = (tab >> (t - 1)) - 1;
1 << (t - 1), tab);
cond_neg_niels(ni, invert);
- if ((i != (int)s - 1) || j) {
- add_niels_to_pt(out, ni, j == n - 1 && i);
- } else {
+ if ((i != s) || j != 0)
+ add_niels_to_pt(out, ni, j == n - 1 && i != 1);
+ else
niels_to_pt(out, ni);
- }
}
}
uint8_t enc[EDDSA_448_PUBLIC_BYTES],
const curve448_point_t p)
{
-
- /* The point is now on the twisted curve. Move it to untwisted. */
gf x, y, z, t;
curve448_point_t q;
+
+ /* The point is now on the twisted curve. Move it to untwisted. */
curve448_point_copy(q, p);
{
enc2[EDDSA_448_PRIVATE_BYTES - 1] &= ~0x80;
succ = gf_deserialize(p->y, enc2, 1, 0);
-#if 0 == 0
succ &= word_is_zero(enc2[EDDSA_448_PRIVATE_BYTES - 1]);
-#endif
gf_sqr(p->x, p->y);
gf_sub(p->z, ONE, p->x); /* num = 1-y^2 */
gf_copy(p->z, ONE);
{
- /* 4-isogeny 2xy/(y^2-ax^2), (y^2+ax^2)/(2-y^2-ax^2) */
gf a, b, c, d;
+
+ /* 4-isogeny 2xy/(y^2-ax^2), (y^2+ax^2)/(2-y^2-ax^2) */
gf_sqr(c, p->x);
gf_sqr(a, p->y);
gf_add(d, c, a);
const curve448_point_t p)
{
curve448_point_t q;
+
curve448_point_copy(q, p);
gf_invert(q->t, q->x, 0); /* 1/x */
gf_mul(q->z, q->t, q->y); /* y/x */
curve448_scalar_decode_long(the_scalar, scalar2, sizeof(scalar2));
/* Compensate for the encoding ratio */
- for (i = 1; i < X448_ENCODE_RATIO; i <<= 1) {
+ for (i = 1; i < X448_ENCODE_RATIO; i <<= 1)
curve448_scalar_halve(the_scalar, the_scalar);
- }
+
curve448_precomputed_scalarmul(p, curve448_precomputed_base, the_scalar);
curve448_point_mul_by_ratio_and_encode_like_x448(out, p);
curve448_point_destroy(p);
# define NUMTRAILINGZEROS numtrailingzeros
static uint32_t numtrailingzeros(uint32_t i)
{
- unsigned int tmp;
+ uint32_t tmp;
uint32_t num = 31;
if (i == 0)
i = tmp;
num -= 2;
}
- if ((i << 1) != 0)
+ tmp = i << 1;
+ if (tmp != 0)
num--;
return num;
if (w < (C448_SCALAR_BITS - 1) / 16 + 1) {
/* Refill the 16 high bits of current */
current += (uint32_t)((scalar->limb[w / B_OVER_16]
- >> (16 * (w % B_OVER_16))) << 16);
+ >> (16 * (w % B_OVER_16))) << 16);
}
while (current & 0xFFFF) {
int32_t delta = odd & mask;
assert(position >= 0);
- if (odd & 1 << (table_bits + 1))
+ if (odd & (1 << (table_bits + 1)))
delta -= (1 << (table_bits + 1));
current -= delta << pos;
control[position].power = pos + 16 * (w - 1);
position++;
n = table_size - position;
- for (i = 0; i < n; i++) {
+ for (i = 0; i < n; i++)
control[i] = control[i + position];
- }
+
return n - 1;
}
OPENSSL_cleanse(twop, sizeof(twop));
}
-extern const gf curve448_precomputed_wnaf_as_fe[];
-static const niels_t *curve448_wnaf_base =
- (const niels_t *)curve448_precomputed_wnaf_as_fe;
-
void curve448_base_double_scalarmul_non_secret(curve448_point_t combo,
const curve448_scalar_t scalar1,
const curve448_point_t base2,
const curve448_scalar_t scalar2)
{
- const int table_bits_var = C448_WNAF_VAR_TABLE_BITS,
- table_bits_pre = C448_WNAF_FIXED_TABLE_BITS;
+ const int table_bits_var = C448_WNAF_VAR_TABLE_BITS;
+ const int table_bits_pre = C448_WNAF_FIXED_TABLE_BITS;
struct smvt_control control_var[C448_SCALAR_BITS /
(C448_WNAF_VAR_TABLE_BITS + 1) + 3];
struct smvt_control control_pre[C448_SCALAR_BITS /
if (i < 0) {
curve448_point_copy(combo, curve448_point_identity);
return;
- } else if (i > control_pre[0].power) {
+ }
+ if (i > control_pre[0].power) {
pniels_to_pt(combo, precmp_var[control_var[0].addend >> 1]);
contv++;
} else if (i == control_pre[0].power && i >= 0) {
}
for (i--; i >= 0; i--) {
- int cv = (i == control_var[contv].power), cp =
- (i == control_pre[contp].power);
+ int cv = (i == control_var[contv].power);
+ int cp = (i == control_pre[contp].power);
+
point_double_internal(combo, combo, i && !(cv || cp));
if (cv) {
assert(control_var[contv].addend);
- if (control_var[contv].addend > 0) {
+ if (control_var[contv].addend > 0)
add_pniels_to_pt(combo,
precmp_var[control_var[contv].addend >> 1],
i && !cp);
- } else {
+ else
sub_pniels_from_pt(combo,
precmp_var[(-control_var[contv].addend)
>> 1], i && !cp);
- }
contv++;
}
if (cp) {
assert(control_pre[contp].addend);
- if (control_pre[contp].addend > 0) {
+ if (control_pre[contp].addend > 0)
add_niels_to_pt(combo,
curve448_wnaf_base[control_pre[contp].addend
>> 1], i);
- } else {
+ else
sub_niels_from_pt(combo,
curve448_wnaf_base[(-control_pre
[contp].addend) >> 1], i);
- }
contp++;
}
}
projects / openssl.git / blobdiff