* ecp_nistz256_bignum_to_field_elem copies the contents of |in| to |out| and
* returns one if it fits. Otherwise it returns zero.
*/
-static int ecp_nistz256_bignum_to_field_elem(BN_ULONG out[P256_LIMBS],
- const BIGNUM *in)
+__owur static int ecp_nistz256_bignum_to_field_elem(BN_ULONG out[P256_LIMBS],
+ const BIGNUM *in)
{
return bn_copy_words(out, in, P256_LIMBS);
}
/* r = sum(scalar[i]*point[i]) */
-static void ecp_nistz256_windowed_mul(const EC_GROUP *group,
- P256_POINT *r,
- const BIGNUM **scalar,
- const EC_POINT **point,
- size_t num, BN_CTX *ctx)
+__owur static int ecp_nistz256_windowed_mul(const EC_GROUP *group,
+ P256_POINT *r,
+ const BIGNUM **scalar,
+ const EC_POINT **point,
+ size_t num, BN_CTX *ctx)
{
size_t i;
- int j;
+ int j, ret = 0;
unsigned int idx;
unsigned char (*p_str)[33] = NULL;
const unsigned int window_size = 5;
for (i = 0; i < num; i++) {
P256_POINT *row = table[i];
+ /* This is an unusual input, we don't guarantee constant-timeness. */
if ((BN_num_bits(scalar[i]) > 256) || BN_is_negative(scalar[i])) {
BIGNUM *mod;
ecp_nistz256_point_add(r, r, &temp[0]);
}
+ ret = 1;
err:
if (table_storage)
OPENSSL_free(table_storage);
OPENSSL_free(p_str);
if (scalars)
OPENSSL_free(scalars);
+ return ret;
}
/* Coordinates of G, for which we have precomputed tables */
is_one(bn_get_words(generator->Z));
}
-static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx)
+__owur static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx)
{
/*
* We precompute a table for a Booth encoded exponent (wNAF) based
EC_POINT *P = NULL, *T = NULL;
const EC_POINT *generator;
EC_PRE_COMP *pre_comp;
+ BN_CTX *new_ctx = NULL;
int i, j, k, ret = 0;
size_t w;
return 0;
if (ctx == NULL) {
- ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new();
if (ctx == NULL)
goto err;
}
P = EC_POINT_new(group);
T = EC_POINT_new(group);
+ if (P == NULL || T == NULL)
+ goto err;
/*
* The zero entry is implicitly infinity, and we skip it, storing other
* values with -1 offset.
*/
- EC_POINT_copy(T, generator);
+ if (!EC_POINT_copy(T, generator))
+ goto err;
for (k = 0; k < 64; k++) {
- EC_POINT_copy(P, T);
+ if (!EC_POINT_copy(P, T))
+ goto err;
for (j = 0; j < 37; j++) {
P256_POINT_AFFINE temp;
/*
- * It would be faster to use ec_GFp_simple_points_make_affine and
+ * It would be faster to use EC_POINTs_make_affine and
* make multiple points affine at the same time.
*/
- ec_GFp_simple_make_affine(group, P, ctx);
- ecp_nistz256_bignum_to_field_elem(temp.X, P->X);
- ecp_nistz256_bignum_to_field_elem(temp.Y, P->Y);
+ if (!EC_POINT_make_affine(group, P, ctx))
+ goto err;
+ if (!ecp_nistz256_bignum_to_field_elem(temp.X, P->X) ||
+ !ecp_nistz256_bignum_to_field_elem(temp.Y, P->Y)) {
+ ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE,
+ EC_R_COORDINATES_OUT_OF_RANGE);
+ goto err;
+ }
ecp_nistz256_scatter_w7(preComputedTable[j], &temp, k);
- for (i = 0; i < 7; i++)
- ec_GFp_simple_dbl(group, P, P, ctx);
+ for (i = 0; i < 7; i++) {
+ if (!EC_POINT_dbl(group, P, P, ctx))
+ goto err;
+ }
}
- ec_GFp_simple_add(group, T, T, generator, ctx);
+ if (!EC_POINT_add(group, T, T, generator, ctx))
+ goto err;
}
pre_comp->group = group;
err:
if (ctx != NULL)
BN_CTX_end(ctx);
+ BN_CTX_free(new_ctx);
+
ecp_nistz256_pre_comp_free(pre_comp);
if (precomp_storage)
OPENSSL_free(precomp_storage);
# endif
#endif
-static int ecp_nistz256_set_from_affine(EC_POINT *out, const EC_GROUP *group,
- const P256_POINT_AFFINE *in,
- BN_CTX *ctx)
+__owur static int ecp_nistz256_set_from_affine(EC_POINT *out, const EC_GROUP *group,
+ const P256_POINT_AFFINE *in,
+ BN_CTX *ctx)
{
BIGNUM *x, *y;
BN_ULONG d_x[P256_LIMBS], d_y[P256_LIMBS];
}
/* r = scalar*G + sum(scalars[i]*points[i]) */
-static int ecp_nistz256_points_mul(const EC_GROUP *group,
- EC_POINT *r,
- const BIGNUM *scalar,
- size_t num,
- const EC_POINT *points[],
- const BIGNUM *scalars[], BN_CTX *ctx)
+__owur static int ecp_nistz256_points_mul(const EC_GROUP *group,
+ EC_POINT *r,
+ const BIGNUM *scalar,
+ size_t num,
+ const EC_POINT *points[],
+ const BIGNUM *scalars[], BN_CTX *ctx)
{
int i = 0, ret = 0, no_precomp_for_generator = 0, p_is_infinity = 0;
size_t j;
const PRECOMP256_ROW *preComputedTable = NULL;
const EC_PRE_COMP *pre_comp = NULL;
const EC_POINT *generator = NULL;
+ BN_CTX *new_ctx = NULL;
+ const BIGNUM **new_scalars = NULL;
+ const EC_POINT **new_points = NULL;
unsigned int idx = 0;
const unsigned int window_size = 7;
const unsigned int mask = (1 << (window_size + 1)) - 1;
ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
return 0;
}
+
if ((scalar == NULL) && (num == 0))
return EC_POINT_set_to_infinity(group, r);
}
}
- /* Need 256 bits for space for all coordinates. */
- bn_wexpand(r->X, P256_LIMBS);
- bn_wexpand(r->Y, P256_LIMBS);
- bn_wexpand(r->Z, P256_LIMBS);
- bn_set_top(r->X, P256_LIMBS);
- bn_set_top(r->Y, P256_LIMBS);
- bn_set_top(r->Z, P256_LIMBS);
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ goto err;
+ }
+
+ BN_CTX_start(ctx);
if (scalar) {
generator = EC_GROUP_get0_generator(group);
if (!ecp_nistz256_set_from_affine(pre_comp_generator,
group, pre_comp->precomp[0],
- ctx))
+ ctx)) {
+ EC_POINT_free(pre_comp_generator);
goto err;
+ }
if (0 == EC_POINT_cmp(group, generator, pre_comp_generator, ctx))
preComputedTable = (const PRECOMP256_ROW *)pre_comp->precomp;
* Without a precomputed table for the generator, it has to be
* handled like a normal point.
*/
- const BIGNUM **new_scalars;
- const EC_POINT **new_points;
-
new_scalars = OPENSSL_malloc((num + 1) * sizeof(BIGNUM *));
if (!new_scalars) {
ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE);
- return 0;
+ goto err;
}
new_points = OPENSSL_malloc((num + 1) * sizeof(EC_POINT *));
if (!new_points) {
- OPENSSL_free(new_scalars);
ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE);
- return 0;
+ goto err;
}
memcpy(new_scalars, scalars, num * sizeof(BIGNUM *));
if (p_is_infinity)
out = &p.p;
- ecp_nistz256_windowed_mul(group, out, scalars, points, num, ctx);
+ if (!ecp_nistz256_windowed_mul(group, out, scalars, points, num, ctx))
+ goto err;
if (!p_is_infinity)
ecp_nistz256_point_add(&p.p, &p.p, out);
}
- if (no_precomp_for_generator) {
- OPENSSL_free(points);
- OPENSSL_free(scalars);
+ /* Not constant-time, but we're only operating on the public output. */
+ if (!bn_set_words(r->X, p.p.X, P256_LIMBS) ||
+ !bn_set_words(r->Y, p.p.Y, P256_LIMBS) ||
+ !bn_set_words(r->Z, p.p.Z, P256_LIMBS)) {
+ goto err;
}
-
- bn_set_data(r->X, p.p.X, sizeof(p.p.X));
- bn_set_data(r->Y, p.p.Y, sizeof(p.p.Y));
- bn_set_data(r->Z, p.p.Z, sizeof(p.p.Z));
- bn_correct_top(r->X);
- bn_correct_top(r->Y);
- bn_correct_top(r->Z);
+ r->Z_is_one = is_one(p.p.Z) & 1;
ret = 1;
- err:
+err:
+ if (ctx)
+ BN_CTX_end(ctx);
+ BN_CTX_free(new_ctx);
+ if (new_points)
+ OPENSSL_free(new_points);
+ if (new_scalars)
+ OPENSSL_free(new_scalars);
return ret;
}
-static int ecp_nistz256_get_affine(const EC_GROUP *group,
- const EC_POINT *point,
- BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
+__owur static int ecp_nistz256_get_affine(const EC_GROUP *group,
+ const EC_POINT *point,
+ BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
{
BN_ULONG z_inv2[P256_LIMBS];
BN_ULONG z_inv3[P256_LIMBS];
BN_ULONG x_aff[P256_LIMBS];
BN_ULONG y_aff[P256_LIMBS];
BN_ULONG point_x[P256_LIMBS], point_y[P256_LIMBS], point_z[P256_LIMBS];
+ BN_ULONG x_ret[P256_LIMBS], y_ret[P256_LIMBS];
if (EC_POINT_is_at_infinity(group, point)) {
ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_POINT_AT_INFINITY);
ecp_nistz256_mul_mont(x_aff, z_inv2, point_x);
if (x != NULL) {
- bn_wexpand(x, P256_LIMBS);
- bn_set_top(x, P256_LIMBS);
- ecp_nistz256_from_mont(bn_get_words(x), x_aff);
- bn_correct_top(x);
+ ecp_nistz256_from_mont(x_ret, x_aff);
+ if (!bn_set_words(x, x_ret, P256_LIMBS))
+ return 0;
}
if (y != NULL) {
ecp_nistz256_mul_mont(z_inv3, z_inv3, z_inv2);
ecp_nistz256_mul_mont(y_aff, z_inv3, point_y);
- bn_wexpand(y, P256_LIMBS);
- bn_set_top(y, P256_LIMBS);
- ecp_nistz256_from_mont(bn_get_words(y), y_aff);
- bn_correct_top(y);
+ ecp_nistz256_from_mont(y_ret, y_aff);
+ if (!bn_set_words(y, y_ret, P256_LIMBS))
+ return 0;
}
return 1;
projects / openssl.git / blobdiff