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Imported OpenSSL 1.1.1d

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This commit is contained in:
Steve Dower
2019-09-16 11:16:33 +01:00
parent ea3c37b9ec
commit 6f2f71e7ea
325 changed files with 5375 additions and 11047 deletions
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103
crypto/ec/ec_lib.c
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@@ -265,6 +265,67 @@ int EC_METHOD_get_field_type(const EC_METHOD *meth)
static int ec_precompute_mont_data(EC_GROUP *);
/*-
* Try computing cofactor from the generator order (n) and field cardinality (q).
* This works for all curves of cryptographic interest.
*
* Hasse thm: q + 1 - 2*sqrt(q) <= n*h <= q + 1 + 2*sqrt(q)
* h_min = (q + 1 - 2*sqrt(q))/n
* h_max = (q + 1 + 2*sqrt(q))/n
* h_max - h_min = 4*sqrt(q)/n
* So if n > 4*sqrt(q) holds, there is only one possible value for h:
* h = \lfloor (h_min + h_max)/2 \rceil = \lfloor (q + 1)/n \rceil
*
* Otherwise, zero cofactor and return success.
*/
static int ec_guess_cofactor(EC_GROUP *group) {
int ret = 0;
BN_CTX *ctx = NULL;
BIGNUM *q = NULL;
/*-
* If the cofactor is too large, we cannot guess it.
* The RHS of below is a strict overestimate of lg(4 * sqrt(q))
*/
if (BN_num_bits(group->order) <= (BN_num_bits(group->field) + 1) / 2 + 3) {
/* default to 0 */
BN_zero(group->cofactor);
/* return success */
return 1;
}
if ((ctx = BN_CTX_new()) == NULL)
return 0;
BN_CTX_start(ctx);
if ((q = BN_CTX_get(ctx)) == NULL)
goto err;
/* set q = 2**m for binary fields; q = p otherwise */
if (group->meth->field_type == NID_X9_62_characteristic_two_field) {
BN_zero(q);
if (!BN_set_bit(q, BN_num_bits(group->field) - 1))
goto err;
} else {
if (!BN_copy(q, group->field))
goto err;
}
/* compute h = \lfloor (q + 1)/n \rceil = \lfloor (q + 1 + n/2)/n \rfloor */
if (!BN_rshift1(group->cofactor, group->order) /* n/2 */
|| !BN_add(group->cofactor, group->cofactor, q) /* q + n/2 */
/* q + 1 + n/2 */
|| !BN_add(group->cofactor, group->cofactor, BN_value_one())
/* (q + 1 + n/2)/n */
|| !BN_div(group->cofactor, NULL, group->cofactor, group->order, ctx))
goto err;
ret = 1;
err:
BN_CTX_end(ctx);
BN_CTX_free(ctx);
return ret;
}
int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
const BIGNUM *order, const BIGNUM *cofactor)
{
@@ -273,6 +334,34 @@ int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
return 0;
}
/* require group->field >= 1 */
if (group->field == NULL || BN_is_zero(group->field)
|| BN_is_negative(group->field)) {
ECerr(EC_F_EC_GROUP_SET_GENERATOR, EC_R_INVALID_FIELD);
return 0;
}
/*-
* - require order >= 1
* - enforce upper bound due to Hasse thm: order can be no more than one bit
* longer than field cardinality
*/
if (order == NULL || BN_is_zero(order) || BN_is_negative(order)
|| BN_num_bits(order) > BN_num_bits(group->field) + 1) {
ECerr(EC_F_EC_GROUP_SET_GENERATOR, EC_R_INVALID_GROUP_ORDER);
return 0;
}
/*-
* Unfortunately the cofactor is an optional field in many standards.
* Internally, the lib uses 0 cofactor as a marker for "unknown cofactor".
* So accept cofactor == NULL or cofactor >= 0.
*/
if (cofactor != NULL && BN_is_negative(cofactor)) {
ECerr(EC_F_EC_GROUP_SET_GENERATOR, EC_R_UNKNOWN_COFACTOR);
return 0;
}
if (group->generator == NULL) {
group->generator = EC_POINT_new(group);
if (group->generator == NULL)
@@ -281,17 +370,17 @@ int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
if (!EC_POINT_copy(group->generator, generator))
return 0;
if (order != NULL) {
if (!BN_copy(group->order, order))
return 0;
} else
BN_zero(group->order);
if (!BN_copy(group->order, order))
return 0;
if (cofactor != NULL) {
/* Either take the provided positive cofactor, or try to compute it */
if (cofactor != NULL && !BN_is_zero(cofactor)) {
if (!BN_copy(group->cofactor, cofactor))
return 0;
} else
} else if (!ec_guess_cofactor(group)) {
BN_zero(group->cofactor);
return 0;
}
/*
* Some groups have an order with