fixed public range check in ec_GF2m_simple_oct2point

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/8607)

(cherry picked from commit cad8347be23c5e0c0d9eea02d090d42daf2dd7a9)
This commit is contained in:
Shane Lontis 2019-03-27 17:38:28 +10:00 committed by Bernd Edlinger
parent c3e7beab2a
commit d3299a33e5

View File

@ -299,7 +299,7 @@ int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
BN_CTX *ctx)
{
point_conversion_form_t form;
int y_bit;
int y_bit, m;
BN_CTX *new_ctx = NULL;
BIGNUM *x, *y, *yxi;
size_t field_len, enc_len;
@ -332,7 +332,8 @@ int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
return EC_POINT_set_to_infinity(group, point);
}
field_len = (EC_GROUP_get_degree(group) + 7) / 8;
m = EC_GROUP_get_degree(group);
field_len = (m + 7) / 8;
enc_len =
(form ==
POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2 * field_len;
@ -357,7 +358,7 @@ int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
if (!BN_bin2bn(buf + 1, field_len, x))
goto err;
if (BN_ucmp(x, &group->field) >= 0) {
if (BN_num_bits(x) > m) {
ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
goto err;
}
@ -369,7 +370,7 @@ int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
} else {
if (!BN_bin2bn(buf + 1 + field_len, field_len, y))
goto err;
if (BN_ucmp(y, &group->field) >= 0) {
if (BN_num_bits(y) > m) {
ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
goto err;
}