Commit a4d5269e authored by Emilia Kasper's avatar Emilia Kasper
Browse files

NISTZ256: don't swallow malloc errors 



Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
parent 4446044a

crypto/ec/ecp_nistz256.c

+12 −12
Original line number Diff line number Diff line
@@ -553,14 +553,14 @@ static int ecp_nistz256_bignum_to_field_elem(BN_ULONG out[P256_LIMBS], 
}



/* r = sum(scalar[i]*point[i]) */

static void ecp_nistz256_windowed_mul(const EC_GROUP *group,

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;
@@ -719,6 +719,7 @@ static void ecp_nistz256_windowed_mul(const EC_GROUP *group, 
        ecp_nistz256_point_add(r, r, &temp[0]);

    }



    ret = 1;

 err:

    if (table_storage)

        OPENSSL_free(table_storage);
@@ -726,6 +727,7 @@ static void ecp_nistz256_windowed_mul(const EC_GROUP *group, 
        OPENSSL_free(p_str);

    if (scalars)

        OPENSSL_free(scalars);

    return ret;

}



/* Coordinates of G, for which we have precomputed tables */
@@ -1134,6 +1136,8 @@ static int ecp_nistz256_points_mul(const EC_GROUP *group, 
    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;
@@ -1298,9 +1302,6 @@ static int ecp_nistz256_points_mul(const EC_GROUP *group, 
         * 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);
@@ -1309,7 +1310,6 @@ static int ecp_nistz256_points_mul(const EC_GROUP *group, 


        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);

            goto err;

        }
@@ -1329,17 +1329,13 @@ static int ecp_nistz256_points_mul(const EC_GROUP *group, 
        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) ||
@@ -1354,6 +1350,10 @@ 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;

}