Commit 9ed55313 authored by Emilia Kasper's avatar Emilia Kasper
Browse files

Fix error checking and memory leaks in NISTZ256 precomputation. 



Thanks to Brian Smith for reporting these issues.

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
(cherry picked from commit 53dd4ddf)
parent 7238a82c

crypto/ec/ecp_nistz256.c

+10 −3
Original line number Diff line number Diff line
@@ -743,6 +743,7 @@ static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx) 
    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;
@@ -772,7 +773,7 @@ static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx) 
        return 0;



    if (ctx == NULL) {

        ctx = BN_CTX_new();

        ctx = new_ctx = BN_CTX_new();

        if (ctx == NULL)

            goto err;

    }
@@ -803,15 +804,19 @@ static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx) 


    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++) {

            /*

             * It would be faster to use
@@ -850,6 +855,8 @@ static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx) 
 err:

    if (ctx != NULL)

        BN_CTX_end(ctx);

    BN_CTX_free(new_ctx);



    if (pre_comp)

        ecp_nistz256_pre_comp_free(pre_comp);

    if (precomp_storage)