Does `ecc_set_curve` need a counterpart `ecc_free`?

[zwhfly]

The documentation of ecc_set_curve and ecc_free have no mention of each other now.
But the following code leaks memory:

    ltc_ecc_curve const * cu = 0;
    if (CRYPT_OK != ecc_find_curve("P-256", &cu))
        return;
    for (unsigned i = 0; i < 100000000; ++i)
    {
        ecc_key key;
        if (CRYPT_OK != ecc_set_curve(cu, &key))
            return;
    }

Should I call ecc_free after a successful ecc_set_curve followed by a failed ecc_set_key .etc?

[sjaeckel]

Should I call ecc_free after a successful ecc_set_curve

Yes.

And yes, this could also be documented in the code. The developer manual crypt.pdf mentions it though.

[zwhfly]

The developer manual crypt.pdf mentions it though.

• The ecc_set_curve paragraph does not mention the need to call ecc_free.

• And the ecc_free paragraph says:

  To free the memory allocated by one of ecc_generate_key(), ecc_make_key(), ecc_make_key_ex(), ecc_import(),
  ecc_import_openssl(), ecc_import_x509(), ecc_import_pkcs8(), ecc_ansi_x963_import(),
  ecc_ansi_x963_import_ex(), or ecc_set_key() the following function is provided:

  • void ecc_free(ecc_key *key);

  There is also no mention of ecc_set_curve in it.

Do you mean this line:

The function ecc_generate_key does the actual key generation. The function will free any internally allocated resources if there is an error.

1. It's not clear what does "internally allocated" mean. It could mean that resources allocated in the internal process of ecc_generate_key are freed, but what's originally in the key is intact.
2. There is no similar statement for other functions (e.g. ecc_set_key).