Method getCurrentKeyAndNonce

src/Compression/CompressionCodecEncrypted.cpp:432–456

}

void CompressionCodecEncrypted::Configuration::getCurrentKeyAndNonce(EncryptionMethod method, UInt64 & current_key_id, String &current_key, String & nonce) const
{
    /// It parameters were not set, throw exception
    if (!params.get())
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "Empty params in CompressionCodecEncrypted configuration");

    /// Save parameters in variable, because they can always change.
    /// As this function not atomic, we should be certain that we get information from one particular version for correct work.
    const auto current_params = params.get();
    current_key_id = current_params->current_key_id[method];

    /// As parameters can be created empty, we need to check that this key is available.
    if (current_params->keys_storage[method].contains(current_key_id))
        current_key = current_params->keys_storage[method].at(current_key_id);
    else
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "There is no current_key {} in config. Please, put it in config and reload.", current_key_id);

    /// If there is no nonce in config, we need to generate particular one,
    /// because all encryptions should have nonce and random nonce generation will lead to cases
    /// when nonce after config reload (nonce is not defined in config) will differ from previously generated one.
    /// This will lead to data loss.
    nonce = current_params->nonce[method];
    if (nonce.empty())
        nonce = empty_nonce;
}

String CompressionCodecEncrypted::Configuration::getKey(EncryptionMethod method, const UInt64 & key_id) const
{