encryption_get.c

/**
 * Callback function that shows the current encryption status (encrypted or
 * unencrypted).
 *
 * Example output:
 * {"encryption-status":"encrypted"}
 *
 * @param[in]   request   incoming HTTP request
 * @param[out]  response  HTTP response to the request
 * @param[in]   user_data extra data to pass between main thread and callbacks
 * @return                internal status code
 */
int callback_encryption_get(const struct _u_request * request,
    struct _u_response * response, void * user_data)
{
    bool encrypted;
    bool * can_encrypt_nullable = NULL;
    bool can_encrypt = true;
    json_t * messages = json_array();

    if (path_exists(config.data_partition_device) &&
        is_encrypted_device(config.data_partition_device))
    {
        encrypted = true;
    }
    else
    {
        encrypted = false;
        can_encrypt_nullable = &can_encrypt;

        // Mount the filesystem on the unencrypted device.
        int r = temporary_mount(config.root_device, UNENCRYPTED_TMP_MOUNTPOINT,
            FILESYSTEM_TYPE);
        if (r != 0)
        {
            y_log_message(Y_LOG_LEVEL_ERROR, "mounting root device failed: return code %d", r);
            return send_simple_response(response, 500, "error",
               "mounting root device failed");
        }
        bool fits = filesystem_fits_in_memory(UNENCRYPTED_TMP_MOUNTPOINT,
            MEMORY_USAGE);
        umount(UNENCRYPTED_TMP_MOUNTPOINT);
        if (! fits)
        {
            can_encrypt = false;
            json_array_append_new(messages, json_string(
                "existing files do not fit in memory"));
        }
    }

    json_t * json_body = NULL;
    json_body = json_object();

    json_object_set_new(json_body, "encrypted",
        encrypted ? json_true() : json_false());

    json_object_set_new(json_body, "can-encrypt",
        can_encrypt_nullable == NULL ? json_null() :
            (can_encrypt ? json_true() : json_false()));
    json_object_set_new(json_body, "messages", messages);

    ulfius_set_json_body_response(response, 200, json_body);
    json_decref(json_body);
    return U_CALLBACK_CONTINUE;
}