The lack of Box support parity with Linux and other platforms has been an issue raised by several people. The University has requested that Box develop an official solution due to the concentration of Linux usage on-campus. Nothing has been confirmed but Box has said they are working on a solution. No timetable has been offered.
For now, the best option is FTPS which is described in this Box community post.
To use WebDav, visit this community page.
Other CMU community members have tested auto-mounting WebDav folders on Linux with some success. Please visit this page for details.
Box also has a full-featured API that developers can use to create their own toolkit for usage on Linux.