If you're trying to skip ahead and view your homework assignments beforehand, I don't think there's any way to do this short of accessing the server via SSH, SFTP, etc. and looking in that directory. Other ways to circumvent this sort of "security" is by looking for information leakage:
- Search engines are quite good at seeking out hidden directories by virtue of their web crawlers.
- Server logs are sometimes accidentally left publicly accessible, which can also give away such information.
- Error messages are another common source of information leakage, which can tell you about directory structure.
Otherwise, you'll have to resort to more extreme measures:
Brute force search
Brute-forcing the directory names using a script to flood the server with requests until you get a
200 OK reply.
However, short of finding out what kind of hash function is being used or a vulnerability in the PRNG used, you'll have about 36^11 or 1.31621704E17 combinations to try.
And, given that a typical web server can only handle anywhere from 10-20 requests per second to 70K requests per second on the very high end, you'd be looking at 59,584.7029 years to exhaust the search space—that's per directory.
Now, maybe they're using multiple load balanced servers, but even then your homework probably isn't hosted on the fastest servers in the world. And hammering the web server at those speeds will probably raise a few red flags both at your ISP and at the web host, even if you're using many random proxies to send the requests through.
Hack the web server
You could use a vulnerability scanner and/or fuzzer to find an exploitable bug in the system and gain access to data that way. Who knows, maybe they're using an old unpatched version of IIS or Apache, or they're running web software that has a known SQL injection or file upload vulnerability, or their web server is misconfigured and you can use WebDAV to get a directory listing. If you can access the user account under which the files are hosted or run a backdoor script under that user, then you'll be able to see the full directory contents.
I suppose it all just depends on how badly you want to get an early look at your homework assignments. But I'm guessing it's probably less effort to sneak into your professor's office and just look up the assignments on his computer.
And there's always looking at last year's assignments for the same course, which are bound to be pretty close to what you'll have this year.