Authenticate file downloads - requires server updates to deploy

[peetucket]

Fixes #392

Verified on hydrus-stage

Deployment notes

• Coordinate deployment with Hannah - currently the week of Feb 3 looks good
• After deploy:
  • confirm that the previous insecure /opt/app/hydrus/hydrus/current/public/uploads symlink is gone.
  • confirm that the new /opt/app/hydrus/hydrus/current/uploads symlink exists and goes to /opt/app/hydrus/hydrus/shared/uploads, which goes to /data/hydrus-files
  • test by uploading a file to a new test object and confirm you can't download that file from hydrus in a private browser (not logged in)
  • publish the test object and verify it accessioned correctly with a PURL
  • test a download of a file from a previously created object
• After verified working, we should remove the now unused symlink that goes from /opt/app/hydrus/hydrus/shared/public/uploads --> /data/hydrus_files ... note that because we don't symlink in from the currently deployed public directory anymore, leaving this symlink is not a security risk, but it should be cleaned up anyway to avoid future confusion:
  • rm /opt/app/hydrus/hydrus/shared/public/uploads

Why the change?

Currently anyone can request download of any file that has been uploaded by other users (since they are all just dumped into the public/uploads folder), which is a potential security risk. This is an attempt to verify the person requesting to download the file (from within hydrus, not the stacks) is the one who owns it. To fix this, this PR:

• Creates a new controller to manage file downloads so we can authenticate before streaming file.
• Changes file upload location so files do not end up in public folder.
• Changes tmp folder location to regular rails tmp folder.
• Overrides default URLs to files generated by CarrierWave gem to our new route that confirms access restrictions.
• Moves configuration information on upload file location to the new settings file.

[coveralls]

Coverage decreased (-1.6%) to 91.896% when pulling cd5f736 on authenticate-file-downloads into 97ff319 on master.

[ndushay]

can this be closed and the branch removed? it's over 2 years old.

[peetucket]

I'll double-check with @hannahfrost about this and #149 ... if we don't feel concerned about the issues there were attempting to address, we can close.

[hannahfrost]

After some discussion with @peetucket, I propose we pick this work back up rather than dispose of it. There is good reason to make sure access to these files on the Hydrus mount is authenticated.