util.py

[akonst]

In path_in_confined_paths(), what is the reason for the following?

# Get the directory name (i.e., strip off the file_path+extension)
directory_name = os.path.dirname(test_path)

if directory_name == os.path.dirname(pattern):
  return True

I've mentioned this issue before. This is where a relative path
'test_path' is checked against a 'confined_paths'. The paths are
stripped, and only the directories are compared. What is the reason
behind this?
So, if the 'test_path' is 'a/c.txt' and a confined path is
'/a/b/c.txt' (given c.txt's are the same) it's a no go. They'll
match only when test_path = 'a/b/c.txt' and a confined path =
'/a/b/c.txt'.

I, probably, should have said: a path in the list of the confined
paths instead of a "confined path", to be more clear.

[vladimir-v-diaz]

Note: This function has been renamed and affected modules modified (after reviewing util.py and test_util.py): akonst/tuf@d2a799f

file_in_confined_directories() determines if 'filepath' (first argument) is in at least one of the directories of 'confined_directories'. We are checking path strings, not actual files on the local file system.

tuf.util.file_in_confined_directories('a/b/target.jpg', ['a/'])
False
tuf.util.file_in_confined_directories('a/b/target.jpg', ['a/b/'])
True

We are not checking if two files are the same, only that the file's parent directory is in 'confined_paths'.
This function is provided to allow a soft of mixed selection of targets a client may download. The updater methods provided to the client include updater.all_targets(), updater.targets_of_role(), and updater.target(). If the client adds restricted directories to a mirror's 'confined_target_dirs' field, he could then do an updater.all_targets()
and only download targets from those listed in 'confined_target_dirs'. This might be a useful option for client code written by software updaters.

Let me know if my explanation is clear and the modified function correct. I updated some the test cases for this function.

[akonst]

Okay, looks good.