Check imports created from importlib

[Rajath Agasthya]

Bandit only checks for imports if 'import' keyword or '__import__()' function is used. It should also check for imports using 'importlib.import_module()' and 'importlib.__import__()' functions.

Example:

$ cat import.py

import importlib
s = importlib.import_module('subprocess')
t = importlib.__import__('subprocess')

$ bandit import.py

[main] INFO profile include tests: None
[main] INFO profile exclude tests: None
[main] INFO cli include tests: None
[main] INFO cli exclude tests: None
[main] INFO running on Python 2.7.13
[node_visitor] INFO Unable to find qualified name for module: import.py
Run started:2017-09-20 18:31:32.185419

Test results:
 No issues identified.

Code scanned:
 Total lines of code: 3
 Total lines skipped (#nosec): 0

Run metrics:
 Total issues (by severity):
  Undefined: 0
  Low: 0
  Medium: 0
  High: 0
 Total issues (by confidence):
  Undefined: 0
  Low: 0
  Medium: 0
  High: 0
Files skipped (0):

I'm happy to help fix this if this is confirmed.

[Colin Best (cbest47)]

Official Python documentation suggests the use of importlib.import_module(), and not importlib._import_() for programmatic imports. The bug fix will only additionally support the importlib.import_module() function.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/530335
Committed: https://git.openstack.org/cgit/openstack/bandit/commit/?id=bb1bf81856c1467f85ee138b727568d192bd179a
Submitter: Zuul
Branch: master

commit bb1bf81856c1467f85ee138b727568d192bd179a
Author: Tin Lam <email address hidden>
Date: Thu Dec 28 04:09:01 2017 -0600

    Add module loaded through importlib

    Bandit only checks if imports is done using keyword ``import`` or
    ``__import__()`` and does not check for blacklisted module loaded
    via importlib. This patch set adds additional check for blacklisted
    modules loaded via importlib.

    Change-Id: I97ed93af1066fa39dfc5be0868ab814c8eadd147
    Closes-Bug: #1718516
    Signed-off-by: Tin Lam <email address hidden>