Bug in Indicator class setter for observables property

[kralca]

Offending code (starting line 283):

        elif utils.is_sequence(value):
            if len(value) == 1:
                self.observable = value
                return

Third line should be as follows, right?

                self.observable = value[0]

[gtback]

Thanks, @kralca. I haven't had the chance to test this out, but what exactly is the bug? If you can share some example code that either causes an error or leads to invalid output, that will make it much quicker for us to incorporate your fix.

[kralca]

Hi @gtback. Sorry for the lack of detail. I appreciate you looking into this.

The bug is that the observables.setter method doesn't correctly handle a list of length one. Here's proof of concept code to reproduce the error:

from stix.indicator import Indicator
from cybox.core import Observable

i = Indicator()
o1 = Observable()
o2 = Observable()

i.observables = o1  # works
i.observables = [o1, o2]  # works
i.observables = [o1]  # fails

The last line above throws an exception (/tmp/poc.py contains the code above):

Traceback (most recent call last):
  File "/tmp/poc.py", line 10, in <module>
    i.observables = [o1] # fails
  File "build/bdist.macosx-10.12-intel/egg/stix/indicator/indicator.py", line 285, in observables
  File "/Users/bruce/venvs/cti-toolkit-v1/lib/python2.7/site-packages/mixbox/fields.py", line 210, in __set__
    value = self._clean(value)
  File "/Users/bruce/venvs/cti-toolkit-v1/lib/python2.7/site-packages/mixbox/fields.py", line 186, in _clean
    return self.type_(value)
  File "/Users/bruce/venvs/cti-toolkit-v1/lib/python2.7/site-packages/cybox-2.1.0.13-py2.7.egg/cybox/core/observable.py", line 120, in __init__
    raise TypeError(msg)
TypeError: item must be an Object, Event, ObservableComposition, or subclass of ObjectProperties. Received an <type 'list'>

The fix I suggested in the original post seems to address the problem.

[gtback]

Is this related to #23 at all?

[emmanvg]

I don't think so. The problem he presented happens when you try to set the observables property. The Indicator class does not have a positional argument for Observables in init().