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Should python-cybox try to validate passed input values? #216
Description
In this example the API tries to cast portObj/port_value as a number rather than leave it as a string.
input.xml
<?xml version="1.0" encoding="UTF-8" ?>
<stix:STIX_Package
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:stix="http://stix.mitre.org/stix-1"
xmlns:stixCommon="http://stix.mitre.org/common-1"
xmlns:cybox="http://cybox.mitre.org/cybox-2"
xmlns:PortObj="http://cybox.mitre.org/objects#PortObject-2"
xsi:schemaLocation="
http://stix.mitre.org/stix-1 http://stix.mitre.org/XMLSchema/core/1.1.1/stix_core.xsd
http://stix.mitre.org/common-1 http://stix.mitre.org/XMLSchema/common/1.1.1/stix_common.xsd
http://cybox.mitre.org/cybox-2 http://cybox.mitre.org/XMLSchema/core/2.1/cybox_core.xsd
http://cybox.mitre.org/objects#PortObject-2 http://cybox.mitre.org/XMLSchema/objects/Port/2.1/Port_Object.xsd
"
version="1.1.1"
xmlns:example_namespace="example_namespace/">
<stix:Observables cybox_major_version="2" cybox_minor_version="1" cybox_update_version="0">
<cybox:Observable id="example_namespace:Observable-e4a7f977-687b-4e0f-9e50-0e9dfa6e4d99">
<cybox:Title>PortObj Title</cybox:Title>
<cybox:Description>PortObj Description</cybox:Description>
<cybox:Object id="example_namespace:Object-893dcdb4-312a-4dd7-8e6d-40c991d51ab6">
<cybox:Properties xsi:type="PortObj:PortObjectType">
<PortObj:Port_Value>port value</PortObj:Port_Value>
<PortObj:Layer4_Protocol>DCCP</PortObj:Layer4_Protocol>
</cybox:Properties>
</cybox:Object>
</cybox:Observable>
</stix:Observables>
</stix:STIX_Package>script.py
#!/usr/bin/env python
# Copyright (c) 2014, The MITRE Corporation. All rights reserved.
# See LICENSE.txt for complete terms.
'''
Description: Round-trip example. This script takes a STIX instance document from XML to
a binding object, then to a api object and then to a dictionary. That dictionary is then
converted back into an api object, which is then used to generate an XML document.
'''
import io
from pprint import pprint
from stix.core import STIXPackage
from stix.indicator import Indicator
import stix.bindings.stix_core as stix_core_binding
def main():
fn = 'input.xml'
stix_package = STIXPackage.from_xml(fn)
stix_dict = stix_package.to_dict() # parse to dictionary
pprint(stix_dict)
stix_package_two = STIXPackage.from_dict(stix_dict) # create python-stix object from dictionary
xml = stix_package_two.to_xml() # generate xml from python-stix object
print(xml)
if __name__ == '__main__':
main()error
Traceback (most recent call last):
File "script.py", line 25, in <module>
main()
File "script.py", line 17, in main
stix_package = STIXPackage.from_xml(fn)
File "/usr/lib/python2.6/site-packages/stix/core/stix_package.py", line 431, in from_xml
return parser.parse_xml(xml_file)
File "/usr/lib/python2.6/site-packages/stix/utils/parser.py", line 185, in parse_xml
stix_package = STIXPackage().from_obj(stix_package_obj)
File "/usr/lib/python2.6/site-packages/stix/core/stix_package.py", line 395, in from_obj
return_obj.observables = Observables.from_obj(obj.Observables)
File "/usr/lib/python2.6/site-packages/cybox/core/observable.py", line 326, in from_obj
obs.add(Observable.from_obj(o))
File "/usr/lib/python2.6/site-packages/cybox/core/observable.py", line 212, in from_obj
obs.object_ = Object.from_obj(observable_obj.Object)
File "/usr/lib/python2.6/site-packages/cybox/core/object.py", line 130, in from_obj
obj.properties = ObjectProperties.from_obj(object_obj.Properties)
File "/usr/lib/python2.6/site-packages/cybox/common/object_properties.py", line 158, in from_obj
defobj = klass.from_obj(defobj_obj)
File "/usr/lib/python2.6/site-packages/cybox/common/object_properties.py", line 145, in from_obj
return super(ObjectProperties, cls()).from_obj(defobj_obj)
File "/usr/lib/python2.6/site-packages/cybox/__init__.py", line 194, in from_obj
val = field.type_.from_obj(val)
File "/usr/lib/python2.6/site-packages/cybox/common/properties.py", line 275, in from_obj
attr._populate_from_obj(attr_obj)
File "/usr/lib/python2.6/site-packages/cybox/common/properties.py", line 297, in _populate_from_obj
self.delimiter)
File "/usr/lib/python2.6/site-packages/cybox/common/properties.py", line 68, in value
self._value = self._parse_value(value_)
File "/usr/lib/python2.6/site-packages/cybox/common/properties.py", line 362, in _parse_value
return int(value, 0)
ValueError: invalid literal for int() with base 0: 'port value'
Activity
gtback commentedon Nov 7, 2014
Under what cases do you anticipate needing to use non-integer values for
Port_Value?The default datatype value is
integer. I forget whether we actually implemented logic that checks for non-default data types and parses the value differently.gtback commentedon Dec 1, 2014
I think it makes sense to try to do the
intconversion, but if it fails, store the value as a string rather than raising a crypticValueErrorto the user.