in functions/source/KeyGen/asn1crypto/core.py [0:0]
def _parse_children(self, recurse=False):
"""
Parses the contents and generates Asn1Value objects based on the
definitions from _fields.
:param recurse:
If child objects that are Sequence or SequenceOf objects should
be recursively parsed
:raises:
ValueError - when an error occurs parsing child objects
"""
cls = self.__class__
if self._contents is None:
if self._fields:
self.children = [VOID] * len(self._fields)
for index, (_, _, params) in enumerate(self._fields):
if 'default' in params:
if cls._precomputed_specs[index]:
field_name, field_spec, value_spec, field_params, _ = cls._precomputed_specs[index]
else:
field_name, field_spec, value_spec, field_params, _ = self._determine_spec(index)
self.children[index] = self._make_value(field_name, field_spec, value_spec, field_params, None)
return
try:
self.children = []
contents_length = len(self._contents)
child_pointer = 0
field = 0
field_len = len(self._fields)
parts = None
again = child_pointer < contents_length
while again:
if parts is None:
parts, child_pointer = _parse(self._contents, contents_length, pointer=child_pointer)
again = child_pointer < contents_length
if field < field_len:
_, field_spec, value_spec, field_params, spec_override = (
cls._precomputed_specs[field] or self._determine_spec(field))
# If the next value is optional or default, allow it to be absent
if field_params and ('optional' in field_params or 'default' in field_params):
if self._field_ids[field] != (parts[0], parts[2]) and field_spec != Any:
# See if the value is a valid choice before assuming
# that we have a missing optional or default value
choice_match = False
if issubclass(field_spec, Choice):
try:
tester = field_spec(**field_params)
tester.validate(parts[0], parts[2], parts[4])
choice_match = True
except (ValueError):
pass
if not choice_match:
if 'optional' in field_params:
self.children.append(VOID)
else:
self.children.append(field_spec(**field_params))
field += 1
again = True
continue
if field_spec is None or (spec_override and issubclass(field_spec, Any)):
field_spec = value_spec
spec_override = None
if spec_override:
child = parts + (field_spec, field_params, value_spec)
else:
child = parts + (field_spec, field_params)
# Handle situations where an optional or defaulted field definition is incorrect
elif field_len > 0 and field + 1 <= field_len:
missed_fields = []
prev_field = field - 1
while prev_field >= 0:
prev_field_info = self._fields[prev_field]
if len(prev_field_info) < 3:
break
if 'optional' in prev_field_info[2] or 'default' in prev_field_info[2]:
missed_fields.append(prev_field_info[0])
prev_field -= 1
plural = 's' if len(missed_fields) > 1 else ''
missed_field_names = ', '.join(missed_fields)
raise ValueError(unwrap(
'''
Data for field %s (%s class, %s method, tag %s) does
not match the field definition%s of %s
''',
field + 1,
CLASS_NUM_TO_NAME_MAP.get(parts[0]),
METHOD_NUM_TO_NAME_MAP.get(parts[1]),
parts[2],
plural,
missed_field_names
))
else:
child = parts
if recurse:
child = _build(*child)
if isinstance(child, (Sequence, SequenceOf)):
child._parse_children(recurse=True)
self.children.append(child)
field += 1
parts = None
index = len(self.children)
while index < field_len:
name, field_spec, field_params = self._fields[index]
if 'default' in field_params:
self.children.append(field_spec(**field_params))
elif 'optional' in field_params:
self.children.append(VOID)
else:
raise ValueError(unwrap(
'''
Field "%s" is missing from structure
''',
name
))
index += 1
except (ValueError, TypeError) as e:
args = e.args[1:]
e.args = (e.args[0] + '\n while parsing %s' % type_name(self),) + args
raise e