keystone/keystone/contrib/federation/utils.py

388 lines
12 KiB
Python

# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Utilities for Federation Extension."""
import re
import jsonschema
import six
from keystone import exception
from keystone.openstack.common.gettextutils import _
from keystone.openstack.common import log
LOG = log.getLogger(__name__)
MAPPING_SCHEMA = {
"type": "object",
"required": ['rules'],
"properties": {
"rules": {
"minItems": 1,
"type": "array",
"items": {
"type": "object",
"required": ['local', 'remote'],
"additionalProperties": False,
"properties": {
"local": {
"type": "array"
},
"remote": {
"minItems": 1,
"type": "array",
"items": {
"type": "object",
"oneOf": [
{"$ref": "#/definitions/empty"},
{"$ref": "#/definitions/any_one_of"},
{"$ref": "#/definitions/not_any_of"}
],
}
}
}
}
}
},
"definitions": {
"empty": {
"type": "object",
"required": ['type'],
"properties": {
"type": {
"type": "string"
},
},
"additionalProperties": False,
},
"any_one_of": {
"type": "object",
"additionalProperties": False,
"required": ['type', 'any_one_of'],
"properties": {
"type": {
"type": "string"
},
"any_one_of": {
"type": "array"
},
"regex": {
"type": "boolean"
}
}
},
"not_any_of": {
"type": "object",
"additionalProperties": False,
"required": ['type', 'not_any_of'],
"properties": {
"type": {
"type": "string"
},
"not_any_of": {
"type": "array"
},
"regex": {
"type": "boolean"
}
}
}
}
}
def validate_mapping_structure(ref):
v = jsonschema.Draft4Validator(MAPPING_SCHEMA)
messages = ''
for error in sorted(v.iter_errors(ref), key=str):
messages = messages + error.message + "\n"
if messages:
raise exception.ValidationError(messages)
class RuleProcessor(object):
"""A class to process assertions and mapping rules."""
class _EvalType(object):
"""Mapping rule evaluation types."""
ANY_ONE_OF = 'any_one_of'
NOT_ANY_OF = 'not_any_of'
def __init__(self, rules):
"""Initialize RuleProcessor.
Example rules can be found at:
:class:`keystone.tests.mapping_fixtures`
:param rules: rules from a mapping
:type rules: dict
"""
self.rules = rules
def process(self, assertion_data):
"""Transform assertion to a dictionary of user name and group ids
based on mapping rules.
This function will iterate through the mapping rules to find
assertions that are valid.
:param assertion_data: an assertion containing values from an IdP
:type assertion_data: dict
Example assertion_data::
{
'Email': 'testacct@example.com',
'UserName': 'testacct',
'FirstName': 'Test',
'LastName': 'Account',
'orgPersonType': 'Tester'
}
:returns: dictionary with user and group_ids
The expected return structure is::
{
'name': 'foobar',
'group_ids': ['abc123', 'def456']
}
"""
# Assertions will come in as string key-value pairs, and will use a
# semi-colon to indicate multiple values, i.e. groups.
# This will create a new dictionary where the values are arrays, and
# any multiple values are stored in the arrays.
assertion = dict((n, v.split(';')) for n, v in assertion_data.items()
if isinstance(v, six.string_types))
identity_values = []
for rule in self.rules:
direct_maps = self._verify_all_requirements(rule['remote'],
assertion)
# If the compare comes back as None, then the rule did not apply
# to the assertion data, go on to the next rule
if direct_maps is None:
continue
# If there are no direct mappings, then add the local mapping
# directly to the array of saved values. However, if there is
# a direct mapping, then perform variable replacement.
if not direct_maps:
identity_values += rule['local']
else:
for local in rule['local']:
new_local = self._update_local_mapping(local, direct_maps)
identity_values.append(new_local)
mapped_properties = self._transform(identity_values)
if mapped_properties.get('name') is None:
raise exception.Unauthorized(_("Could not map user"))
return mapped_properties
def _transform(self, identity_values):
"""Transform local mappings, to an easier to understand format.
Transform the incoming array to generate the return value for
the process function. Generating content for Keystone tokens will
be easier if some pre-processing is done at this level.
:param identity_values: local mapping from valid evaluations
:type identity_values: array of dict
Example identity_values::
[{'group': {'id': '0cd5e9'}, 'user': {'email': 'bob@example.com'}}]
:returns: dictionary with user name and group_ids.
"""
# initialize the group_ids as a set to eliminate duplicates
user_name = None
group_ids = set()
for identity_value in identity_values:
if 'user' in identity_value:
# if a mapping outputs more than one user name, log it
if user_name is not None:
LOG.warning(_('Ignoring user name %s'),
identity_value['user']['name'])
else:
user_name = identity_value['user']['name']
if 'group' in identity_value:
group_ids.add(identity_value['group']['id'])
return {'name': user_name, 'group_ids': list(group_ids)}
def _update_local_mapping(self, local, direct_maps):
"""Replace any {0}, {1} ... values with data from the assertion.
:param local: local mapping reference that needs to be updated
:type local: dict
:param direct_maps: list of identity values, used to update local
:type direct_maps: list
Example local::
{'user': {'name': '{0} {1}', 'email': '{2}'}}
Example direct_maps::
['Bob', 'Thompson', 'bob@example.com']
:returns: new local mapping reference with replaced values.
The expected return structure is::
{'user': {'name': 'Bob Thompson', 'email': 'bob@example.org'}}
"""
new = {}
for k, v in six.iteritems(local):
if isinstance(v, dict):
new_value = self._update_local_mapping(v, direct_maps)
else:
new_value = v.format(*direct_maps)
new[k] = new_value
return new
def _verify_all_requirements(self, requirements, assertion):
"""Go through the remote requirements of a rule, and compare against
the assertion.
If a value of ``None`` is returned, the rule with this assertion
doesn't apply.
If an array of zero length is returned, then there are no direct
mappings to be performed, but the rule is valid.
Otherwise, then it will return the values, in order, to be directly
mapped, again, the rule is valid.
:param requirements: list of remote requirements from rules
:type requirements: list
Example requirements::
[
{
"type": "UserName"
},
{
"type": "orgPersonType",
"any_one_of": [
"Customer"
]
}
]
:param assertion: dict of attributes from an IdP
:type assertion: dict
Example assertion::
{
'UserName': ['testacct'],
'LastName': ['Account'],
'orgPersonType': ['Tester'],
'Email': ['testacct@example.com'],
'FirstName': ['Test']
}
:returns: list of direct mappings or None.
"""
direct_maps = []
for requirement in requirements:
requirement_type = requirement['type']
regex = requirement.get('regex', False)
any_one_values = requirement.get(self._EvalType.ANY_ONE_OF)
if any_one_values is not None:
if self._evaluate_requirement(any_one_values,
requirement_type,
self._EvalType.ANY_ONE_OF,
regex,
assertion):
continue
else:
return None
not_any_values = requirement.get(self._EvalType.NOT_ANY_OF)
if not_any_values is not None:
if self._evaluate_requirement(not_any_values,
requirement_type,
self._EvalType.NOT_ANY_OF,
regex,
assertion):
continue
else:
return None
# If 'any_one_of' or 'not_any_of' are not found, then values are
# within 'type'. Attempt to find that 'type' within the assertion.
direct_map_values = assertion.get(requirement_type)
if direct_map_values:
direct_maps += direct_map_values
return direct_maps
def _evaluate_requirement(self, values, requirement_type,
eval_type, regex, assertion):
"""Evaluate the incoming requirement and assertion.
If the requirement type does not exist in the assertion data, then
return False. If regex is specified, then compare the values and
assertion values. Otherwise, grab the intersection of the values
and use that to compare against the evaluation type.
:param values: list of allowed values, defined in the requirement
:type values: list
:param requirement_type: key to look for in the assertion
:type requirement_type: string
:param eval_type: determine how to evaluate requirements
:type eval_type: string
:param regex: perform evaluation with regex
:type regex: boolean
:param assertion: dict of attributes from the IdP
:type assertion: dict
:returns: boolean, whether requirement is valid or not.
"""
assertion_values = assertion.get(requirement_type)
if not assertion_values:
return False
if regex:
return re.search(values[0], assertion_values[0])
any_match = bool(set(values).intersection(set(assertion_values)))
if any_match and eval_type == self._EvalType.ANY_ONE_OF:
return True
if not any_match and eval_type == self._EvalType.NOT_ANY_OF:
return True
return False