1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
# Copyright 2016, Tresys Technology, LLC
#
# This file is part of SETools.
#
# SETools is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation, either version 2.1 of
# the License, or (at your option) any later version.
#
# SETools is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with SETools. If not, see
# <http://www.gnu.org/licenses/>.
#
from collections import defaultdict, namedtuple
from .descriptors import DiffResultDescriptor
from .difference import Difference, SymbolWrapper, Wrapper
modified_rbacrule_record = namedtuple("modified_rbacrule", ["rule",
"added_default",
"removed_default"])
class RBACRulesDifference(Difference):
"""Determine the difference in RBAC rules between two policies."""
added_role_allows = DiffResultDescriptor("diff_role_allows")
removed_role_allows = DiffResultDescriptor("diff_role_allows")
# role allows cannot be modified, only added/removed
added_role_transitions = DiffResultDescriptor("diff_role_transitions")
removed_role_transitions = DiffResultDescriptor("diff_role_transitions")
modified_role_transitions = DiffResultDescriptor("diff_role_transitions")
# Lists of rules for each policy
_left_rbac_rules = defaultdict(list)
_right_rbac_rules = defaultdict(list)
def diff_role_allows(self):
"""Generate the difference in role allow rules between the policies."""
self.log.info(
"Generating role allow differences from {0.left_policy} to {0.right_policy}".
format(self))
if not self._left_rbac_rules or not self._right_rbac_rules:
self._create_rbac_rule_lists()
self.added_role_allows, self.removed_role_allows, _ = self._set_diff(
self._expand_generator(self._left_rbac_rules["allow"], RoleAllowWrapper),
self._expand_generator(self._right_rbac_rules["allow"], RoleAllowWrapper))
def diff_role_transitions(self):
"""Generate the difference in role_transition rules between the policies."""
self.log.info(
"Generating role_transition differences from {0.left_policy} to {0.right_policy}".
format(self))
if not self._left_rbac_rules or not self._right_rbac_rules:
self._create_rbac_rule_lists()
added, removed, matched = self._set_diff(
self._expand_generator(self._left_rbac_rules["role_transition"], RoleTransitionWrapper),
self._expand_generator(self._right_rbac_rules["role_transition"],
RoleTransitionWrapper))
modified = []
for left_rule, right_rule in matched:
# Criteria for modified rules
# 1. change to default role
if SymbolWrapper(left_rule.default) != SymbolWrapper(right_rule.default):
modified.append(modified_rbacrule_record(left_rule,
right_rule.default,
left_rule.default))
self.added_role_transitions = added
self.removed_role_transitions = removed
self.modified_role_transitions = modified
#
# Internal functions
#
def _create_rbac_rule_lists(self):
"""Create rule lists for both policies."""
# do not expand yet, to keep memory
# use down as long as possible
self.log.debug("Building RBAC rule lists from {0.left_policy}".format(self))
for rule in self.left_policy.rbacrules():
self._left_rbac_rules[rule.ruletype].append(rule)
self.log.debug("Building RBAC rule lists from {0.right_policy}".format(self))
for rule in self.right_policy.rbacrules():
self._right_rbac_rules[rule.ruletype].append(rule)
self.log.debug("Completed building RBAC rule lists.")
def _reset_diff(self):
"""Reset diff results on policy changes."""
self.log.debug("Resetting RBAC rule differences")
self.added_role_allows = None
self.removed_role_allows = None
self.modified_role_allows = None
self.added_role_transitions = None
self.removed_role_transitions = None
self.modified_role_transitions = None
# Sets of rules for each policy
self._left_rbac_rules.clear()
self._right_rbac_rules.clear()
class RoleAllowWrapper(Wrapper):
"""Wrap role allow rules to allow set operations."""
def __init__(self, rule):
self.origin = rule
self.ruletype = rule.ruletype
self.source = SymbolWrapper(rule.source)
self.target = SymbolWrapper(rule.target)
self.key = hash(rule)
def __hash__(self):
return self.key
def __lt__(self, other):
return self.key < other.key
def __eq__(self, other):
# because RBACRuleDifference groups rules by ruletype,
# the ruletype always matches.
return self.source == other.source and self.target == other.target
class RoleTransitionWrapper(Wrapper):
"""Wrap role_transition rules to allow set operations."""
def __init__(self, rule):
self.origin = rule
self.ruletype = rule.ruletype
self.source = SymbolWrapper(rule.source)
self.target = SymbolWrapper(rule.target)
self.tclass = SymbolWrapper(rule.tclass)
self.key = hash(rule)
def __hash__(self):
return self.key
def __lt__(self, other):
return self.key < other.key
def __eq__(self, other):
# because RBACRuleDifference groups rules by ruletype,
# the ruletype always matches.
return self.source == other.source and \
self.target == other.target and \
self.tclass == other.tclass
|
