1 # Copyright 2015, Tresys Technology, LLC 2 # 3 # This file is part of SETools. 4 # 5 # SETools is free software: you can redistribute it and/or modify 6 # it under the terms of the GNU Lesser General Public License as 7 # published by the Free Software Foundation, either version 2.1 of 8 # the License, or (at your option) any later version. 9 # 10 # SETools is distributed in the hope that it will be useful, 11 # but WITHOUT ANY WARRANTY; without even the implied warranty of 12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 # GNU Lesser General Public License for more details. 14 # 15 # You should have received a copy of the GNU Lesser General Public 16 # License along with SETools. If not, see 17 # <http://www.gnu.org/licenses/>. 18 # 19 from collections import namedtuple 20 21 from .descriptors import DiffResultDescriptor 22 from .difference import Difference, SymbolWrapper 23 24 25 modified_commons_record = namedtuple("modified_common", ["added_perms", 26 "removed_perms", 27 "matched_perms"]) 28 29 30 class CommonDifference(Difference): 31 32 """ 33 Determine the difference in common permission sets 34 between two policies. 35 """ 36 37 added_commons = DiffResultDescriptor("diff_commons") 38 removed_commons = DiffResultDescriptor("diff_commons") 39 modified_commons = DiffResultDescriptor("diff_commons") 40 41 def diff_commons(self): 42 """Generate the difference in commons between the policies.""" 43 44 self.log.info( 45 "Generating common differences from {0.left_policy} to {0.right_policy}".format(self)) 46 47 self.added_commons, self.removed_commons, matched_commons = self._set_diff( 48 (SymbolWrapper(c) for c in self.left_policy.commons()), 49 (SymbolWrapper(c) for c in self.right_policy.commons())) 50 51 self.modified_commons = dict() 52 53 for left_common, right_common in matched_commons: 54 # Criteria for modified commons 55 # 1. change to permissions 56 added_perms, removed_perms, matched_perms = self._set_diff(left_common.perms, 57 right_common.perms) 58 59 if added_perms or removed_perms: 60 self.modified_commons[left_common] = modified_commons_record(added_perms, 61 removed_perms, 62 matched_perms) 63 64 # 65 # Internal functions 66 # 67 def _reset_diff(self): 68 """Reset diff results on policy changes.""" 69 self.log.debug("Resetting common differences") 70 self.added_commons = None 71 self.removed_commons = None 72 self.modified_commons = None 73
