python/samba/gpclass.py

   1 # Reads important GPO parameters and updates Samba
   2 # Copyright (C) Luke Morrison <luc785@.hotmail.com> 2013
   3 #
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 import sys
  19 import os
  20 import tdb
  21 sys.path.insert(0, "bin/python")
  22 from samba import NTSTATUSError
  23 from ConfigParser import ConfigParser
  24 from StringIO import StringIO
  25 from abc import ABCMeta, abstractmethod
  26 import xml.etree.ElementTree as etree
  27 import re
  28
  29 try:
  30     from enum import Enum
  31     GPOSTATE = Enum('GPOSTATE', 'APPLY ENFORCE UNAPPLY')
  32 except ImportError:
  33     class GPOSTATE:
  34         APPLY = 1
  35         ENFORCE = 2
  36         UNAPPLY = 3
  37
  38 class gp_log:
  39     ''' Log settings overwritten by gpo apply
  40     The gp_log is an xml file that stores a history of gpo changes (and the
  41     original setting value).
  42
  43     The log is organized like so:
  44
  45 <gp>
  46     <user name="KDC-1$">
  47         <applylog>
  48             <guid count="0" value="{31B2F340-016D-11D2-945F-00C04FB984F9}" />
  49         </applylog>
  50         <guid value="{31B2F340-016D-11D2-945F-00C04FB984F9}">
  51             <gp_ext name="System Access">
  52                 <attribute name="minPwdAge">-864000000000</attribute>
  53                 <attribute name="maxPwdAge">-36288000000000</attribute>
  54                 <attribute name="minPwdLength">7</attribute>
  55                 <attribute name="pwdProperties">1</attribute>
  56             </gp_ext>
  57             <gp_ext name="Kerberos Policy">
  58                 <attribute name="ticket_lifetime">1d</attribute>
  59                 <attribute name="renew_lifetime" />
  60                 <attribute name="clockskew">300</attribute>
  61             </gp_ext>
  62         </guid>
  63     </user>
  64 </gp>
  65
  66     Each guid value contains a list of extensions, which contain a list of
  67     attributes. The guid value represents a GPO. The attributes are the values
  68     of those settings prior to the application of the GPO.
  69     The list of guids is enclosed within a user name, which represents the user
  70     the settings were applied to. This user may be the samaccountname of the
  71     local computer, which implies that these are machine policies.
  72     The applylog keeps track of the order in which the GPOs were applied, so
  73     that they can be rolled back in reverse, returning the machine to the state
  74     prior to policy application.
  75     '''
  76     def __init__(self, user, gpostore, db_log=None):
  77         ''' Initialize the gp_log
  78         param user          - the username (or machine name) that policies are
  79                               being applied to
  80         param gpostore      - the GPOStorage obj which references the tdb which
  81                               contains gp_logs
  82         param db_log        - (optional) a string to initialize the gp_log
  83         '''
  84         self._state = GPOSTATE.APPLY
  85         self.gpostore = gpostore
  86         self.username = user
  87         if db_log:
  88             self.gpdb = etree.fromstring(db_log)
  89         else:
  90             self.gpdb = etree.Element('gp')
  91         self.user = user
  92         user_obj = self.gpdb.find('user[@name="%s"]' % user)
  93         if user_obj is None:
  94             user_obj = etree.SubElement(self.gpdb, 'user')
  95             user_obj.attrib['name'] = user
  96
  97     def state(self, value):
  98         ''' Policy application state
  99         param value         - APPLY, ENFORCE, or UNAPPLY
 100
 101         The behavior of the gp_log depends on whether we are applying policy,
 102         enforcing policy, or unapplying policy. During an apply, old settings
 103         are recorded in the log. During an enforce, settings are being applied
 104         but the gp_log does not change. During an unapply, additions to the log
 105         should be ignored (since function calls to apply settings are actually
 106         reverting policy), but removals from the log are allowed.
 107         '''
 108         # If we're enforcing, but we've unapplied, apply instead
 109         if value == GPOSTATE.ENFORCE:
 110             user_obj = self.gpdb.find('user[@name="%s"]' % self.user)
 111             apply_log = user_obj.find('applylog')
 112             if apply_log is None or len(apply_log) == 0:
 113                 self._state = GPOSTATE.APPLY
 114             else:
 115                 self._state = value
 116         else:
 117             self._state = value
 118
 119     def set_guid(self, guid):
 120         ''' Log to a different GPO guid
 121         param guid          - guid value of the GPO from which we're applying
 122                               policy
 123         '''
 124         self.guid = guid
 125         user_obj = self.gpdb.find('user[@name="%s"]' % self.user)
 126         obj = user_obj.find('guid[@value="%s"]' % guid)
 127         if obj is None:
 128             obj = etree.SubElement(user_obj, 'guid')
 129             obj.attrib['value'] = guid
 130         if self._state == GPOSTATE.APPLY:
 131             apply_log = user_obj.find('applylog')
 132             if apply_log is None:
 133                 apply_log = etree.SubElement(user_obj, 'applylog')
 134             item = etree.SubElement(apply_log, 'guid')
 135             item.attrib['count'] = '%d' % (len(apply_log)-1)
 136             item.attrib['value'] = guid
 137
 138     def apply_log_pop(self):
 139         ''' Pop a GPO guid from the applylog
 140         return              - last applied GPO guid
 141
 142         Removes the GPO guid last added to the list, which is the most recently
 143         applied GPO.
 144         '''
 145         user_obj = self.gpdb.find('user[@name="%s"]' % self.user)
 146         apply_log = user_obj.find('applylog')
 147         if apply_log is not None:
 148             ret = apply_log.find('guid[@count="%d"]' % (len(apply_log)-1))
 149             if ret is not None:
 150                 apply_log.remove(ret)
 151                 return ret.attrib['value']
 152             if len(apply_log) == 0 and apply_log in user_obj:
 153                 user_obj.remove(apply_log)
 154         return None
 155
 156     def store(self, gp_ext_name, attribute, old_val):
 157         ''' Store an attribute in the gp_log
 158         param gp_ext_name   - Name of the extension applying policy
 159         param attribute     - The attribute being modified
 160         param old_val       - The value of the attribute prior to policy
 161                               application
 162         '''
 163         if self._state == GPOSTATE.UNAPPLY or self._state == GPOSTATE.ENFORCE:
 164             return None
 165         user_obj = self.gpdb.find('user[@name="%s"]' % self.user)
 166         guid_obj = user_obj.find('guid[@value="%s"]' % self.guid)
 167         assert guid_obj is not None, "gpo guid was not set"
 168         ext = guid_obj.find('gp_ext[@name="%s"]' % gp_ext_name)
 169         if ext is None:
 170             ext = etree.SubElement(guid_obj, 'gp_ext')
 171             ext.attrib['name'] = gp_ext_name
 172         attr = ext.find('attribute[@name="%s"]' % attribute)
 173         if attr is None:
 174             attr = etree.SubElement(ext, 'attribute')
 175             attr.attrib['name'] = attribute
 176             attr.text = old_val
 177
 178     def retrieve(self, gp_ext_name, attribute):
 179         ''' Retrieve a stored attribute from the gp_log
 180         param gp_ext_name   - Name of the extension which applied policy
 181         param attribute     - The attribute being retrieved
 182         return              - The value of the attribute prior to policy
 183                               application
 184         '''
 185         user_obj = self.gpdb.find('user[@name="%s"]' % self.user)
 186         guid_obj = user_obj.find('guid[@value="%s"]' % self.guid)
 187         assert guid_obj is not None, "gpo guid was not set"
 188         ext = guid_obj.find('gp_ext[@name="%s"]' % gp_ext_name)
 189         if ext is not None:
 190             attr = ext.find('attribute[@name="%s"]' % attribute)
 191             if attr is not None:
 192                 return attr.text
 193         return None
 194
 195     def list(self, gp_extensions):
 196         ''' Return a list of attributes, their previous values, and functions
 197             to set them
 198         param gp_extensions - list of extension objects, for retrieving attr to
 199                               func mappings
 200         return              - list of (attr, value, apply_func) tuples for
 201                               unapplying policy
 202         '''
 203         user_obj = self.gpdb.find('user[@name="%s"]' % self.user)
 204         guid_obj = user_obj.find('guid[@value="%s"]' % self.guid)
 205         assert guid_obj is not None, "gpo guid was not set"
 206         ret = []
 207         data_maps = {}
 208         for gp_ext in gp_extensions:
 209             data_maps.update(gp_ext.apply_map())
 210         exts = guid_obj.findall('gp_ext')
 211         if exts is not None:
 212             for ext in exts:
 213                 attrs = ext.findall('attribute')
 214                 for attr in attrs:
 215                     func = None
 216                     if attr.attrib['name'] in data_maps[ext.attrib['name']]:
 217                         func = data_maps[ext.attrib['name']]\
 218                                [attr.attrib['name']][-1]
 219                     else:
 220                         for dmap in data_maps[ext.attrib['name']].keys():
 221                             if data_maps[ext.attrib['name']][dmap][0] == \
 222                                attr.attrib['name']:
 223                                 func = data_maps[ext.attrib['name']][dmap][-1]
 224                                 break
 225                     ret.append((attr.attrib['name'], attr.text, func))
 226         return ret
 227
 228     def delete(self, gp_ext_name, attribute):
 229         ''' Remove an attribute from the gp_log
 230         param gp_ext_name   - name of extension from which to remove the
 231                               attribute
 232         param attribute     - attribute to remove
 233         '''
 234         user_obj = self.gpdb.find('user[@name="%s"]' % self.user)
 235         guid_obj = user_obj.find('guid[@value="%s"]' % self.guid)
 236         assert guid_obj is not None, "gpo guid was not set"
 237         ext = guid_obj.find('gp_ext[@name="%s"]' % gp_ext_name)
 238         if ext is not None:
 239             attr = ext.find('attribute[@name="%s"]' % attribute)
 240             if attr is not None:
 241                 ext.remove(attr)
 242                 if len(ext) == 0:
 243                     guid_obj.remove(ext)
 244
 245     def commit(self):
 246         ''' Write gp_log changes to disk '''
 247         self.gpostore.store(self.username, etree.tostring(self.gpdb, 'utf-8'))
 248
 249 class GPOStorage:
 250     def __init__(self, log_file):
 251         if os.path.isfile(log_file):
 252             self.log = tdb.open(log_file)
 253         else:
 254             self.log = tdb.Tdb(log_file, 0, tdb.DEFAULT, os.O_CREAT|os.O_RDWR)
 255
 256     def start(self):
 257         self.log.transaction_start()
 258
 259     def get_int(self, key):
 260         try:
 261             return int(self.log.get(key))
 262         except TypeError:
 263             return None
 264
 265     def get(self, key):
 266         return self.log.get(key)
 267
 268     def get_gplog(self, user):
 269         return gp_log(user, self, self.log.get(user))
 270
 271     def store(self, key, val):
 272         self.log.store(key, val)
 273
 274     def cancel(self):
 275         self.log.transaction_cancel()
 276
 277     def delete(self, key):
 278         self.log.delete(key)
 279
 280     def commit(self):
 281         self.log.transaction_commit()
 282
 283     def __del__(self):
 284         self.log.close()
 285
 286 class gp_ext(object):
 287     __metaclass__ = ABCMeta
 288
 289     @abstractmethod
 290     def list(self, rootpath):
 291         pass
 292
 293     @abstractmethod
 294     def apply_map(self):
 295         pass
 296
 297     @abstractmethod
 298     def parse(self, afile, ldb, conn, gp_db, lp):
 299         pass
 300
 301     @abstractmethod
 302     def __str__(self):
 303         pass
 304
 305 class inf_to():
 306     __metaclass__ = ABCMeta
 307
 308     def __init__(self, logger, ldb, gp_db, lp, attribute, val):
 309         self.logger = logger
 310         self.ldb = ldb
 311         self.attribute = attribute
 312         self.val = val
 313         self.lp = lp
 314         self.gp_db = gp_db
 315
 316     def explicit(self):
 317         return self.val
 318
 319     def update_samba(self):
 320         (upd_sam, value) = self.mapper().get(self.attribute)
 321         upd_sam(value())
 322
 323     @abstractmethod
 324     def mapper(self):
 325         pass
 326
 327     @abstractmethod
 328     def __str__(self):
 329         pass
 330
 331 class inf_to_kdc_tdb(inf_to):
 332     def mins_to_hours(self):
 333         return '%d' % (int(self.val)/60)
 334
 335     def days_to_hours(self):
 336         return '%d' % (int(self.val)*24)
 337
 338     def set_kdc_tdb(self, val):
 339         old_val = self.gp_db.gpostore.get(self.attribute)
 340         self.logger.info('%s was changed from %s to %s' % (self.attribute,
 341                                                            old_val, val))
 342         if val is not None:
 343             self.gp_db.gpostore.store(self.attribute, val)
 344             self.gp_db.store(str(self), self.attribute, old_val)
 345         else:
 346             self.gp_db.gpostore.delete(self.attribute)
 347             self.gp_db.delete(str(self), self.attribute)
 348
 349     def mapper(self):
 350         return { 'kdc:user_ticket_lifetime': (self.set_kdc_tdb, self.explicit),
 351                  'kdc:service_ticket_lifetime': (self.set_kdc_tdb,
 352                                                  self.mins_to_hours),
 353                  'kdc:renewal_lifetime': (self.set_kdc_tdb,
 354                                           self.days_to_hours),
 355                }
 356
 357     def __str__(self):
 358         return 'Kerberos Policy'
 359
 360 class inf_to_ldb(inf_to):
 361     '''This class takes the .inf file parameter (essentially a GPO file mapped
 362     to a GUID), hashmaps it to the Samba parameter, which then uses an ldb
 363     object to update the parameter to Samba4. Not registry oriented whatsoever.
 364     '''
 365
 366     def ch_minPwdAge(self, val):
 367         old_val = self.ldb.get_minPwdAge()
 368         self.logger.info('KDC Minimum Password age was changed from %s to %s' \
 369                          % (old_val, val))
 370         self.gp_db.store(str(self), self.attribute, old_val)
 371         self.ldb.set_minPwdAge(val)
 372
 373     def ch_maxPwdAge(self, val):
 374         old_val = self.ldb.get_maxPwdAge()
 375         self.logger.info('KDC Maximum Password age was changed from %s to %s' \
 376                          % (old_val, val))
 377         self.gp_db.store(str(self), self.attribute, old_val)
 378         self.ldb.set_maxPwdAge(val)
 379
 380     def ch_minPwdLength(self, val):
 381         old_val = self.ldb.get_minPwdLength()
 382         self.logger.info(
 383             'KDC Minimum Password length was changed from %s to %s' \
 384              % (old_val, val))
 385         self.gp_db.store(str(self), self.attribute, old_val)
 386         self.ldb.set_minPwdLength(val)
 387
 388     def ch_pwdProperties(self, val):
 389         old_val = self.ldb.get_pwdProperties()
 390         self.logger.info('KDC Password Properties were changed from %s to %s' \
 391                          % (old_val, val))
 392         self.gp_db.store(str(self), self.attribute, old_val)
 393         self.ldb.set_pwdProperties(val)
 394
 395     def days2rel_nttime(self):
 396         seconds = 60
 397         minutes = 60
 398         hours = 24
 399         sam_add = 10000000
 400         val = (self.val)
 401         val = int(val)
 402         return  str(-(val * seconds * minutes * hours * sam_add))
 403
 404     def mapper(self):
 405         '''ldap value : samba setter'''
 406         return { "minPwdAge" : (self.ch_minPwdAge, self.days2rel_nttime),
 407                  "maxPwdAge" : (self.ch_maxPwdAge, self.days2rel_nttime),
 408                  # Could be none, but I like the method assignment in
 409                  # update_samba
 410                  "minPwdLength" : (self.ch_minPwdLength, self.explicit),
 411                  "pwdProperties" : (self.ch_pwdProperties, self.explicit),
 412
 413                }
 414
 415     def __str__(self):
 416         return 'System Access'
 417
 418
 419 class gp_sec_ext(gp_ext):
 420     '''This class does the following two things:
 421         1) Identifies the GPO if it has a certain kind of filepath,
 422         2) Finally parses it.
 423     '''
 424
 425     count = 0
 426
 427     def __init__(self, logger):
 428         self.logger = logger
 429
 430     def __str__(self):
 431         return "Security GPO extension"
 432
 433     def list(self, rootpath):
 434         return os.path.join(rootpath,
 435                             "MACHINE/Microsoft/Windows NT/SecEdit/GptTmpl.inf")
 436
 437     def listmachpol(self, rootpath):
 438         return os.path.join(rootpath, "Machine/Registry.pol")
 439
 440     def listuserpol(self, rootpath):
 441         return os.path.join(rootpath, "User/Registry.pol")
 442
 443     def apply_map(self):
 444         return {"System Access": {"MinimumPasswordAge": ("minPwdAge",
 445                                                          inf_to_ldb),
 446                                   "MaximumPasswordAge": ("maxPwdAge",
 447                                                          inf_to_ldb),
 448                                   "MinimumPasswordLength": ("minPwdLength",
 449                                                             inf_to_ldb),
 450                                   "PasswordComplexity": ("pwdProperties",
 451                                                          inf_to_ldb),
 452                                  },
 453                 "Kerberos Policy": {"MaxTicketAge": (
 454                                         "kdc:user_ticket_lifetime",
 455                                         inf_to_kdc_tdb
 456                                     ),
 457                                     "MaxServiceAge": (
 458                                         "kdc:service_ticket_lifetime",
 459                                         inf_to_kdc_tdb
 460                                     ),
 461                                     "MaxRenewAge": (
 462                                         "kdc:renewal_lifetime",
 463                                         inf_to_kdc_tdb
 464                                     ),
 465                                    }
 466                }
 467
 468     def read_inf(self, path, conn):
 469         ret = False
 470         inftable = self.apply_map()
 471
 472         policy = conn.loadfile(path.replace('/', '\\'))
 473         current_section = None
 474
 475         # So here we would declare a boolean,
 476         # that would get changed to TRUE.
 477         #
 478         # If at any point in time a GPO was applied,
 479         # then we return that boolean at the end.
 480
 481         inf_conf = ConfigParser()
 482         inf_conf.optionxform=str
 483         try:
 484             inf_conf.readfp(StringIO(policy))
 485         except:
 486             inf_conf.readfp(StringIO(policy.decode('utf-16')))
 487
 488         for section in inf_conf.sections():
 489             current_section = inftable.get(section)
 490             if not current_section:
 491                 continue
 492             for key, value in inf_conf.items(section):
 493                 if current_section.get(key):
 494                     (att, setter) = current_section.get(key)
 495                     value = value.encode('ascii', 'ignore')
 496                     ret = True
 497                     setter(self.logger, self.ldb, self.gp_db, self.lp, att,
 498                            value).update_samba()
 499                     self.gp_db.commit()
 500         return ret
 501
 502     def parse(self, afile, ldb, conn, gp_db, lp):
 503         self.ldb = ldb
 504         self.gp_db = gp_db
 505         self.lp = lp
 506
 507         # Fixing the bug where only some Linux Boxes capitalize MACHINE
 508         if afile.endswith('inf'):
 509             try:
 510                 blist = afile.split('/')
 511                 idx = afile.lower().split('/').index('machine')
 512                 for case in [blist[idx].upper(), blist[idx].capitalize(),
 513                              blist[idx].lower()]:
 514                     bfile = '/'.join(blist[:idx]) + '/' + case + '/' + \
 515                             '/'.join(blist[idx+1:])
 516                     try:
 517                         return self.read_inf(bfile, conn)
 518                     except NTSTATUSError:
 519                         continue
 520             except ValueError:
 521                 try:
 522                     return self.read_inf(afile, conn)
 523                 except:
 524                     return None
 525