python/samba/netcmd/dsacl.py

   1 # Manipulate ACLs on directory objects
   2 #
   3 # Copyright (C) Nadezhda Ivanova <nivanova@samba.org> 2010
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program 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 General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 #
  18
  19 import samba.getopt as options
  20 from samba.dcerpc import security
  21 from samba.samdb import SamDB
  22 from samba.ndr import ndr_unpack, ndr_pack
  23 from samba.dcerpc.security import (
  24     GUID_DRS_ALLOCATE_RIDS, GUID_DRS_CHANGE_DOMAIN_MASTER,
  25     GUID_DRS_CHANGE_INFR_MASTER, GUID_DRS_CHANGE_PDC,
  26     GUID_DRS_CHANGE_RID_MASTER, GUID_DRS_CHANGE_SCHEMA_MASTER,
  27     GUID_DRS_GET_CHANGES, GUID_DRS_GET_ALL_CHANGES,
  28     GUID_DRS_GET_FILTERED_ATTRIBUTES, GUID_DRS_MANAGE_TOPOLOGY,
  29     GUID_DRS_MONITOR_TOPOLOGY, GUID_DRS_REPL_SYNCRONIZE,
  30     GUID_DRS_RO_REPL_SECRET_SYNC)
  31
  32
  33 import ldb
  34 from ldb import SCOPE_BASE
  35 import re
  36
  37 from samba.auth import system_session
  38 from samba.netcmd import (
  39     Command,
  40     CommandError,
  41     SuperCommand,
  42     Option,
  43 )
  44
  45
  46 class cmd_dsacl_set(Command):
  47     """Modify access list on a directory object."""
  48
  49     synopsis = "%prog [options]"
  50     car_help = """ The access control right to allow or deny """
  51
  52     takes_optiongroups = {
  53         "sambaopts": options.SambaOptions,
  54         "credopts": options.CredentialsOptions,
  55         "versionopts": options.VersionOptions,
  56     }
  57
  58     takes_options = [
  59         Option("-H", "--URL", help="LDB URL for database or target server",
  60                type=str, metavar="URL", dest="H"),
  61         Option("--car", type="choice", choices=["change-rid",
  62                                                 "change-pdc",
  63                                                 "change-infrastructure",
  64                                                 "change-schema",
  65                                                 "change-naming",
  66                                                 "allocate_rids",
  67                                                 "get-changes",
  68                                                 "get-changes-all",
  69                                                 "get-changes-filtered",
  70                                                 "topology-manage",
  71                                                 "topology-monitor",
  72                                                 "repl-sync",
  73                                                 "ro-repl-secret-sync"],
  74                help=car_help),
  75         Option("--action", type="choice", choices=["allow", "deny"],
  76                help="""Deny or allow access"""),
  77         Option("--objectdn", help="DN of the object whose SD to modify",
  78                type="string"),
  79         Option("--trusteedn", help="DN of the entity that gets access",
  80                type="string"),
  81         Option("--sddl", help="An ACE or group of ACEs to be added on the object",
  82                type="string"),
  83     ]
  84
  85     def find_trustee_sid(self, samdb, trusteedn):
  86         res = samdb.search(base=trusteedn, expression="(objectClass=*)",
  87                            scope=SCOPE_BASE)
  88         assert(len(res) == 1)
  89         return ndr_unpack(security.dom_sid, res[0]["objectSid"][0])
  90
  91     def modify_descriptor(self, samdb, object_dn, desc, controls=None):
  92         assert(isinstance(desc, security.descriptor))
  93         m = ldb.Message()
  94         m.dn = ldb.Dn(samdb, object_dn)
  95         m["nTSecurityDescriptor"]= ldb.MessageElement(
  96                 (ndr_pack(desc)), ldb.FLAG_MOD_REPLACE,
  97                 "nTSecurityDescriptor")
  98         samdb.modify(m)
  99
 100     def read_descriptor(self, samdb, object_dn):
 101         res = samdb.search(base=object_dn, scope=SCOPE_BASE,
 102                            attrs=["nTSecurityDescriptor"])
 103         # we should theoretically always have an SD
 104         assert(len(res) == 1)
 105         desc = res[0]["nTSecurityDescriptor"][0]
 106         return ndr_unpack(security.descriptor, desc)
 107
 108     def get_domain_sid(self, samdb):
 109         res = samdb.search(base=samdb.domain_dn(),
 110                            expression="(objectClass=*)", scope=SCOPE_BASE)
 111         return ndr_unpack(security.dom_sid, res[0]["objectSid"][0])
 112
 113     def add_ace(self, samdb, object_dn, new_ace):
 114         """Add new ace explicitly."""
 115         desc = self.read_descriptor(samdb, object_dn)
 116         desc_sddl = desc.as_sddl(self.get_domain_sid(samdb))
 117         # TODO add bindings for descriptor manipulation and get rid of this
 118         desc_aces = re.findall("\(.*?\)", desc_sddl)
 119         for ace in desc_aces:
 120             if ("ID" in ace):
 121                 desc_sddl = desc_sddl.replace(ace, "")
 122         if new_ace in desc_sddl:
 123             return
 124         if desc_sddl.find("(") >= 0:
 125             desc_sddl = desc_sddl[:desc_sddl.index("(")] + new_ace + desc_sddl[desc_sddl.index("("):]
 126         else:
 127             desc_sddl = desc_sddl + new_ace
 128         desc = security.descriptor.from_sddl(desc_sddl, self.get_domain_sid(samdb))
 129         self.modify_descriptor(samdb, object_dn, desc)
 130
 131     def print_new_acl(self, samdb, object_dn):
 132         desc = self.read_descriptor(samdb, object_dn)
 133         desc_sddl = desc.as_sddl(self.get_domain_sid(samdb))
 134         self.outf.write("new descriptor for %s:\n" % object_dn)
 135         self.outf.write(desc_sddl + "\n")
 136
 137     def run(self, car, action, objectdn, trusteedn, sddl,
 138             H=None, credopts=None, sambaopts=None, versionopts=None):
 139         lp = sambaopts.get_loadparm()
 140         creds = credopts.get_credentials(lp)
 141
 142         if sddl is None and (car is None or action is None
 143                              or objectdn is None or trusteedn is None):
 144             return self.usage()
 145
 146         samdb = SamDB(url=H, session_info=system_session(),
 147                       credentials=creds, lp=lp)
 148         cars = {'change-rid': GUID_DRS_CHANGE_RID_MASTER,
 149                 'change-pdc': GUID_DRS_CHANGE_PDC,
 150                 'change-infrastructure': GUID_DRS_CHANGE_INFR_MASTER,
 151                 'change-schema': GUID_DRS_CHANGE_SCHEMA_MASTER,
 152                 'change-naming': GUID_DRS_CHANGE_DOMAIN_MASTER,
 153                 'allocate_rids': GUID_DRS_ALLOCATE_RIDS,
 154                 'get-changes': GUID_DRS_GET_CHANGES,
 155                 'get-changes-all': GUID_DRS_GET_ALL_CHANGES,
 156                 'get-changes-filtered': GUID_DRS_GET_FILTERED_ATTRIBUTES,
 157                 'topology-manage': GUID_DRS_MANAGE_TOPOLOGY,
 158                 'topology-monitor': GUID_DRS_MONITOR_TOPOLOGY,
 159                 'repl-sync': GUID_DRS_REPL_SYNCRONIZE,
 160                 'ro-repl-secret-sync': GUID_DRS_RO_REPL_SECRET_SYNC,
 161                 }
 162         sid = self.find_trustee_sid(samdb, trusteedn)
 163         if sddl:
 164             new_ace = sddl
 165         elif action == "allow":
 166             new_ace = "(OA;;CR;%s;;%s)" % (cars[car], str(sid))
 167         elif action == "deny":
 168             new_ace = "(OD;;CR;%s;;%s)" % (cars[car], str(sid))
 169         else:
 170             raise CommandError("Wrong argument '%s'!" % action)
 171
 172         self.print_new_acl(samdb, objectdn)
 173         self.add_ace(samdb, objectdn, new_ace)
 174         self.print_new_acl(samdb, objectdn)
 175
 176
 177 class cmd_dsacl(SuperCommand):
 178     """DS ACLs manipulation."""
 179
 180     subcommands = {}
 181     subcommands["set"] = cmd_dsacl_set()