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
  47 class cmd_dsacl_set(Command):
  48     """Modify access list on a directory object."""
  49
  50     synopsis = "%prog [options]"
  51     car_help = """ The access control right to allow or deny """
  52
  53     takes_optiongroups = {
  54         "sambaopts": options.SambaOptions,
  55         "credopts": options.CredentialsOptions,
  56         "versionopts": options.VersionOptions,
  57     }
  58
  59     takes_options = [
  60         Option("-H", "--URL", help="LDB URL for database or target server",
  61                type=str, metavar="URL", dest="H"),
  62         Option("--car", type="choice", choices=["change-rid",
  63                                                 "change-pdc",
  64                                                 "change-infrastructure",
  65                                                 "change-schema",
  66                                                 "change-naming",
  67                                                 "allocate_rids",
  68                                                 "get-changes",
  69                                                 "get-changes-all",
  70                                                 "get-changes-filtered",
  71                                                 "topology-manage",
  72                                                 "topology-monitor",
  73                                                 "repl-sync",
  74                                                 "ro-repl-secret-sync"],
  75                help=car_help),
  76         Option("--action", type="choice", choices=["allow", "deny"],
  77                 help="""Deny or allow access"""),
  78         Option("--objectdn", help="DN of the object whose SD to modify",
  79             type="string"),
  80         Option("--trusteedn", help="DN of the entity that gets access",
  81             type="string"),
  82         Option("--sddl", help="An ACE or group of ACEs to be added on the object",
  83             type="string"),
  84     ]
  85
  86     def find_trustee_sid(self, samdb, trusteedn):
  87         res = samdb.search(base=trusteedn, expression="(objectClass=*)",
  88             scope=SCOPE_BASE)
  89         assert(len(res) == 1)
  90         return ndr_unpack( security.dom_sid,res[0]["objectSid"][0])
  91
  92     def modify_descriptor(self, samdb, object_dn, desc, controls=None):
  93         assert(isinstance(desc, security.descriptor))
  94         m = ldb.Message()
  95         m.dn = ldb.Dn(samdb, object_dn)
  96         m["nTSecurityDescriptor"]= ldb.MessageElement(
  97                 (ndr_pack(desc)), ldb.FLAG_MOD_REPLACE,
  98                 "nTSecurityDescriptor")
  99         samdb.modify(m)
 100
 101     def read_descriptor(self, samdb, object_dn):
 102         res = samdb.search(base=object_dn, scope=SCOPE_BASE,
 103                 attrs=["nTSecurityDescriptor"])
 104         # we should theoretically always have an SD
 105         assert(len(res) == 1)
 106         desc = res[0]["nTSecurityDescriptor"][0]
 107         return ndr_unpack(security.descriptor, desc)
 108
 109     def get_domain_sid(self, samdb):
 110         res = samdb.search(base=samdb.domain_dn(),
 111                 expression="(objectClass=*)", scope=SCOPE_BASE)
 112         return ndr_unpack( security.dom_sid,res[0]["objectSid"][0])
 113
 114     def add_ace(self, samdb, object_dn, new_ace):
 115         """Add new ace explicitly."""
 116         desc = self.read_descriptor(samdb, object_dn)
 117         desc_sddl = desc.as_sddl(self.get_domain_sid(samdb))
 118         #TODO add bindings for descriptor manipulation and get rid of this
 119         desc_aces = re.findall("\(.*?\)", desc_sddl)
 120         for ace in desc_aces:
 121             if ("ID" in ace):
 122                 desc_sddl = desc_sddl.replace(ace, "")
 123         if new_ace in desc_sddl:
 124             return
 125         if desc_sddl.find("(") >= 0:
 126             desc_sddl = desc_sddl[:desc_sddl.index("(")] + new_ace + desc_sddl[desc_sddl.index("("):]
 127         else:
 128             desc_sddl = desc_sddl + new_ace
 129         desc = security.descriptor.from_sddl(desc_sddl, self.get_domain_sid(samdb))
 130         self.modify_descriptor(samdb, object_dn, desc)
 131
 132     def print_new_acl(self, samdb, object_dn):
 133         desc = self.read_descriptor(samdb, object_dn)
 134         desc_sddl = desc.as_sddl(self.get_domain_sid(samdb))
 135         self.outf.write("new descriptor for %s:\n" % object_dn)
 136         self.outf.write(desc_sddl + "\n")
 137
 138     def run(self, car, action, objectdn, trusteedn, sddl,
 139             H=None, credopts=None, sambaopts=None, versionopts=None):
 140         lp = sambaopts.get_loadparm()
 141         creds = credopts.get_credentials(lp)
 142
 143         if sddl is None and (car is None or action is None
 144                              or objectdn is None or trusteedn is None):
 145             return self.usage()
 146
 147         samdb = SamDB(url=H, session_info=system_session(),
 148             credentials=creds, lp=lp)
 149         cars = {'change-rid' : GUID_DRS_CHANGE_RID_MASTER,
 150                 'change-pdc' : GUID_DRS_CHANGE_PDC,
 151                 'change-infrastructure' : GUID_DRS_CHANGE_INFR_MASTER,
 152                 'change-schema' : GUID_DRS_CHANGE_SCHEMA_MASTER,
 153                 'change-naming' : GUID_DRS_CHANGE_DOMAIN_MASTER,
 154                 'allocate_rids' : GUID_DRS_ALLOCATE_RIDS,
 155                 'get-changes' : GUID_DRS_GET_CHANGES,
 156                 'get-changes-all' : GUID_DRS_GET_ALL_CHANGES,
 157                 'get-changes-filtered' : GUID_DRS_GET_FILTERED_ATTRIBUTES,
 158                 'topology-manage' : GUID_DRS_MANAGE_TOPOLOGY,
 159                 'topology-monitor' : GUID_DRS_MONITOR_TOPOLOGY,
 160                 'repl-sync' : GUID_DRS_REPL_SYNCRONIZE,
 161                 'ro-repl-secret-sync' : GUID_DRS_RO_REPL_SECRET_SYNC,
 162                 }
 163         sid = self.find_trustee_sid(samdb, trusteedn)
 164         if sddl:
 165             new_ace = sddl
 166         elif action == "allow":
 167             new_ace = "(OA;;CR;%s;;%s)" % (cars[car], str(sid))
 168         elif action == "deny":
 169             new_ace = "(OD;;CR;%s;;%s)" % (cars[car], str(sid))
 170         else:
 171             raise CommandError("Wrong argument '%s'!" % action)
 172
 173         self.print_new_acl(samdb, objectdn)
 174         self.add_ace(samdb, objectdn, new_ace)
 175         self.print_new_acl(samdb, objectdn)
 176
 177
 178 class cmd_dsacl(SuperCommand):
 179     """DS ACLs manipulation."""
 180
 181     subcommands = {}
 182     subcommands["set"] = cmd_dsacl_set()