samba-tool domain provision: Make ldap_backend_startup.sh +x and take optional arguments
[nivanova/samba-autobuild/.git] / python / samba / sd_utils.py
1 # Utility methods for security descriptor manipulation
2 #
3 # Copyright Nadezhda Ivanova 2010 <nivanova@samba.org>
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 """Utility methods for security descriptor manipulation."""
20
21 import samba
22 from ldb import Message, MessageElement, Dn
23 from ldb import FLAG_MOD_REPLACE, SCOPE_BASE
24 from samba.ndr import ndr_pack, ndr_unpack
25 from samba.dcerpc import security
26
27
28 class SDUtils(object):
29     """Some utilities for manipulation of security descriptors on objects."""
30
31     def __init__(self, samdb):
32         self.ldb = samdb
33         self.domain_sid = security.dom_sid(self.ldb.get_domain_sid())
34
35     def modify_sd_on_dn(self, object_dn, sd, controls=None):
36         """Modify security descriptor using either SDDL string
37             or security.descriptor object
38         """
39         m = Message()
40         m.dn = Dn(self.ldb, object_dn)
41         assert(isinstance(sd, str) or isinstance(sd, security.descriptor))
42         if isinstance(sd, str):
43             tmp_desc = security.descriptor.from_sddl(sd, self.domain_sid)
44         elif isinstance(sd, security.descriptor):
45             tmp_desc = sd
46
47         m["nTSecurityDescriptor"] = MessageElement(ndr_pack(tmp_desc),
48                                                        FLAG_MOD_REPLACE,
49                                                        "nTSecurityDescriptor")
50         self.ldb.modify(m, controls)
51
52     def read_sd_on_dn(self, object_dn, controls=None):
53         res = self.ldb.search(object_dn, SCOPE_BASE, None,
54                               ["nTSecurityDescriptor"], controls=controls)
55         desc = res[0]["nTSecurityDescriptor"][0]
56         return ndr_unpack(security.descriptor, desc)
57
58     def get_object_sid(self, object_dn):
59         res = self.ldb.search(object_dn)
60         return ndr_unpack(security.dom_sid, res[0]["objectSid"][0])
61
62     def dacl_add_ace(self, object_dn, ace):
63         """Add an ACE to an objects security descriptor
64         """
65         desc = self.read_sd_on_dn(object_dn)
66         desc_sddl = desc.as_sddl(self.domain_sid)
67         if ace in desc_sddl:
68             return
69         if desc_sddl.find("(") >= 0:
70             desc_sddl = (desc_sddl[:desc_sddl.index("(")] + ace +
71                          desc_sddl[desc_sddl.index("("):])
72         else:
73             desc_sddl = desc_sddl + ace
74         self.modify_sd_on_dn(object_dn, desc_sddl)
75
76     def get_sd_as_sddl(self, object_dn, controls=None):
77         """Return object nTSecutiryDescriptor in SDDL format
78         """
79         desc = self.read_sd_on_dn(object_dn, controls=controls)
80         return desc.as_sddl(self.domain_sid)