python/samba/ntacls.py

   1 # Unix SMB/CIFS implementation.
   2 # Copyright (C) Matthieu Patou <mat@matws.net> 2009-2010
   3 #
   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 """NT Acls."""
  20
  21
  22 import os
  23 import samba.xattr_native, samba.xattr_tdb, samba.posix_eadb
  24 from samba.dcerpc import security, xattr, idmap
  25 from samba.ndr import ndr_pack, ndr_unpack
  26 from samba.samba3 import smbd
  27
  28 class XattrBackendError(Exception):
  29     """A generic xattr backend error."""
  30
  31
  32 def checkset_backend(lp, backend, eadbfile):
  33     '''return the path to the eadb, or None'''
  34     if backend is None:
  35         xattr_tdb = lp.get("xattr_tdb:file")
  36         if xattr_tdb is not None:
  37             return (samba.xattr_tdb, lp.get("xattr_tdb:file"))
  38         posix_eadb = lp.get("posix:eadb")
  39         if posix_eadb is not None:
  40             return (samba.posix_eadb, lp.get("posix:eadb"))
  41         return (None, None)
  42     elif backend == "native":
  43         return (None, None)
  44     elif backend == "eadb":
  45         if eadbfile is not None:
  46             return (samba.posix_eadb, eadbfile)
  47         else:
  48             return (samba.posix_eadb, os.path.abspath(os.path.join(lp.get("private dir"), "eadb.tdb")))
  49     elif backend == "tdb":
  50         if eadbfile is not None:
  51             return (samba.xattr_tdb, eadbfile)
  52         else:
  53             return (samba.xattr_tdb, os.path.abspath(os.path.join(lp.get("state dir"), "xattr.tdb")))
  54     else:
  55         raise XattrBackendError("Invalid xattr backend choice %s"%backend)
  56
  57 def getdosinfo(lp, file):
  58     try:
  59         attribute = samba.xattr_native.wrap_getxattr(file,
  60                                                      xattr.XATTR_DOSATTRIB_NAME_S3)
  61     except Exception:
  62         return
  63
  64     return ndr_unpack(xattr.DOSATTRIB, attribute)
  65
  66 def getntacl(lp, file, backend=None, eadbfile=None, direct_db_access=True, service=None):
  67     if direct_db_access:
  68         (backend_obj, dbname) = checkset_backend(lp, backend, eadbfile)
  69         if dbname is not None:
  70             try:
  71                 attribute = backend_obj.wrap_getxattr(dbname, file,
  72                                                       xattr.XATTR_NTACL_NAME)
  73             except Exception:
  74                 # FIXME: Don't catch all exceptions, just those related to opening
  75                 # xattrdb
  76                 print "Fail to open %s" % dbname
  77                 attribute = samba.xattr_native.wrap_getxattr(file,
  78                                                              xattr.XATTR_NTACL_NAME)
  79         else:
  80             attribute = samba.xattr_native.wrap_getxattr(file,
  81                                                          xattr.XATTR_NTACL_NAME)
  82         ntacl = ndr_unpack(xattr.NTACL, attribute)
  83         if ntacl.version == 1:
  84             return ntacl.info
  85         elif ntacl.version == 2:
  86             return ntacl.info.sd
  87         elif ntacl.version == 3:
  88             return ntacl.info.sd
  89         elif ntacl.version == 4:
  90             return ntacl.info.sd
  91     else:
  92         return smbd.get_nt_acl(file, security.SECINFO_OWNER | security.SECINFO_GROUP | security.SECINFO_DACL | security.SECINFO_SACL, service=service)
  93
  94
  95 def setntacl(lp, file, sddl, domsid, backend=None, eadbfile=None, use_ntvfs=True, skip_invalid_chown=False, passdb=None, service=None):
  96     assert(isinstance(domsid, str) or isinstance(domsid, security.dom_sid))
  97     if isinstance(domsid, str):
  98         sid = security.dom_sid(domsid)
  99     elif isinstance(domsid, security.dom_sid):
 100         sid = domsid
 101         domsid = str(sid)
 102
 103     assert(isinstance(sddl, str) or isinstance(sddl, security.descriptor))
 104     if isinstance(sddl, str):
 105         sd = security.descriptor.from_sddl(sddl, sid)
 106     elif isinstance(sddl, security.descriptor):
 107         sd = sddl
 108         sddl = sd.as_sddl(sid)
 109
 110     if not use_ntvfs and skip_invalid_chown:
 111         # Check if the owner can be resolved as a UID
 112         (owner_id, owner_type) = passdb.sid_to_id(sd.owner_sid)
 113         if ((owner_type != idmap.ID_TYPE_UID) and (owner_type != idmap.ID_TYPE_BOTH)):
 114             # Check if this particular owner SID was domain admins,
 115             # because we special-case this as mapping to
 116             # 'administrator' instead.
 117             if sd.owner_sid == security.dom_sid("%s-%d" % (domsid, security.DOMAIN_RID_ADMINS)):
 118                 administrator = security.dom_sid("%s-%d" % (domsid, security.DOMAIN_RID_ADMINISTRATOR))
 119                 (admin_id, admin_type) = passdb.sid_to_id(administrator)
 120
 121                 # Confirm we have a UID for administrator
 122                 if ((admin_type == idmap.ID_TYPE_UID) or (admin_type == idmap.ID_TYPE_BOTH)):
 123
 124                     # Set it, changing the owner to 'administrator' rather than domain admins
 125                     sd2 = sd
 126                     sd2.owner_sid = administrator
 127
 128                     smbd.set_nt_acl(file, security.SECINFO_OWNER |security.SECINFO_GROUP | security.SECINFO_DACL | security.SECINFO_SACL, sd2, service=service)
 129
 130                     # and then set an NTVFS ACL (which does not set the posix ACL) to pretend the owner really was set
 131                     use_ntvfs = True
 132                 else:
 133                     raise XattrBackendError("Unable to find UID for domain administrator %s, got id %d of type %d" % (administrator, admin_id, admin_type))
 134             else:
 135                 # For all other owning users, reset the owner to root
 136                 # and then set the ACL without changing the owner
 137                 #
 138                 # This won't work in test environments, as it tries a real (rather than xattr-based fake) chown
 139
 140                 os.chown(file, 0, 0)
 141                 smbd.set_nt_acl(file, security.SECINFO_GROUP | security.SECINFO_DACL | security.SECINFO_SACL, sd, service=service)
 142
 143     if use_ntvfs:
 144         (backend_obj, dbname) = checkset_backend(lp, backend, eadbfile)
 145         ntacl = xattr.NTACL()
 146         ntacl.version = 1
 147         ntacl.info = sd
 148         if dbname is not None:
 149             try:
 150                 backend_obj.wrap_setxattr(dbname,
 151                                           file, xattr.XATTR_NTACL_NAME, ndr_pack(ntacl))
 152             except Exception:
 153                 # FIXME: Don't catch all exceptions, just those related to opening
 154                 # xattrdb
 155                 print "Fail to open %s" % dbname
 156                 samba.xattr_native.wrap_setxattr(file, xattr.XATTR_NTACL_NAME,
 157                                                  ndr_pack(ntacl))
 158         else:
 159             samba.xattr_native.wrap_setxattr(file, xattr.XATTR_NTACL_NAME,
 160                                              ndr_pack(ntacl))
 161     else:
 162         smbd.set_nt_acl(file, security.SECINFO_OWNER | security.SECINFO_GROUP | security.SECINFO_DACL | security.SECINFO_SACL, sd, service=service)
 163
 164
 165 def ldapmask2filemask(ldm):
 166     """Takes the access mask of a DS ACE and transform them in a File ACE mask.
 167     """
 168     RIGHT_DS_CREATE_CHILD     = 0x00000001
 169     RIGHT_DS_DELETE_CHILD     = 0x00000002
 170     RIGHT_DS_LIST_CONTENTS    = 0x00000004
 171     ACTRL_DS_SELF             = 0x00000008
 172     RIGHT_DS_READ_PROPERTY    = 0x00000010
 173     RIGHT_DS_WRITE_PROPERTY   = 0x00000020
 174     RIGHT_DS_DELETE_TREE      = 0x00000040
 175     RIGHT_DS_LIST_OBJECT      = 0x00000080
 176     RIGHT_DS_CONTROL_ACCESS   = 0x00000100
 177     FILE_READ_DATA            = 0x0001
 178     FILE_LIST_DIRECTORY       = 0x0001
 179     FILE_WRITE_DATA           = 0x0002
 180     FILE_ADD_FILE             = 0x0002
 181     FILE_APPEND_DATA          = 0x0004
 182     FILE_ADD_SUBDIRECTORY     = 0x0004
 183     FILE_CREATE_PIPE_INSTANCE = 0x0004
 184     FILE_READ_EA              = 0x0008
 185     FILE_WRITE_EA             = 0x0010
 186     FILE_EXECUTE              = 0x0020
 187     FILE_TRAVERSE             = 0x0020
 188     FILE_DELETE_CHILD         = 0x0040
 189     FILE_READ_ATTRIBUTES      = 0x0080
 190     FILE_WRITE_ATTRIBUTES     = 0x0100
 191     DELETE                    = 0x00010000
 192     READ_CONTROL              = 0x00020000
 193     WRITE_DAC                 = 0x00040000
 194     WRITE_OWNER               = 0x00080000
 195     SYNCHRONIZE               = 0x00100000
 196     STANDARD_RIGHTS_ALL       = 0x001F0000
 197
 198     filemask = ldm & STANDARD_RIGHTS_ALL
 199
 200     if (ldm & RIGHT_DS_READ_PROPERTY) and (ldm & RIGHT_DS_LIST_CONTENTS):
 201         filemask = filemask | (SYNCHRONIZE | FILE_LIST_DIRECTORY |
 202                                 FILE_READ_ATTRIBUTES | FILE_READ_EA |
 203                                 FILE_READ_DATA | FILE_EXECUTE)
 204
 205     if ldm & RIGHT_DS_WRITE_PROPERTY:
 206         filemask = filemask | (SYNCHRONIZE | FILE_WRITE_DATA |
 207                                 FILE_APPEND_DATA | FILE_WRITE_EA |
 208                                 FILE_WRITE_ATTRIBUTES | FILE_ADD_FILE |
 209                                 FILE_ADD_SUBDIRECTORY)
 210
 211     if ldm & RIGHT_DS_CREATE_CHILD:
 212         filemask = filemask | (FILE_ADD_SUBDIRECTORY | FILE_ADD_FILE)
 213
 214     if ldm & RIGHT_DS_DELETE_CHILD:
 215         filemask = filemask | FILE_DELETE_CHILD
 216
 217     return filemask
 218
 219
 220 def dsacl2fsacl(dssddl, sid, as_sddl=True):
 221     """
 222
 223     This function takes an the SDDL representation of a DS
 224     ACL and return the SDDL representation of this ACL adapted
 225     for files. It's used for Policy object provision
 226     """
 227     ref = security.descriptor.from_sddl(dssddl, sid)
 228     fdescr = security.descriptor()
 229     fdescr.owner_sid = ref.owner_sid
 230     fdescr.group_sid = ref.group_sid
 231     fdescr.type = ref.type
 232     fdescr.revision = ref.revision
 233     aces = ref.dacl.aces
 234     for i in range(0, len(aces)):
 235         ace = aces[i]
 236         if not ace.type & security.SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT and str(ace.trustee) != security.SID_BUILTIN_PREW2K:
 237        #    if fdescr.type & security.SEC_DESC_DACL_AUTO_INHERITED:
 238             ace.flags = ace.flags | security.SEC_ACE_FLAG_OBJECT_INHERIT | security.SEC_ACE_FLAG_CONTAINER_INHERIT
 239             if str(ace.trustee) == security.SID_CREATOR_OWNER:
 240                 # For Creator/Owner the IO flag is set as this ACE has only a sense for child objects
 241                 ace.flags = ace.flags | security.SEC_ACE_FLAG_INHERIT_ONLY
 242             ace.access_mask =  ldapmask2filemask(ace.access_mask)
 243             fdescr.dacl_add(ace)
 244
 245     if not as_sddl:
 246         return fdescr
 247
 248     return fdescr.as_sddl(sid)