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samba-mirror/python/samba/ntacls.py
Björn Baumbach ab558fa14c pysmbd: add option to pass a session info to set_nt_acl() function
A filled session info is needed by some vfs modules, e.g. full_audit.

Signed-off-by: Björn Baumbach <bb@sernet.de>
Reviewed-by: Volker Lendecke <vl@samba.org>
2018-10-11 10:28:18 +02:00

621 lines
22 KiB
Python

# Unix SMB/CIFS implementation.
# Copyright (C) Matthieu Patou <mat@matws.net> 2009-2010
#
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
from __future__ import print_function
"""NT Acls."""
import os
import tarfile
import tempfile
import shutil
import samba.xattr_native
import samba.xattr_tdb
import samba.posix_eadb
from samba.samba3 import param as s3param
from samba.dcerpc import security, xattr, idmap
from samba.ndr import ndr_pack, ndr_unpack
from samba.samba3 import smbd
from samba.auth import admin_session
from samba import smb
# don't include volumes
SMB_FILE_ATTRIBUTE_FLAGS = smb.FILE_ATTRIBUTE_SYSTEM | \
smb.FILE_ATTRIBUTE_DIRECTORY | \
smb.FILE_ATTRIBUTE_ARCHIVE | \
smb.FILE_ATTRIBUTE_HIDDEN
SECURITY_SECINFO_FLAGS = security.SECINFO_OWNER | \
security.SECINFO_GROUP | \
security.SECINFO_DACL | \
security.SECINFO_SACL
# SEC_FLAG_SYSTEM_SECURITY is required otherwise get Access Denied
SECURITY_SEC_FLAGS = security.SEC_FLAG_SYSTEM_SECURITY | \
security.SEC_FLAG_MAXIMUM_ALLOWED
class XattrBackendError(Exception):
"""A generic xattr backend error."""
def checkset_backend(lp, backend, eadbfile):
'''return the path to the eadb, or None'''
if backend is None:
xattr_tdb = lp.get("xattr_tdb:file")
if xattr_tdb is not None:
return (samba.xattr_tdb, lp.get("xattr_tdb:file"))
posix_eadb = lp.get("posix:eadb")
if posix_eadb is not None:
return (samba.posix_eadb, lp.get("posix:eadb"))
return (None, None)
elif backend == "native":
return (None, None)
elif backend == "eadb":
if eadbfile is not None:
return (samba.posix_eadb, eadbfile)
else:
return (samba.posix_eadb, os.path.abspath(os.path.join(lp.get("private dir"), "eadb.tdb")))
elif backend == "tdb":
if eadbfile is not None:
return (samba.xattr_tdb, eadbfile)
else:
return (samba.xattr_tdb, os.path.abspath(os.path.join(lp.get("state dir"), "xattr.tdb")))
else:
raise XattrBackendError("Invalid xattr backend choice %s" % backend)
def getdosinfo(lp, file):
try:
attribute = samba.xattr_native.wrap_getxattr(file,
xattr.XATTR_DOSATTRIB_NAME_S3)
except Exception:
return
return ndr_unpack(xattr.DOSATTRIB, attribute)
def getntacl(lp,
file,
backend=None,
eadbfile=None,
direct_db_access=True,
service=None,
session_info=None):
if direct_db_access:
(backend_obj, dbname) = checkset_backend(lp, backend, eadbfile)
if dbname is not None:
try:
attribute = backend_obj.wrap_getxattr(dbname, file,
xattr.XATTR_NTACL_NAME)
except Exception:
# FIXME: Don't catch all exceptions, just those related to opening
# xattrdb
print("Fail to open %s" % dbname)
attribute = samba.xattr_native.wrap_getxattr(file,
xattr.XATTR_NTACL_NAME)
else:
attribute = samba.xattr_native.wrap_getxattr(file,
xattr.XATTR_NTACL_NAME)
ntacl = ndr_unpack(xattr.NTACL, attribute)
if ntacl.version == 1:
return ntacl.info
elif ntacl.version == 2:
return ntacl.info.sd
elif ntacl.version == 3:
return ntacl.info.sd
elif ntacl.version == 4:
return ntacl.info.sd
else:
return smbd.get_nt_acl(file,
SECURITY_SECINFO_FLAGS,
service=service,
session_info=session_info)
def setntacl(lp, file, sddl, domsid,
backend=None, eadbfile=None,
use_ntvfs=True, skip_invalid_chown=False,
passdb=None, service=None, session_info=None):
"""
A wrapper for smbd set_nt_acl api.
Args:
lp (LoadParam): load param from conf
file (str): a path to file or dir
sddl (str): ntacl sddl string
service (str): name of share service, e.g.: sysvol
session_info (auth_session_info): session info for authentication
Note:
Get `session_info` with `samba.auth.user_session`, do not use the
`admin_session` api.
Returns:
None
"""
assert(isinstance(domsid, str) or isinstance(domsid, security.dom_sid))
if isinstance(domsid, str):
sid = security.dom_sid(domsid)
elif isinstance(domsid, security.dom_sid):
sid = domsid
domsid = str(sid)
assert(isinstance(sddl, str) or isinstance(sddl, security.descriptor))
if isinstance(sddl, str):
sd = security.descriptor.from_sddl(sddl, sid)
elif isinstance(sddl, security.descriptor):
sd = sddl
sddl = sd.as_sddl(sid)
if not use_ntvfs and skip_invalid_chown:
# Check if the owner can be resolved as a UID
(owner_id, owner_type) = passdb.sid_to_id(sd.owner_sid)
if ((owner_type != idmap.ID_TYPE_UID) and (owner_type != idmap.ID_TYPE_BOTH)):
# Check if this particular owner SID was domain admins,
# because we special-case this as mapping to
# 'administrator' instead.
if sd.owner_sid == security.dom_sid("%s-%d" % (domsid, security.DOMAIN_RID_ADMINS)):
administrator = security.dom_sid("%s-%d" % (domsid, security.DOMAIN_RID_ADMINISTRATOR))
(admin_id, admin_type) = passdb.sid_to_id(administrator)
# Confirm we have a UID for administrator
if ((admin_type == idmap.ID_TYPE_UID) or (admin_type == idmap.ID_TYPE_BOTH)):
# Set it, changing the owner to 'administrator' rather than domain admins
sd2 = sd
sd2.owner_sid = administrator
smbd.set_nt_acl(
file, SECURITY_SECINFO_FLAGS, sd2,
service=service, session_info=session_info)
# and then set an NTVFS ACL (which does not set the posix ACL) to pretend the owner really was set
use_ntvfs = True
else:
raise XattrBackendError("Unable to find UID for domain administrator %s, got id %d of type %d" % (administrator, admin_id, admin_type))
else:
# For all other owning users, reset the owner to root
# and then set the ACL without changing the owner
#
# This won't work in test environments, as it tries a real (rather than xattr-based fake) chown
os.chown(file, 0, 0)
smbd.set_nt_acl(
file,
security.SECINFO_GROUP |
security.SECINFO_DACL |
security.SECINFO_SACL,
sd, service=service, session_info=session_info)
if use_ntvfs:
(backend_obj, dbname) = checkset_backend(lp, backend, eadbfile)
ntacl = xattr.NTACL()
ntacl.version = 1
ntacl.info = sd
if dbname is not None:
try:
backend_obj.wrap_setxattr(dbname,
file, xattr.XATTR_NTACL_NAME, ndr_pack(ntacl))
except Exception:
# FIXME: Don't catch all exceptions, just those related to opening
# xattrdb
print("Fail to open %s" % dbname)
samba.xattr_native.wrap_setxattr(file, xattr.XATTR_NTACL_NAME,
ndr_pack(ntacl))
else:
samba.xattr_native.wrap_setxattr(file, xattr.XATTR_NTACL_NAME,
ndr_pack(ntacl))
else:
smbd.set_nt_acl(
file, SECURITY_SECINFO_FLAGS, sd,
service=service, session_info=session_info)
def ldapmask2filemask(ldm):
"""Takes the access mask of a DS ACE and transform them in a File ACE mask.
"""
RIGHT_DS_CREATE_CHILD = 0x00000001
RIGHT_DS_DELETE_CHILD = 0x00000002
RIGHT_DS_LIST_CONTENTS = 0x00000004
ACTRL_DS_SELF = 0x00000008
RIGHT_DS_READ_PROPERTY = 0x00000010
RIGHT_DS_WRITE_PROPERTY = 0x00000020
RIGHT_DS_DELETE_TREE = 0x00000040
RIGHT_DS_LIST_OBJECT = 0x00000080
RIGHT_DS_CONTROL_ACCESS = 0x00000100
FILE_READ_DATA = 0x0001
FILE_LIST_DIRECTORY = 0x0001
FILE_WRITE_DATA = 0x0002
FILE_ADD_FILE = 0x0002
FILE_APPEND_DATA = 0x0004
FILE_ADD_SUBDIRECTORY = 0x0004
FILE_CREATE_PIPE_INSTANCE = 0x0004
FILE_READ_EA = 0x0008
FILE_WRITE_EA = 0x0010
FILE_EXECUTE = 0x0020
FILE_TRAVERSE = 0x0020
FILE_DELETE_CHILD = 0x0040
FILE_READ_ATTRIBUTES = 0x0080
FILE_WRITE_ATTRIBUTES = 0x0100
DELETE = 0x00010000
READ_CONTROL = 0x00020000
WRITE_DAC = 0x00040000
WRITE_OWNER = 0x00080000
SYNCHRONIZE = 0x00100000
STANDARD_RIGHTS_ALL = 0x001F0000
filemask = ldm & STANDARD_RIGHTS_ALL
if (ldm & RIGHT_DS_READ_PROPERTY) and (ldm & RIGHT_DS_LIST_CONTENTS):
filemask = filemask | (SYNCHRONIZE | FILE_LIST_DIRECTORY |
FILE_READ_ATTRIBUTES | FILE_READ_EA |
FILE_READ_DATA | FILE_EXECUTE)
if ldm & RIGHT_DS_WRITE_PROPERTY:
filemask = filemask | (SYNCHRONIZE | FILE_WRITE_DATA |
FILE_APPEND_DATA | FILE_WRITE_EA |
FILE_WRITE_ATTRIBUTES | FILE_ADD_FILE |
FILE_ADD_SUBDIRECTORY)
if ldm & RIGHT_DS_CREATE_CHILD:
filemask = filemask | (FILE_ADD_SUBDIRECTORY | FILE_ADD_FILE)
if ldm & RIGHT_DS_DELETE_CHILD:
filemask = filemask | FILE_DELETE_CHILD
return filemask
def dsacl2fsacl(dssddl, sid, as_sddl=True):
"""
This function takes an the SDDL representation of a DS
ACL and return the SDDL representation of this ACL adapted
for files. It's used for Policy object provision
"""
ref = security.descriptor.from_sddl(dssddl, sid)
fdescr = security.descriptor()
fdescr.owner_sid = ref.owner_sid
fdescr.group_sid = ref.group_sid
fdescr.type = ref.type
fdescr.revision = ref.revision
aces = ref.dacl.aces
for i in range(0, len(aces)):
ace = aces[i]
if not ace.type & security.SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT and str(ace.trustee) != security.SID_BUILTIN_PREW2K:
# if fdescr.type & security.SEC_DESC_DACL_AUTO_INHERITED:
ace.flags = ace.flags | security.SEC_ACE_FLAG_OBJECT_INHERIT | security.SEC_ACE_FLAG_CONTAINER_INHERIT
if str(ace.trustee) == security.SID_CREATOR_OWNER:
# For Creator/Owner the IO flag is set as this ACE has only a sense for child objects
ace.flags = ace.flags | security.SEC_ACE_FLAG_INHERIT_ONLY
ace.access_mask = ldapmask2filemask(ace.access_mask)
fdescr.dacl_add(ace)
if not as_sddl:
return fdescr
return fdescr.as_sddl(sid)
class SMBHelper:
"""
A wrapper class for SMB connection
smb_path: path with separator "\\" other than "/"
"""
def __init__(self, smb_conn, dom_sid):
self.smb_conn = smb_conn
self.dom_sid = dom_sid
def get_acl(self, smb_path, as_sddl=False):
assert '/' not in smb_path
ntacl_sd = self.smb_conn.get_acl(
smb_path, SECURITY_SECINFO_FLAGS, SECURITY_SEC_FLAGS)
return ntacl_sd.as_sddl(self.dom_sid) if as_sddl else ntacl_sd
def list(self, smb_path=''):
"""
List file and dir base names in smb_path without recursive.
"""
assert '/' not in smb_path
return self.smb_conn.list(smb_path, attribs=SMB_FILE_ATTRIBUTE_FLAGS)
def is_dir(self, attrib):
"""
Check whether the attrib value is a directory.
attrib is from list method.
"""
return bool(attrib & smb.FILE_ATTRIBUTE_DIRECTORY)
def join(self, root, name):
"""
Join path with '\\'
"""
return root + '\\' + name if root else name
def loadfile(self, smb_path):
assert '/' not in smb_path
return self.smb_conn.loadfile(smb_path)
def create_tree(self, tree, smb_path=''):
"""
Create files as defined in tree
"""
for name, content in tree.items():
fullname = self.join(smb_path, name)
if isinstance(content, dict): # a dir
if not self.smb_conn.chkpath(fullname):
self.smb_conn.mkdir(fullname)
self.create_tree(content, smb_path=fullname)
else: # a file
self.smb_conn.savefile(fullname, content)
def get_tree(self, smb_path=''):
"""
Get the tree structure via smb conn
self.smb_conn.list example:
[
{
'attrib': 16,
'mtime': 1528848309,
'name': 'dir1',
'short_name': 'dir1',
'size': 0L
}, {
'attrib': 32,
'mtime': 1528848309,
'name': 'file0.txt',
'short_name': 'file0.txt',
'size': 10L
}
]
"""
tree = {}
for item in self.list(smb_path):
name = item['name']
fullname = self.join(smb_path, name)
if self.is_dir(item['attrib']):
tree[name] = self.get_tree(smb_path=fullname)
else:
tree[name] = self.loadfile(fullname)
return tree
def get_ntacls(self, smb_path=''):
"""
Get ntacl for each file and dir via smb conn
"""
ntacls = {}
for item in self.list(smb_path):
name = item['name']
fullname = self.join(smb_path, name)
if self.is_dir(item['attrib']):
ntacls.update(self.get_ntacls(smb_path=fullname))
else:
ntacl_sd = self.get_acl(fullname)
ntacls[fullname] = ntacl_sd.as_sddl(self.dom_sid)
return ntacls
def delete_tree(self):
for item in self.list():
name = item['name']
if self.is_dir(item['attrib']):
self.smb_conn.deltree(name)
else:
self.smb_conn.unlink(name)
class NtaclsHelper:
def __init__(self, service, smb_conf_path, dom_sid):
self.service = service
self.dom_sid = dom_sid
# this is important to help smbd find services.
self.lp = s3param.get_context()
self.lp.load(smb_conf_path)
self.use_ntvfs = "smb" in self.lp.get("server services")
def getntacl(self, path, as_sddl=False, direct_db_access=None):
if direct_db_access is None:
direct_db_access = self.use_ntvfs
ntacl_sd = getntacl(
self.lp, path,
direct_db_access=direct_db_access,
service=self.service)
return ntacl_sd.as_sddl(self.dom_sid) if as_sddl else ntacl_sd
def setntacl(self, path, ntacl_sd):
# ntacl_sd can be obj or str
return setntacl(self.lp, path, ntacl_sd, self.dom_sid)
def _create_ntacl_file(dst, ntacl_sddl_str):
with open(dst + '.NTACL', 'w') as f:
f.write(ntacl_sddl_str)
def _read_ntacl_file(src):
with open(src + '.NTACL', 'r') as f:
return f.read()
def backup_online(smb_conn, dest_tarfile_path, dom_sid):
"""
Backup all files and dirs with ntacl for the serive behind smb_conn.
1. Create a temp dir as container dir
2. Backup all files with dir structure into container dir
3. Generate file.NTACL files for each file and dir in contianer dir
4. Create a tar file from container dir(without top level folder)
5. Delete contianer dir
"""
if isinstance(dom_sid, str):
dom_sid = security.dom_sid(dom_sid)
smb_helper = SMBHelper(smb_conn, dom_sid)
remotedir = '' # root dir
localdir = tempfile.mkdtemp()
r_dirs = [remotedir]
l_dirs = [localdir]
while r_dirs:
r_dir = r_dirs.pop()
l_dir = l_dirs.pop()
for e in smb_helper.list(smb_path=r_dir):
r_name = smb_helper.join(r_dir, e['name'])
l_name = os.path.join(l_dir, e['name'])
if smb_helper.is_dir(e['attrib']):
r_dirs.append(r_name)
l_dirs.append(l_name)
os.mkdir(l_name)
else:
data = smb_helper.loadfile(r_name)
with open(l_name, 'wb') as f:
f.write(data)
# get ntacl for this entry and save alongside
ntacl_sddl_str = smb_helper.get_acl(r_name, as_sddl=True)
_create_ntacl_file(l_name, ntacl_sddl_str)
with tarfile.open(name=dest_tarfile_path, mode='w:gz') as tar:
for name in os.listdir(localdir):
path = os.path.join(localdir, name)
tar.add(path, arcname=name)
shutil.rmtree(localdir)
def backup_offline(src_service_path, dest_tarfile_path, samdb_conn, smb_conf_path):
"""
Backup files and ntacls to a tarfile for a service
"""
service = src_service_path.rstrip('/').rsplit('/', 1)[-1]
tempdir = tempfile.mkdtemp()
dom_sid_str = samdb_conn.get_domain_sid()
dom_sid = security.dom_sid(dom_sid_str)
ntacls_helper = NtaclsHelper(service, smb_conf_path, dom_sid)
for dirpath, dirnames, filenames in os.walk(src_service_path):
# each dir only cares about its direct children
rel_dirpath = os.path.relpath(dirpath, start=src_service_path)
dst_dirpath = os.path.join(tempdir, rel_dirpath)
# create sub dirs and NTACL file
for dirname in dirnames:
src = os.path.join(dirpath, dirname)
dst = os.path.join(dst_dirpath, dirname)
# mkdir with metadata
smbd.mkdir(dst, service)
ntacl_sddl_str = ntacls_helper.getntacl(src, as_sddl=True)
_create_ntacl_file(dst, ntacl_sddl_str)
# create files and NTACL file, then copy data
for filename in filenames:
src = os.path.join(dirpath, filename)
dst = os.path.join(dst_dirpath, filename)
# create an empty file with metadata
smbd.create_file(dst, service)
ntacl_sddl_str = ntacls_helper.getntacl(src, as_sddl=True)
_create_ntacl_file(dst, ntacl_sddl_str)
# now put data in
with open(src, 'rb') as src_file:
data = src_file.read()
with open(dst, 'wb') as dst_file:
dst_file.write(data)
# add all files in tempdir to tarfile without a top folder
with tarfile.open(name=dest_tarfile_path, mode='w:gz') as tar:
for name in os.listdir(tempdir):
path = os.path.join(tempdir, name)
tar.add(path, arcname=name)
shutil.rmtree(tempdir)
def backup_restore(src_tarfile_path, dst_service_path, samdb_conn, smb_conf_path):
"""
Restore files and ntacls from a tarfile to a service
"""
service = dst_service_path.rstrip('/').rsplit('/', 1)[-1]
tempdir = tempfile.mkdtemp() # src files
dom_sid_str = samdb_conn.get_domain_sid()
dom_sid = security.dom_sid(dom_sid_str)
ntacls_helper = NtaclsHelper(service, smb_conf_path, dom_sid)
with tarfile.open(src_tarfile_path) as f:
f.extractall(path=tempdir)
# e.g.: /tmp/tmpRNystY/{dir1,dir1.NTACL,...file1,file1.NTACL}
for dirpath, dirnames, filenames in os.walk(tempdir):
rel_dirpath = os.path.relpath(dirpath, start=tempdir)
dst_dirpath = os.path.normpath(
os.path.join(dst_service_path, rel_dirpath))
for dirname in dirnames:
if not dirname.endswith('.NTACL'):
src = os.path.join(dirpath, dirname)
dst = os.path.join(dst_dirpath, dirname)
if not os.path.isdir(dst):
# dst must be absolute path for smbd API
smbd.mkdir(dst, service)
ntacl_sddl_str = _read_ntacl_file(src)
ntacls_helper.setntacl(dst, ntacl_sddl_str)
for filename in filenames:
if not filename.endswith('.NTACL'):
src = os.path.join(dirpath, filename)
dst = os.path.join(dst_dirpath, filename)
if not os.path.isfile(dst):
# dst must be absolute path for smbd API
smbd.create_file(dst, service)
ntacl_sddl_str = _read_ntacl_file(src)
ntacls_helper.setntacl(dst, ntacl_sddl_str)
# now put data in
with open(src, 'rb') as src_file:
data = src_file.read()
with open(dst, 'wb') as dst_file:
dst_file.write(data)
shutil.rmtree(tempdir)