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#!/usr/bin/env python
#
# update our servicePrincipalName names from spn_update_list
#
# Copyright (C) Andrew Tridgell 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/>.
import os, sys
# ensure we get messages out immediately, so they get in the samba logs,
# and don't get swallowed by a timeout
os.environ['PYTHONUNBUFFERED'] = '1'
# forcing GMT avoids a problem in some timezones with kerberos. Both MIT
# heimdal can get mutual authentication errors due to the 24 second difference
# between UTC and GMT when using some zone files (eg. the PDT zone from
# the US)
os.environ["TZ"] = "GMT"
# Find right directory when running from source tree
sys.path.insert(0, "bin/python")
import samba, ldb
import optparse
from samba import Ldb
from samba import getopt as options
from samba.auth import system_session
from samba.samdb import SamDB
from samba.credentials import Credentials, DONT_USE_KERBEROS
parser = optparse.OptionParser("samba_spnupdate")
sambaopts = options.SambaOptions(parser)
parser.add_option_group(sambaopts)
parser.add_option_group(options.VersionOptions(parser))
parser.add_option("--verbose", action="store_true")
credopts = options.CredentialsOptions(parser)
parser.add_option_group(credopts)
ccachename = None
opts, args = parser.parse_args()
if len(args) != 0:
parser.print_usage()
sys.exit(1)
lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)
domain = lp.get("realm")
host = lp.get("netbios name")
# get the list of substitution vars
def get_subst_vars(samdb):
global lp
vars = {}
vars['DNSDOMAIN'] = lp.get('realm').lower()
vars['HOSTNAME'] = lp.get('netbios name').lower() + "." + vars['DNSDOMAIN']
vars['NETBIOSNAME'] = lp.get('netbios name').upper()
vars['WORKGROUP'] = lp.get('workgroup')
vars['NTDSGUID'] = samdb.get_ntds_GUID()
res = samdb.search(base=None, scope=ldb.SCOPE_BASE, attrs=["objectGUID"])
guid = samdb.schema_format_value("objectGUID", res[0]['objectGUID'][0])
vars['DOMAINGUID'] = guid
return vars
try:
private_dir = lp.get("private dir")
secrets_path = os.path.join(private_dir, "secrets.ldb")
secrets_db = Ldb(url=secrets_path, session_info=system_session(),
credentials=creds, lp=lp)
res = secrets_db.search(base=None,
expression="(&(objectclass=ldapSecret)(cn=SAMDB Credentials))",
attrs=["samAccountName", "secret"])
if len(res) == 1:
credentials = Credentials()
credentials.set_kerberos_state(DONT_USE_KERBEROS)
if "samAccountName" in res[0]:
credentials.set_username(res[0]["samAccountName"][0])
if "secret" in res[0]:
credentials.set_password(res[0]["secret"][0])
else:
credentials = None
samdb = SamDB(url=lp.samdb_url(), session_info=system_session(), credentials=credentials, lp=lp)
except ldb.LdbError, (num, msg):
print("Unable to open sam database %s : %s" % (lp.samdb_url(), msg))
sys.exit(1)
# get the substitution dictionary
sub_vars = get_subst_vars(samdb)
# get the list of SPN entries we should have
spn_update_list = lp.private_path('spn_update_list')
file = open(spn_update_list, "r")
spn_list = []
# build the spn list
for line in file:
line = line.strip()
if line == '' or line[0] == "#":
continue
line = samba.substitute_var(line, sub_vars)
spn_list.append(line)
# get the current list of SPNs in our sam
res = samdb.search(base="",
expression='(&(objectClass=computer)(samaccountname=%s$))' % sub_vars['NETBIOSNAME'],
attrs=["servicePrincipalName"])
if not res or len(res) != 1:
print("Failed to find computer object for %s$" % sub_vars['NETBIOSNAME'])
sys.exit(1)
machine_dn = res[0]["dn"]
old_spns = []
if "servicePrincipalName" in res[0]:
for s in res[0]["servicePrincipalName"]:
old_spns.append(s)
if opts.verbose:
print("Existing SPNs: %s" % old_spns)
add_list = []
# work out what needs to be added
for s in spn_list:
in_list = False
for s2 in old_spns:
if s2.upper() == s.upper():
in_list = True
break
if not in_list:
add_list.append(s)
if opts.verbose:
print("New SPNs: %s" % add_list)
if add_list == []:
if opts.verbose:
print("Nothing to add")
sys.exit(0)
def local_update(add_list):
'''store locally'''
global res
msg = ldb.Message()
msg.dn = res[0]['dn']
msg[""] = ldb.MessageElement(add_list,
ldb.FLAG_MOD_ADD, "servicePrincipalName")
res = samdb.modify(msg)
def call_rodc_update(d):
'''RODCs need to use the writeSPN DRS call'''
global lp, sub_vars
from samba import drs_utils
from samba.dcerpc import drsuapi, nbt
from samba.net import Net
if opts.verbose:
print("Using RODC SPN update")
creds = credopts.get_credentials(lp)
creds.set_machine_account(lp)
net = Net(creds=creds, lp=lp)
try:
cldap_ret = net.finddc(domain, nbt.NBT_SERVER_DS | nbt.NBT_SERVER_WRITABLE)
except Exception, reason:
print("Unable to find writeable DC for domain '%s' to send DRS writeSPN to : %s" % (domain, reason))
sys.exit(1)
server = cldap_ret.pdc_dns_name
try:
binding_options = "seal"
if int(lp.get("log level")) >= 5:
binding_options += ",print"
drs = drsuapi.drsuapi('ncacn_ip_tcp:%s[%s]' % (server, binding_options), lp, creds)
(drs_handle, supported_extensions) = drs_utils.drs_DsBind(drs)
except Exception, reason:
print("Unable to connect to DC '%s' for domain '%s' : %s" % (server, domain, reason))
sys.exit(1)
req1 = drsuapi.DsWriteAccountSpnRequest1()
req1.operation = drsuapi.DRSUAPI_DS_SPN_OPERATION_ADD
req1.object_dn = str(machine_dn)
req1.count = 0
spn_names = []
for n in add_list:
if n.find('E3514235-4B06-11D1-AB04-00C04FC2DCD2') != -1:
# this one isn't allowed for RODCs, but we don't know why yet
continue
ns = drsuapi.DsNameString()
ns.str = n
spn_names.append(ns)
req1.count = req1.count + 1
if spn_names == []:
return
req1.spn_names = spn_names
(level, res) = drs.DsWriteAccountSpn(drs_handle, 1, req1)
if samdb.am_rodc():
call_rodc_update(add_list)
else:
local_update(add_list)
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