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#!/usr/bin/env python3
# Unix SMB/CIFS implementation.
# Copyright (C) Stefan Metzmacher 2020
#
# 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 sys
import os
sys.path.insert(0, "bin/python")
os.environ["PYTHONUNBUFFERED"] = "1"
from samba.tests import env_get_var_value
from samba.tests.krb5.kcrypto import Cksumtype
from samba.tests.krb5.raw_testcase import RawKerberosTest
from samba.tests.krb5.rfc4120_constants import (
KU_PA_ENC_TIMESTAMP,
KU_AS_REP_ENC_PART,
KU_TGS_REP_ENC_PART_SUB_KEY,
)
import samba.tests.krb5.rfc4120_pyasn1 as krb5_asn1
global_asn1_print = False
global_hexdump = False
class S4UKerberosTests(RawKerberosTest):
def setUp(self):
super(S4UKerberosTests, self).setUp()
self.do_asn1_print = global_asn1_print
self.do_hexdump = global_hexdump
def _test_s4u2self(self, pa_s4u2self_ctype=None):
service_creds = self.get_service_creds()
service = service_creds.get_username()
realm = service_creds.get_realm()
cname = self.PrincipalName_create(name_type=1, names=[service])
sname = self.PrincipalName_create(name_type=2, names=["krbtgt", realm])
till = self.get_KerberosTime(offset=36000)
kdc_options = krb5_asn1.KDCOptions('forwardable')
padata = None
etypes = (18, 17, 23)
req = self.AS_REQ_create(padata=padata,
kdc_options=str(kdc_options),
cname=cname,
realm=realm,
sname=sname,
from_time=None,
till_time=till,
renew_time=None,
nonce=0x7fffffff,
etypes=etypes,
addresses=None,
EncAuthorizationData=None,
EncAuthorizationData_key=None,
additional_tickets=None)
rep = self.send_recv_transaction(req)
self.assertIsNotNone(rep)
self.assertEqual(rep['msg-type'], 30)
self.assertEqual(rep['error-code'], 25)
rep_padata = self.der_decode(
rep['e-data'], asn1Spec=krb5_asn1.METHOD_DATA())
for pa in rep_padata:
if pa['padata-type'] == 19:
etype_info2 = pa['padata-value']
break
etype_info2 = self.der_decode(
etype_info2, asn1Spec=krb5_asn1.ETYPE_INFO2())
key = self.PasswordKey_from_etype_info2(service_creds, etype_info2[0])
(patime, pausec) = self.get_KerberosTimeWithUsec()
pa_ts = self.PA_ENC_TS_ENC_create(patime, pausec)
pa_ts = self.der_encode(pa_ts, asn1Spec=krb5_asn1.PA_ENC_TS_ENC())
pa_ts = self.EncryptedData_create(key, KU_PA_ENC_TIMESTAMP, pa_ts)
pa_ts = self.der_encode(pa_ts, asn1Spec=krb5_asn1.EncryptedData())
pa_ts = self.PA_DATA_create(2, pa_ts)
kdc_options = krb5_asn1.KDCOptions('forwardable')
padata = [pa_ts]
req = self.AS_REQ_create(padata=padata,
kdc_options=str(kdc_options),
cname=cname,
realm=realm,
sname=sname,
from_time=None,
till_time=till,
renew_time=None,
nonce=0x7fffffff,
etypes=etypes,
addresses=None,
EncAuthorizationData=None,
EncAuthorizationData_key=None,
additional_tickets=None)
rep = self.send_recv_transaction(req)
self.assertIsNotNone(rep)
msg_type = rep['msg-type']
self.assertEqual(msg_type, 11)
enc_part2 = key.decrypt(KU_AS_REP_ENC_PART, rep['enc-part']['cipher'])
enc_part2 = self.der_decode(
enc_part2, asn1Spec=krb5_asn1.EncASRepPart())
# S4U2Self Request
sname = cname
for_user_name = env_get_var_value('FOR_USER')
uname = self.PrincipalName_create(name_type=1, names=[for_user_name])
kdc_options = krb5_asn1.KDCOptions('forwardable')
till = self.get_KerberosTime(offset=36000)
ticket = rep['ticket']
ticket_session_key = self.EncryptionKey_import(enc_part2['key'])
pa_s4u = self.PA_S4U2Self_create(name=uname, realm=realm,
tgt_session_key=ticket_session_key,
ctype=pa_s4u2self_ctype)
padata = [pa_s4u]
subkey = self.RandomKey(ticket_session_key.etype)
(ctime, cusec) = self.get_KerberosTimeWithUsec()
req = self.TGS_REQ_create(padata=padata,
cusec=cusec,
ctime=ctime,
ticket=ticket,
kdc_options=str(kdc_options),
cname=cname,
realm=realm,
sname=sname,
from_time=None,
till_time=till,
renew_time=None,
nonce=0x7ffffffe,
etypes=etypes,
addresses=None,
EncAuthorizationData=None,
EncAuthorizationData_key=None,
additional_tickets=None,
ticket_session_key=ticket_session_key,
authenticator_subkey=subkey)
rep = self.send_recv_transaction(req)
self.assertIsNotNone(rep)
msg_type = rep['msg-type']
if msg_type == 13:
enc_part2 = subkey.decrypt(
KU_TGS_REP_ENC_PART_SUB_KEY, rep['enc-part']['cipher'])
enc_part2 = self.der_decode(
enc_part2, asn1Spec=krb5_asn1.EncTGSRepPart())
return msg_type
# Using the checksum type from the tgt_session_key happens to work
# everywhere
def test_s4u2self(self):
msg_type = self._test_s4u2self()
self.assertEqual(msg_type, 13)
# Per spec, the checksum of PA-FOR-USER is HMAC_MD5, see [MS-SFU] 2.2.1
def test_s4u2self_hmac_md5_checksum(self):
msg_type = self._test_s4u2self(pa_s4u2self_ctype=Cksumtype.HMAC_MD5)
self.assertEqual(msg_type, 13)
def test_s4u2self_md5_unkeyed_checksum(self):
msg_type = self._test_s4u2self(pa_s4u2self_ctype=Cksumtype.MD5)
self.assertEqual(msg_type, 30)
def test_s4u2self_sha1_unkeyed_checksum(self):
msg_type = self._test_s4u2self(pa_s4u2self_ctype=Cksumtype.SHA1)
self.assertEqual(msg_type, 30)
def test_s4u2self_crc32_unkeyed_checksum(self):
msg_type = self._test_s4u2self(pa_s4u2self_ctype=Cksumtype.CRC32)
self.assertEqual(msg_type, 30)
if __name__ == "__main__":
global_asn1_print = True
global_hexdump = True
import unittest
unittest.main()
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