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#!/usr/bin/env python3
# Unix SMB/CIFS implementation.
# Copyright (C) Stefan Metzmacher 2020
# Copyright (C) Catalyst.Net Ltd 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.krb5.kdc_base_test import KDCBaseTest
import samba.tests.krb5.rfc4120_pyasn1 as krb5_asn1
from samba.tests.krb5.rfc4120_constants import (
AES128_CTS_HMAC_SHA1_96,
AES256_CTS_HMAC_SHA1_96,
ARCFOUR_HMAC_MD5,
KDC_ERR_PREAUTH_REQUIRED,
KRB_AS_REP,
KRB_ERROR,
KU_AS_REP_ENC_PART,
KU_PA_ENC_TIMESTAMP,
PADATA_ENC_TIMESTAMP,
PADATA_ETYPE_INFO2,
NT_PRINCIPAL,
NT_SRV_INST,
)
global_asn1_print = False
global_hexdump = False
HEIMDAL_ENC_AS_REP_PART_TYPE_TAG = 0x79
# MIT uses the EncTGSRepPart tag for the EncASRepPart
MIT_ENC_AS_REP_PART_TYPE_TAG = 0x7A
ENC_PA_REP_FLAG = 0x00010000
class CompatabilityTests(KDCBaseTest):
def setUp(self):
super().setUp()
self.do_asn1_print = global_asn1_print
self.do_hexdump = global_hexdump
def test_mit_EncASRepPart_tag(self):
creds = self.get_user_creds()
(enc, _) = self.as_req(creds)
self.assertEqual(MIT_ENC_AS_REP_PART_TYPE_TAG, enc[0])
def test_heimdal_EncASRepPart_tag(self):
creds = self.get_user_creds()
(enc, _) = self.as_req(creds)
self.assertEqual(HEIMDAL_ENC_AS_REP_PART_TYPE_TAG, enc[0])
def test_mit_EncryptedData_kvno(self):
creds = self.get_user_creds()
(_, enc) = self.as_req(creds)
if 'kvno' in enc:
self.fail("kvno present in EncryptedData")
def test_heimdal_EncryptedData_kvno(self):
creds = self.get_user_creds()
(_, enc) = self.as_req(creds)
if 'kvno' not in enc:
self.fail("kvno absent in EncryptedData")
def test_mit_EncASRepPart_FAST_support(self):
creds = self.get_user_creds()
(enc, _) = self.as_req(creds)
self.assertEqual(MIT_ENC_AS_REP_PART_TYPE_TAG, enc[0])
as_rep = self.der_decode(enc, asn1Spec=krb5_asn1.EncTGSRepPart())
flags = int(as_rep['flags'], base=2)
# MIT sets enc-pa-rep, flag bit 15
# RFC 6806 11. Negotiation of FAST and Detecting Modified Requests
self.assertTrue(ENC_PA_REP_FLAG & flags)
def test_heimdal_and_windows_EncASRepPart_FAST_support(self):
creds = self.get_user_creds()
(enc, _) = self.as_req(creds)
self.assertEqual(HEIMDAL_ENC_AS_REP_PART_TYPE_TAG, enc[0])
as_rep = self.der_decode(enc, asn1Spec=krb5_asn1.EncASRepPart())
flags = as_rep['flags']
flags = int(as_rep['flags'], base=2)
# Heimdal and Windows does set enc-pa-rep, flag bit 15
# RFC 6806 11. Negotiation of FAST and Detecting Modified Requests
self.assertTrue(ENC_PA_REP_FLAG & flags)
def test_mit_arcfour_salt(self):
creds = self.get_user_creds()
etypes = (ARCFOUR_HMAC_MD5,)
(rep, *_) = self.as_pre_auth_req(creds, etypes)
self.check_preauth_rep(rep)
etype_info2 = self.get_etype_info2(rep)
if 'salt' not in etype_info2[0]:
self.fail(
"(MIT) Salt not populated for ARCFOUR_HMAC_MD5 encryption")
def test_heimdal_arcfour_salt(self):
creds = self.get_user_creds()
etypes = (ARCFOUR_HMAC_MD5,)
(rep, *_) = self.as_pre_auth_req(creds, etypes)
self.check_preauth_rep(rep)
etype_info2 = self.get_etype_info2(rep)
if 'salt' in etype_info2[0]:
self.fail(
"(Heimdal) Salt populated for ARCFOUR_HMAC_MD5 encryption")
def as_pre_auth_req(self, creds, etypes):
user = creds.get_username()
realm = creds.get_realm()
cname = self.PrincipalName_create(
name_type=NT_PRINCIPAL,
names=[user])
sname = self.PrincipalName_create(
name_type=NT_SRV_INST,
names=["krbtgt", realm])
till = self.get_KerberosTime(offset=36000)
kdc_options = krb5_asn1.KDCOptions('forwardable')
padata = None
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,
additional_tickets=None)
rep = self.send_recv_transaction(req)
return (rep, cname, sname, realm, till)
def check_preauth_rep(self, rep):
self.assertIsNotNone(rep)
self.assertEqual(rep['msg-type'], KRB_ERROR)
self.assertEqual(rep['error-code'], KDC_ERR_PREAUTH_REQUIRED)
def get_etype_info2(self, rep):
rep_padata = self.der_decode(
rep['e-data'],
asn1Spec=krb5_asn1.METHOD_DATA())
for pa in rep_padata:
if pa['padata-type'] == PADATA_ETYPE_INFO2:
etype_info2 = pa['padata-value']
break
etype_info2 = self.der_decode(
etype_info2,
asn1Spec=krb5_asn1.ETYPE_INFO2())
return etype_info2
def as_req(self, creds):
etypes = (
AES256_CTS_HMAC_SHA1_96,
AES128_CTS_HMAC_SHA1_96,
ARCFOUR_HMAC_MD5)
(rep, cname, sname, realm, till) = self.as_pre_auth_req(creds, etypes)
self.check_preauth_rep(rep)
etype_info2 = self.get_etype_info2(rep)
key = self.PasswordKey_from_etype_info2(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(PADATA_ENC_TIMESTAMP, 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,
additional_tickets=None)
rep = self.send_recv_transaction(req)
self.assertIsNotNone(rep)
msg_type = rep['msg-type']
self.assertEqual(msg_type, KRB_AS_REP)
enc_part = rep['enc-part']
enc_as_rep_part = key.decrypt(
KU_AS_REP_ENC_PART, rep['enc-part']['cipher'])
return (enc_as_rep_part, enc_part)
if __name__ == "__main__":
global_asn1_print = False
global_hexdump = False
import unittest
unittest.main()
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