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Mini Shell
Mini Shell
# Unix SMB/CIFS implementation.
# Copyright (C) Isaac Boukris 2020
# 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 socket
import struct
import time
import datetime
import random
import binascii
import itertools
import collections
from enum import Enum
from pyasn1.codec.der.decoder import decode as pyasn1_der_decode
from pyasn1.codec.der.encoder import encode as pyasn1_der_encode
from pyasn1.codec.native.decoder import decode as pyasn1_native_decode
from pyasn1.codec.native.encoder import encode as pyasn1_native_encode
from pyasn1.codec.ber.encoder import BitStringEncoder
from pyasn1.error import PyAsn1Error
from samba.credentials import Credentials
from samba.dcerpc import krb5pac, security
from samba.gensec import FEATURE_SEAL
from samba.ndr import ndr_pack, ndr_unpack
from samba.dcerpc.misc import (
SEC_CHAN_WKSTA,
SEC_CHAN_BDC,
)
import samba.tests
from samba.tests import TestCaseInTempDir
import samba.tests.krb5.rfc4120_pyasn1 as krb5_asn1
from samba.tests.krb5.rfc4120_constants import (
AD_IF_RELEVANT,
AD_WIN2K_PAC,
FX_FAST_ARMOR_AP_REQUEST,
KDC_ERR_GENERIC,
KDC_ERR_PREAUTH_FAILED,
KDC_ERR_UNKNOWN_CRITICAL_FAST_OPTIONS,
KERB_ERR_TYPE_EXTENDED,
KRB_AP_REP,
KRB_AP_REQ,
KRB_AS_REP,
KRB_AS_REQ,
KRB_ERROR,
KRB_PRIV,
KRB_TGS_REP,
KRB_TGS_REQ,
KU_AP_REQ_AUTH,
KU_AS_REP_ENC_PART,
KU_AP_REQ_ENC_PART,
KU_AS_REQ,
KU_ENC_CHALLENGE_KDC,
KU_FAST_ENC,
KU_FAST_FINISHED,
KU_FAST_REP,
KU_FAST_REQ_CHKSUM,
KU_KRB_PRIV,
KU_NON_KERB_CKSUM_SALT,
KU_TGS_REP_ENC_PART_SESSION,
KU_TGS_REP_ENC_PART_SUB_KEY,
KU_TGS_REQ_AUTH,
KU_TGS_REQ_AUTH_CKSUM,
KU_TGS_REQ_AUTH_DAT_SESSION,
KU_TGS_REQ_AUTH_DAT_SUBKEY,
KU_TICKET,
NT_PRINCIPAL,
NT_SRV_INST,
NT_WELLKNOWN,
PADATA_ENCRYPTED_CHALLENGE,
PADATA_ENC_TIMESTAMP,
PADATA_ETYPE_INFO,
PADATA_ETYPE_INFO2,
PADATA_FOR_USER,
PADATA_FX_COOKIE,
PADATA_FX_ERROR,
PADATA_FX_FAST,
PADATA_KDC_REQ,
PADATA_PAC_OPTIONS,
PADATA_PAC_REQUEST,
PADATA_PK_AS_REQ,
PADATA_PK_AS_REP_19,
PADATA_REQ_ENC_PA_REP,
PADATA_SUPPORTED_ETYPES
)
import samba.tests.krb5.kcrypto as kcrypto
def BitStringEncoder_encodeValue32(
self, value, asn1Spec, encodeFun, **options):
#
# BitStrings like KDCOptions or TicketFlags should at least
# be 32-Bit on the wire
#
if asn1Spec is not None:
# TODO: try to avoid ASN.1 schema instantiation
value = asn1Spec.clone(value)
valueLength = len(value)
if valueLength % 8:
alignedValue = value << (8 - valueLength % 8)
else:
alignedValue = value
substrate = alignedValue.asOctets()
length = len(substrate)
# We need at least 32-Bit / 4-Bytes
if length < 4:
padding = 4 - length
else:
padding = 0
ret = b'\x00' + substrate + (b'\x00' * padding)
return ret, False, True
BitStringEncoder.encodeValue = BitStringEncoder_encodeValue32
def BitString_NamedValues_prettyPrint(self, scope=0):
ret = "%s" % self.asBinary()
bits = []
highest_bit = 32
for byte in self.asNumbers():
for bit in [7, 6, 5, 4, 3, 2, 1, 0]:
mask = 1 << bit
if byte & mask:
val = 1
else:
val = 0
bits.append(val)
if len(bits) < highest_bit:
for bitPosition in range(len(bits), highest_bit):
bits.append(0)
indent = " " * scope
delim = ": (\n%s " % indent
for bitPosition in range(highest_bit):
if bitPosition in self.prettyPrintNamedValues:
name = self.prettyPrintNamedValues[bitPosition]
elif bits[bitPosition] != 0:
name = "unknown-bit-%u" % bitPosition
else:
continue
ret += "%s%s:%u" % (delim, name, bits[bitPosition])
delim = ",\n%s " % indent
ret += "\n%s)" % indent
return ret
krb5_asn1.TicketFlags.prettyPrintNamedValues =\
krb5_asn1.TicketFlagsValues.namedValues
krb5_asn1.TicketFlags.namedValues =\
krb5_asn1.TicketFlagsValues.namedValues
krb5_asn1.TicketFlags.prettyPrint =\
BitString_NamedValues_prettyPrint
krb5_asn1.KDCOptions.prettyPrintNamedValues =\
krb5_asn1.KDCOptionsValues.namedValues
krb5_asn1.KDCOptions.namedValues =\
krb5_asn1.KDCOptionsValues.namedValues
krb5_asn1.KDCOptions.prettyPrint =\
BitString_NamedValues_prettyPrint
krb5_asn1.APOptions.prettyPrintNamedValues =\
krb5_asn1.APOptionsValues.namedValues
krb5_asn1.APOptions.namedValues =\
krb5_asn1.APOptionsValues.namedValues
krb5_asn1.APOptions.prettyPrint =\
BitString_NamedValues_prettyPrint
krb5_asn1.PACOptionFlags.prettyPrintNamedValues =\
krb5_asn1.PACOptionFlagsValues.namedValues
krb5_asn1.PACOptionFlags.namedValues =\
krb5_asn1.PACOptionFlagsValues.namedValues
krb5_asn1.PACOptionFlags.prettyPrint =\
BitString_NamedValues_prettyPrint
def Integer_NamedValues_prettyPrint(self, scope=0):
intval = int(self)
if intval in self.prettyPrintNamedValues:
name = self.prettyPrintNamedValues[intval]
else:
name = "<__unknown__>"
ret = "%d (0x%x) %s" % (intval, intval, name)
return ret
krb5_asn1.NameType.prettyPrintNamedValues =\
krb5_asn1.NameTypeValues.namedValues
krb5_asn1.NameType.prettyPrint =\
Integer_NamedValues_prettyPrint
krb5_asn1.AuthDataType.prettyPrintNamedValues =\
krb5_asn1.AuthDataTypeValues.namedValues
krb5_asn1.AuthDataType.prettyPrint =\
Integer_NamedValues_prettyPrint
krb5_asn1.PADataType.prettyPrintNamedValues =\
krb5_asn1.PADataTypeValues.namedValues
krb5_asn1.PADataType.prettyPrint =\
Integer_NamedValues_prettyPrint
krb5_asn1.EncryptionType.prettyPrintNamedValues =\
krb5_asn1.EncryptionTypeValues.namedValues
krb5_asn1.EncryptionType.prettyPrint =\
Integer_NamedValues_prettyPrint
krb5_asn1.ChecksumType.prettyPrintNamedValues =\
krb5_asn1.ChecksumTypeValues.namedValues
krb5_asn1.ChecksumType.prettyPrint =\
Integer_NamedValues_prettyPrint
krb5_asn1.KerbErrorDataType.prettyPrintNamedValues =\
krb5_asn1.KerbErrorDataTypeValues.namedValues
krb5_asn1.KerbErrorDataType.prettyPrint =\
Integer_NamedValues_prettyPrint
class Krb5EncryptionKey:
def __init__(self, key, kvno):
EncTypeChecksum = {
kcrypto.Enctype.AES256: kcrypto.Cksumtype.SHA1_AES256,
kcrypto.Enctype.AES128: kcrypto.Cksumtype.SHA1_AES128,
kcrypto.Enctype.RC4: kcrypto.Cksumtype.HMAC_MD5,
}
self.key = key
self.etype = key.enctype
self.ctype = EncTypeChecksum[self.etype]
self.kvno = kvno
def encrypt(self, usage, plaintext):
ciphertext = kcrypto.encrypt(self.key, usage, plaintext)
return ciphertext
def decrypt(self, usage, ciphertext):
plaintext = kcrypto.decrypt(self.key, usage, ciphertext)
return plaintext
def make_zeroed_checksum(self, ctype=None):
if ctype is None:
ctype = self.ctype
checksum_len = kcrypto.checksum_len(ctype)
return bytes(checksum_len)
def make_checksum(self, usage, plaintext, ctype=None):
if ctype is None:
ctype = self.ctype
cksum = kcrypto.make_checksum(ctype, self.key, usage, plaintext)
return cksum
def verify_checksum(self, usage, plaintext, ctype, cksum):
if self.ctype != ctype:
raise AssertionError(f'key checksum type ({self.ctype}) != '
f'checksum type ({ctype})')
kcrypto.verify_checksum(ctype,
self.key,
usage,
plaintext,
cksum)
def export_obj(self):
EncryptionKey_obj = {
'keytype': self.etype,
'keyvalue': self.key.contents,
}
return EncryptionKey_obj
class RodcPacEncryptionKey(Krb5EncryptionKey):
def __init__(self, key, kvno, rodc_id=None):
super().__init__(key, kvno)
if rodc_id is None:
kvno = self.kvno
if kvno is not None:
kvno >>= 16
kvno &= (1 << 16) - 1
rodc_id = kvno or None
if rodc_id is not None:
self.rodc_id = rodc_id.to_bytes(2, byteorder='little')
else:
self.rodc_id = b''
def make_rodc_zeroed_checksum(self, ctype=None):
checksum = super().make_zeroed_checksum(ctype)
return checksum + bytes(len(self.rodc_id))
def make_rodc_checksum(self, usage, plaintext, ctype=None):
checksum = super().make_checksum(usage, plaintext, ctype)
return checksum + self.rodc_id
def verify_rodc_checksum(self, usage, plaintext, ctype, cksum):
if self.rodc_id:
cksum, cksum_rodc_id = cksum[:-2], cksum[-2:]
if self.rodc_id != cksum_rodc_id:
raise AssertionError(f'{self.rodc_id.hex()} != '
f'{cksum_rodc_id.hex()}')
super().verify_checksum(usage,
plaintext,
ctype,
cksum)
class ZeroedChecksumKey(RodcPacEncryptionKey):
def make_checksum(self, usage, plaintext, ctype=None):
return self.make_zeroed_checksum(ctype)
def make_rodc_checksum(self, usage, plaintext, ctype=None):
return self.make_rodc_zeroed_checksum(ctype)
class WrongLengthChecksumKey(RodcPacEncryptionKey):
def __init__(self, key, kvno, length):
super().__init__(key, kvno)
self._length = length
@classmethod
def _adjust_to_length(cls, checksum, length):
diff = length - len(checksum)
if diff > 0:
checksum += bytes(diff)
elif diff < 0:
checksum = checksum[:length]
return checksum
def make_zeroed_checksum(self, ctype=None):
return bytes(self._length)
def make_checksum(self, usage, plaintext, ctype=None):
checksum = super().make_checksum(usage, plaintext, ctype)
return self._adjust_to_length(checksum, self._length)
def make_rodc_zeroed_checksum(self, ctype=None):
return bytes(self._length)
def make_rodc_checksum(self, usage, plaintext, ctype=None):
checksum = super().make_rodc_checksum(usage, plaintext, ctype)
return self._adjust_to_length(checksum, self._length)
class KerberosCredentials(Credentials):
fast_supported_bits = (security.KERB_ENCTYPE_FAST_SUPPORTED |
security.KERB_ENCTYPE_COMPOUND_IDENTITY_SUPPORTED |
security.KERB_ENCTYPE_CLAIMS_SUPPORTED)
non_etype_bits = fast_supported_bits | (
security.KERB_ENCTYPE_RESOURCE_SID_COMPRESSION_DISABLED) | (
security.KERB_ENCTYPE_AES256_CTS_HMAC_SHA1_96_SK)
def __init__(self):
super(KerberosCredentials, self).__init__()
all_enc_types = 0
all_enc_types |= security.KERB_ENCTYPE_RC4_HMAC_MD5
all_enc_types |= security.KERB_ENCTYPE_AES128_CTS_HMAC_SHA1_96
all_enc_types |= security.KERB_ENCTYPE_AES256_CTS_HMAC_SHA1_96
self.as_supported_enctypes = all_enc_types
self.tgs_supported_enctypes = all_enc_types
self.ap_supported_enctypes = all_enc_types
self.kvno = None
self.forced_keys = {}
self.forced_salt = None
self.dn = None
self.upn = None
self.spn = None
def set_as_supported_enctypes(self, value):
self.as_supported_enctypes = int(value)
def set_tgs_supported_enctypes(self, value):
self.tgs_supported_enctypes = int(value)
def set_ap_supported_enctypes(self, value):
self.ap_supported_enctypes = int(value)
etype_map = collections.OrderedDict([
(kcrypto.Enctype.AES256,
security.KERB_ENCTYPE_AES256_CTS_HMAC_SHA1_96),
(kcrypto.Enctype.AES128,
security.KERB_ENCTYPE_AES128_CTS_HMAC_SHA1_96),
(kcrypto.Enctype.RC4,
security.KERB_ENCTYPE_RC4_HMAC_MD5),
(kcrypto.Enctype.DES_MD5,
security.KERB_ENCTYPE_DES_CBC_MD5),
(kcrypto.Enctype.DES_CRC,
security.KERB_ENCTYPE_DES_CBC_CRC)
])
@classmethod
def etypes_to_bits(cls, etypes):
bits = 0
for etype in etypes:
bit = cls.etype_map[etype]
if bits & bit:
raise ValueError(f'Got duplicate etype: {etype}')
bits |= bit
return bits
@classmethod
def bits_to_etypes(cls, bits):
etypes = ()
for etype, bit in cls.etype_map.items():
if bit & bits:
bits &= ~bit
etypes += (etype,)
bits &= ~cls.non_etype_bits
if bits != 0:
raise ValueError(f'Unsupported etype bits: {bits}')
return etypes
def get_as_krb5_etypes(self):
return self.bits_to_etypes(self.as_supported_enctypes)
def get_tgs_krb5_etypes(self):
return self.bits_to_etypes(self.tgs_supported_enctypes)
def get_ap_krb5_etypes(self):
return self.bits_to_etypes(self.ap_supported_enctypes)
def set_kvno(self, kvno):
# Sign-extend from 32 bits.
if kvno & 1 << 31:
kvno |= -1 << 31
self.kvno = kvno
def get_kvno(self):
return self.kvno
def set_forced_key(self, etype, hexkey):
etype = int(etype)
contents = binascii.a2b_hex(hexkey)
key = kcrypto.Key(etype, contents)
self.forced_keys[etype] = RodcPacEncryptionKey(key, self.kvno)
def get_forced_key(self, etype):
etype = int(etype)
return self.forced_keys.get(etype)
def set_forced_salt(self, salt):
self.forced_salt = bytes(salt)
def get_forced_salt(self):
return self.forced_salt
def get_salt(self):
if self.forced_salt is not None:
return self.forced_salt
upn = self.get_upn()
if upn is not None:
salt_name = upn.rsplit('@', 1)[0].replace('/', '')
else:
salt_name = self.get_username()
secure_schannel_type = self.get_secure_channel_type()
if secure_schannel_type in [SEC_CHAN_WKSTA,SEC_CHAN_BDC]:
salt_name = self.get_username().lower()
if salt_name[-1] == '$':
salt_name = salt_name[:-1]
salt_string = '%shost%s.%s' % (
self.get_realm().upper(),
salt_name,
self.get_realm().lower())
else:
salt_string = self.get_realm().upper() + salt_name
return salt_string.encode('utf-8')
def set_dn(self, dn):
self.dn = dn
def get_dn(self):
return self.dn
def set_spn(self, spn):
self.spn = spn
def get_spn(self):
return self.spn
def set_upn(self, upn):
self.upn = upn
def get_upn(self):
return self.upn
def update_password(self, password):
self.set_password(password)
self.set_kvno(self.get_kvno() + 1)
class KerberosTicketCreds:
def __init__(self, ticket, session_key,
crealm=None, cname=None,
srealm=None, sname=None,
decryption_key=None,
ticket_private=None,
encpart_private=None):
self.ticket = ticket
self.session_key = session_key
self.crealm = crealm
self.cname = cname
self.srealm = srealm
self.sname = sname
self.decryption_key = decryption_key
self.ticket_private = ticket_private
self.encpart_private = encpart_private
def set_sname(self, sname):
self.ticket['sname'] = sname
self.sname = sname
class RawKerberosTest(TestCaseInTempDir):
"""A raw Kerberos Test case."""
class KpasswdMode(Enum):
SET = object()
CHANGE = object()
pac_checksum_types = {krb5pac.PAC_TYPE_SRV_CHECKSUM,
krb5pac.PAC_TYPE_KDC_CHECKSUM,
krb5pac.PAC_TYPE_TICKET_CHECKSUM,
krb5pac.PAC_TYPE_FULL_CHECKSUM}
etypes_to_test = (
{"value": -1111, "name": "dummy", },
{"value": kcrypto.Enctype.AES256, "name": "aes128", },
{"value": kcrypto.Enctype.AES128, "name": "aes256", },
{"value": kcrypto.Enctype.RC4, "name": "rc4", },
)
expect_padata_outer = object()
setup_etype_test_permutations_done = False
@classmethod
def setup_etype_test_permutations(cls):
if cls.setup_etype_test_permutations_done:
return
res = []
num_idxs = len(cls.etypes_to_test)
permutations = []
for num in range(1, num_idxs + 1):
chunk = list(itertools.permutations(range(num_idxs), num))
for e in chunk:
el = list(e)
permutations.append(el)
for p in permutations:
name = None
etypes = ()
for idx in p:
n = cls.etypes_to_test[idx]["name"]
if name is None:
name = n
else:
name += "_%s" % n
etypes += (cls.etypes_to_test[idx]["value"],)
r = {"name": name, "etypes": etypes, }
res.append(r)
cls.etype_test_permutations = res
cls.setup_etype_test_permutations_done = True
@classmethod
def etype_test_permutation_name_idx(cls):
cls.setup_etype_test_permutations()
res = []
idx = 0
for e in cls.etype_test_permutations:
r = (e['name'], idx)
idx += 1
res.append(r)
return res
def etype_test_permutation_by_idx(self, idx):
e = self.etype_test_permutations[idx]
return (e['name'], e['etypes'])
@classmethod
def setUpClass(cls):
super().setUpClass()
cls.host = samba.tests.env_get_var_value('SERVER')
cls.dc_host = samba.tests.env_get_var_value('DC_SERVER')
# A dictionary containing credentials that have already been
# obtained.
cls.creds_dict = {}
kdc_fast_support = samba.tests.env_get_var_value('FAST_SUPPORT',
allow_missing=True)
if kdc_fast_support is None:
kdc_fast_support = '0'
cls.kdc_fast_support = bool(int(kdc_fast_support))
kdc_claims_support = samba.tests.env_get_var_value('CLAIMS_SUPPORT',
allow_missing=True)
if kdc_claims_support is None:
kdc_claims_support = '0'
cls.kdc_claims_support = bool(int(kdc_claims_support))
kdc_compound_id_support = samba.tests.env_get_var_value(
'COMPOUND_ID_SUPPORT',
allow_missing=True)
if kdc_compound_id_support is None:
kdc_compound_id_support = '0'
cls.kdc_compound_id_support = bool(int(kdc_compound_id_support))
tkt_sig_support = samba.tests.env_get_var_value('TKT_SIG_SUPPORT',
allow_missing=True)
if tkt_sig_support is None:
tkt_sig_support = '0'
cls.tkt_sig_support = bool(int(tkt_sig_support))
full_sig_support = samba.tests.env_get_var_value('FULL_SIG_SUPPORT',
allow_missing=True)
if full_sig_support is None:
full_sig_support = '0'
cls.full_sig_support = bool(int(full_sig_support))
expect_pac = samba.tests.env_get_var_value('EXPECT_PAC',
allow_missing=True)
if expect_pac is None:
expect_pac = '1'
cls.expect_pac = bool(int(expect_pac))
expect_extra_pac_buffers = samba.tests.env_get_var_value(
'EXPECT_EXTRA_PAC_BUFFERS',
allow_missing=True)
if expect_extra_pac_buffers is None:
expect_extra_pac_buffers = '1'
cls.expect_extra_pac_buffers = bool(int(expect_extra_pac_buffers))
default_etypes = samba.tests.env_get_var_value('DEFAULT_ETYPES',
allow_missing=True)
if default_etypes is not None:
default_etypes = int(default_etypes)
cls.default_etypes = default_etypes
forced_rc4 = samba.tests.env_get_var_value('FORCED_RC4',
allow_missing=True)
if forced_rc4 is None:
forced_rc4 = '0'
cls.forced_rc4 = bool(int(forced_rc4))
def setUp(self):
super().setUp()
self.do_asn1_print = False
self.do_hexdump = False
strict_checking = samba.tests.env_get_var_value('STRICT_CHECKING',
allow_missing=True)
if strict_checking is None:
strict_checking = '1'
self.strict_checking = bool(int(strict_checking))
self.s = None
self.unspecified_kvno = object()
def tearDown(self):
self._disconnect("tearDown")
super().tearDown()
def _disconnect(self, reason):
if self.s is None:
return
self.s.close()
self.s = None
if self.do_hexdump:
sys.stderr.write("disconnect[%s]\n" % reason)
def _connect_tcp(self, host, port=None):
if port is None:
port = 88
try:
self.a = socket.getaddrinfo(host, port, socket.AF_UNSPEC,
socket.SOCK_STREAM, socket.SOL_TCP,
0)
self.s = socket.socket(self.a[0][0], self.a[0][1], self.a[0][2])
self.s.settimeout(10)
self.s.connect(self.a[0][4])
except socket.error:
self.s.close()
raise
except IOError:
self.s.close()
raise
def connect(self, host, port=None):
self.assertNotConnected()
self._connect_tcp(host, port)
if self.do_hexdump:
sys.stderr.write("connected[%s]\n" % host)
def env_get_var(self, varname, prefix,
fallback_default=True,
allow_missing=False):
val = None
if prefix is not None:
allow_missing_prefix = allow_missing or fallback_default
val = samba.tests.env_get_var_value(
'%s_%s' % (prefix, varname),
allow_missing=allow_missing_prefix)
else:
fallback_default = True
if val is None and fallback_default:
val = samba.tests.env_get_var_value(varname,
allow_missing=allow_missing)
return val
def _get_krb5_creds_from_env(self, prefix,
default_username=None,
allow_missing_password=False,
allow_missing_keys=True,
require_strongest_key=False):
c = KerberosCredentials()
c.guess()
domain = self.env_get_var('DOMAIN', prefix)
realm = self.env_get_var('REALM', prefix)
allow_missing_username = default_username is not None
username = self.env_get_var('USERNAME', prefix,
fallback_default=False,
allow_missing=allow_missing_username)
if username is None:
username = default_username
password = self.env_get_var('PASSWORD', prefix,
fallback_default=False,
allow_missing=allow_missing_password)
c.set_domain(domain)
c.set_realm(realm)
c.set_username(username)
if password is not None:
c.set_password(password)
as_supported_enctypes = self.env_get_var('AS_SUPPORTED_ENCTYPES',
prefix, allow_missing=True)
if as_supported_enctypes is not None:
c.set_as_supported_enctypes(as_supported_enctypes)
tgs_supported_enctypes = self.env_get_var('TGS_SUPPORTED_ENCTYPES',
prefix, allow_missing=True)
if tgs_supported_enctypes is not None:
c.set_tgs_supported_enctypes(tgs_supported_enctypes)
ap_supported_enctypes = self.env_get_var('AP_SUPPORTED_ENCTYPES',
prefix, allow_missing=True)
if ap_supported_enctypes is not None:
c.set_ap_supported_enctypes(ap_supported_enctypes)
if require_strongest_key:
kvno_allow_missing = False
if password is None:
aes256_allow_missing = False
else:
aes256_allow_missing = True
else:
kvno_allow_missing = allow_missing_keys
aes256_allow_missing = allow_missing_keys
kvno = self.env_get_var('KVNO', prefix,
fallback_default=False,
allow_missing=kvno_allow_missing)
if kvno is not None:
c.set_kvno(int(kvno))
aes256_key = self.env_get_var('AES256_KEY_HEX', prefix,
fallback_default=False,
allow_missing=aes256_allow_missing)
if aes256_key is not None:
c.set_forced_key(kcrypto.Enctype.AES256, aes256_key)
aes128_key = self.env_get_var('AES128_KEY_HEX', prefix,
fallback_default=False,
allow_missing=True)
if aes128_key is not None:
c.set_forced_key(kcrypto.Enctype.AES128, aes128_key)
rc4_key = self.env_get_var('RC4_KEY_HEX', prefix,
fallback_default=False, allow_missing=True)
if rc4_key is not None:
c.set_forced_key(kcrypto.Enctype.RC4, rc4_key)
if not allow_missing_keys:
self.assertTrue(c.forced_keys,
'Please supply %s encryption keys '
'in environment' % prefix)
return c
def _get_krb5_creds(self,
prefix,
default_username=None,
allow_missing_password=False,
allow_missing_keys=True,
require_strongest_key=False,
fallback_creds_fn=None):
if prefix in self.creds_dict:
return self.creds_dict[prefix]
# We don't have the credentials already
creds = None
env_err = None
try:
# Try to obtain them from the environment
creds = self._get_krb5_creds_from_env(
prefix,
default_username=default_username,
allow_missing_password=allow_missing_password,
allow_missing_keys=allow_missing_keys,
require_strongest_key=require_strongest_key)
except Exception as err:
# An error occurred, so save it for later
env_err = err
else:
self.assertIsNotNone(creds)
# Save the obtained credentials
self.creds_dict[prefix] = creds
return creds
if fallback_creds_fn is not None:
try:
# Try to use the fallback method
creds = fallback_creds_fn()
except Exception as err:
print("ERROR FROM ENV: %r" % (env_err))
print("FALLBACK-FN: %s" % (fallback_creds_fn))
print("FALLBACK-ERROR: %r" % (err))
else:
self.assertIsNotNone(creds)
# Save the obtained credentials
self.creds_dict[prefix] = creds
return creds
# Both methods failed, so raise the exception from the
# environment method
raise env_err
def get_user_creds(self,
allow_missing_password=False,
allow_missing_keys=True):
c = self._get_krb5_creds(prefix=None,
allow_missing_password=allow_missing_password,
allow_missing_keys=allow_missing_keys)
return c
def get_service_creds(self,
allow_missing_password=False,
allow_missing_keys=True):
c = self._get_krb5_creds(prefix='SERVICE',
allow_missing_password=allow_missing_password,
allow_missing_keys=allow_missing_keys)
return c
def get_client_creds(self,
allow_missing_password=False,
allow_missing_keys=True):
c = self._get_krb5_creds(prefix='CLIENT',
allow_missing_password=allow_missing_password,
allow_missing_keys=allow_missing_keys)
return c
def get_server_creds(self,
allow_missing_password=False,
allow_missing_keys=True):
c = self._get_krb5_creds(prefix='SERVER',
allow_missing_password=allow_missing_password,
allow_missing_keys=allow_missing_keys)
return c
def get_admin_creds(self,
allow_missing_password=False,
allow_missing_keys=True):
c = self._get_krb5_creds(prefix='ADMIN',
allow_missing_password=allow_missing_password,
allow_missing_keys=allow_missing_keys)
c.set_gensec_features(c.get_gensec_features() | FEATURE_SEAL)
c.set_workstation('')
return c
def get_rodc_krbtgt_creds(self,
require_keys=True,
require_strongest_key=False):
if require_strongest_key:
self.assertTrue(require_keys)
c = self._get_krb5_creds(prefix='RODC_KRBTGT',
allow_missing_password=True,
allow_missing_keys=not require_keys,
require_strongest_key=require_strongest_key)
return c
def get_krbtgt_creds(self,
require_keys=True,
require_strongest_key=False):
if require_strongest_key:
self.assertTrue(require_keys)
c = self._get_krb5_creds(prefix='KRBTGT',
default_username='krbtgt',
allow_missing_password=True,
allow_missing_keys=not require_keys,
require_strongest_key=require_strongest_key)
return c
def get_anon_creds(self):
c = Credentials()
c.set_anonymous()
return c
def asn1_dump(self, name, obj, asn1_print=None):
if asn1_print is None:
asn1_print = self.do_asn1_print
if asn1_print:
if name is not None:
sys.stderr.write("%s:\n%s" % (name, obj))
else:
sys.stderr.write("%s" % (obj))
def hex_dump(self, name, blob, hexdump=None):
if hexdump is None:
hexdump = self.do_hexdump
if hexdump:
sys.stderr.write(
"%s: %d\n%s" % (name, len(blob), self.hexdump(blob)))
def der_decode(
self,
blob,
asn1Spec=None,
native_encode=True,
asn1_print=None,
hexdump=None):
if asn1Spec is not None:
class_name = type(asn1Spec).__name__.split(':')[0]
else:
class_name = "<None-asn1Spec>"
self.hex_dump(class_name, blob, hexdump=hexdump)
obj, _ = pyasn1_der_decode(blob, asn1Spec=asn1Spec)
self.asn1_dump(None, obj, asn1_print=asn1_print)
if native_encode:
obj = pyasn1_native_encode(obj)
return obj
def der_encode(
self,
obj,
asn1Spec=None,
native_decode=True,
asn1_print=None,
hexdump=None):
if native_decode:
obj = pyasn1_native_decode(obj, asn1Spec=asn1Spec)
class_name = type(obj).__name__.split(':')[0]
if class_name is not None:
self.asn1_dump(None, obj, asn1_print=asn1_print)
blob = pyasn1_der_encode(obj)
if class_name is not None:
self.hex_dump(class_name, blob, hexdump=hexdump)
return blob
def send_pdu(self, req, asn1_print=None, hexdump=None):
k5_pdu = self.der_encode(
req, native_decode=False, asn1_print=asn1_print, hexdump=False)
self.send_msg(k5_pdu, hexdump=hexdump)
def send_msg(self, msg, hexdump=None):
header = struct.pack('>I', len(msg))
req_pdu = header
req_pdu += msg
self.hex_dump("send_msg", header, hexdump=hexdump)
self.hex_dump("send_msg", msg, hexdump=hexdump)
try:
while True:
sent = self.s.send(req_pdu, 0)
if sent == len(req_pdu):
return
req_pdu = req_pdu[sent:]
except socket.error as e:
self._disconnect("send_msg: %s" % e)
raise
except IOError as e:
self._disconnect("send_msg: %s" % e)
raise
def recv_raw(self, num_recv=0xffff, hexdump=None, timeout=None):
rep_pdu = None
try:
if timeout is not None:
self.s.settimeout(timeout)
rep_pdu = self.s.recv(num_recv, 0)
self.s.settimeout(10)
if len(rep_pdu) == 0:
self._disconnect("recv_raw: EOF")
return None
self.hex_dump("recv_raw", rep_pdu, hexdump=hexdump)
except socket.timeout:
self.s.settimeout(10)
sys.stderr.write("recv_raw: TIMEOUT\n")
except socket.error as e:
self._disconnect("recv_raw: %s" % e)
raise
except IOError as e:
self._disconnect("recv_raw: %s" % e)
raise
return rep_pdu
def recv_pdu_raw(self, asn1_print=None, hexdump=None, timeout=None):
raw_pdu = self.recv_raw(
num_recv=4, hexdump=hexdump, timeout=timeout)
if raw_pdu is None:
return None
header = struct.unpack(">I", raw_pdu[0:4])
k5_len = header[0]
if k5_len == 0:
return ""
missing = k5_len
rep_pdu = b''
while missing > 0:
raw_pdu = self.recv_raw(
num_recv=missing, hexdump=hexdump, timeout=timeout)
self.assertGreaterEqual(len(raw_pdu), 1)
rep_pdu += raw_pdu
missing = k5_len - len(rep_pdu)
return rep_pdu
def recv_reply(self, asn1_print=None, hexdump=None, timeout=None):
rep_pdu = self.recv_pdu_raw(asn1_print=asn1_print,
hexdump=hexdump,
timeout=timeout)
if not rep_pdu:
return None, rep_pdu
k5_raw = self.der_decode(
rep_pdu,
asn1Spec=None,
native_encode=False,
asn1_print=False,
hexdump=False)
pvno = k5_raw['field-0']
self.assertEqual(pvno, 5)
msg_type = k5_raw['field-1']
self.assertIn(msg_type, [KRB_AS_REP, KRB_TGS_REP, KRB_ERROR])
if msg_type == KRB_AS_REP:
asn1Spec = krb5_asn1.AS_REP()
elif msg_type == KRB_TGS_REP:
asn1Spec = krb5_asn1.TGS_REP()
elif msg_type == KRB_ERROR:
asn1Spec = krb5_asn1.KRB_ERROR()
rep = self.der_decode(rep_pdu, asn1Spec=asn1Spec,
asn1_print=asn1_print, hexdump=False)
return (rep, rep_pdu)
def recv_pdu(self, asn1_print=None, hexdump=None, timeout=None):
(rep, rep_pdu) = self.recv_reply(asn1_print=asn1_print,
hexdump=hexdump,
timeout=timeout)
return rep
def assertIsConnected(self):
self.assertIsNotNone(self.s, msg="Not connected")
def assertNotConnected(self):
self.assertIsNone(self.s, msg="Is connected")
def send_recv_transaction(
self,
req,
asn1_print=None,
hexdump=None,
timeout=None,
to_rodc=False):
host = self.host if to_rodc else self.dc_host
self.connect(host)
try:
self.send_pdu(req, asn1_print=asn1_print, hexdump=hexdump)
rep = self.recv_pdu(
asn1_print=asn1_print, hexdump=hexdump, timeout=timeout)
except Exception:
self._disconnect("transaction failed")
raise
self._disconnect("transaction done")
return rep
def assertNoValue(self, value):
self.assertTrue(value.isNoValue)
def assertHasValue(self, value):
self.assertIsNotNone(value)
def getElementValue(self, obj, elem):
return obj.get(elem)
def assertElementMissing(self, obj, elem):
v = self.getElementValue(obj, elem)
self.assertIsNone(v)
def assertElementPresent(self, obj, elem, expect_empty=False):
v = self.getElementValue(obj, elem)
self.assertIsNotNone(v)
if self.strict_checking:
if isinstance(v, collections.abc.Container):
if expect_empty:
self.assertEqual(0, len(v))
else:
self.assertNotEqual(0, len(v))
def assertElementEqual(self, obj, elem, value):
v = self.getElementValue(obj, elem)
self.assertIsNotNone(v)
self.assertEqual(v, value)
def assertElementEqualUTF8(self, obj, elem, value):
v = self.getElementValue(obj, elem)
self.assertIsNotNone(v)
self.assertEqual(v, bytes(value, 'utf8'))
def assertPrincipalEqual(self, princ1, princ2):
self.assertEqual(princ1['name-type'], princ2['name-type'])
self.assertEqual(
len(princ1['name-string']),
len(princ2['name-string']),
msg="princ1=%s != princ2=%s" % (princ1, princ2))
for idx in range(len(princ1['name-string'])):
self.assertEqual(
princ1['name-string'][idx],
princ2['name-string'][idx],
msg="princ1=%s != princ2=%s" % (princ1, princ2))
def assertElementEqualPrincipal(self, obj, elem, value):
v = self.getElementValue(obj, elem)
self.assertIsNotNone(v)
v = pyasn1_native_decode(v, asn1Spec=krb5_asn1.PrincipalName())
self.assertPrincipalEqual(v, value)
def assertElementKVNO(self, obj, elem, value):
v = self.getElementValue(obj, elem)
if value == "autodetect":
value = v
if value is not None:
self.assertIsNotNone(v)
# The value on the wire should never be 0
self.assertNotEqual(v, 0)
# unspecified_kvno means we don't know the kvno,
# but want to enforce its presence
if value is not self.unspecified_kvno:
value = int(value)
self.assertNotEqual(value, 0)
self.assertEqual(v, value)
else:
self.assertIsNone(v)
def assertElementFlags(self, obj, elem, expected, unexpected):
v = self.getElementValue(obj, elem)
self.assertIsNotNone(v)
if expected is not None:
self.assertIsInstance(expected, krb5_asn1.TicketFlags)
for i, flag in enumerate(expected):
if flag == 1:
self.assertEqual('1', v[i],
f"'{expected.namedValues[i]}' "
f"expected in {v}")
if unexpected is not None:
self.assertIsInstance(unexpected, krb5_asn1.TicketFlags)
for i, flag in enumerate(unexpected):
if flag == 1:
self.assertEqual('0', v[i],
f"'{unexpected.namedValues[i]}' "
f"unexpected in {v}")
def assertSequenceElementsEqual(self, expected, got, *,
require_strict=None,
require_ordered=True):
if self.strict_checking and require_ordered:
self.assertEqual(expected, got)
else:
fail_msg = f'expected: {expected} got: {got}'
if not self.strict_checking and require_strict is not None:
fail_msg += f' (ignoring: {require_strict})'
expected = (x for x in expected if x not in require_strict)
got = (x for x in got if x not in require_strict)
self.assertCountEqual(expected, got, fail_msg)
def get_KerberosTimeWithUsec(self, epoch=None, offset=None):
if epoch is None:
epoch = time.time()
if offset is not None:
epoch = epoch + int(offset)
dt = datetime.datetime.fromtimestamp(epoch, tz=datetime.timezone.utc)
return (dt.strftime("%Y%m%d%H%M%SZ"), dt.microsecond)
def get_KerberosTime(self, epoch=None, offset=None):
(s, _) = self.get_KerberosTimeWithUsec(epoch=epoch, offset=offset)
return s
def get_EpochFromKerberosTime(self, kerberos_time):
if isinstance(kerberos_time, bytes):
kerberos_time = kerberos_time.decode()
epoch = datetime.datetime.strptime(kerberos_time,
'%Y%m%d%H%M%SZ')
epoch = epoch.replace(tzinfo=datetime.timezone.utc)
epoch = int(epoch.timestamp())
return epoch
def get_Nonce(self):
nonce_min = 0x7f000000
nonce_max = 0x7fffffff
v = random.randint(nonce_min, nonce_max)
return v
def get_pa_dict(self, pa_data):
pa_dict = {}
if pa_data is not None:
for pa in pa_data:
pa_type = pa['padata-type']
if pa_type in pa_dict:
raise RuntimeError(f'Duplicate type {pa_type}')
pa_dict[pa_type] = pa['padata-value']
return pa_dict
def SessionKey_create(self, etype, contents, kvno=None):
key = kcrypto.Key(etype, contents)
return RodcPacEncryptionKey(key, kvno)
def PasswordKey_create(self, etype=None, pwd=None, salt=None, kvno=None,
params=None):
self.assertIsNotNone(pwd)
self.assertIsNotNone(salt)
key = kcrypto.string_to_key(etype, pwd, salt, params=params)
return RodcPacEncryptionKey(key, kvno)
def PasswordKey_from_etype_info2(self, creds, etype_info2, kvno=None):
e = etype_info2['etype']
salt = etype_info2.get('salt')
if e == kcrypto.Enctype.RC4:
nthash = creds.get_nt_hash()
return self.SessionKey_create(etype=e, contents=nthash, kvno=kvno)
params = etype_info2.get('s2kparams')
password = creds.get_password()
return self.PasswordKey_create(
etype=e, pwd=password, salt=salt, kvno=kvno, params=params)
def TicketDecryptionKey_from_creds(self, creds, etype=None):
if etype is None:
etypes = creds.get_tgs_krb5_etypes()
if etypes and etypes[0] not in (kcrypto.Enctype.DES_CRC,
kcrypto.Enctype.DES_MD5):
etype = etypes[0]
else:
etype = kcrypto.Enctype.RC4
forced_key = creds.get_forced_key(etype)
if forced_key is not None:
return forced_key
kvno = creds.get_kvno()
fail_msg = ("%s has no fixed key for etype[%s] kvno[%s] "
"nor a password specified, " % (
creds.get_username(), etype, kvno))
if etype == kcrypto.Enctype.RC4:
nthash = creds.get_nt_hash()
self.assertIsNotNone(nthash, msg=fail_msg)
return self.SessionKey_create(etype=etype,
contents=nthash,
kvno=kvno)
password = creds.get_password()
self.assertIsNotNone(password, msg=fail_msg)
salt = creds.get_salt()
return self.PasswordKey_create(etype=etype,
pwd=password,
salt=salt,
kvno=kvno)
def RandomKey(self, etype):
e = kcrypto._get_enctype_profile(etype)
contents = samba.generate_random_bytes(e.keysize)
return self.SessionKey_create(etype=etype, contents=contents)
def EncryptionKey_import(self, EncryptionKey_obj):
return self.SessionKey_create(EncryptionKey_obj['keytype'],
EncryptionKey_obj['keyvalue'])
def EncryptedData_create(self, key, usage, plaintext):
# EncryptedData ::= SEQUENCE {
# etype [0] Int32 -- EncryptionType --,
# kvno [1] Int32 OPTIONAL,
# cipher [2] OCTET STRING -- ciphertext
# }
ciphertext = key.encrypt(usage, plaintext)
EncryptedData_obj = {
'etype': key.etype,
'cipher': ciphertext
}
if key.kvno is not None:
EncryptedData_obj['kvno'] = key.kvno
return EncryptedData_obj
def Checksum_create(self, key, usage, plaintext, ctype=None):
# Checksum ::= SEQUENCE {
# cksumtype [0] Int32,
# checksum [1] OCTET STRING
# }
if ctype is None:
ctype = key.ctype
checksum = key.make_checksum(usage, plaintext, ctype=ctype)
Checksum_obj = {
'cksumtype': ctype,
'checksum': checksum,
}
return Checksum_obj
@classmethod
def PrincipalName_create(cls, name_type, names):
# PrincipalName ::= SEQUENCE {
# name-type [0] Int32,
# name-string [1] SEQUENCE OF KerberosString
# }
PrincipalName_obj = {
'name-type': name_type,
'name-string': names,
}
return PrincipalName_obj
def AuthorizationData_create(self, ad_type, ad_data):
# AuthorizationData ::= SEQUENCE {
# ad-type [0] Int32,
# ad-data [1] OCTET STRING
# }
AUTH_DATA_obj = {
'ad-type': ad_type,
'ad-data': ad_data
}
return AUTH_DATA_obj
def PA_DATA_create(self, padata_type, padata_value):
# PA-DATA ::= SEQUENCE {
# -- NOTE: first tag is [1], not [0]
# padata-type [1] Int32,
# padata-value [2] OCTET STRING -- might be encoded AP-REQ
# }
PA_DATA_obj = {
'padata-type': padata_type,
'padata-value': padata_value,
}
return PA_DATA_obj
def PA_ENC_TS_ENC_create(self, ts, usec):
# PA-ENC-TS-ENC ::= SEQUENCE {
# patimestamp[0] KerberosTime, -- client's time
# pausec[1] krb5int32 OPTIONAL
# }
PA_ENC_TS_ENC_obj = {
'patimestamp': ts,
'pausec': usec,
}
return PA_ENC_TS_ENC_obj
def PA_PAC_OPTIONS_create(self, options):
# PA-PAC-OPTIONS ::= SEQUENCE {
# options [0] PACOptionFlags
# }
PA_PAC_OPTIONS_obj = {
'options': options
}
return PA_PAC_OPTIONS_obj
def KRB_FAST_ARMOR_create(self, armor_type, armor_value):
# KrbFastArmor ::= SEQUENCE {
# armor-type [0] Int32,
# armor-value [1] OCTET STRING,
# ...
# }
KRB_FAST_ARMOR_obj = {
'armor-type': armor_type,
'armor-value': armor_value
}
return KRB_FAST_ARMOR_obj
def KRB_FAST_REQ_create(self, fast_options, padata, req_body):
# KrbFastReq ::= SEQUENCE {
# fast-options [0] FastOptions,
# padata [1] SEQUENCE OF PA-DATA,
# req-body [2] KDC-REQ-BODY,
# ...
# }
KRB_FAST_REQ_obj = {
'fast-options': fast_options,
'padata': padata,
'req-body': req_body
}
return KRB_FAST_REQ_obj
def KRB_FAST_ARMORED_REQ_create(self, armor, req_checksum, enc_fast_req):
# KrbFastArmoredReq ::= SEQUENCE {
# armor [0] KrbFastArmor OPTIONAL,
# req-checksum [1] Checksum,
# enc-fast-req [2] EncryptedData -- KrbFastReq --
# }
KRB_FAST_ARMORED_REQ_obj = {
'req-checksum': req_checksum,
'enc-fast-req': enc_fast_req
}
if armor is not None:
KRB_FAST_ARMORED_REQ_obj['armor'] = armor
return KRB_FAST_ARMORED_REQ_obj
def PA_FX_FAST_REQUEST_create(self, armored_data):
# PA-FX-FAST-REQUEST ::= CHOICE {
# armored-data [0] KrbFastArmoredReq,
# ...
# }
PA_FX_FAST_REQUEST_obj = {
'armored-data': armored_data
}
return PA_FX_FAST_REQUEST_obj
def KERB_PA_PAC_REQUEST_create(self, include_pac, pa_data_create=True):
# KERB-PA-PAC-REQUEST ::= SEQUENCE {
# include-pac[0] BOOLEAN --If TRUE, and no pac present,
# -- include PAC.
# --If FALSE, and PAC present,
# -- remove PAC.
# }
KERB_PA_PAC_REQUEST_obj = {
'include-pac': include_pac,
}
if not pa_data_create:
return KERB_PA_PAC_REQUEST_obj
pa_pac = self.der_encode(KERB_PA_PAC_REQUEST_obj,
asn1Spec=krb5_asn1.KERB_PA_PAC_REQUEST())
pa_data = self.PA_DATA_create(PADATA_PAC_REQUEST, pa_pac)
return pa_data
def get_pa_pac_options(self, options):
pac_options = self.PA_PAC_OPTIONS_create(options)
pac_options = self.der_encode(pac_options,
asn1Spec=krb5_asn1.PA_PAC_OPTIONS())
pac_options = self.PA_DATA_create(PADATA_PAC_OPTIONS, pac_options)
return pac_options
def KDC_REQ_BODY_create(self,
kdc_options,
cname,
realm,
sname,
from_time,
till_time,
renew_time,
nonce,
etypes,
addresses,
additional_tickets,
EncAuthorizationData,
EncAuthorizationData_key,
EncAuthorizationData_usage,
asn1_print=None,
hexdump=None):
# KDC-REQ-BODY ::= SEQUENCE {
# kdc-options [0] KDCOptions,
# cname [1] PrincipalName OPTIONAL
# -- Used only in AS-REQ --,
# realm [2] Realm
# -- Server's realm
# -- Also client's in AS-REQ --,
# sname [3] PrincipalName OPTIONAL,
# from [4] KerberosTime OPTIONAL,
# till [5] KerberosTime,
# rtime [6] KerberosTime OPTIONAL,
# nonce [7] UInt32,
# etype [8] SEQUENCE OF Int32
# -- EncryptionType
# -- in preference order --,
# addresses [9] HostAddresses OPTIONAL,
# enc-authorization-data [10] EncryptedData OPTIONAL
# -- AuthorizationData --,
# additional-tickets [11] SEQUENCE OF Ticket OPTIONAL
# -- NOTE: not empty
# }
if EncAuthorizationData is not None:
enc_ad_plain = self.der_encode(
EncAuthorizationData,
asn1Spec=krb5_asn1.AuthorizationData(),
asn1_print=asn1_print,
hexdump=hexdump)
enc_ad = self.EncryptedData_create(EncAuthorizationData_key,
EncAuthorizationData_usage,
enc_ad_plain)
else:
enc_ad = None
KDC_REQ_BODY_obj = {
'kdc-options': kdc_options,
'realm': realm,
'till': till_time,
'nonce': nonce,
'etype': etypes,
}
if cname is not None:
KDC_REQ_BODY_obj['cname'] = cname
if sname is not None:
KDC_REQ_BODY_obj['sname'] = sname
if from_time is not None:
KDC_REQ_BODY_obj['from'] = from_time
if renew_time is not None:
KDC_REQ_BODY_obj['rtime'] = renew_time
if addresses is not None:
KDC_REQ_BODY_obj['addresses'] = addresses
if enc_ad is not None:
KDC_REQ_BODY_obj['enc-authorization-data'] = enc_ad
if additional_tickets is not None:
KDC_REQ_BODY_obj['additional-tickets'] = additional_tickets
return KDC_REQ_BODY_obj
def KDC_REQ_create(self,
msg_type,
padata,
req_body,
asn1Spec=None,
asn1_print=None,
hexdump=None):
# KDC-REQ ::= SEQUENCE {
# -- NOTE: first tag is [1], not [0]
# pvno [1] INTEGER (5) ,
# msg-type [2] INTEGER (10 -- AS -- | 12 -- TGS --),
# padata [3] SEQUENCE OF PA-DATA OPTIONAL
# -- NOTE: not empty --,
# req-body [4] KDC-REQ-BODY
# }
#
KDC_REQ_obj = {
'pvno': 5,
'msg-type': msg_type,
'req-body': req_body,
}
if padata is not None:
KDC_REQ_obj['padata'] = padata
if asn1Spec is not None:
KDC_REQ_decoded = pyasn1_native_decode(
KDC_REQ_obj, asn1Spec=asn1Spec)
else:
KDC_REQ_decoded = None
return KDC_REQ_obj, KDC_REQ_decoded
def AS_REQ_create(self,
padata, # optional
kdc_options, # required
cname, # optional
realm, # required
sname, # optional
from_time, # optional
till_time, # required
renew_time, # optional
nonce, # required
etypes, # required
addresses, # optional
additional_tickets,
native_decoded_only=True,
asn1_print=None,
hexdump=None):
# KDC-REQ ::= SEQUENCE {
# -- NOTE: first tag is [1], not [0]
# pvno [1] INTEGER (5) ,
# msg-type [2] INTEGER (10 -- AS -- | 12 -- TGS --),
# padata [3] SEQUENCE OF PA-DATA OPTIONAL
# -- NOTE: not empty --,
# req-body [4] KDC-REQ-BODY
# }
#
# KDC-REQ-BODY ::= SEQUENCE {
# kdc-options [0] KDCOptions,
# cname [1] PrincipalName OPTIONAL
# -- Used only in AS-REQ --,
# realm [2] Realm
# -- Server's realm
# -- Also client's in AS-REQ --,
# sname [3] PrincipalName OPTIONAL,
# from [4] KerberosTime OPTIONAL,
# till [5] KerberosTime,
# rtime [6] KerberosTime OPTIONAL,
# nonce [7] UInt32,
# etype [8] SEQUENCE OF Int32
# -- EncryptionType
# -- in preference order --,
# addresses [9] HostAddresses OPTIONAL,
# enc-authorization-data [10] EncryptedData OPTIONAL
# -- AuthorizationData --,
# additional-tickets [11] SEQUENCE OF Ticket OPTIONAL
# -- NOTE: not empty
# }
KDC_REQ_BODY_obj = self.KDC_REQ_BODY_create(
kdc_options,
cname,
realm,
sname,
from_time,
till_time,
renew_time,
nonce,
etypes,
addresses,
additional_tickets,
EncAuthorizationData=None,
EncAuthorizationData_key=None,
EncAuthorizationData_usage=None,
asn1_print=asn1_print,
hexdump=hexdump)
obj, decoded = self.KDC_REQ_create(
msg_type=KRB_AS_REQ,
padata=padata,
req_body=KDC_REQ_BODY_obj,
asn1Spec=krb5_asn1.AS_REQ(),
asn1_print=asn1_print,
hexdump=hexdump)
if native_decoded_only:
return decoded
return decoded, obj
def AP_REQ_create(self, ap_options, ticket, authenticator):
# AP-REQ ::= [APPLICATION 14] SEQUENCE {
# pvno [0] INTEGER (5),
# msg-type [1] INTEGER (14),
# ap-options [2] APOptions,
# ticket [3] Ticket,
# authenticator [4] EncryptedData -- Authenticator
# }
AP_REQ_obj = {
'pvno': 5,
'msg-type': KRB_AP_REQ,
'ap-options': ap_options,
'ticket': ticket,
'authenticator': authenticator,
}
return AP_REQ_obj
def Authenticator_create(
self, crealm, cname, cksum, cusec, ctime, subkey, seq_number,
authorization_data):
# -- Unencrypted authenticator
# Authenticator ::= [APPLICATION 2] SEQUENCE {
# authenticator-vno [0] INTEGER (5),
# crealm [1] Realm,
# cname [2] PrincipalName,
# cksum [3] Checksum OPTIONAL,
# cusec [4] Microseconds,
# ctime [5] KerberosTime,
# subkey [6] EncryptionKey OPTIONAL,
# seq-number [7] UInt32 OPTIONAL,
# authorization-data [8] AuthorizationData OPTIONAL
# }
Authenticator_obj = {
'authenticator-vno': 5,
'crealm': crealm,
'cname': cname,
'cusec': cusec,
'ctime': ctime,
}
if cksum is not None:
Authenticator_obj['cksum'] = cksum
if subkey is not None:
Authenticator_obj['subkey'] = subkey
if seq_number is not None:
Authenticator_obj['seq-number'] = seq_number
if authorization_data is not None:
Authenticator_obj['authorization-data'] = authorization_data
return Authenticator_obj
def TGS_REQ_create(self,
padata, # optional
cusec,
ctime,
ticket,
kdc_options, # required
cname, # optional
realm, # required
sname, # optional
from_time, # optional
till_time, # required
renew_time, # optional
nonce, # required
etypes, # required
addresses, # optional
EncAuthorizationData,
EncAuthorizationData_key,
additional_tickets,
ticket_session_key,
authenticator_subkey=None,
body_checksum_type=None,
native_decoded_only=True,
asn1_print=None,
hexdump=None):
# KDC-REQ ::= SEQUENCE {
# -- NOTE: first tag is [1], not [0]
# pvno [1] INTEGER (5) ,
# msg-type [2] INTEGER (10 -- AS -- | 12 -- TGS --),
# padata [3] SEQUENCE OF PA-DATA OPTIONAL
# -- NOTE: not empty --,
# req-body [4] KDC-REQ-BODY
# }
#
# KDC-REQ-BODY ::= SEQUENCE {
# kdc-options [0] KDCOptions,
# cname [1] PrincipalName OPTIONAL
# -- Used only in AS-REQ --,
# realm [2] Realm
# -- Server's realm
# -- Also client's in AS-REQ --,
# sname [3] PrincipalName OPTIONAL,
# from [4] KerberosTime OPTIONAL,
# till [5] KerberosTime,
# rtime [6] KerberosTime OPTIONAL,
# nonce [7] UInt32,
# etype [8] SEQUENCE OF Int32
# -- EncryptionType
# -- in preference order --,
# addresses [9] HostAddresses OPTIONAL,
# enc-authorization-data [10] EncryptedData OPTIONAL
# -- AuthorizationData --,
# additional-tickets [11] SEQUENCE OF Ticket OPTIONAL
# -- NOTE: not empty
# }
if authenticator_subkey is not None:
EncAuthorizationData_usage = KU_TGS_REQ_AUTH_DAT_SUBKEY
else:
EncAuthorizationData_usage = KU_TGS_REQ_AUTH_DAT_SESSION
req_body = self.KDC_REQ_BODY_create(
kdc_options=kdc_options,
cname=None,
realm=realm,
sname=sname,
from_time=from_time,
till_time=till_time,
renew_time=renew_time,
nonce=nonce,
etypes=etypes,
addresses=addresses,
additional_tickets=additional_tickets,
EncAuthorizationData=EncAuthorizationData,
EncAuthorizationData_key=EncAuthorizationData_key,
EncAuthorizationData_usage=EncAuthorizationData_usage)
req_body_blob = self.der_encode(req_body,
asn1Spec=krb5_asn1.KDC_REQ_BODY(),
asn1_print=asn1_print, hexdump=hexdump)
req_body_checksum = self.Checksum_create(ticket_session_key,
KU_TGS_REQ_AUTH_CKSUM,
req_body_blob,
ctype=body_checksum_type)
subkey_obj = None
if authenticator_subkey is not None:
subkey_obj = authenticator_subkey.export_obj()
seq_number = random.randint(0, 0xfffffffe)
authenticator = self.Authenticator_create(
crealm=realm,
cname=cname,
cksum=req_body_checksum,
cusec=cusec,
ctime=ctime,
subkey=subkey_obj,
seq_number=seq_number,
authorization_data=None)
authenticator = self.der_encode(
authenticator,
asn1Spec=krb5_asn1.Authenticator(),
asn1_print=asn1_print,
hexdump=hexdump)
authenticator = self.EncryptedData_create(
ticket_session_key, KU_TGS_REQ_AUTH, authenticator)
ap_options = krb5_asn1.APOptions('0')
ap_req = self.AP_REQ_create(ap_options=str(ap_options),
ticket=ticket,
authenticator=authenticator)
ap_req = self.der_encode(ap_req, asn1Spec=krb5_asn1.AP_REQ(),
asn1_print=asn1_print, hexdump=hexdump)
pa_tgs_req = self.PA_DATA_create(PADATA_KDC_REQ, ap_req)
if padata is not None:
padata.append(pa_tgs_req)
else:
padata = [pa_tgs_req]
obj, decoded = self.KDC_REQ_create(
msg_type=KRB_TGS_REQ,
padata=padata,
req_body=req_body,
asn1Spec=krb5_asn1.TGS_REQ(),
asn1_print=asn1_print,
hexdump=hexdump)
if native_decoded_only:
return decoded
return decoded, obj
def PA_S4U2Self_create(self, name, realm, tgt_session_key, ctype=None):
# PA-S4U2Self ::= SEQUENCE {
# name [0] PrincipalName,
# realm [1] Realm,
# cksum [2] Checksum,
# auth [3] GeneralString
# }
cksum_data = name['name-type'].to_bytes(4, byteorder='little')
for n in name['name-string']:
cksum_data += n.encode()
cksum_data += realm.encode()
cksum_data += "Kerberos".encode()
cksum = self.Checksum_create(tgt_session_key,
KU_NON_KERB_CKSUM_SALT,
cksum_data,
ctype)
PA_S4U2Self_obj = {
'name': name,
'realm': realm,
'cksum': cksum,
'auth': "Kerberos",
}
pa_s4u2self = self.der_encode(
PA_S4U2Self_obj, asn1Spec=krb5_asn1.PA_S4U2Self())
return self.PA_DATA_create(PADATA_FOR_USER, pa_s4u2self)
def ChangePasswdDataMS_create(self,
new_password,
target_princ=None,
target_realm=None):
ChangePasswdDataMS_obj = {
'newpasswd': new_password,
}
if target_princ is not None:
ChangePasswdDataMS_obj['targname'] = target_princ
if target_realm is not None:
ChangePasswdDataMS_obj['targrealm'] = target_realm
change_password_data = self.der_encode(
ChangePasswdDataMS_obj, asn1Spec=krb5_asn1.ChangePasswdDataMS())
return change_password_data
def KRB_PRIV_create(self,
subkey,
user_data,
s_address,
timestamp=None,
usec=None,
seq_number=None,
r_address=None):
EncKrbPrivPart_obj = {
'user-data': user_data,
's-address': s_address,
}
if timestamp is not None:
EncKrbPrivPart_obj['timestamp'] = timestamp
if usec is not None:
EncKrbPrivPart_obj['usec'] = usec
if seq_number is not None:
EncKrbPrivPart_obj['seq-number'] = seq_number
if r_address is not None:
EncKrbPrivPart_obj['r-address'] = r_address
enc_krb_priv_part = self.der_encode(
EncKrbPrivPart_obj, asn1Spec=krb5_asn1.EncKrbPrivPart())
enc_data = self.EncryptedData_create(subkey,
KU_KRB_PRIV,
enc_krb_priv_part)
KRB_PRIV_obj = {
'pvno': 5,
'msg-type': KRB_PRIV,
'enc-part': enc_data,
}
krb_priv = self.der_encode(
KRB_PRIV_obj, asn1Spec=krb5_asn1.KRB_PRIV())
return krb_priv
def kpasswd_create(self,
subkey,
user_data,
version,
seq_number,
ap_req,
local_address,
remote_address):
self.assertIsNotNone(self.s, 'call self.connect() first')
timestamp, usec = self.get_KerberosTimeWithUsec()
krb_priv = self.KRB_PRIV_create(subkey,
user_data,
s_address=local_address,
timestamp=timestamp,
usec=usec,
seq_number=seq_number,
r_address=remote_address)
size = 6 + len(ap_req) + len(krb_priv)
self.assertLess(size, 0x10000)
msg = bytearray()
msg.append(size >> 8)
msg.append(size & 0xff)
msg.append(version >> 8)
msg.append(version & 0xff)
msg.append(len(ap_req) >> 8)
msg.append(len(ap_req) & 0xff)
# Note: for sets, there could be a little-endian four-byte length here.
msg.extend(ap_req)
msg.extend(krb_priv)
return msg
def get_enc_part(self, obj, key, usage):
self.assertElementEqual(obj, 'pvno', 5)
enc_part = obj['enc-part']
self.assertElementEqual(enc_part, 'etype', key.etype)
self.assertElementKVNO(enc_part, 'kvno', key.kvno)
enc_part = key.decrypt(usage, enc_part['cipher'])
return enc_part
def kpasswd_exchange(self,
ticket,
new_password,
expected_code,
expected_msg,
mode,
target_princ=None,
target_realm=None,
ap_options=None,
send_seq_number=True):
if mode is self.KpasswdMode.SET:
version = 0xff80
user_data = self.ChangePasswdDataMS_create(new_password,
target_princ,
target_realm)
elif mode is self.KpasswdMode.CHANGE:
self.assertIsNone(target_princ,
'target_princ only valid for pw set')
self.assertIsNone(target_realm,
'target_realm only valid for pw set')
version = 1
user_data = new_password.encode('utf-8')
else:
self.fail(f'invalid mode {mode}')
subkey = self.RandomKey(kcrypto.Enctype.AES256)
if ap_options is None:
ap_options = '0'
ap_options = str(krb5_asn1.APOptions(ap_options))
kdc_exchange_dict = {
'tgt': ticket,
'authenticator_subkey': subkey,
'auth_data': None,
'ap_options': ap_options,
}
if send_seq_number:
seq_number = random.randint(0, 0xfffffffe)
else:
seq_number = None
ap_req = self.generate_ap_req(kdc_exchange_dict,
None,
req_body=None,
armor=False,
usage=KU_AP_REQ_AUTH,
seq_number=seq_number)
self.connect(self.host, port=464)
self.assertIsNotNone(self.s)
family = self.s.family
if family == socket.AF_INET:
addr_type = 2 # IPv4
elif family == socket.AF_INET6:
addr_type = 24 # IPv6
else:
self.fail(f'unknown family {family}')
def create_address(ip):
return {
'addr-type': addr_type,
'address': socket.inet_pton(family, ip),
}
local_ip = self.s.getsockname()[0]
local_address = create_address(local_ip)
# remote_ip = self.s.getpeername()[0]
# remote_address = create_address(remote_ip)
# TODO: due to a bug (?), MIT Kerberos will not accept the request
# unless r-address is set to our _local_ address. Heimdal, on the other
# hand, requires the r-address is set to the remote address (as
# expected). To avoid problems, avoid sending r-address for now.
remote_address = None
msg = self.kpasswd_create(subkey,
user_data,
version,
seq_number,
ap_req,
local_address,
remote_address)
self.send_msg(msg)
rep_pdu = self.recv_pdu_raw()
self._disconnect('transaction done')
self.assertIsNotNone(rep_pdu)
header = rep_pdu[:6]
reply = rep_pdu[6:]
reply_len = (header[0] << 8) | header[1]
reply_version = (header[2] << 8) | header[3]
ap_rep_len = (header[4] << 8) | header[5]
self.assertEqual(reply_len, len(rep_pdu))
self.assertEqual(1, reply_version) # KRB5_KPASSWD_VERS_CHANGEPW
self.assertLess(ap_rep_len, reply_len)
self.assertNotEqual(0x7e, rep_pdu[1])
self.assertNotEqual(0x5e, rep_pdu[1])
if ap_rep_len:
# We received an AP-REQ and KRB-PRIV as a response. This may or may
# not indicate an error, depending on the status code.
ap_rep = reply[:ap_rep_len]
krb_priv = reply[ap_rep_len:]
key = ticket.session_key
ap_rep = self.der_decode(ap_rep, asn1Spec=krb5_asn1.AP_REP())
self.assertElementEqual(ap_rep, 'msg-type', KRB_AP_REP)
enc_part = self.get_enc_part(ap_rep, key, KU_AP_REQ_ENC_PART)
enc_part = self.der_decode(
enc_part, asn1Spec=krb5_asn1.EncAPRepPart())
self.assertElementPresent(enc_part, 'ctime')
self.assertElementPresent(enc_part, 'cusec')
# self.assertElementMissing(enc_part, 'subkey') # TODO
# self.assertElementPresent(enc_part, 'seq-number') # TODO
try:
krb_priv = self.der_decode(krb_priv, asn1Spec=krb5_asn1.KRB_PRIV())
except PyAsn1Error:
self.fail()
self.assertElementEqual(krb_priv, 'msg-type', KRB_PRIV)
priv_enc_part = self.get_enc_part(krb_priv, subkey, KU_KRB_PRIV)
priv_enc_part = self.der_decode(
priv_enc_part, asn1Spec=krb5_asn1.EncKrbPrivPart())
self.assertElementMissing(priv_enc_part, 'timestamp')
self.assertElementMissing(priv_enc_part, 'usec')
# self.assertElementPresent(priv_enc_part, 'seq-number') # TODO
# self.assertElementEqual(priv_enc_part, 's-address', remote_address) # TODO
# self.assertElementMissing(priv_enc_part, 'r-address') # TODO
result_data = priv_enc_part['user-data']
else:
# We received a KRB-ERROR as a response, indicating an error.
krb_error = self.der_decode(reply, asn1Spec=krb5_asn1.KRB_ERROR())
sname = self.PrincipalName_create(
name_type=NT_PRINCIPAL,
names=['kadmin', 'changepw'])
realm = self.get_krbtgt_creds().get_realm().upper()
self.assertElementEqual(krb_error, 'pvno', 5)
self.assertElementEqual(krb_error, 'msg-type', KRB_ERROR)
self.assertElementMissing(krb_error, 'ctime')
self.assertElementMissing(krb_error, 'usec')
self.assertElementPresent(krb_error, 'stime')
self.assertElementPresent(krb_error, 'susec')
error_code = krb_error['error-code']
if isinstance(expected_code, int):
self.assertEqual(error_code, expected_code)
else:
self.assertIn(error_code, expected_code)
self.assertElementMissing(krb_error, 'crealm')
self.assertElementMissing(krb_error, 'cname')
self.assertElementEqual(krb_error, 'realm', realm.encode('utf-8'))
self.assertElementEqualPrincipal(krb_error, 'sname', sname)
self.assertElementMissing(krb_error, 'e-text')
result_data = krb_error['e-data']
status = result_data[:2]
message = result_data[2:]
status_code = (status[0] << 8) | status[1]
if isinstance(expected_code, int):
self.assertEqual(status_code, expected_code)
else:
self.assertIn(status_code, expected_code)
if not message:
self.assertEqual(0, status_code,
'got an error result, but no message')
return
# Check the first character of the message.
if message[0]:
if isinstance(expected_msg, bytes):
self.assertEqual(message, expected_msg)
else:
self.assertIn(message, expected_msg)
else:
# We got AD password policy information.
self.assertEqual(30, len(message))
(empty_bytes,
min_length,
history_length,
properties,
expire_time,
min_age) = struct.unpack('>HIIIQQ', message)
def _generic_kdc_exchange(self,
kdc_exchange_dict, # required
cname=None, # optional
realm=None, # required
sname=None, # optional
from_time=None, # optional
till_time=None, # required
renew_time=None, # optional
etypes=None, # required
addresses=None, # optional
additional_tickets=None, # optional
EncAuthorizationData=None, # optional
EncAuthorizationData_key=None, # optional
EncAuthorizationData_usage=None): # optional
check_error_fn = kdc_exchange_dict['check_error_fn']
check_rep_fn = kdc_exchange_dict['check_rep_fn']
generate_fast_fn = kdc_exchange_dict['generate_fast_fn']
generate_fast_armor_fn = kdc_exchange_dict['generate_fast_armor_fn']
generate_fast_padata_fn = kdc_exchange_dict['generate_fast_padata_fn']
generate_padata_fn = kdc_exchange_dict['generate_padata_fn']
callback_dict = kdc_exchange_dict['callback_dict']
req_msg_type = kdc_exchange_dict['req_msg_type']
req_asn1Spec = kdc_exchange_dict['req_asn1Spec']
rep_msg_type = kdc_exchange_dict['rep_msg_type']
expected_error_mode = kdc_exchange_dict['expected_error_mode']
kdc_options = kdc_exchange_dict['kdc_options']
pac_request = kdc_exchange_dict['pac_request']
pac_options = kdc_exchange_dict['pac_options']
# Parameters specific to the inner request body
inner_req = kdc_exchange_dict['inner_req']
# Parameters specific to the outer request body
outer_req = kdc_exchange_dict['outer_req']
if till_time is None:
till_time = self.get_KerberosTime(offset=36000)
if 'nonce' in kdc_exchange_dict:
nonce = kdc_exchange_dict['nonce']
else:
nonce = self.get_Nonce()
kdc_exchange_dict['nonce'] = nonce
req_body = self.KDC_REQ_BODY_create(
kdc_options=kdc_options,
cname=cname,
realm=realm,
sname=sname,
from_time=from_time,
till_time=till_time,
renew_time=renew_time,
nonce=nonce,
etypes=etypes,
addresses=addresses,
additional_tickets=additional_tickets,
EncAuthorizationData=EncAuthorizationData,
EncAuthorizationData_key=EncAuthorizationData_key,
EncAuthorizationData_usage=EncAuthorizationData_usage)
inner_req_body = dict(req_body)
if inner_req is not None:
for key, value in inner_req.items():
if value is not None:
inner_req_body[key] = value
else:
del inner_req_body[key]
if outer_req is not None:
for key, value in outer_req.items():
if value is not None:
req_body[key] = value
else:
del req_body[key]
additional_padata = []
if pac_request is not None:
pa_pac_request = self.KERB_PA_PAC_REQUEST_create(pac_request)
additional_padata.append(pa_pac_request)
if pac_options is not None:
pa_pac_options = self.get_pa_pac_options(pac_options)
additional_padata.append(pa_pac_options)
if req_msg_type == KRB_AS_REQ:
tgs_req = None
tgs_req_padata = None
else:
self.assertEqual(KRB_TGS_REQ, req_msg_type)
tgs_req = self.generate_ap_req(kdc_exchange_dict,
callback_dict,
req_body,
armor=False)
tgs_req_padata = self.PA_DATA_create(PADATA_KDC_REQ, tgs_req)
if generate_fast_padata_fn is not None:
self.assertIsNotNone(generate_fast_fn)
# This can alter req_body...
fast_padata, req_body = generate_fast_padata_fn(kdc_exchange_dict,
callback_dict,
req_body)
else:
fast_padata = []
if generate_fast_armor_fn is not None:
self.assertIsNotNone(generate_fast_fn)
fast_ap_req = generate_fast_armor_fn(kdc_exchange_dict,
callback_dict,
None,
armor=True)
fast_armor_type = kdc_exchange_dict['fast_armor_type']
fast_armor = self.KRB_FAST_ARMOR_create(fast_armor_type,
fast_ap_req)
else:
fast_armor = None
if generate_padata_fn is not None:
# This can alter req_body...
outer_padata, req_body = generate_padata_fn(kdc_exchange_dict,
callback_dict,
req_body)
self.assertIsNotNone(outer_padata)
self.assertNotIn(PADATA_KDC_REQ,
[pa['padata-type'] for pa in outer_padata],
'Don\'t create TGS-REQ manually')
else:
outer_padata = None
if generate_fast_fn is not None:
armor_key = kdc_exchange_dict['armor_key']
self.assertIsNotNone(armor_key)
if req_msg_type == KRB_AS_REQ:
checksum_blob = self.der_encode(
req_body,
asn1Spec=krb5_asn1.KDC_REQ_BODY())
else:
self.assertEqual(KRB_TGS_REQ, req_msg_type)
checksum_blob = tgs_req
checksum = self.Checksum_create(armor_key,
KU_FAST_REQ_CHKSUM,
checksum_blob)
fast_padata += additional_padata
fast = generate_fast_fn(kdc_exchange_dict,
callback_dict,
inner_req_body,
fast_padata,
fast_armor,
checksum)
else:
fast = None
padata = []
if tgs_req_padata is not None:
padata.append(tgs_req_padata)
if fast is not None:
padata.append(fast)
if outer_padata is not None:
padata += outer_padata
if fast is None:
padata += additional_padata
if not padata:
padata = None
kdc_exchange_dict['req_padata'] = padata
kdc_exchange_dict['fast_padata'] = fast_padata
kdc_exchange_dict['req_body'] = inner_req_body
req_obj, req_decoded = self.KDC_REQ_create(msg_type=req_msg_type,
padata=padata,
req_body=req_body,
asn1Spec=req_asn1Spec())
kdc_exchange_dict['req_obj'] = req_obj
to_rodc = kdc_exchange_dict['to_rodc']
rep = self.send_recv_transaction(req_decoded, to_rodc=to_rodc)
self.assertIsNotNone(rep)
msg_type = self.getElementValue(rep, 'msg-type')
self.assertIsNotNone(msg_type)
expected_msg_type = None
if check_error_fn is not None:
expected_msg_type = KRB_ERROR
self.assertIsNone(check_rep_fn)
self.assertNotEqual(0, len(expected_error_mode))
self.assertNotIn(0, expected_error_mode)
if check_rep_fn is not None:
expected_msg_type = rep_msg_type
self.assertIsNone(check_error_fn)
self.assertEqual(0, len(expected_error_mode))
self.assertIsNotNone(expected_msg_type)
if msg_type == KRB_ERROR:
error_code = self.getElementValue(rep, 'error-code')
fail_msg = f'Got unexpected error: {error_code}'
else:
fail_msg = f'Expected to fail with error: {expected_error_mode}'
self.assertEqual(msg_type, expected_msg_type, fail_msg)
if msg_type == KRB_ERROR:
return check_error_fn(kdc_exchange_dict,
callback_dict,
rep)
return check_rep_fn(kdc_exchange_dict, callback_dict, rep)
def as_exchange_dict(self,
expected_crealm=None,
expected_cname=None,
expected_anon=False,
expected_srealm=None,
expected_sname=None,
expected_account_name=None,
expected_upn_name=None,
expected_sid=None,
expected_supported_etypes=None,
expected_flags=None,
unexpected_flags=None,
ticket_decryption_key=None,
expect_ticket_checksum=None,
expect_full_checksum=None,
generate_fast_fn=None,
generate_fast_armor_fn=None,
generate_fast_padata_fn=None,
fast_armor_type=FX_FAST_ARMOR_AP_REQUEST,
generate_padata_fn=None,
check_error_fn=None,
check_rep_fn=None,
check_kdc_private_fn=None,
callback_dict=None,
expected_error_mode=0,
expected_status=None,
client_as_etypes=None,
expected_salt=None,
authenticator_subkey=None,
preauth_key=None,
armor_key=None,
armor_tgt=None,
armor_subkey=None,
auth_data=None,
kdc_options='',
inner_req=None,
outer_req=None,
pac_request=None,
pac_options=None,
expect_edata=None,
expect_pac=True,
expect_claims=True,
expect_upn_dns_info_ex=None,
expect_pac_attrs=None,
expect_pac_attrs_pac_request=None,
expect_requester_sid=None,
strict_etype_info=True,
to_rodc=False):
if expected_error_mode == 0:
expected_error_mode = ()
elif not isinstance(expected_error_mode, collections.abc.Container):
expected_error_mode = (expected_error_mode,)
kdc_exchange_dict = {
'req_msg_type': KRB_AS_REQ,
'req_asn1Spec': krb5_asn1.AS_REQ,
'rep_msg_type': KRB_AS_REP,
'rep_asn1Spec': krb5_asn1.AS_REP,
'rep_encpart_asn1Spec': krb5_asn1.EncASRepPart,
'expected_crealm': expected_crealm,
'expected_cname': expected_cname,
'expected_anon': expected_anon,
'expected_srealm': expected_srealm,
'expected_sname': expected_sname,
'expected_account_name': expected_account_name,
'expected_upn_name': expected_upn_name,
'expected_sid': expected_sid,
'expected_supported_etypes': expected_supported_etypes,
'expected_flags': expected_flags,
'unexpected_flags': unexpected_flags,
'ticket_decryption_key': ticket_decryption_key,
'expect_ticket_checksum': expect_ticket_checksum,
'expect_full_checksum': expect_full_checksum,
'generate_fast_fn': generate_fast_fn,
'generate_fast_armor_fn': generate_fast_armor_fn,
'generate_fast_padata_fn': generate_fast_padata_fn,
'fast_armor_type': fast_armor_type,
'generate_padata_fn': generate_padata_fn,
'check_error_fn': check_error_fn,
'check_rep_fn': check_rep_fn,
'check_kdc_private_fn': check_kdc_private_fn,
'callback_dict': callback_dict,
'expected_error_mode': expected_error_mode,
'expected_status': expected_status,
'client_as_etypes': client_as_etypes,
'expected_salt': expected_salt,
'authenticator_subkey': authenticator_subkey,
'preauth_key': preauth_key,
'armor_key': armor_key,
'armor_tgt': armor_tgt,
'armor_subkey': armor_subkey,
'auth_data': auth_data,
'kdc_options': kdc_options,
'inner_req': inner_req,
'outer_req': outer_req,
'pac_request': pac_request,
'pac_options': pac_options,
'expect_edata': expect_edata,
'expect_pac': expect_pac,
'expect_claims': expect_claims,
'expect_upn_dns_info_ex': expect_upn_dns_info_ex,
'expect_pac_attrs': expect_pac_attrs,
'expect_pac_attrs_pac_request': expect_pac_attrs_pac_request,
'expect_requester_sid': expect_requester_sid,
'strict_etype_info': strict_etype_info,
'to_rodc': to_rodc
}
if callback_dict is None:
callback_dict = {}
return kdc_exchange_dict
def tgs_exchange_dict(self,
expected_crealm=None,
expected_cname=None,
expected_anon=False,
expected_srealm=None,
expected_sname=None,
expected_account_name=None,
expected_upn_name=None,
expected_sid=None,
expected_supported_etypes=None,
expected_flags=None,
unexpected_flags=None,
ticket_decryption_key=None,
expect_ticket_checksum=None,
expect_full_checksum=None,
generate_fast_fn=None,
generate_fast_armor_fn=None,
generate_fast_padata_fn=None,
fast_armor_type=FX_FAST_ARMOR_AP_REQUEST,
generate_padata_fn=None,
check_error_fn=None,
check_rep_fn=None,
check_kdc_private_fn=None,
expected_error_mode=0,
expected_status=None,
callback_dict=None,
tgt=None,
armor_key=None,
armor_tgt=None,
armor_subkey=None,
authenticator_subkey=None,
auth_data=None,
body_checksum_type=None,
kdc_options='',
inner_req=None,
outer_req=None,
pac_request=None,
pac_options=None,
expect_edata=None,
expect_pac=True,
expect_claims=True,
expect_upn_dns_info_ex=None,
expect_pac_attrs=None,
expect_pac_attrs_pac_request=None,
expect_requester_sid=None,
expected_proxy_target=None,
expected_transited_services=None,
strict_etype_info=True,
to_rodc=False):
if expected_error_mode == 0:
expected_error_mode = ()
elif not isinstance(expected_error_mode, collections.abc.Container):
expected_error_mode = (expected_error_mode,)
kdc_exchange_dict = {
'req_msg_type': KRB_TGS_REQ,
'req_asn1Spec': krb5_asn1.TGS_REQ,
'rep_msg_type': KRB_TGS_REP,
'rep_asn1Spec': krb5_asn1.TGS_REP,
'rep_encpart_asn1Spec': krb5_asn1.EncTGSRepPart,
'expected_crealm': expected_crealm,
'expected_cname': expected_cname,
'expected_anon': expected_anon,
'expected_srealm': expected_srealm,
'expected_sname': expected_sname,
'expected_account_name': expected_account_name,
'expected_upn_name': expected_upn_name,
'expected_sid': expected_sid,
'expected_supported_etypes': expected_supported_etypes,
'expected_flags': expected_flags,
'unexpected_flags': unexpected_flags,
'ticket_decryption_key': ticket_decryption_key,
'expect_ticket_checksum': expect_ticket_checksum,
'expect_full_checksum': expect_full_checksum,
'generate_fast_fn': generate_fast_fn,
'generate_fast_armor_fn': generate_fast_armor_fn,
'generate_fast_padata_fn': generate_fast_padata_fn,
'fast_armor_type': fast_armor_type,
'generate_padata_fn': generate_padata_fn,
'check_error_fn': check_error_fn,
'check_rep_fn': check_rep_fn,
'check_kdc_private_fn': check_kdc_private_fn,
'callback_dict': callback_dict,
'expected_error_mode': expected_error_mode,
'expected_status': expected_status,
'tgt': tgt,
'body_checksum_type': body_checksum_type,
'armor_key': armor_key,
'armor_tgt': armor_tgt,
'armor_subkey': armor_subkey,
'auth_data': auth_data,
'authenticator_subkey': authenticator_subkey,
'kdc_options': kdc_options,
'inner_req': inner_req,
'outer_req': outer_req,
'pac_request': pac_request,
'pac_options': pac_options,
'expect_edata': expect_edata,
'expect_pac': expect_pac,
'expect_claims': expect_claims,
'expect_upn_dns_info_ex': expect_upn_dns_info_ex,
'expect_pac_attrs': expect_pac_attrs,
'expect_pac_attrs_pac_request': expect_pac_attrs_pac_request,
'expect_requester_sid': expect_requester_sid,
'expected_proxy_target': expected_proxy_target,
'expected_transited_services': expected_transited_services,
'strict_etype_info': strict_etype_info,
'to_rodc': to_rodc
}
if callback_dict is None:
callback_dict = {}
return kdc_exchange_dict
def generic_check_kdc_rep(self,
kdc_exchange_dict,
callback_dict,
rep):
expected_crealm = kdc_exchange_dict['expected_crealm']
expected_anon = kdc_exchange_dict['expected_anon']
expected_srealm = kdc_exchange_dict['expected_srealm']
expected_sname = kdc_exchange_dict['expected_sname']
ticket_decryption_key = kdc_exchange_dict['ticket_decryption_key']
check_kdc_private_fn = kdc_exchange_dict['check_kdc_private_fn']
rep_encpart_asn1Spec = kdc_exchange_dict['rep_encpart_asn1Spec']
msg_type = kdc_exchange_dict['rep_msg_type']
armor_key = kdc_exchange_dict['armor_key']
self.assertElementEqual(rep, 'msg-type', msg_type) # AS-REP | TGS-REP
padata = self.getElementValue(rep, 'padata')
if self.strict_checking:
self.assertElementEqualUTF8(rep, 'crealm', expected_crealm)
if expected_anon:
expected_cname = self.PrincipalName_create(
name_type=NT_WELLKNOWN,
names=['WELLKNOWN', 'ANONYMOUS'])
else:
expected_cname = kdc_exchange_dict['expected_cname']
self.assertElementEqualPrincipal(rep, 'cname', expected_cname)
self.assertElementPresent(rep, 'ticket')
ticket = self.getElementValue(rep, 'ticket')
ticket_encpart = None
ticket_cipher = None
self.assertIsNotNone(ticket)
if ticket is not None: # Never None, but gives indentation
self.assertElementEqual(ticket, 'tkt-vno', 5)
self.assertElementEqualUTF8(ticket, 'realm', expected_srealm)
self.assertElementEqualPrincipal(ticket, 'sname', expected_sname)
self.assertElementPresent(ticket, 'enc-part')
ticket_encpart = self.getElementValue(ticket, 'enc-part')
self.assertIsNotNone(ticket_encpart)
if ticket_encpart is not None: # Never None, but gives indentation
self.assertElementPresent(ticket_encpart, 'etype')
kdc_options = kdc_exchange_dict['kdc_options']
pos = len(tuple(krb5_asn1.KDCOptions('enc-tkt-in-skey'))) - 1
expect_kvno = (pos >= len(kdc_options)
or kdc_options[pos] != '1')
if expect_kvno:
# 'unspecified' means present, with any value != 0
self.assertElementKVNO(ticket_encpart, 'kvno',
self.unspecified_kvno)
else:
# For user-to-user, don't expect a kvno.
self.assertElementMissing(ticket_encpart, 'kvno')
self.assertElementPresent(ticket_encpart, 'cipher')
ticket_cipher = self.getElementValue(ticket_encpart, 'cipher')
self.assertElementPresent(rep, 'enc-part')
encpart = self.getElementValue(rep, 'enc-part')
encpart_cipher = None
self.assertIsNotNone(encpart)
if encpart is not None: # Never None, but gives indentation
self.assertElementPresent(encpart, 'etype')
self.assertElementKVNO(ticket_encpart, 'kvno', 'autodetect')
self.assertElementPresent(encpart, 'cipher')
encpart_cipher = self.getElementValue(encpart, 'cipher')
ticket_checksum = None
# Get the decryption key for the encrypted part
encpart_decryption_key, encpart_decryption_usage = (
self.get_preauth_key(kdc_exchange_dict))
if armor_key is not None:
pa_dict = self.get_pa_dict(padata)
if PADATA_FX_FAST in pa_dict:
fx_fast_data = pa_dict[PADATA_FX_FAST]
fast_response = self.check_fx_fast_data(kdc_exchange_dict,
fx_fast_data,
armor_key,
finished=True)
if 'strengthen-key' in fast_response:
strengthen_key = self.EncryptionKey_import(
fast_response['strengthen-key'])
encpart_decryption_key = (
self.generate_strengthen_reply_key(
strengthen_key,
encpart_decryption_key))
fast_finished = fast_response.get('finished')
if fast_finished is not None:
ticket_checksum = fast_finished['ticket-checksum']
self.check_rep_padata(kdc_exchange_dict,
callback_dict,
fast_response['padata'],
error_code=0)
ticket_private = None
if ticket_decryption_key is not None:
self.assertElementEqual(ticket_encpart, 'etype',
ticket_decryption_key.etype)
self.assertElementKVNO(ticket_encpart, 'kvno',
ticket_decryption_key.kvno)
ticket_decpart = ticket_decryption_key.decrypt(KU_TICKET,
ticket_cipher)
ticket_private = self.der_decode(
ticket_decpart,
asn1Spec=krb5_asn1.EncTicketPart())
encpart_private = None
self.assertIsNotNone(encpart_decryption_key)
if encpart_decryption_key is not None:
self.assertElementEqual(encpart, 'etype',
encpart_decryption_key.etype)
if self.strict_checking:
self.assertElementKVNO(encpart, 'kvno',
encpart_decryption_key.kvno)
rep_decpart = encpart_decryption_key.decrypt(
encpart_decryption_usage,
encpart_cipher)
# MIT KDC encodes both EncASRepPart and EncTGSRepPart with
# application tag 26
try:
encpart_private = self.der_decode(
rep_decpart,
asn1Spec=rep_encpart_asn1Spec())
except Exception:
encpart_private = self.der_decode(
rep_decpart,
asn1Spec=krb5_asn1.EncTGSRepPart())
kdc_exchange_dict['reply_key'] = encpart_decryption_key
self.assertIsNotNone(check_kdc_private_fn)
if check_kdc_private_fn is not None:
check_kdc_private_fn(kdc_exchange_dict, callback_dict,
rep, ticket_private, encpart_private,
ticket_checksum)
return rep
def check_fx_fast_data(self,
kdc_exchange_dict,
fx_fast_data,
armor_key,
finished=False,
expect_strengthen_key=True):
fx_fast_data = self.der_decode(fx_fast_data,
asn1Spec=krb5_asn1.PA_FX_FAST_REPLY())
enc_fast_rep = fx_fast_data['armored-data']['enc-fast-rep']
self.assertEqual(enc_fast_rep['etype'], armor_key.etype)
fast_rep = armor_key.decrypt(KU_FAST_REP, enc_fast_rep['cipher'])
fast_response = self.der_decode(fast_rep,
asn1Spec=krb5_asn1.KrbFastResponse())
if expect_strengthen_key and self.strict_checking:
self.assertIn('strengthen-key', fast_response)
if finished:
self.assertIn('finished', fast_response)
# Ensure that the nonce matches the nonce in the body of the request
# (RFC6113 5.4.3).
nonce = kdc_exchange_dict['nonce']
self.assertEqual(nonce, fast_response['nonce'])
return fast_response
def generic_check_kdc_private(self,
kdc_exchange_dict,
callback_dict,
rep,
ticket_private,
encpart_private,
ticket_checksum):
kdc_options = kdc_exchange_dict['kdc_options']
canon_pos = len(tuple(krb5_asn1.KDCOptions('canonicalize'))) - 1
canonicalize = (canon_pos < len(kdc_options)
and kdc_options[canon_pos] == '1')
renewable_pos = len(tuple(krb5_asn1.KDCOptions('renewable'))) - 1
renewable = (renewable_pos < len(kdc_options)
and kdc_options[renewable_pos] == '1')
renew_pos = len(tuple(krb5_asn1.KDCOptions('renew'))) - 1
renew = (renew_pos < len(kdc_options)
and kdc_options[renew_pos] == '1')
expect_renew_till = renewable or renew
expected_crealm = kdc_exchange_dict['expected_crealm']
expected_cname = kdc_exchange_dict['expected_cname']
expected_srealm = kdc_exchange_dict['expected_srealm']
expected_sname = kdc_exchange_dict['expected_sname']
ticket_decryption_key = kdc_exchange_dict['ticket_decryption_key']
rep_msg_type = kdc_exchange_dict['rep_msg_type']
expected_flags = kdc_exchange_dict.get('expected_flags')
unexpected_flags = kdc_exchange_dict.get('unexpected_flags')
ticket = self.getElementValue(rep, 'ticket')
if ticket_checksum is not None:
armor_key = kdc_exchange_dict['armor_key']
self.verify_ticket_checksum(ticket, ticket_checksum, armor_key)
to_rodc = kdc_exchange_dict['to_rodc']
if to_rodc:
krbtgt_creds = self.get_rodc_krbtgt_creds()
else:
krbtgt_creds = self.get_krbtgt_creds()
krbtgt_key = self.TicketDecryptionKey_from_creds(krbtgt_creds)
krbtgt_keys = [krbtgt_key]
if not self.strict_checking:
krbtgt_key_rc4 = self.TicketDecryptionKey_from_creds(
krbtgt_creds,
etype=kcrypto.Enctype.RC4)
krbtgt_keys.append(krbtgt_key_rc4)
if self.expect_pac and self.is_tgs(expected_sname):
expect_pac = True
else:
expect_pac = kdc_exchange_dict['expect_pac']
ticket_session_key = None
if ticket_private is not None:
self.assertElementFlags(ticket_private, 'flags',
expected_flags,
unexpected_flags)
self.assertElementPresent(ticket_private, 'key')
ticket_key = self.getElementValue(ticket_private, 'key')
self.assertIsNotNone(ticket_key)
if ticket_key is not None: # Never None, but gives indentation
self.assertElementPresent(ticket_key, 'keytype')
self.assertElementPresent(ticket_key, 'keyvalue')
ticket_session_key = self.EncryptionKey_import(ticket_key)
self.assertElementEqualUTF8(ticket_private, 'crealm',
expected_crealm)
if self.strict_checking:
self.assertElementEqualPrincipal(ticket_private, 'cname',
expected_cname)
self.assertElementPresent(ticket_private, 'transited')
self.assertElementPresent(ticket_private, 'authtime')
if self.strict_checking:
self.assertElementPresent(ticket_private, 'starttime')
self.assertElementPresent(ticket_private, 'endtime')
if expect_renew_till:
if self.strict_checking:
self.assertElementPresent(ticket_private, 'renew-till')
else:
self.assertElementMissing(ticket_private, 'renew-till')
if self.strict_checking:
self.assertElementMissing(ticket_private, 'caddr')
if expect_pac is not None:
self.assertElementPresent(ticket_private, 'authorization-data',
expect_empty=not expect_pac)
encpart_session_key = None
if encpart_private is not None:
self.assertElementPresent(encpart_private, 'key')
encpart_key = self.getElementValue(encpart_private, 'key')
self.assertIsNotNone(encpart_key)
if encpart_key is not None: # Never None, but gives indentation
self.assertElementPresent(encpart_key, 'keytype')
self.assertElementPresent(encpart_key, 'keyvalue')
encpart_session_key = self.EncryptionKey_import(encpart_key)
self.assertElementPresent(encpart_private, 'last-req')
self.assertElementEqual(encpart_private, 'nonce',
kdc_exchange_dict['nonce'])
if rep_msg_type == KRB_AS_REP:
if self.strict_checking:
self.assertElementPresent(encpart_private,
'key-expiration')
else:
self.assertElementMissing(encpart_private,
'key-expiration')
self.assertElementFlags(encpart_private, 'flags',
expected_flags,
unexpected_flags)
self.assertElementPresent(encpart_private, 'authtime')
if self.strict_checking:
self.assertElementPresent(encpart_private, 'starttime')
self.assertElementPresent(encpart_private, 'endtime')
if expect_renew_till:
if self.strict_checking:
self.assertElementPresent(encpart_private, 'renew-till')
else:
self.assertElementMissing(encpart_private, 'renew-till')
self.assertElementEqualUTF8(encpart_private, 'srealm',
expected_srealm)
self.assertElementEqualPrincipal(encpart_private, 'sname',
expected_sname)
if self.strict_checking:
self.assertElementMissing(encpart_private, 'caddr')
sent_pac_options = self.get_sent_pac_options(kdc_exchange_dict)
sent_enc_pa_rep = self.sent_enc_pa_rep(kdc_exchange_dict)
enc_padata = self.getElementValue(encpart_private,
'encrypted-pa-data')
if (canonicalize or '1' in sent_pac_options or (
rep_msg_type == KRB_AS_REP and sent_enc_pa_rep)):
if self.strict_checking:
self.assertIsNotNone(enc_padata)
if enc_padata is not None:
enc_pa_dict = self.get_pa_dict(enc_padata)
if self.strict_checking:
if canonicalize:
self.assertIn(PADATA_SUPPORTED_ETYPES, enc_pa_dict)
else:
self.assertNotIn(PADATA_SUPPORTED_ETYPES,
enc_pa_dict)
if '1' in sent_pac_options:
self.assertIn(PADATA_PAC_OPTIONS, enc_pa_dict)
else:
self.assertNotIn(PADATA_PAC_OPTIONS, enc_pa_dict)
if rep_msg_type == KRB_AS_REP and sent_enc_pa_rep:
self.assertIn(PADATA_REQ_ENC_PA_REP, enc_pa_dict)
else:
self.assertNotIn(PADATA_REQ_ENC_PA_REP, enc_pa_dict)
if PADATA_SUPPORTED_ETYPES in enc_pa_dict:
expected_supported_etypes = kdc_exchange_dict[
'expected_supported_etypes']
(supported_etypes,) = struct.unpack(
'<L',
enc_pa_dict[PADATA_SUPPORTED_ETYPES])
ignore_bits = (security.KERB_ENCTYPE_DES_CBC_CRC |
security.KERB_ENCTYPE_DES_CBC_MD5)
self.assertEqual(
supported_etypes & ~ignore_bits,
expected_supported_etypes & ~ignore_bits,
f'PADATA_SUPPORTED_ETYPES: got: {supported_etypes} (0x{supported_etypes:X}), '
f'expected: {expected_supported_etypes} (0x{expected_supported_etypes:X})')
if PADATA_PAC_OPTIONS in enc_pa_dict:
pac_options = self.der_decode(
enc_pa_dict[PADATA_PAC_OPTIONS],
asn1Spec=krb5_asn1.PA_PAC_OPTIONS())
self.assertElementEqual(pac_options, 'options',
sent_pac_options)
if PADATA_REQ_ENC_PA_REP in enc_pa_dict:
enc_pa_rep = enc_pa_dict[PADATA_REQ_ENC_PA_REP]
enc_pa_rep = self.der_decode(
enc_pa_rep,
asn1Spec=krb5_asn1.Checksum())
reply_key = kdc_exchange_dict['reply_key']
req_obj = kdc_exchange_dict['req_obj']
req_asn1Spec = kdc_exchange_dict['req_asn1Spec']
req_obj = self.der_encode(req_obj,
asn1Spec=req_asn1Spec())
checksum = enc_pa_rep['checksum']
ctype = enc_pa_rep['cksumtype']
reply_key.verify_checksum(KU_AS_REQ,
req_obj,
ctype,
checksum)
else:
if enc_padata is not None:
self.assertEqual(enc_padata, [])
if ticket_session_key is not None and encpart_session_key is not None:
self.assertEqual(ticket_session_key.etype,
encpart_session_key.etype)
self.assertEqual(ticket_session_key.key.contents,
encpart_session_key.key.contents)
if encpart_session_key is not None:
session_key = encpart_session_key
else:
session_key = ticket_session_key
ticket_creds = KerberosTicketCreds(
ticket,
session_key,
crealm=expected_crealm,
cname=expected_cname,
srealm=expected_srealm,
sname=expected_sname,
decryption_key=ticket_decryption_key,
ticket_private=ticket_private,
encpart_private=encpart_private)
if ticket_private is not None:
pac_data = self.get_ticket_pac(ticket_creds, expect_pac=expect_pac)
if expect_pac is True:
self.assertIsNotNone(pac_data)
elif expect_pac is False:
self.assertIsNone(pac_data)
if pac_data is not None:
self.check_pac_buffers(pac_data, kdc_exchange_dict)
expect_ticket_checksum = kdc_exchange_dict['expect_ticket_checksum']
expect_full_checksum = kdc_exchange_dict['expect_full_checksum']
if expect_ticket_checksum or expect_full_checksum:
self.assertIsNotNone(ticket_decryption_key)
if ticket_decryption_key is not None:
service_ticket = (not self.is_tgs(expected_sname)
and rep_msg_type == KRB_TGS_REP)
self.verify_ticket(ticket_creds, krbtgt_keys,
service_ticket=service_ticket,
expect_pac=expect_pac,
expect_ticket_checksum=expect_ticket_checksum
or self.tkt_sig_support,
expect_full_checksum=expect_full_checksum
or self.full_sig_support)
kdc_exchange_dict['rep_ticket_creds'] = ticket_creds
def check_pac_buffers(self, pac_data, kdc_exchange_dict):
pac = ndr_unpack(krb5pac.PAC_DATA, pac_data)
rep_msg_type = kdc_exchange_dict['rep_msg_type']
armor_tgt = kdc_exchange_dict['armor_tgt']
expected_sname = kdc_exchange_dict['expected_sname']
expect_claims = kdc_exchange_dict['expect_claims']
expected_types = [krb5pac.PAC_TYPE_LOGON_INFO,
krb5pac.PAC_TYPE_SRV_CHECKSUM,
krb5pac.PAC_TYPE_KDC_CHECKSUM,
krb5pac.PAC_TYPE_LOGON_NAME,
krb5pac.PAC_TYPE_UPN_DNS_INFO]
kdc_options = kdc_exchange_dict['kdc_options']
pos = len(tuple(krb5_asn1.KDCOptions('cname-in-addl-tkt'))) - 1
constrained_delegation = (pos < len(kdc_options)
and kdc_options[pos] == '1')
if constrained_delegation:
expected_types.append(krb5pac.PAC_TYPE_CONSTRAINED_DELEGATION)
if self.kdc_fast_support:
if expect_claims:
expected_types.append(krb5pac.PAC_TYPE_CLIENT_CLAIMS_INFO)
if (rep_msg_type == KRB_TGS_REP
and armor_tgt is not None):
expected_types.append(krb5pac.PAC_TYPE_DEVICE_INFO)
expected_types.append(krb5pac.PAC_TYPE_DEVICE_CLAIMS_INFO)
if not self.is_tgs(expected_sname) and rep_msg_type == KRB_TGS_REP:
expected_types.append(krb5pac.PAC_TYPE_TICKET_CHECKSUM)
expected_types.append(krb5pac.PAC_TYPE_FULL_CHECKSUM)
require_strict = {krb5pac.PAC_TYPE_CLIENT_CLAIMS_INFO}
if not self.tkt_sig_support:
require_strict.add(krb5pac.PAC_TYPE_TICKET_CHECKSUM)
if not self.full_sig_support:
require_strict.add(krb5pac.PAC_TYPE_FULL_CHECKSUM)
expect_extra_pac_buffers = self.is_tgs(expected_sname)
expect_pac_attrs = kdc_exchange_dict['expect_pac_attrs']
if expect_pac_attrs:
expect_pac_attrs_pac_request = kdc_exchange_dict[
'expect_pac_attrs_pac_request']
else:
expect_pac_attrs_pac_request = kdc_exchange_dict[
'pac_request']
if expect_pac_attrs is None:
if self.expect_extra_pac_buffers:
expect_pac_attrs = expect_extra_pac_buffers
else:
require_strict.add(krb5pac.PAC_TYPE_ATTRIBUTES_INFO)
if expect_pac_attrs:
expected_types.append(krb5pac.PAC_TYPE_ATTRIBUTES_INFO)
expect_requester_sid = kdc_exchange_dict['expect_requester_sid']
if expect_requester_sid is None:
if self.expect_extra_pac_buffers:
expect_requester_sid = expect_extra_pac_buffers
else:
require_strict.add(krb5pac.PAC_TYPE_REQUESTER_SID)
if expect_requester_sid:
expected_types.append(krb5pac.PAC_TYPE_REQUESTER_SID)
buffer_types = [pac_buffer.type
for pac_buffer in pac.buffers]
self.assertSequenceElementsEqual(
expected_types, buffer_types,
require_ordered=False,
require_strict=require_strict)
expected_account_name = kdc_exchange_dict['expected_account_name']
expected_sid = kdc_exchange_dict['expected_sid']
expect_upn_dns_info_ex = kdc_exchange_dict['expect_upn_dns_info_ex']
if expect_upn_dns_info_ex is None and (
expected_account_name is not None
or expected_sid is not None):
expect_upn_dns_info_ex = True
for pac_buffer in pac.buffers:
if pac_buffer.type == krb5pac.PAC_TYPE_CONSTRAINED_DELEGATION:
expected_proxy_target = kdc_exchange_dict[
'expected_proxy_target']
expected_transited_services = kdc_exchange_dict[
'expected_transited_services']
delegation_info = pac_buffer.info.info
self.assertEqual(expected_proxy_target,
str(delegation_info.proxy_target))
transited_services = list(map(
str, delegation_info.transited_services))
self.assertEqual(expected_transited_services,
transited_services)
elif pac_buffer.type == krb5pac.PAC_TYPE_LOGON_NAME:
expected_cname = kdc_exchange_dict['expected_cname']
account_name = expected_cname['name-string'][0]
self.assertEqual(account_name, pac_buffer.info.account_name)
elif pac_buffer.type == krb5pac.PAC_TYPE_LOGON_INFO:
logon_info = pac_buffer.info.info.info3.base
if expected_account_name is not None:
self.assertEqual(expected_account_name,
str(logon_info.account_name))
if expected_sid is not None:
expected_rid = int(expected_sid.rsplit('-', 1)[1])
self.assertEqual(expected_rid, logon_info.rid)
elif pac_buffer.type == krb5pac.PAC_TYPE_UPN_DNS_INFO:
upn_dns_info = pac_buffer.info
upn_dns_info_ex = upn_dns_info.ex
expected_realm = kdc_exchange_dict['expected_crealm']
self.assertEqual(expected_realm,
upn_dns_info.dns_domain_name)
expected_upn_name = kdc_exchange_dict['expected_upn_name']
if expected_upn_name is not None:
self.assertEqual(expected_upn_name,
upn_dns_info.upn_name)
if expect_upn_dns_info_ex:
self.assertIsNotNone(upn_dns_info_ex)
if upn_dns_info_ex is not None:
if expected_account_name is not None:
self.assertEqual(expected_account_name,
upn_dns_info_ex.samaccountname)
if expected_sid is not None:
self.assertEqual(expected_sid,
str(upn_dns_info_ex.objectsid))
elif (pac_buffer.type == krb5pac.PAC_TYPE_ATTRIBUTES_INFO
and expect_pac_attrs):
attr_info = pac_buffer.info
self.assertEqual(2, attr_info.flags_length)
flags = attr_info.flags
requested_pac = bool(flags & 1)
given_pac = bool(flags & 2)
self.assertEqual(expect_pac_attrs_pac_request is True,
requested_pac)
self.assertEqual(expect_pac_attrs_pac_request is None,
given_pac)
elif (pac_buffer.type == krb5pac.PAC_TYPE_REQUESTER_SID
and expect_requester_sid):
requester_sid = pac_buffer.info.sid
if expected_sid is not None:
self.assertEqual(expected_sid, str(requester_sid))
def generic_check_kdc_error(self,
kdc_exchange_dict,
callback_dict,
rep,
inner=False):
rep_msg_type = kdc_exchange_dict['rep_msg_type']
expected_anon = kdc_exchange_dict['expected_anon']
expected_srealm = kdc_exchange_dict['expected_srealm']
expected_sname = kdc_exchange_dict['expected_sname']
expected_error_mode = kdc_exchange_dict['expected_error_mode']
sent_fast = self.sent_fast(kdc_exchange_dict)
fast_armor_type = kdc_exchange_dict['fast_armor_type']
self.assertElementEqual(rep, 'pvno', 5)
self.assertElementEqual(rep, 'msg-type', KRB_ERROR)
error_code = self.getElementValue(rep, 'error-code')
self.assertIn(error_code, expected_error_mode)
if self.strict_checking:
self.assertElementMissing(rep, 'ctime')
self.assertElementMissing(rep, 'cusec')
self.assertElementPresent(rep, 'stime')
self.assertElementPresent(rep, 'susec')
# error-code checked above
if self.strict_checking:
self.assertElementMissing(rep, 'crealm')
if expected_anon and not inner:
expected_cname = self.PrincipalName_create(
name_type=NT_WELLKNOWN,
names=['WELLKNOWN', 'ANONYMOUS'])
self.assertElementEqualPrincipal(rep, 'cname', expected_cname)
else:
self.assertElementMissing(rep, 'cname')
self.assertElementEqualUTF8(rep, 'realm', expected_srealm)
self.assertElementEqualPrincipal(rep, 'sname', expected_sname)
self.assertElementMissing(rep, 'e-text')
expected_status = kdc_exchange_dict['expected_status']
expect_edata = kdc_exchange_dict['expect_edata']
if expect_edata is None:
expect_edata = (error_code != KDC_ERR_UNKNOWN_CRITICAL_FAST_OPTIONS
and (not sent_fast or fast_armor_type is None
or fast_armor_type == FX_FAST_ARMOR_AP_REQUEST)
and not inner)
if inner and expect_edata is self.expect_padata_outer:
expect_edata = False
if not expect_edata:
self.assertIsNone(expected_status)
self.assertElementMissing(rep, 'e-data')
return rep
edata = self.getElementValue(rep, 'e-data')
if self.strict_checking:
self.assertIsNotNone(edata)
if edata is not None:
if rep_msg_type == KRB_TGS_REP and not sent_fast:
error_data = self.der_decode(
edata,
asn1Spec=krb5_asn1.KERB_ERROR_DATA())
self.assertEqual(KERB_ERR_TYPE_EXTENDED,
error_data['data-type'])
extended_error = error_data['data-value']
self.assertEqual(12, len(extended_error))
status = int.from_bytes(extended_error[:4], 'little')
flags = int.from_bytes(extended_error[8:], 'little')
self.assertEqual(expected_status, status)
self.assertEqual(3, flags)
else:
self.assertIsNone(expected_status)
rep_padata = self.der_decode(edata,
asn1Spec=krb5_asn1.METHOD_DATA())
self.assertGreater(len(rep_padata), 0)
if sent_fast:
self.assertEqual(1, len(rep_padata))
rep_pa_dict = self.get_pa_dict(rep_padata)
self.assertIn(PADATA_FX_FAST, rep_pa_dict)
armor_key = kdc_exchange_dict['armor_key']
self.assertIsNotNone(armor_key)
fast_response = self.check_fx_fast_data(
kdc_exchange_dict,
rep_pa_dict[PADATA_FX_FAST],
armor_key,
expect_strengthen_key=False)
rep_padata = fast_response['padata']
etype_info2 = self.check_rep_padata(kdc_exchange_dict,
callback_dict,
rep_padata,
error_code)
kdc_exchange_dict['preauth_etype_info2'] = etype_info2
return rep
def check_rep_padata(self,
kdc_exchange_dict,
callback_dict,
rep_padata,
error_code):
rep_msg_type = kdc_exchange_dict['rep_msg_type']
req_body = kdc_exchange_dict['req_body']
proposed_etypes = req_body['etype']
client_as_etypes = kdc_exchange_dict.get('client_as_etypes', [])
sent_fast = self.sent_fast(kdc_exchange_dict)
sent_enc_challenge = self.sent_enc_challenge(kdc_exchange_dict)
if rep_msg_type == KRB_TGS_REP:
self.assertTrue(sent_fast)
expect_etype_info2 = ()
expect_etype_info = False
expected_aes_type = 0
expected_rc4_type = 0
if kcrypto.Enctype.RC4 in proposed_etypes:
expect_etype_info = True
for etype in proposed_etypes:
if etype not in client_as_etypes:
continue
if etype in (kcrypto.Enctype.AES256, kcrypto.Enctype.AES128):
expect_etype_info = False
if etype > expected_aes_type:
expected_aes_type = etype
if etype in (kcrypto.Enctype.RC4,) and error_code != 0:
if etype > expected_rc4_type:
expected_rc4_type = etype
if expected_aes_type != 0:
expect_etype_info2 += (expected_aes_type,)
if expected_rc4_type != 0:
expect_etype_info2 += (expected_rc4_type,)
expected_patypes = ()
if sent_fast and error_code != 0:
expected_patypes += (PADATA_FX_ERROR,)
expected_patypes += (PADATA_FX_COOKIE,)
if rep_msg_type == KRB_TGS_REP:
sent_pac_options = self.get_sent_pac_options(kdc_exchange_dict)
if ('1' in sent_pac_options
and error_code not in (0, KDC_ERR_GENERIC)):
expected_patypes += (PADATA_PAC_OPTIONS,)
elif error_code != KDC_ERR_GENERIC:
if expect_etype_info:
self.assertGreater(len(expect_etype_info2), 0)
expected_patypes += (PADATA_ETYPE_INFO,)
if len(expect_etype_info2) != 0:
expected_patypes += (PADATA_ETYPE_INFO2,)
if error_code != KDC_ERR_PREAUTH_FAILED:
if sent_fast:
expected_patypes += (PADATA_ENCRYPTED_CHALLENGE,)
else:
expected_patypes += (PADATA_ENC_TIMESTAMP,)
if not sent_enc_challenge:
expected_patypes += (PADATA_PK_AS_REQ,)
expected_patypes += (PADATA_PK_AS_REP_19,)
if (self.kdc_fast_support
and not sent_fast
and not sent_enc_challenge):
expected_patypes += (PADATA_FX_FAST,)
expected_patypes += (PADATA_FX_COOKIE,)
require_strict = {
PADATA_FX_COOKIE,
PADATA_FX_FAST,
PADATA_PAC_OPTIONS,
PADATA_PK_AS_REP_19,
PADATA_PK_AS_REQ
}
strict_etype_info = kdc_exchange_dict['strict_etype_info']
if not strict_etype_info:
require_strict.add(PADATA_ETYPE_INFO)
got_patypes = tuple(pa['padata-type'] for pa in rep_padata)
self.assertSequenceElementsEqual(expected_patypes, got_patypes,
require_strict=require_strict)
if not expected_patypes:
return None
pa_dict = self.get_pa_dict(rep_padata)
enc_timestamp = pa_dict.get(PADATA_ENC_TIMESTAMP)
if enc_timestamp is not None:
self.assertEqual(len(enc_timestamp), 0)
pk_as_req = pa_dict.get(PADATA_PK_AS_REQ)
if pk_as_req is not None:
self.assertEqual(len(pk_as_req), 0)
pk_as_rep19 = pa_dict.get(PADATA_PK_AS_REP_19)
if pk_as_rep19 is not None:
self.assertEqual(len(pk_as_rep19), 0)
fx_fast = pa_dict.get(PADATA_FX_FAST)
if fx_fast is not None:
self.assertEqual(len(fx_fast), 0)
fast_cookie = pa_dict.get(PADATA_FX_COOKIE)
if fast_cookie is not None:
kdc_exchange_dict['fast_cookie'] = fast_cookie
fast_error = pa_dict.get(PADATA_FX_ERROR)
if fast_error is not None:
fast_error = self.der_decode(fast_error,
asn1Spec=krb5_asn1.KRB_ERROR())
self.generic_check_kdc_error(kdc_exchange_dict,
callback_dict,
fast_error,
inner=True)
pac_options = pa_dict.get(PADATA_PAC_OPTIONS)
if pac_options is not None:
pac_options = self.der_decode(
pac_options,
asn1Spec=krb5_asn1.PA_PAC_OPTIONS())
self.assertElementEqual(pac_options, 'options', sent_pac_options)
enc_challenge = pa_dict.get(PADATA_ENCRYPTED_CHALLENGE)
if enc_challenge is not None:
if not sent_enc_challenge:
self.assertEqual(len(enc_challenge), 0)
else:
armor_key = kdc_exchange_dict['armor_key']
self.assertIsNotNone(armor_key)
preauth_key, _ = self.get_preauth_key(kdc_exchange_dict)
kdc_challenge_key = self.generate_kdc_challenge_key(
armor_key, preauth_key)
# Ensure that the encrypted challenge FAST factor is supported
# (RFC6113 5.4.6).
if self.strict_checking:
self.assertNotEqual(len(enc_challenge), 0)
if len(enc_challenge) != 0:
encrypted_challenge = self.der_decode(
enc_challenge,
asn1Spec=krb5_asn1.EncryptedData())
self.assertEqual(encrypted_challenge['etype'],
kdc_challenge_key.etype)
challenge = kdc_challenge_key.decrypt(
KU_ENC_CHALLENGE_KDC,
encrypted_challenge['cipher'])
challenge = self.der_decode(
challenge,
asn1Spec=krb5_asn1.PA_ENC_TS_ENC())
# Retrieve the returned timestamp.
rep_patime = challenge['patimestamp']
self.assertIn('pausec', challenge)
# Ensure the returned time is within five minutes of the
# current time.
rep_time = self.get_EpochFromKerberosTime(rep_patime)
current_time = time.time()
self.assertLess(current_time - 300, rep_time)
self.assertLess(rep_time, current_time + 300)
etype_info2 = pa_dict.get(PADATA_ETYPE_INFO2)
if etype_info2 is not None:
etype_info2 = self.der_decode(etype_info2,
asn1Spec=krb5_asn1.ETYPE_INFO2())
self.assertGreaterEqual(len(etype_info2), 1)
if self.strict_checking:
self.assertEqual(len(etype_info2), len(expect_etype_info2))
for i in range(0, len(etype_info2)):
e = self.getElementValue(etype_info2[i], 'etype')
if self.strict_checking:
self.assertEqual(e, expect_etype_info2[i])
salt = self.getElementValue(etype_info2[i], 'salt')
if e == kcrypto.Enctype.RC4:
if self.strict_checking:
self.assertIsNone(salt)
else:
self.assertIsNotNone(salt)
expected_salt = kdc_exchange_dict['expected_salt']
if expected_salt is not None:
self.assertEqual(salt, expected_salt)
s2kparams = self.getElementValue(etype_info2[i], 's2kparams')
if self.strict_checking:
self.assertIsNone(s2kparams)
etype_info = pa_dict.get(PADATA_ETYPE_INFO)
if etype_info is not None:
strict_etype_info = kdc_exchange_dict['strict_etype_info']
etype_info = self.der_decode(etype_info,
asn1Spec=krb5_asn1.ETYPE_INFO())
self.assertEqual(len(etype_info), 1)
e = self.getElementValue(etype_info[0], 'etype')
self.assertEqual(e, kcrypto.Enctype.RC4)
if strict_etype_info:
self.assertEqual(e, expect_etype_info2[0])
salt = self.getElementValue(etype_info[0], 'salt')
if self.strict_checking:
self.assertIsNotNone(salt)
self.assertEqual(len(salt), 0)
return etype_info2
def generate_simple_fast(self,
kdc_exchange_dict,
_callback_dict,
req_body,
fast_padata,
fast_armor,
checksum,
fast_options=''):
armor_key = kdc_exchange_dict['armor_key']
fast_req = self.KRB_FAST_REQ_create(fast_options,
fast_padata,
req_body)
fast_req = self.der_encode(fast_req,
asn1Spec=krb5_asn1.KrbFastReq())
fast_req = self.EncryptedData_create(armor_key,
KU_FAST_ENC,
fast_req)
fast_armored_req = self.KRB_FAST_ARMORED_REQ_create(fast_armor,
checksum,
fast_req)
fx_fast_request = self.PA_FX_FAST_REQUEST_create(fast_armored_req)
fx_fast_request = self.der_encode(
fx_fast_request,
asn1Spec=krb5_asn1.PA_FX_FAST_REQUEST())
fast_padata = self.PA_DATA_create(PADATA_FX_FAST,
fx_fast_request)
return fast_padata
def generate_ap_req(self,
kdc_exchange_dict,
_callback_dict,
req_body,
armor,
usage=None,
seq_number=None):
req_body_checksum = None
if armor:
self.assertIsNone(req_body)
tgt = kdc_exchange_dict['armor_tgt']
authenticator_subkey = kdc_exchange_dict['armor_subkey']
else:
tgt = kdc_exchange_dict['tgt']
authenticator_subkey = kdc_exchange_dict['authenticator_subkey']
if req_body is not None:
body_checksum_type = kdc_exchange_dict['body_checksum_type']
req_body_blob = self.der_encode(
req_body, asn1Spec=krb5_asn1.KDC_REQ_BODY())
req_body_checksum = self.Checksum_create(
tgt.session_key,
KU_TGS_REQ_AUTH_CKSUM,
req_body_blob,
ctype=body_checksum_type)
auth_data = kdc_exchange_dict['auth_data']
subkey_obj = None
if authenticator_subkey is not None:
subkey_obj = authenticator_subkey.export_obj()
if seq_number is None:
seq_number = random.randint(0, 0xfffffffe)
(ctime, cusec) = self.get_KerberosTimeWithUsec()
authenticator_obj = self.Authenticator_create(
crealm=tgt.crealm,
cname=tgt.cname,
cksum=req_body_checksum,
cusec=cusec,
ctime=ctime,
subkey=subkey_obj,
seq_number=seq_number,
authorization_data=auth_data)
authenticator_blob = self.der_encode(
authenticator_obj,
asn1Spec=krb5_asn1.Authenticator())
if usage is None:
usage = KU_AP_REQ_AUTH if armor else KU_TGS_REQ_AUTH
authenticator = self.EncryptedData_create(tgt.session_key,
usage,
authenticator_blob)
ap_options = krb5_asn1.APOptions('0')
ap_req_obj = self.AP_REQ_create(ap_options=str(ap_options),
ticket=tgt.ticket,
authenticator=authenticator)
ap_req = self.der_encode(ap_req_obj, asn1Spec=krb5_asn1.AP_REQ())
return ap_req
def generate_simple_tgs_padata(self,
kdc_exchange_dict,
callback_dict,
req_body):
ap_req = self.generate_ap_req(kdc_exchange_dict,
callback_dict,
req_body,
armor=False)
pa_tgs_req = self.PA_DATA_create(PADATA_KDC_REQ, ap_req)
padata = [pa_tgs_req]
return padata, req_body
def get_preauth_key(self, kdc_exchange_dict):
msg_type = kdc_exchange_dict['rep_msg_type']
if msg_type == KRB_AS_REP:
key = kdc_exchange_dict['preauth_key']
usage = KU_AS_REP_ENC_PART
else: # KRB_TGS_REP
authenticator_subkey = kdc_exchange_dict['authenticator_subkey']
if authenticator_subkey is not None:
key = authenticator_subkey
usage = KU_TGS_REP_ENC_PART_SUB_KEY
else:
tgt = kdc_exchange_dict['tgt']
key = tgt.session_key
usage = KU_TGS_REP_ENC_PART_SESSION
self.assertIsNotNone(key)
return key, usage
def generate_armor_key(self, subkey, session_key):
armor_key = kcrypto.cf2(subkey.key,
session_key.key,
b'subkeyarmor',
b'ticketarmor')
armor_key = Krb5EncryptionKey(armor_key, None)
return armor_key
def generate_strengthen_reply_key(self, strengthen_key, reply_key):
strengthen_reply_key = kcrypto.cf2(strengthen_key.key,
reply_key.key,
b'strengthenkey',
b'replykey')
strengthen_reply_key = Krb5EncryptionKey(strengthen_reply_key,
reply_key.kvno)
return strengthen_reply_key
def generate_client_challenge_key(self, armor_key, longterm_key):
client_challenge_key = kcrypto.cf2(armor_key.key,
longterm_key.key,
b'clientchallengearmor',
b'challengelongterm')
client_challenge_key = Krb5EncryptionKey(client_challenge_key, None)
return client_challenge_key
def generate_kdc_challenge_key(self, armor_key, longterm_key):
kdc_challenge_key = kcrypto.cf2(armor_key.key,
longterm_key.key,
b'kdcchallengearmor',
b'challengelongterm')
kdc_challenge_key = Krb5EncryptionKey(kdc_challenge_key, None)
return kdc_challenge_key
def verify_ticket_checksum(self, ticket, expected_checksum, armor_key):
expected_type = expected_checksum['cksumtype']
self.assertEqual(armor_key.ctype, expected_type)
ticket_blob = self.der_encode(ticket,
asn1Spec=krb5_asn1.Ticket())
checksum = self.Checksum_create(armor_key,
KU_FAST_FINISHED,
ticket_blob)
self.assertEqual(expected_checksum, checksum)
def verify_ticket(self, ticket, krbtgt_keys, service_ticket,
expect_pac=True,
expect_ticket_checksum=True,
expect_full_checksum=None):
# Decrypt the ticket.
key = ticket.decryption_key
enc_part = ticket.ticket['enc-part']
self.assertElementEqual(enc_part, 'etype', key.etype)
self.assertElementKVNO(enc_part, 'kvno', key.kvno)
enc_part = key.decrypt(KU_TICKET, enc_part['cipher'])
enc_part = self.der_decode(
enc_part, asn1Spec=krb5_asn1.EncTicketPart())
# Fetch the authorization data from the ticket.
auth_data = enc_part.get('authorization-data')
if expect_pac:
self.assertIsNotNone(auth_data)
elif auth_data is None:
return
# Get a copy of the authdata with an empty PAC, and the existing PAC
# (if present).
empty_pac = self.get_empty_pac()
auth_data, pac_data = self.replace_pac(auth_data,
empty_pac,
expect_pac=expect_pac)
if not expect_pac:
return
# Unpack the PAC as both PAC_DATA and PAC_DATA_RAW types. We use the
# raw type to create a new PAC with zeroed signatures for
# verification. This is because on Windows, the resource_groups field
# is added to PAC_LOGON_INFO after the info3 field has been created,
# which results in a different ordering of pointer values than Samba
# (see commit 0e201ecdc53). Using the raw type avoids changing
# PAC_LOGON_INFO, so verification against Windows can work. We still
# need the PAC_DATA type to retrieve the actual checksums, because the
# signatures in the raw type may contain padding bytes.
pac = ndr_unpack(krb5pac.PAC_DATA,
pac_data)
raw_pac = ndr_unpack(krb5pac.PAC_DATA_RAW,
pac_data)
checksums = {}
full_checksum_buffer = None
for pac_buffer, raw_pac_buffer in zip(pac.buffers, raw_pac.buffers):
buffer_type = pac_buffer.type
if buffer_type in self.pac_checksum_types:
self.assertNotIn(buffer_type, checksums,
f'Duplicate checksum type {buffer_type}')
# Fetch the checksum and the checksum type from the PAC buffer.
checksum = pac_buffer.info.signature
ctype = pac_buffer.info.type
if ctype & 1 << 31:
ctype |= -1 << 31
checksums[buffer_type] = checksum, ctype
if buffer_type == krb5pac.PAC_TYPE_FULL_CHECKSUM:
full_checksum_buffer = raw_pac_buffer
elif buffer_type != krb5pac.PAC_TYPE_TICKET_CHECKSUM:
# Zero the checksum field so that we can later verify the
# checksums. The ticket checksum field is not zeroed.
signature = ndr_unpack(
krb5pac.PAC_SIGNATURE_DATA,
raw_pac_buffer.info.remaining)
signature.signature = bytes(len(checksum))
raw_pac_buffer.info.remaining = ndr_pack(
signature)
# Re-encode the PAC.
pac_data = ndr_pack(raw_pac)
if full_checksum_buffer is not None:
signature = ndr_unpack(
krb5pac.PAC_SIGNATURE_DATA,
full_checksum_buffer.info.remaining)
signature.signature = bytes(len(checksum))
full_checksum_buffer.info.remaining = ndr_pack(
signature)
# Re-encode the PAC.
full_pac_data = ndr_pack(raw_pac)
# Verify the signatures.
server_checksum, server_ctype = checksums[
krb5pac.PAC_TYPE_SRV_CHECKSUM]
key.verify_checksum(KU_NON_KERB_CKSUM_SALT,
pac_data,
server_ctype,
server_checksum)
kdc_checksum, kdc_ctype = checksums[
krb5pac.PAC_TYPE_KDC_CHECKSUM]
if isinstance(krbtgt_keys, collections.abc.Container):
if self.strict_checking:
krbtgt_key = krbtgt_keys[0]
else:
krbtgt_key = next(key for key in krbtgt_keys
if key.ctype == kdc_ctype)
else:
krbtgt_key = krbtgt_keys
krbtgt_key.verify_rodc_checksum(KU_NON_KERB_CKSUM_SALT,
server_checksum,
kdc_ctype,
kdc_checksum)
if not service_ticket:
self.assertNotIn(krb5pac.PAC_TYPE_TICKET_CHECKSUM, checksums)
self.assertNotIn(krb5pac.PAC_TYPE_FULL_CHECKSUM, checksums)
else:
ticket_checksum, ticket_ctype = checksums.get(
krb5pac.PAC_TYPE_TICKET_CHECKSUM,
(None, None))
if expect_ticket_checksum:
self.assertIsNotNone(ticket_checksum)
elif expect_ticket_checksum is False:
self.assertIsNone(ticket_checksum)
if ticket_checksum is not None:
enc_part['authorization-data'] = auth_data
enc_part = self.der_encode(enc_part,
asn1Spec=krb5_asn1.EncTicketPart())
krbtgt_key.verify_rodc_checksum(KU_NON_KERB_CKSUM_SALT,
enc_part,
ticket_ctype,
ticket_checksum)
full_checksum, full_ctype = checksums.get(
krb5pac.PAC_TYPE_FULL_CHECKSUM,
(None, None))
if expect_full_checksum:
self.assertIsNotNone(full_checksum)
elif expect_full_checksum is False:
self.assertIsNone(full_checksum)
if full_checksum is not None:
krbtgt_key.verify_rodc_checksum(KU_NON_KERB_CKSUM_SALT,
full_pac_data,
full_ctype,
full_checksum)
def modified_ticket(self,
ticket, *,
new_ticket_key=None,
modify_fn=None,
modify_pac_fn=None,
exclude_pac=False,
allow_empty_authdata=False,
update_pac_checksums=True,
checksum_keys=None,
include_checksums=None):
if checksum_keys is None:
# A dict containing a key for each checksum type to be created in
# the PAC.
checksum_keys = {}
if include_checksums is None:
# A dict containing a value for each checksum type; True if the
# checksum type is to be included in the PAC, False if it is to be
# excluded, or None/not present if the checksum is to be included
# based on its presence in the original PAC.
include_checksums = {}
# Check that the values passed in by the caller make sense.
self.assertLessEqual(checksum_keys.keys(), self.pac_checksum_types)
self.assertLessEqual(include_checksums.keys(), self.pac_checksum_types)
if exclude_pac:
self.assertIsNone(modify_pac_fn)
update_pac_checksums = False
if not update_pac_checksums:
self.assertFalse(checksum_keys)
self.assertFalse(include_checksums)
expect_pac = modify_pac_fn is not None
key = ticket.decryption_key
if new_ticket_key is None:
# Use the same key to re-encrypt the ticket.
new_ticket_key = key
if krb5pac.PAC_TYPE_SRV_CHECKSUM not in checksum_keys:
# If the server signature key is not present, fall back to the key
# used to encrypt the ticket.
checksum_keys[krb5pac.PAC_TYPE_SRV_CHECKSUM] = new_ticket_key
if krb5pac.PAC_TYPE_TICKET_CHECKSUM not in checksum_keys:
# If the ticket signature key is not present, fall back to the key
# used for the KDC signature.
kdc_checksum_key = checksum_keys.get(krb5pac.PAC_TYPE_KDC_CHECKSUM)
if kdc_checksum_key is not None:
checksum_keys[krb5pac.PAC_TYPE_TICKET_CHECKSUM] = (
kdc_checksum_key)
if krb5pac.PAC_TYPE_FULL_CHECKSUM not in checksum_keys:
# If the full signature key is not present, fall back to the key
# used for the KDC signature.
kdc_checksum_key = checksum_keys.get(krb5pac.PAC_TYPE_KDC_CHECKSUM)
if kdc_checksum_key is not None:
checksum_keys[krb5pac.PAC_TYPE_FULL_CHECKSUM] = (
kdc_checksum_key)
# Decrypt the ticket.
enc_part = ticket.ticket['enc-part']
self.assertElementEqual(enc_part, 'etype', key.etype)
self.assertElementKVNO(enc_part, 'kvno', key.kvno)
enc_part = key.decrypt(KU_TICKET, enc_part['cipher'])
enc_part = self.der_decode(
enc_part, asn1Spec=krb5_asn1.EncTicketPart())
# Modify the ticket here.
if modify_fn is not None:
enc_part = modify_fn(enc_part)
auth_data = enc_part.get('authorization-data')
if expect_pac:
self.assertIsNotNone(auth_data)
if auth_data is not None:
new_pac = None
if not exclude_pac:
# Get a copy of the authdata with an empty PAC, and the
# existing PAC (if present).
empty_pac = self.get_empty_pac()
empty_pac_auth_data, pac_data = self.replace_pac(
auth_data,
empty_pac,
expect_pac=expect_pac)
if pac_data is not None:
pac = ndr_unpack(krb5pac.PAC_DATA, pac_data)
# Modify the PAC here.
if modify_pac_fn is not None:
pac = modify_pac_fn(pac)
if update_pac_checksums:
# Get the enc-part with an empty PAC, which is needed
# to create a ticket signature.
enc_part_to_sign = enc_part.copy()
enc_part_to_sign['authorization-data'] = (
empty_pac_auth_data)
enc_part_to_sign = self.der_encode(
enc_part_to_sign,
asn1Spec=krb5_asn1.EncTicketPart())
self.update_pac_checksums(pac,
checksum_keys,
include_checksums,
enc_part_to_sign)
# Re-encode the PAC.
pac_data = ndr_pack(pac)
new_pac = self.AuthorizationData_create(AD_WIN2K_PAC,
pac_data)
# Replace the PAC in the authorization data and re-add it to the
# ticket enc-part.
auth_data, _ = self.replace_pac(
auth_data, new_pac,
expect_pac=expect_pac,
allow_empty_authdata=allow_empty_authdata)
enc_part['authorization-data'] = auth_data
# Re-encrypt the ticket enc-part with the new key.
enc_part_new = self.der_encode(enc_part,
asn1Spec=krb5_asn1.EncTicketPart())
enc_part_new = self.EncryptedData_create(new_ticket_key,
KU_TICKET,
enc_part_new)
# Create a copy of the ticket with the new enc-part.
new_ticket = ticket.ticket.copy()
new_ticket['enc-part'] = enc_part_new
new_ticket_creds = KerberosTicketCreds(
new_ticket,
session_key=ticket.session_key,
crealm=ticket.crealm,
cname=ticket.cname,
srealm=ticket.srealm,
sname=ticket.sname,
decryption_key=new_ticket_key,
ticket_private=enc_part,
encpart_private=ticket.encpart_private)
return new_ticket_creds
def update_pac_checksums(self,
pac,
checksum_keys,
include_checksums,
enc_part=None):
pac_buffers = pac.buffers
checksum_buffers = {}
# Find the relevant PAC checksum buffers.
for pac_buffer in pac_buffers:
buffer_type = pac_buffer.type
if buffer_type in self.pac_checksum_types:
self.assertNotIn(buffer_type, checksum_buffers,
f'Duplicate checksum type {buffer_type}')
checksum_buffers[buffer_type] = pac_buffer
# Create any additional buffers that were requested but not
# present. Conversely, remove any buffers that were requested to be
# removed.
for buffer_type in self.pac_checksum_types:
if buffer_type in checksum_buffers:
if include_checksums.get(buffer_type) is False:
checksum_buffer = checksum_buffers.pop(buffer_type)
pac.num_buffers -= 1
pac_buffers.remove(checksum_buffer)
elif include_checksums.get(buffer_type) is True:
info = krb5pac.PAC_SIGNATURE_DATA()
checksum_buffer = krb5pac.PAC_BUFFER()
checksum_buffer.type = buffer_type
checksum_buffer.info = info
pac_buffers.append(checksum_buffer)
pac.num_buffers += 1
checksum_buffers[buffer_type] = checksum_buffer
# Fill the relevant checksum buffers.
for buffer_type, checksum_buffer in checksum_buffers.items():
checksum_key = checksum_keys[buffer_type]
ctype = checksum_key.ctype & ((1 << 32) - 1)
if buffer_type == krb5pac.PAC_TYPE_TICKET_CHECKSUM:
self.assertIsNotNone(enc_part)
signature = checksum_key.make_rodc_checksum(
KU_NON_KERB_CKSUM_SALT,
enc_part)
elif buffer_type == krb5pac.PAC_TYPE_SRV_CHECKSUM:
signature = checksum_key.make_zeroed_checksum()
else:
signature = checksum_key.make_rodc_zeroed_checksum()
checksum_buffer.info.signature = signature
checksum_buffer.info.type = ctype
# Add the new checksum buffers to the PAC.
pac.buffers = pac_buffers
# Calculate the full checksum and insert it into the PAC.
full_checksum_buffer = checksum_buffers.get(
krb5pac.PAC_TYPE_FULL_CHECKSUM)
if full_checksum_buffer is not None:
full_checksum_key = checksum_keys[krb5pac.PAC_TYPE_FULL_CHECKSUM]
pac_data = ndr_pack(pac)
full_checksum = full_checksum_key.make_checksum(
KU_NON_KERB_CKSUM_SALT,
pac_data)
full_checksum_buffer.info.signature = full_checksum
# Calculate the server and KDC checksums and insert them into the PAC.
server_checksum_buffer = checksum_buffers.get(
krb5pac.PAC_TYPE_SRV_CHECKSUM)
if server_checksum_buffer is not None:
server_checksum_key = checksum_keys[krb5pac.PAC_TYPE_SRV_CHECKSUM]
pac_data = ndr_pack(pac)
server_checksum = server_checksum_key.make_checksum(
KU_NON_KERB_CKSUM_SALT,
pac_data)
server_checksum_buffer.info.signature = server_checksum
kdc_checksum_buffer = checksum_buffers.get(
krb5pac.PAC_TYPE_KDC_CHECKSUM)
if kdc_checksum_buffer is not None:
if server_checksum_buffer is None:
# There's no server signature to make the checksum over, so
# just make the checksum over an empty bytes object.
server_checksum = bytes()
kdc_checksum_key = checksum_keys[krb5pac.PAC_TYPE_KDC_CHECKSUM]
kdc_checksum = kdc_checksum_key.make_rodc_checksum(
KU_NON_KERB_CKSUM_SALT,
server_checksum)
kdc_checksum_buffer.info.signature = kdc_checksum
def replace_pac(self, auth_data, new_pac, expect_pac=True,
allow_empty_authdata=False):
if new_pac is not None:
self.assertElementEqual(new_pac, 'ad-type', AD_WIN2K_PAC)
self.assertElementPresent(new_pac, 'ad-data')
new_auth_data = []
ad_relevant = None
old_pac = None
for authdata_elem in auth_data:
if authdata_elem['ad-type'] == AD_IF_RELEVANT:
ad_relevant = self.der_decode(
authdata_elem['ad-data'],
asn1Spec=krb5_asn1.AD_IF_RELEVANT())
relevant_elems = []
for relevant_elem in ad_relevant:
if relevant_elem['ad-type'] == AD_WIN2K_PAC:
self.assertIsNone(old_pac, 'Multiple PACs detected')
old_pac = relevant_elem['ad-data']
if new_pac is not None:
relevant_elems.append(new_pac)
else:
relevant_elems.append(relevant_elem)
if expect_pac:
self.assertIsNotNone(old_pac, 'Expected PAC')
if relevant_elems or allow_empty_authdata:
ad_relevant = self.der_encode(
relevant_elems,
asn1Spec=krb5_asn1.AD_IF_RELEVANT())
authdata_elem = self.AuthorizationData_create(
AD_IF_RELEVANT,
ad_relevant)
else:
authdata_elem = None
if authdata_elem is not None or allow_empty_authdata:
new_auth_data.append(authdata_elem)
if expect_pac:
self.assertIsNotNone(ad_relevant, 'Expected AD-RELEVANT')
return new_auth_data, old_pac
def get_pac(self, auth_data, expect_pac=True):
_, pac = self.replace_pac(auth_data, None, expect_pac)
return pac
def get_ticket_pac(self, ticket, expect_pac=True):
auth_data = ticket.ticket_private.get('authorization-data')
if expect_pac:
self.assertIsNotNone(auth_data)
elif auth_data is None:
return None
return self.get_pac(auth_data, expect_pac=expect_pac)
def get_krbtgt_checksum_key(self):
krbtgt_creds = self.get_krbtgt_creds()
krbtgt_key = self.TicketDecryptionKey_from_creds(krbtgt_creds)
return {
krb5pac.PAC_TYPE_KDC_CHECKSUM: krbtgt_key
}
def is_tgs(self, principal):
name = principal['name-string'][0]
return name in ('krbtgt', b'krbtgt')
def is_tgt(self, ticket):
sname = ticket.ticket['sname']
return self.is_tgs(sname)
def get_empty_pac(self):
return self.AuthorizationData_create(AD_WIN2K_PAC, bytes(1))
def get_outer_pa_dict(self, kdc_exchange_dict):
return self.get_pa_dict(kdc_exchange_dict['req_padata'])
def get_fast_pa_dict(self, kdc_exchange_dict):
req_pa_dict = self.get_pa_dict(kdc_exchange_dict['fast_padata'])
if req_pa_dict:
return req_pa_dict
return self.get_outer_pa_dict(kdc_exchange_dict)
def sent_fast(self, kdc_exchange_dict):
outer_pa_dict = self.get_outer_pa_dict(kdc_exchange_dict)
return PADATA_FX_FAST in outer_pa_dict
def sent_enc_challenge(self, kdc_exchange_dict):
fast_pa_dict = self.get_fast_pa_dict(kdc_exchange_dict)
return PADATA_ENCRYPTED_CHALLENGE in fast_pa_dict
def sent_enc_pa_rep(self, kdc_exchange_dict):
fast_pa_dict = self.get_fast_pa_dict(kdc_exchange_dict)
return PADATA_REQ_ENC_PA_REP in fast_pa_dict
def get_sent_pac_options(self, kdc_exchange_dict):
fast_pa_dict = self.get_fast_pa_dict(kdc_exchange_dict)
if PADATA_PAC_OPTIONS not in fast_pa_dict:
return ''
pac_options = self.der_decode(fast_pa_dict[PADATA_PAC_OPTIONS],
asn1Spec=krb5_asn1.PA_PAC_OPTIONS())
pac_options = pac_options['options']
# Mask out unsupported bits.
pac_options, remaining = pac_options[:4], pac_options[4:]
pac_options += '0' * len(remaining)
return pac_options
def get_krbtgt_sname(self):
krbtgt_creds = self.get_krbtgt_creds()
krbtgt_username = krbtgt_creds.get_username()
krbtgt_realm = krbtgt_creds.get_realm()
krbtgt_sname = self.PrincipalName_create(
name_type=NT_SRV_INST, names=[krbtgt_username, krbtgt_realm])
return krbtgt_sname
def _test_as_exchange(self,
cname,
realm,
sname,
till,
client_as_etypes,
expected_error_mode,
expected_crealm,
expected_cname,
expected_srealm,
expected_sname,
expected_salt,
etypes,
padata,
kdc_options,
expected_account_name=None,
expected_upn_name=None,
expected_sid=None,
expected_flags=None,
unexpected_flags=None,
expected_supported_etypes=None,
preauth_key=None,
ticket_decryption_key=None,
pac_request=None,
pac_options=None,
expect_pac=True,
expect_pac_attrs=None,
expect_pac_attrs_pac_request=None,
expect_requester_sid=None,
expect_edata=None,
strict_etype_info=True,
to_rodc=False):
def _generate_padata_copy(_kdc_exchange_dict,
_callback_dict,
req_body):
return padata, req_body
if not expected_error_mode:
check_error_fn = None
check_rep_fn = self.generic_check_kdc_rep
else:
check_error_fn = self.generic_check_kdc_error
check_rep_fn = None
if padata is not None:
generate_padata_fn = _generate_padata_copy
else:
generate_padata_fn = None
kdc_exchange_dict = self.as_exchange_dict(
expected_crealm=expected_crealm,
expected_cname=expected_cname,
expected_srealm=expected_srealm,
expected_sname=expected_sname,
expected_account_name=expected_account_name,
expected_upn_name=expected_upn_name,
expected_sid=expected_sid,
expected_supported_etypes=expected_supported_etypes,
ticket_decryption_key=ticket_decryption_key,
generate_padata_fn=generate_padata_fn,
check_error_fn=check_error_fn,
check_rep_fn=check_rep_fn,
check_kdc_private_fn=self.generic_check_kdc_private,
expected_error_mode=expected_error_mode,
client_as_etypes=client_as_etypes,
expected_salt=expected_salt,
expected_flags=expected_flags,
unexpected_flags=unexpected_flags,
preauth_key=preauth_key,
kdc_options=str(kdc_options),
pac_request=pac_request,
pac_options=pac_options,
expect_pac=expect_pac,
expect_pac_attrs=expect_pac_attrs,
expect_pac_attrs_pac_request=expect_pac_attrs_pac_request,
expect_requester_sid=expect_requester_sid,
expect_edata=expect_edata,
strict_etype_info=strict_etype_info,
to_rodc=to_rodc)
rep = self._generic_kdc_exchange(kdc_exchange_dict,
cname=cname,
realm=realm,
sname=sname,
till_time=till,
etypes=etypes)
return rep, kdc_exchange_dict
Zerion Mini Shell 1.0