def GSS_Unwrap(self, sessionKey, data, sequenceNumber, direction = 'init', encrypt=True, authData=None):
from impacket.dcerpc.v5.rpcrt import SEC_TRAILER
cipher = self.cipherType()
token = self.WRAP(authData[len(SEC_TRAILER()):])
rotated = authData[len(self.WRAP())+len(SEC_TRAILER()):] + data
cipherText = self.unrotate(rotated, token['RRC'] + token['EC'])
plainText = cipher.decrypt(sessionKey, KG_USAGE_ACCEPTOR_SEAL, cipherText)
return plainText[:-(token['EC']+len(self.WRAP()))], None
def sendBindType1(self, iface_uuid, auth_data):
bind = MSRPCBind()
item = CtxItem()
item['AbstractSyntax'] = iface_uuid
item['TransferSyntax'] = self.transfer_syntax
item['ContextID'] = 0
item['TransItems'] = 1
bind.addCtxItem(item)
packet = MSRPCHeader()
packet['type'] = rpcrt.MSRPC_BIND
packet['pduData'] = bind.getData()
packet['call_id'] = 0
sec_trailer = SEC_TRAILER()
sec_trailer['auth_type'] = RPC_C_AUTHN_WINNT
sec_trailer['auth_level'] = RPC_C_AUTHN_LEVEL_CONNECT
sec_trailer['auth_ctx_id'] = 79231
pad = (4 - (len(packet.get_packet()) % 4)) % 4
if pad != 0:
packet['pduData'] += b'\xFF' * pad
sec_trailer['auth_pad_len'] = pad
packet['sec_trailer'] = sec_trailer
packet['auth_data'] = auth_data
self._transport.send(packet.get_packet())
s = self._transport.recv()
if s != 0:
resp = MSRPCHeader(s)
else:
return 0 #mmm why not None?
if resp['type'] == rpcrt.MSRPC_BINDACK or resp['type'] == rpcrt.MSRPC_ALTERCTX_R:
bindResp = MSRPCBindAck(resp.getData())
elif resp['type'] == rpcrt.MSRPC_BINDNAK or resp['type'] == rpcrt.MSRPC_FAULT:
if resp['type'] == rpcrt.MSRPC_FAULT:
resp = MSRPCRespHeader(resp.getData())
status_code = unpack('<L', resp['pduData'][:4])[0]
else:
resp = MSRPCBindNak(resp['pduData'])
status_code = resp['RejectedReason']
if status_code in rpc_status_codes:
raise DCERPCException(error_code = status_code)
elif status_code in rpc_provider_reason:
raise DCERPCException("Bind context rejected: %s" % rpc_provider_reason[status_code])
else:
raise DCERPCException('Unknown DCE RPC fault status code: %.8x' % status_code)
else:
raise DCERPCException('Unknown DCE RPC packet type received: %d' % resp['type'])
self.set_max_tfrag(bindResp['max_rfrag'])
return bindResp
def sendBindType3(self, auth_data):
sec_trailer = SEC_TRAILER()
sec_trailer['auth_type'] = RPC_C_AUTHN_WINNT
sec_trailer['auth_level'] = RPC_C_AUTHN_LEVEL_PKT_PRIVACY
sec_trailer['auth_ctx_id'] = 79231
auth3 = MSRPCHeader()
auth3['type'] = rpcrt.MSRPC_AUTH3
# pad (4 bytes): Can be set to any arbitrary value when set and MUST be
# ignored on receipt. The pad field MUST be immediately followed by a
# sec_trailer structure whose layout, location, and alignment are as
# specified in section 2.2.2.11
auth3['pduData'] = b' '
auth3['sec_trailer'] = sec_trailer
auth3['auth_data'] = auth_data
auth3['call_id'] = 0
self._transport.send(auth3.get_packet(), forceWriteAndx=1)
def bind_ntlm_authinfo(dcerpc, iface_uuid):
# Build MSRPCBind information
bind = MSRPCBind()
item = CtxItem()
item['AbstractSyntax'] = iface_uuid
item['TransferSyntax'] = uuidtup_to_bin(
('8a885d04-1ceb-11c9-9fe8-08002b104860', '2.0'))
item['ContextID'] = 0
item['TransItems'] = 1
bind.addCtxItem(item)
# Build NTLM Authentication Negociate
auth = ntlm.NTLMAuthNegotiate()
auth['flags'] = ntlm.NTLMSSP_NEGOTIATE_UNICODE
# Build Security Trailer
sec_trailer = SEC_TRAILER()
sec_trailer['auth_type'] = RPC_C_AUTHN_WINNT
sec_trailer['auth_level'] = RPC_C_AUTHN_LEVEL_CONNECT
sec_trailer['auth_ctx_id'] = 0xb0b0d0ba
# Build MSRPC Header
packet = MSRPCHeader()
packet['type'] = MSRPC_BIND
packet['call_id'] = 1
packet['flags'] = 0x03
packet['pduData'] = str(bind)
packet['sec_trailer'] = sec_trailer
packet['auth_data'] = str(auth)
# Send MSRPC request
dcerpc._transport.send(packet.get_packet())
# Receive MSRPC response
s = dcerpc._transport.recv()
if s == 0:
print "Failed to retrieve a Bind response!"
return 0
resp = MSRPCHeader(s)
return resp
def GSS_Wrap(self,
sessionKey,
data,
sequenceNumber,
direction='init',
encrypt=True,
authData=None):
# Damn inacurate RFC, useful info from here
# https://social.msdn.microsoft.com/Forums/en-US/fb98e8f4-e697-4652-bcb7-604e027e14cc/gsswrap-token-size-kerberos-and-rc4hmac?forum=os_windowsprotocols
# and here
# http://www.rfc-editor.org/errata_search.php?rfc=4757
GSS_WRAP_HEADER = '\x60\x2b\x06\x09\x2a\x86\x48\x86\xf7\x12\x01\x02\x02'
token = self.WRAP()
# Let's pad the data
pad = (8 - (len(data) % 8)) & 0x7
padStr = chr(pad) * pad
data = data + padStr
token['SGN_ALG'] = GSS_HMAC
token['SEAL_ALG'] = GSS_RC4
if direction == 'init':
token['SND_SEQ'] = struct.pack('>L', sequenceNumber) + '\x00' * 4
else:
token['SND_SEQ'] = struct.pack('>L', sequenceNumber) + '\xff' * 4
# Random confounder :)
token['Confounder'] = '12345678'
Ksign = HMAC.new(sessionKey.contents, 'signaturekey\0', MD5).digest()
Sgn_Cksum = MD5.new(
struct.pack('<L', 13) + str(token)[:8] + token['Confounder'] +
data).digest()
Klocal = ''
for n in sessionKey.contents:
Klocal += chr(ord(n) ^ 0xF0)
Kcrypt = HMAC.new(Klocal, struct.pack('<L', 0), MD5).digest()
Kcrypt = HMAC.new(Kcrypt, struct.pack('>L', sequenceNumber),
MD5).digest()
Sgn_Cksum = HMAC.new(Ksign, Sgn_Cksum, MD5).digest()
token['SGN_CKSUM'] = Sgn_Cksum[:8]
Kseq = HMAC.new(sessionKey.contents, struct.pack('<L', 0),
MD5).digest()
Kseq = HMAC.new(Kseq, token['SGN_CKSUM'], MD5).digest()
token['SND_SEQ'] = ARC4.new(Kseq).encrypt(token['SND_SEQ'])
if authData is not None:
from impacket.dcerpc.v5.rpcrt import SEC_TRAILER
wrap = self.WRAP(authData[len(SEC_TRAILER()) +
len(GSS_WRAP_HEADER):])
snd_seq = wrap['SND_SEQ']
Kseq = HMAC.new(sessionKey.contents, struct.pack('<L', 0),
MD5).digest()
Kseq = HMAC.new(Kseq, wrap['SGN_CKSUM'], MD5).digest()
snd_seq = ARC4.new(Kseq).encrypt(wrap['SND_SEQ'])
Kcrypt = HMAC.new(Klocal, struct.pack('<L', 0), MD5).digest()
Kcrypt = HMAC.new(Kcrypt, snd_seq[:4], MD5).digest()
rc4 = ARC4.new(Kcrypt)
cipherText = rc4.decrypt(token['Confounder'] + data)[8:]
elif encrypt is True:
rc4 = ARC4.new(Kcrypt)
token['Confounder'] = rc4.encrypt(token['Confounder'])
cipherText = rc4.encrypt(data)
else:
cipherText = data
finalData = GSS_WRAP_HEADER + token.getData()
return cipherText, finalData