# Copyright (c) 2003-2006 CORE Security Technologies
#
# This software is provided under under a slightly modified version
# of the Apache Software License. See the accompanying LICENSE file
# for more information.
#
# $Id: dcerpc.py,v 1.7 2006/05/23 22:26:51 gera Exp $
#
import array
from binascii import crc32
try:
from Crypto.Cipher import ARC4
from Crypto.Hash import MD4
POW = None
except Exception:
try:
import POW
except Exception:
print "WARNING: Crypto package not found. Some features will fail."
from impacket import ntlm
from impacket import ImpactPacket
from impacket.structure import Structure,pack,unpack
# MS/RPC Constants
MSRPC_REQUEST = 0x00
MSRPC_RESPONSE = 0x02
MSRPC_FAULT = 0x03
MSRPC_ACK = 0x07
MSRPC_BIND = 0x0B
MSRPC_BINDACK = 0x0C
MSRPC_BINDNAK = 0x0D
MSRPC_ALTERCTX = 0x0E
MSRPC_AUTH3 = 0x10
# MS/RPC Packet Flags
MSRPC_FIRSTFRAG = 0x01
MSRPC_LASTFRAG = 0x02
MSRPC_NOTAFRAG = 0x04
MSRPC_RECRESPOND= 0x08
MSRPC_NOMULTIPLEX = 0x10
MSRPC_NOTFORIDEMP = 0x20
MSRPC_NOTFORBCAST = 0x40
MSRPC_NOUUID = 0x80
#Reasons for rejection of a context element, included in bind_ack result reason
rpc_provider_reason = {
0 : 'reason_not_specified',
1 : 'abstract_syntax_not_supported',
2 : 'proposed_transfer_syntaxes_not_supported',
3 : 'local_limit_exceeded'
}
MSRPC_CONT_RESULT_ACCEPT = 0
MSRPC_CONT_RESULT_USER_REJECT = 1
MSRPC_CONT_RESULT_PROV_REJECT = 2
#Results of a presentation context negotiation
rpc_cont_def_result = {
0 : 'acceptance',
1 : 'user_rejection',
2 : 'provider_rejection'
}
#status codes, references:
#http://msdn.microsoft.com/library/default.asp?url=/library/en-us/rpc/rpc/rpc_return_values.asp
#http://msdn.microsoft.com/library/default.asp?url=/library/en-us/randz/protocol/common_return_values.asp
#winerror.h
#http://www.opengroup.org/onlinepubs/9629399/apdxn.htm
rpc_status_codes = {
0x00000005L : 'rpc_s_access_denied',
0x00000008L : 'Authentication type not recognized',
0x000006C6L : 'rpc_x_invalid_bound', # the arrays bound are invalid
0x000006F7L : 'rpc_x_bad_stub_data', # the stub data is invalid, doesn't match with the IDL definition
0x1C010001L : 'nca_s_comm_failure', # unable to get response from server:
0x1C010002L : 'nca_s_op_rng_error', # bad operation number in call
0x1C010003L : 'nca_s_unk_if', # unknown interface
0x1C010006L : 'nca_s_wrong_boot_time', # client passed server wrong server boot time
0x1C010009L : 'nca_s_you_crashed', # a restarted server called back a client
0x1C01000BL : 'nca_s_proto_error', # someone messed up the protocol
0x1C010013L : 'nca_s_out_args_too_big ', # output args too big
0x1C010014L : 'nca_s_server_too_busy', # server is too busy to handle call
0x1C010015L : 'nca_s_fault_string_too_long', # string argument longer than declared max len
0x1C010017L : 'nca_s_unsupported_type ', # no implementation of generic operation for object
0x1C000001L : 'nca_s_fault_int_div_by_zero',
0x1C000002L : 'nca_s_fault_addr_error ',
0x1C000003L : 'nca_s_fault_fp_div_zero',
0x1C000004L : 'nca_s_fault_fp_underflow',
0x1C000005L : 'nca_s_fault_fp_overflow',
0x1C000006L : 'nca_s_fault_invalid_tag',
0x1C000007L : 'nca_s_fault_invalid_bound ',
0x1C000008L : 'nca_s_rpc_version_mismatch',
0x1C000009L : 'nca_s_unspec_reject ',
0x1C00000AL : 'nca_s_bad_actid',
0x1C00000BL : 'nca_s_who_are_you_failed',
0x1C00000CL : 'nca_s_manager_not_entered ',
0x1C00000DL : 'nca_s_fault_cancel',
0x1C00000EL : 'nca_s_fault_ill_inst',
0x1C00000FL : 'nca_s_fault_fp_error',
0x1C000010L : 'nca_s_fault_int_overflow',
0x1C000012L : 'nca_s_fault_unspec',
0x1C000013L : 'nca_s_fault_remote_comm_failure ',
0x1C000014L : 'nca_s_fault_pipe_empty ',
0x1C000015L : 'nca_s_fault_pipe_closed',
0x1C000016L : 'nca_s_fault_pipe_order ',
0x1C000017L : 'nca_s_fault_pipe_discipline',
0x1C000018L : 'nca_s_fault_pipe_comm_error',
0x1C000019L : 'nca_s_fault_pipe_memory',
0x1C00001AL : 'nca_s_fault_context_mismatch ',
0x1C00001BL : 'nca_s_fault_remote_no_memory ',
0x1C00001CL : 'nca_s_invalid_pres_context_id',
0x1C00001DL : 'nca_s_unsupported_authn_level',
0x1C00001FL : 'nca_s_invalid_checksum ',
0x1C000020L : 'nca_s_invalid_crc',
0x1C000021L : 'nca_s_fault_user_defined',
0x1C000022L : 'nca_s_fault_tx_open_failed',
0x1C000023L : 'nca_s_fault_codeset_conv_error',
0x1C000024L : 'nca_s_fault_object_not_found ',
0x1C000025L : 'nca_s_fault_no_client_stub'
}
class MSRPCArray:
def __init__(self, id=0, len=0, size=0):
self._length = len
self._size = size
self._id = id
self._max_len = 0
self._offset = 0
self._length2 = 0
self._name = ''
def set_max_len(self, n):
self._max_len = n
def set_offset(self, n):
self._offset = n
def set_length2(self, n):
self._length2 = n
def get_size(self):
return self._size
def set_name(self, n):
self._name = n
def get_name(self):
return self._name
def get_id(self):
return self._id
def rawData(self):
return pack('<HHLLLL', self._length, self._size, 0x12345678, self._max_len, self._offset, self._length2) + self._name.encode('utf-16le')
class MSRPCNameArray:
def __init__(self, data = None):
self._count = 0
self._max_count = 0
self._elements = []
if data: self.load(data)
def load(self, data):
ptr = unpack('<L', data[:4])[0]
index = 4
if 0 == ptr: # No data. May be a bug in certain versions of Samba.
return
self._count, _, self._max_count = unpack('<LLL', data[index:index+12])
index += 12
# Read each object's header.
for i in range(0, self._count):
aindex, length, size, _ = unpack('<LHHL', data[index:index+12])
self._elements.append(MSRPCArray(aindex, length, size))
index += 12
# Read the objects themselves.
for element in self._elements:
max_len, offset, curlen = unpack('<LLL', data[index:index+12])
index += 12
element.set_name(unicode(data[index:index+2*curlen], 'utf-16le'))
element.set_max_len(max_len)
element.set_offset(offset)
element.set_length2(curlen)
index += 2*curlen
if curlen & 0x1: index += 2 # Skip padding.
def elements(self):
return self._elements
def rawData(self):
ret = pack('<LLLL', 0x74747474, self._count, 0x47474747, self._max_count)
pos_ret = []
for i in xrange(0, self._count):
ret += pack('<L', self._elements[i].get_id())
data = self._elements[i].rawData()
ret += data[:8]
pos_ret += data[8:]
return ret + pos_ret
class MSRPCHeader(ImpactPacket.Header):
_SIZE = 16
commonHdr = ( # not used, just for doc and future use
('ver_major','B'), # 0
('ver_minor','B'), # 1
('type','B=MSRPC_REQUEST'), # 2
('flags','B=MSRPC_FIRSTFRAG | MSRPC_LASTFRAG'), # 3
('represntation','<L=0x10'), # 4
('frag_len','<H=24+len(data)+len(auth_data)'), # 8
('auth_len','<H=len(auth_data)-8'), # 10
('call_id','<L=1'), # 12 <-- Common up to here (including this)
)
structure = ( # not used, just for documentation and future use
('data',':'), # 24
('auth_data',':'),
)
def __init__(self, aBuffer = None, endianness = '<'):
ImpactPacket.Header.__init__(self, self._SIZE)
self.endianness = endianness
self.set_version((5, 0))
self.set_flags(MSRPC_FIRSTFRAG | MSRPC_LASTFRAG)
if endianness == '<':
self.set_representation(0x10)
else:
self.set_representation(0x0)
self.__frag_len_set = 0
self.set_auth_len(0)
self.set_call_id(1)
self.set_auth_data('')
if aBuffer: self.load_header(aBuffer)
def get_version(self):
""" This method returns a tuple in (major, minor) form."""
return (self.get_byte(0), self.get_byte(1))
def set_version(self, version):
""" This method takes a tuple in (major, minor) form."""
self.set_byte(0, version[0])
self.set_byte(1, version[1])
def get_type(self):
return self.get_byte(2)
def set_type(self, type):
self.set_byte(2, type)
def get_flags(self):
return self.get_byte(3)
def set_flags(self, flags):
self.set_byte(3, flags)
def get_representation(self):
return self.get_long(4, self.endianness)
def set_representation(self, representation):
self.set_long(4, representation, self.endianness)
def get_frag_len(self):
return self.get_word(8, self.endianness)
def set_frag_len(self, len):
self.__frag_len_set == 1
self.set_word(8, len, self.endianness)
def get_auth_len(self):
return self.get_word(10, self.endianness)
def set_auth_len(self, len):
self.set_word(10, len, self.endianness)
def set_auth_data(self, data):
self._auth_data = data
def get_call_id(self):
return self.get_long(12, self.endianness)
def set_call_id(self, id):
self.set_long(12, id, self.endianness)
def get_header_size(self):
return self._SIZE
def contains(self, aHeader):
ImpactPacket.Header.contains(self, aHeader)
if self.child():
self.set_op_num(self.child().OP_NUM)
def set_alloc_hint(self, hint):
pass
def get_packet(self):
if self._auth_data:
self.set_auth_len(len(self._auth_data)-8)
if self.child():
contents_size = self.child().get_size()
else:
contents_size = 0
contents_size += len(self._auth_data)
if not self.__frag_len_set:
self.set_frag_len(self.get_header_size() + contents_size)
self.set_alloc_hint(contents_size)
return ImpactPacket.Header.get_packet(self)+self._auth_data
class MSRPCRequestHeader(MSRPCHeader):
_SIZE = 24
structure = ( # not used, just for documentation and future use
('alloc_hint','<L=frag_len'), # 16
('ctx_id','<H=0'), # 20
('op_num','<H'), # 22
('data',':'), # 24
('auth_data',':'),
)
def __init__(self, aBuffer = None, endianness = '<'):
MSRPCHeader.__init__(self, aBuffer = aBuffer, endianness = endianness)
self.set_type(MSRPC_REQUEST)
self.set_ctx_id(0)
self.set_alloc_hint(0)
def get_alloc_hint(self):
return self.get_long(16, self.endianness)
def set_alloc_hint(self, len):
self.set_long(16, len, self.endianness)
def get_ctx_id(self):
return self.get_word(20, self.endianness)
def set_ctx_id(self, id):
self.set_word(20, id, self.endianness)
def get_op_num(self):
return self.get_word(22, self.endianness)
def set_op_num(self, op):
self.set_word(22, op, self.endianness)
class MSRPCRespHeader(MSRPCHeader):
_SIZE = 24
structure = ( # not used, just for documentation and future use
('alloc_hint','<L=frag_len'), # 16 <-- Common up to here (including this)
('ctx_id','<H=0'), # 20
('cancel_count','<B'), # 22
('padding','<B=0'), # 23
('data',':'), # 24
('auth_data',':'),
)
def __init__(self, aBuffer = None, endianness = '<'):
MSRPCHeader.__init__(self, aBuffer = aBuffer, endianness = endianness)
self.set_type(MSRPC_RESPONSE)
self.set_ctx_id(0)
self.set_alloc_hint(0)
def get_alloc_hint(self):
return self.get_long(16, self.endianness)
def set_alloc_hint(self, len):
self.set_long(16, len, self.endianness)
def get_ctx_id(self):
return self.get_word(20, self.endianness)
def set_ctx_id(self, id):
self.set_word(20, id, self.endianness)
def get_cancel_count(self):
return self.get_byte(22)
class MSRPCBind(MSRPCHeader):
_SIZE = 72-44
structure = ( # not used, just for documentation and future use
('max_tfrag','<H=4280'),
('max_rfrag','<H=4280'),
('assoc_group','<L=0'),
('ctx_num','B'),
)
def __init__(self, aBuffer = None, endianness = '<'):
MSRPCHeader.__init__(self, aBuffer = aBuffer, endianness = endianness)
self.set_type(MSRPC_BIND)
self.set_max_tfrag(4280)
self.set_max_rfrag(4280)
self.set_assoc_group(0)
self.set_ctx_num(1)
def get_max_tfrag(self):
return self.get_word(16, self.endianness)
def set_max_tfrag(self, size):
self.set_word(16, size, self.endianness)
def get_max_rfrag(self):
return self.get_word(18, self.endianness)
def set_max_rfrag(self, size):
self.set_word(18, size, self.endianness)
def get_assoc_group(self):
return self.get_long(20, self.endianness)
def set_assoc_group(self, id):
self.set_long(20, id, self.endianness)
def get_ctx_num(self):
return self.get_byte(24)
def set_ctx_num(self, num):
self._SIZE = 28+num*44
self.set_byte(24, num)
# --- next fields repeated for each interface to bind to
def get_ctx_id(self, index = 0):
return self.get_word(28+44*index, self.endianness)
def set_ctx_id(self, id, index = 0):
self.set_word(28+44*index, id, self.endianness)
def get_trans_num(self, index = 0):
return self.get_byte(30+44*index)
def set_trans_num(self, op, index = 0):
self.set_byte(30+44*index, op)
self.set_byte(31+44*index, 0)
def get_if_binuuid(self, index = 0):
return self.get_bytes().tolist()[32+44*index:32+44*index+16]
def set_if_binuuid(self, binuuid, index = 0):
self.get_bytes()[32+44*index:32+len(binuuid)+44*index] = array.array('B', binuuid)
def set_if_ver(self,ver,minor, index = 0):
self.set_word(48+44*index, ver, self.endianness)
self.set_word(50+44*index, minor, self.endianness)
def get_if_ver(self, index = 0):
return self.get_word(48+44*index, self.endianness)
def get_if_ver_minor(self, index = 0):
return self.get_word(50+44*index, self.endianness)
def get_xfer_syntax_binuuid(self, index = 0):
return self.get_bytes().tolist()[52+44*index:52+44*index+16]
def set_xfer_syntax_binuuid(self, binuuid, index = 0):
self.get_bytes()[52+44*index:52+len(binuuid)+44*index] = array.array('B', binuuid)
def set_xfer_syntax_ver(self,ver, index = 0):
self.set_long(68+44*index, ver, self.endianness)
def get_xfer_syntax_ver(self, index = 0):
self.get_long(68+44*index, ver, self.endianness)
class MSRPCBindAck(ImpactPacket.Header):
_SIZE = 56
def __init__(self, aBuffer = None):
ImpactPacket.Header.__init__(self, self._SIZE)
self.set_type(MSRPC_BINDACK)
if aBuffer: self.load_header(aBuffer)
def get_version(self):
""" This method returns a tuple in (major, minor) form."""
return (self.get_byte(0), self.get_byte(1))
def set_version(self, version):
""" This method takes a tuple in (major, minor) form."""
self.set_byte(0, version[0])
self.set_byte(1, version[1])
def get_type(self):
return self.get_byte(2)
def set_type(self, type):
self.set_byte(2, type)
def get_flags(self):
return self.get_byte(3)
def set_flags(self, flags):
self.set_byte(3, flags)
def get_representation(self):
return self.get_long(4, '<')
def set_representation(self, representation):
self.set_long(4, representation, '<')
def get_frag_len(self):
return self.get_word(8, '<')
def set_frag_len(self, len):
self.set_word(8, len, '<')
def get_auth_len(self):
return self.get_word(10, '<')
def set_auth_len(self, len):
self.set_word(10, len, '<')
def get_auth_data(self):
data = self.get_bytes()
return data[-self.get_auth_len()-8:]
def get_call_id(self):
return self.get_long(12, '<')
def set_call_id(self, id):
self.set_long(12, id, '<')
def get_max_tfrag(self):
return self.get_word(16, '<')
def set_max_tfrag(self, size):
self.set_word(16, size, '<')
def get_max_rfrag(self):
return self.get_word(18, '<')
def set_max_rfrag(self, size):
self.set_word(18, size, '<')
def get_assoc_group(self):
return self.get_long(20, '<')
def set_assoc_group(self, id):
self.set_long(20, id, '<')
def get_secondary_addr_len(self):
return self.get_word(24, '<')
def set_secondary_addr_len(self, len):
self.set_word(24, len, '<')
def get_secondary_addr(self):
return self.get_bytes().tolist()[26:26+self.get_secondary_addr_len()]
def set_secondary_addr(self, addr):
self.get_bytes()[26:26+self.get_secondary_addr_len()] = array.array('B', addr)
self.set_secondary_addr_len(len(addr))
def _get_results_offset(self):
answer = 26+self.get_secondary_addr_len()
answer +=3
answer -= answer % 4
return answer+2
def get_results_num(self):
return self.get_byte(self._get_results_offset()-2)
def set_results_num(self, num):
self.set_byte(self._get_results_offset()-2, num)
def get_result(self, index = 0):
return self.get_word(self._get_results_offset()+2*index, '<' )
def set_result(self, res, index = 0):
self.set_word(self._get_results_offset()+2*index, '<' )
def get_xfer_syntax_binuuid(self):
return self.get_bytes().tolist()[-20:]
def set_xfer_syntax_binuuid(self, binuuid):
assert 20 == len(binuuid)
self.get_bytes()[-20:] = array.array('B', binuuid)
def get_header_size(self):
var_size = len(self.get_bytes()) - self._SIZE
# assert var_size > 0
return self._SIZE + var_size
def contains(self, aHeader):
ImpactPacket.Header.contains(self, aHeader)
if self.child():
contents_size = self.child().get_size()
self.set_op_num(self.child().OP_NUM)
self.set_frag_len(self.get_header_size() + contents_size)
self.set_alloc_hint(contents_size)
class MSRPCBindNak(ImpactPacket.Header):
_SIZE = 24
def __init__(self, aBuffer = None):
ImpactPacket.Header.__init__(self, self._SIZE)
self.set_type(MSRPC_BINDNAK)
if aBuffer: self.load_header(aBuffer)
def get_version(self):
""" This method returns a tuple in (major, minor) form."""
return (self.get_byte(0), self.get_byte(1))
def set_version(self, version):
""" This method takes a tuple in (major, minor) form."""
self.set_byte(0, version[0])
self.set_byte(1, version[1])
def get_type(self):
return self.get_byte(2)
def set_type(self, type):
self.set_byte(2, type)
def get_flags(self):
return self.get_byte(3)
def set_flags(self, flags):
self.set_byte(3, flags)
def get_representation(self):
return self.get_long(4, '<')
def set_representation(self, representation):
self.set_long(4, representation, '<')
def get_frag_len(self):
return self.get_word(8, '<')
def set_frag_len(self, len):
self.set_word(8, len, '<')
def get_auth_len(self):
return self.get_word(10, '<')
def set_auth_len(self, len):
self.set_word(10, len, '<')
def get_call_id(self):
return self.get_long(12, '<')
def set_call_id(self, id):
self.set_long(12, id, '<')
def get_reason(self):
return self.get_word(16, '<')
def set_reason(self, reason):
self.set_word(16, reason, '<')
def get_assoc_group(self):
return self.get_long(20, '<')
def set_assoc_group(self, id):
self.set_long(20, id, '<')
def get_header_size(self):
return self._SIZE
class DCERPC:
_max_ctx = 0
def __init__(self,transport):
self._transport = transport
self.set_ctx_id(0)
self._max_frag = None
self.set_default_max_fragment_size()
def set_ctx_id(self, ctx_id):
self._ctx = ctx_id
def connect(self):
return self._transport.connect()
def disconnect(self):
return self._transport.disconnect()
def set_max_fragment_size(self, fragment_size):
# -1 is default fragment size: 0 for v5, 1300 y pico for v4
# 0 is don't fragment
# other values are max fragment size
if fragment_size == -1:
self.set_default_max_fragment_size()
else:
self._max_frag = fragment_size
def set_default_max_fragment_size(self):
# default is 0: don'fragment. v4 will override this method
self._max_frag = 0
def send(self, data): raise RuntimeError, 'virtual method. Not implemented in subclass'
def recv(self): raise RuntimeError, 'virtual method. Not implemented in subclass'
def alter_ctx(self, newUID, bogus_binds = ''): raise RuntimeError, 'virtual method. Not implemented in subclass'
def set_credentials(self, username, password): pass
def set_auth_level(self, auth_level): pass
def get_idempotent(self): return 0
def set_idempotent(self, flag): pass
def call(self, function, body):
return self.send(DCERPC_RawCall(function, str(body)))
class DCERPC_v5(DCERPC):
endianness = '<'
def __init__(self, transport):
DCERPC.__init__(self, transport)
self.__auth_level = ntlm.NTLM_AUTH_NONE
self.__username = None
self.__password = None
def set_auth_level(self, auth_level):
# auth level is ntlm.NTLM_AUTH_*
self.__auth_level = auth_level
def set_credentials(self, username, password):
self.set_auth_level(ntlm.NTLM_AUTH_CONNECT)
# self.set_auth_level(ntlm.NTLM_AUTH_CALL)
# self.set_auth_level(ntlm.NTLM_AUTH_PKT_INTEGRITY)
# self.set_auth_level(ntlm.NTLM_AUTH_PKT_PRIVACY)
self.__username = username
self.__password = password
def bind(self, uuid, alter = 0, bogus_binds = 0):
bind = MSRPCBind(endianness = self.endianness)
syntax = '\x04\x5d\x88\x8a\xeb\x1c\xc9\x11\x9f\xe8\x08\x00\x2b\x10\x48\x60'
if self.endianness == '>':
syntax = unpack('<LHHBB6s', syntax)
syntax = pack('>LHHBB6s', *syntax)
uuid = list(unpack('<LHHBB6sHH', uuid))
uuid[-1] ^= uuid[-2]
uuid[-2] ^= uuid[-1]
uuid[-1] ^= uuid[-2]
uuid = pack('>LHHBB6sHH', *uuid)
ctx = 0
for i in range(bogus_binds):
bind.set_ctx_id(self._ctx, index = ctx)
bind.set_trans_num(1, index = ctx)
bind.set_if_binuuid('A'*20, index = ctx)
bind.set_xfer_syntax_binuuid(syntax, index = ctx)
bind.set_xfer_syntax_ver(2, index = ctx)
self._ctx += 1
ctx += 1
bind.set_ctx_id(self._ctx, index = ctx)
bind.set_trans_num(1, index = ctx)
bind.set_if_binuuid(uuid,index = ctx)
bind.set_xfer_syntax_binuuid(syntax, index = ctx)
bind.set_xfer_syntax_ver(2, index = ctx)
bind.set_ctx_num(ctx+1)
if alter:
bind.set_type(MSRPC_ALTERCTX)
if (self.__auth_level != ntlm.NTLM_AUTH_NONE):
if (self.__username is None) or (self.__password is None):
self.__username, self.__password, nth, lmh = self._transport.get_credentials()
auth = ntlm.NTLMAuthNegotiate()
auth['auth_level'] = self.__auth_level
auth['auth_ctx_id'] = self._ctx + 79231
bind.set_auth_data(str(auth))
self._transport.send(bind.get_packet())
s = self._transport.recv()
if s != 0:
resp = MSRPCBindAck(s)
else:
return 0 #mmm why not None?
if resp.get_type() == MSRPC_BINDNAK:
resp = MSRPCBindNak(s)
status_code = resp.get_reason()
if rpc_status_codes.has_key(status_code):
raise Exception(rpc_status_codes[status_code], resp)
else:
raise Exception('Unknown DCE RPC fault status code: %.8x' % status_code, resp)
self.__max_xmit_size = resp.get_max_tfrag()
if self.__auth_level != ntlm.NTLM_AUTH_NONE:
authResp = ntlm.NTLMAuthChallenge(data = resp.get_auth_data().tostring())
self._ntlm_challenge = authResp['challenge']
response = ntlm.NTLMAuthChallengeResponse(self.__username,self.__password, self._ntlm_challenge)
response['auth_ctx_id'] = self._ctx + 79231
response['auth_level'] = self.__auth_level
if self.__auth_level in (ntlm.NTLM_AUTH_CONNECT, ntlm.NTLM_AUTH_PKT_INTEGRITY, ntlm.NTLM_AUTH_PKT_PRIVACY):
if self.__password:
key = ntlm.compute_nthash(self.__password)
if POW:
hash = POW.Digest(POW.MD4_DIGEST)
else:
hash = MD4.new()
hash.update(key)
key = hash.digest()
else:
key = '\x00'*16
if POW:
cipher = POW.Symmetric(POW.RC4)
cipher.encryptInit(key)
self.cipher_encrypt = cipher.update
else:
cipher = ARC4.new(key)
self.cipher_encrypt = cipher.encrypt
if response['flags'] & ntlm.NTLMSSP_KEY_EXCHANGE:
session_key = 'A'*16 # XXX Generate random session key
response['session_key'] = self.cipher_encrypt(session_key)
if POW:
cipher = POW.Symmetric(POW.RC4)
cipher.encryptInit(session_key)
self.cipher_encrypt = cipher.update
else:
cipher = ARC4.new(session_key)
self.cipher_encrypt = cipher.encrypt
self.sequence = 0
auth3 = MSRPCHeader()
auth3.set_type(MSRPC_AUTH3)
auth3.set_auth_data(str(response))
self._transport.send(auth3.get_packet(), forceWriteAndx = 1)
return resp # means packet is signed, if verifier is wrong it fails
def _transport_send(self, rpc_packet, forceWriteAndx = 0, forceRecv = 0):
if self.__auth_level == ntlm.NTLM_AUTH_CALL:
if rpc_packet.get_type() == MSRPC_REQUEST:
response = ntlm.NTLMAuthChallengeResponse(self.__username,self.__password, self._ntlm_challenge)
response['auth_ctx_id'] = self._ctx + 79231
response['auth_level'] = self.__auth_level
rpc_packet.set_auth_data(str(response))
if self.__auth_level in [ntlm.NTLM_AUTH_PKT_INTEGRITY, ntlm.NTLM_AUTH_PKT_PRIVACY]:
verifier = ntlm.NTLMAuthVerifier()
verifier['auth_level'] = self.__auth_level
verifier['auth_ctx_id'] = self._ctx + 79231
verifier['data'] = ' '*12
rpc_packet.set_auth_data(str(verifier))
rpc_call = rpc_packet.child()
if self.__auth_level == ntlm.NTLM_AUTH_PKT_PRIVACY:
data = DCERPC_RawCall(rpc_call.OP_NUM)
data.setData(self.cipher_encrypt(rpc_call.get_packet()))
rpc_packet.contains(data)
crc = crc32(rpc_call.get_packet())
data = pack('<LLL',0,crc,self.sequence) # XXX 0 can be anything: randomize
data = self.cipher_encrypt(data)
verifier['data'] = data
rpc_packet.set_auth_data(str(verifier))
self.sequence += 1
self._transport.send(rpc_packet.get_packet(), forceWriteAndx = forceWriteAndx, forceRecv = forceRecv)
def send(self, data):
# This endianness does necesary have to be the same as the one used in the bind
# however, the endianness of the stub data MUST be the same as the one in the bind
# i.e. the endianness on the next call could be hardcoded to any
rpc = MSRPCRequestHeader(endianness = self.endianness)
rpc.set_ctx_id(self._ctx)
max_frag = self._max_frag
if data.get_size() > self.__max_xmit_size - 32:
max_frag = self.__max_xmit_size - 32 # XXX: 32 is a safe margin for auth data
if self._max_frag:
max_frag = min(max_frag, self._max_frag)
if max_frag:
packet = str(data.get_bytes().tostring())
offset = 0
rawcall = DCERPC_RawCall(data.OP_NUM)
while 1:
toSend = packet[offset:offset+max_frag]
if not toSend:
break
flags = 0
if offset == 0:
flags |= MSRPC_FIRSTFRAG
offset += len(toSend)
if offset == len(packet):
flags |= MSRPC_LASTFRAG
rpc.set_flags(flags)
rawcall.setData(toSend)
rpc.contains(rawcall)
self._transport_send(rpc, forceWriteAndx = 1, forceRecv = flags & MSRPC_LASTFRAG)
else:
rpc.contains(data)
self._transport_send(rpc)
def recv(self):
self.response_data = self._transport.recv()
self.response_header = MSRPCRespHeader(self.response_data)
off = self.response_header.get_header_size()
if self.response_header.get_type() == MSRPC_FAULT and self.response_header.get_frag_len() >= off+4:
status_code = unpack("<L",self.response_data[off:off+4])[0]
if rpc_status_codes.has_key(status_code):
raise Exception(rpc_status_codes[status_code])
else:
raise Exception('Unknown DCE RPC fault status code: %.8x' % status_code)
answer = self.response_data[off:]
auth_len = self.response_header.get_auth_len()
if auth_len:
auth_len += 8
auth_data = answer[-auth_len:]
ntlmssp = ntlm.NTLMAuthHeader(data = auth_data)
answer = answer[:-auth_len]
if ntlmssp['auth_level'] == ntlm.NTLM_AUTH_PKT_PRIVACY:
answer = self.cipher_encrypt(answer)
if ntlmssp['auth_pad_len']:
answer = answer[:-ntlmssp['auth_pad_len']]
if ntlmssp['auth_level'] in [ntlm.NTLM_AUTH_PKT_INTEGRITY, ntlm.NTLM_AUTH_PKT_PRIVACY]:
ntlmssp = ntlm.NTLMAuthVerifier(data = auth_data)
data = self.cipher_encrypt(ntlmssp['data'])
zero, crc, sequence = unpack('<LLL', data)
self.sequence = sequence + 1
return answer
def alter_ctx(self, newUID, bogus_binds = 0):
answer = self.__class__(self._transport)
answer.set_credentials(self.__username, self.__password)
answer.set_auth_level(self.__auth_level)
self._max_ctx += 1
answer.set_ctx_id(self._max_ctx)
answer.bind(newUID, alter = 1, bogus_binds = bogus_binds)
return answer
class DCERPC_RawCall(ImpactPacket.Header):
def __init__(self, op_num, data = ''):
self.OP_NUM = op_num
ImpactPacket.Header.__init__(self)
self.setData(data)
def setData(self, data):
self.get_bytes()[:] = array.array('B', data)
def get_header_size(self):
return len(self.get_bytes())
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