class NtlmContext(object):
def __init__(self, username, password, domain=None, workstation=None,
cbt_data=None, ntlm_compatibility=3):
r"""
Initialises a NTLM context to use when authenticating using the NTLM
protocol.
Initialises the NTLM context to use when sending and receiving messages
to and from the server. You should be using this object as it supports
NTLMv2 authenticate and it easier to use than before. It also brings in
the ability to use signing and sealing with session_security and
generate a MIC structure.
:param username: The username to authenticate with
:param password: The password for the username
:param domain: The domain part of the username (None if n/a)
:param workstation: The localworkstation (None if n/a)
:param cbt_data: A GssChannelBindingsStruct or None to bind channel
data with the auth process
:param ntlm_compatibility: (Default 3)
The Lan Manager Compatibility Level to use with the auth message
This is set by an Administrator in the registry key
'HKLM\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel'
The values correspond to the following;
0 : LM and NTLMv1
1 : LM, NTLMv1 and NTLMv1 with Extended Session Security
2 : NTLMv1 and NTLMv1 with Extended Session Security
3-5 : NTLMv2 Only
Note: Values 3 to 5 are no different from a client perspective
"""
self.username = username
self.password = password
self.domain = domain
self.workstation = workstation
self.cbt_data = cbt_data
self._server_certificate_hash = None # deprecated for backwards compat
self.ntlm_compatibility = ntlm_compatibility
self.complete = False
# Setting up our flags so the challenge message returns the target info
# block if supported
self.negotiate_flags = NegotiateFlags.NTLMSSP_NEGOTIATE_TARGET_INFO | \
NegotiateFlags.NTLMSSP_NEGOTIATE_128 | \
NegotiateFlags.NTLMSSP_NEGOTIATE_56 | \
NegotiateFlags.NTLMSSP_NEGOTIATE_UNICODE | \
NegotiateFlags.NTLMSSP_NEGOTIATE_VERSION | \
NegotiateFlags.NTLMSSP_NEGOTIATE_KEY_EXCH | \
NegotiateFlags.NTLMSSP_NEGOTIATE_ALWAYS_SIGN | \
NegotiateFlags.NTLMSSP_NEGOTIATE_SIGN | \
NegotiateFlags.NTLMSSP_NEGOTIATE_SEAL
# Setting the message types based on the ntlm_compatibility level
self._set_ntlm_compatibility_flags(self.ntlm_compatibility)
self._negotiate_message = None
self._challenge_message = None
self._authenticate_message = None
self._session_security = None
@property
def mic_present(self):
if self._authenticate_message:
return bool(self._authenticate_message.mic)
return False
@property
def session_key(self):
if self._authenticate_message:
return self._authenticate_message.exported_session_key
def reset_rc4_state(self, outgoing=True):
""" Resets the signing cipher for the incoming or outgoing cipher. For SPNEGO for calculating mechListMIC. """
if self._session_security:
self._session_security.reset_rc4_state(outgoing=outgoing)
def step(self, input_token=None):
if self._negotiate_message is None:
self._negotiate_message = NegotiateMessage(self.negotiate_flags,
self.domain,
self.workstation)
return self._negotiate_message.get_data()
else:
self._challenge_message = ChallengeMessage(input_token)
self._authenticate_message = AuthenticateMessage(
self.username, self.password, self.domain, self.workstation,
self._challenge_message, self.ntlm_compatibility,
server_certificate_hash=self._server_certificate_hash,
cbt_data=self.cbt_data
)
self._authenticate_message.add_mic(self._negotiate_message,
self._challenge_message)
flag_bytes = self._authenticate_message.negotiate_flags
flags = struct.unpack("<I", flag_bytes)[0]
if flags & NegotiateFlags.NTLMSSP_NEGOTIATE_SEAL or \
flags & NegotiateFlags.NTLMSSP_NEGOTIATE_SIGN:
self._session_security = SessionSecurity(
flags, self.session_key
)
self.complete = True
return self._authenticate_message.get_data()
def sign(self, data):
return self._session_security.get_signature(data)
def verify(self, data, signature):
self._session_security.verify_signature(data, signature)
def wrap(self, data):
if self._session_security is None:
raise NoAuthContextError("Cannot wrap data as no security context "
"has been established")
data, header = self._session_security.wrap(data)
return header + data
def unwrap(self, data):
if self._session_security is None:
raise NoAuthContextError("Cannot unwrap data as no security "
"context has been established")
header = data[0:16]
data = data[16:]
message = self._session_security.unwrap(data, header)
return message
def _set_ntlm_compatibility_flags(self, ntlm_compatibility):
if (ntlm_compatibility >= 0) and (ntlm_compatibility <= 5):
if ntlm_compatibility == 0:
self.negotiate_flags |= \
NegotiateFlags.NTLMSSP_NEGOTIATE_NTLM | \
NegotiateFlags.NTLMSSP_NEGOTIATE_LM_KEY
elif ntlm_compatibility == 1:
self.negotiate_flags |= \
NegotiateFlags.NTLMSSP_NEGOTIATE_NTLM | \
NegotiateFlags.NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY
else:
self.negotiate_flags |= \
NegotiateFlags.NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY
else:
raise Exception("Unknown ntlm_compatibility level - "
"expecting value between 0 and 5")
def test_ntlm_context_with_mic(self, monkeypatch):
monkeypatch.setattr('os.urandom', lambda s: b"\xaa" * 8)
monkeypatch.setattr('ntlm_auth.messages.get_version',
lambda s: b"\x05\x01\x28\x0A\x00\x00\x00\x0F")
monkeypatch.setattr('ntlm_auth.messages.get_random_export_session_key',
lambda: b"\x55" * 16)
monkeypatch.setattr('ntlm_auth.compute_response.get_windows_timestamp',
lambda: b"\x00" * 8)
ch = 'E3CA49271E5089CC48CE82109F1324F41DBEDDC29A777410C738F7868C4FF405'
cbt_data = GssChannelBindingsStruct()
cbt_data[cbt_data.APPLICATION_DATA] = b"tls-server-end-point:" + \
base64.b16decode(ch)
ntlm_context = NtlmContext("User",
"Password",
"Domain",
"COMPUTER",
cbt_data=cbt_data)
ntlm_context.reset_rc4_state(
) # Verifies it won't fail when the session security isn't set up.
actual_nego = ntlm_context.step()
expected_nego = b"\x4e\x54\x4c\x4d\x53\x53\x50\x00" \
b"\x01\x00\x00\x00\x31\xb0\x88\xe2" \
b"\x06\x00\x06\x00\x28\x00\x00\x00" \
b"\x08\x00\x08\x00\x2e\x00\x00\x00" \
b"\x05\x01\x28\x0a\x00\x00\x00\x0f" \
b"\x44\x6f\x6d\x61\x69\x6e\x43\x4f" \
b"\x4d\x50\x55\x54\x45\x52"
assert actual_nego == expected_nego
assert not ntlm_context.mic_present
assert not ntlm_context.complete
challenge_msg = b"\x4E\x54\x4C\x4D\x53\x53\x50\x00" \
b"\x02\x00\x00\x00\x00\x00\x00\x00" \
b"\x38\x00\x00\x00\x33\x82\x8A\xE2" \
b"\x01\x23\x45\x67\x89\xAB\xCD\xEF" \
b"\x00\x00\x00\x00\x00\x00\x00\x00" \
b"\x30\x00\x30\x00\x38\x00\x00\x00" \
b"\x06\x01\xB1\x1D\x00\x00\x00\x0F" \
b"\x02\x00\x0C\x00\x44\x00\x6F\x00" \
b"\x6D\x00\x61\x00\x69\x00\x6E\x00" \
b"\x01\x00\x0C\x00\x53\x00\x65\x00" \
b"\x72\x00\x76\x00\x65\x00\x72\x00" \
b"\x07\x00\x08\x00\x00\x00\x00\x00" \
b"\x00\x00\x00\x00\x00\x00\x00\x00"
actual_auth = ntlm_context.step(challenge_msg)
expected_auth = b'\x4E\x54\x4C\x4D\x53\x53\x50\x00' \
b'\x03\x00\x00\x00\x18\x00\x18\x00' \
b'\x7C\x00\x00\x00\x7C\x00\x7C\x00' \
b'\x94\x00\x00\x00\x0C\x00\x0C\x00' \
b'\x58\x00\x00\x00\x08\x00\x08\x00' \
b'\x64\x00\x00\x00\x10\x00\x10\x00' \
b'\x6C\x00\x00\x00\x10\x00\x10\x00' \
b'\x10\x01\x00\x00\x31\x82\x8A\xE2' \
b'\x05\x01\x28\x0A\x00\x00\x00\x0F' \
b'\xC4\x45\x2C\xF7\xA8\x1E\x4D\x11' \
b'\xD0\x78\x18\x94\x09\x57\x5D\x9E' \
b'\x44\x00\x6F\x00\x6D\x00\x61\x00' \
b'\x69\x00\x6E\x00\x55\x00\x73\x00' \
b'\x65\x00\x72\x00\x43\x00\x4F\x00' \
b'\x4D\x00\x50\x00\x55\x00\x54\x00' \
b'\x45\x00\x52\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x00\xA1\x3D\x03\x8A' \
b'\xD0\xCA\x02\x64\x33\x89\x7C\x33' \
b'\x5E\x0F\x56\xDF\x01\x01\x00\x00' \
b'\x00\x00\x00\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x00\xAA\xAA\xAA\xAA' \
b'\xAA\xAA\xAA\xAA\x00\x00\x00\x00' \
b'\x02\x00\x0C\x00\x44\x00\x6F\x00' \
b'\x6D\x00\x61\x00\x69\x00\x6E\x00' \
b'\x01\x00\x0C\x00\x53\x00\x65\x00' \
b'\x72\x00\x76\x00\x65\x00\x72\x00' \
b'\x07\x00\x08\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x00\x06\x00\x04\x00' \
b'\x02\x00\x00\x00\x0A\x00\x10\x00' \
b'\x6E\xA1\x9D\xF0\x66\xDA\x46\x22' \
b'\x05\x1F\x9C\x4F\x92\xC6\xDF\x74' \
b'\x00\x00\x00\x00\x00\x00\x00\x00' \
b'\x1D\x08\x89\xD1\xA5\xEE\xED\x21' \
b'\x91\x9E\x1A\xB8\x27\xC3\x0B\x17'
assert actual_auth == expected_auth
assert ntlm_context.complete
assert ntlm_context.mic_present
request_msg = b"test req"
response_msg = b"test res"
actual_wrapped = ntlm_context.wrap(request_msg)
expected_wrapped = b"\x01\x00\x00\x00\xbc\xe3\x23\xa1" \
b"\x72\x06\x23\x78\x00\x00\x00\x00" \
b"\x70\x80\x1e\x11\xfe\x6b\x3a\xad"
assert actual_wrapped == expected_wrapped
server_sec = SessionSecurity(
ntlm_context._session_security.negotiate_flags,
ntlm_context._session_security.exported_session_key, "server")
server_unwrap = server_sec.unwrap(actual_wrapped[16:],
actual_wrapped[0:16])
assert server_unwrap == request_msg
response_wrapped = server_sec.wrap(response_msg)
actual_unwrap = ntlm_context.unwrap(response_wrapped[1] +
response_wrapped[0])
assert actual_unwrap == response_msg
msg = b"Hello"
actual_sig1 = ntlm_context.sign(msg)
expected_sig1 = b"\x01\x00\x00\x00\x08\xF0\x0D\x86\x34\x05\x1A\x1D\x01\x00\x00\x00"
assert actual_sig1 == expected_sig1
server_sec.verify_signature(msg, actual_sig1)
actual_sig2 = ntlm_context.sign(msg)
expected_sig2 = b"\x01\x00\x00\x00\x07\x64\x0C\x30\x1C\xD7\x76\xF0\x02\x00\x00\x00"
assert actual_sig2 == expected_sig2
server_sec.verify_signature(msg, actual_sig2)
ntlm_context.reset_rc4_state()
actual_sig3 = ntlm_context.sign(msg)
expected_sig3 = b"\x01\x00\x00\x00\x1E\xD4\xA3\xE5\xE8\x05\x74\x01\x03\x00\x00\x00"
assert actual_sig3 == expected_sig3
server_sec.reset_rc4_state(outgoing=False)
server_sec.verify_signature(msg, actual_sig3)
server_sig = server_sec.get_signature(msg)
ntlm_context.verify(msg, server_sig)
