1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
module Net
module NTLM
class Client::Session
VERSION_MAGIC = "\x01\x00\x00\x00"
TIME_OFFSET = 11644473600
MAX64 = 0xffffffffffffffff
CLIENT_TO_SERVER_SIGNING = "session key to client-to-server signing key magic constant\0"
SERVER_TO_CLIENT_SIGNING = "session key to server-to-client signing key magic constant\0"
CLIENT_TO_SERVER_SEALING = "session key to client-to-server sealing key magic constant\0"
SERVER_TO_CLIENT_SEALING = "session key to server-to-client sealing key magic constant\0"
attr_reader :client, :challenge_message, :channel_binding
# @param client [Net::NTLM::Client] the client instance
# @param challenge_message [Net::NTLM::Message::Type2] server message
def initialize(client, challenge_message, channel_binding = nil)
@client = client
@challenge_message = challenge_message
@channel_binding = channel_binding
end
# Generate an NTLMv2 AUTHENTICATE_MESSAGE
# @see http://msdn.microsoft.com/en-us/library/cc236643.aspx
# @return [Net::NTLM::Message::Type3]
def authenticate!
calculate_user_session_key!
type3_opts = {
:lm_response => lmv2_resp,
:ntlm_response => ntlmv2_resp,
:domain => domain,
:user => username,
:workstation => workstation,
:flag => (challenge_message.flag & client.flags)
}
t3 = Message::Type3.create type3_opts
if negotiate_key_exchange?
t3.enable(:session_key)
rc4 = Net::NTLM::Rc4.new(user_session_key)
sk = rc4.encrypt exported_session_key
t3.session_key = sk
end
t3
end
def exported_session_key
@exported_session_key ||=
begin
if negotiate_key_exchange?
OpenSSL::Random.random_bytes(16)
else
user_session_key
end
end
end
def sign_message(message)
seq = sequence
sig = OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, client_sign_key, "#{seq}#{message}")[0..7]
if negotiate_key_exchange?
sig = client_cipher.encrypt sig
end
"#{VERSION_MAGIC}#{sig}#{seq}"
end
def verify_signature(signature, message)
seq = signature[-4..-1]
sig = OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, server_sign_key, "#{seq}#{message}")[0..7]
if negotiate_key_exchange?
sig = server_cipher.encrypt sig
end
"#{VERSION_MAGIC}#{sig}#{seq}" == signature
end
def seal_message(message)
client_cipher.encrypt(message)
end
def unseal_message(emessage)
server_cipher.encrypt(emessage)
end
private
def user_session_key
@user_session_key ||= nil
end
def sequence
[raw_sequence].pack("V*")
end
def raw_sequence
if defined? @raw_sequence
@raw_sequence += 1
else
@raw_sequence = 0
end
end
def client_sign_key
@client_sign_key ||= OpenSSL::Digest::MD5.digest "#{exported_session_key}#{CLIENT_TO_SERVER_SIGNING}"
end
def server_sign_key
@server_sign_key ||= OpenSSL::Digest::MD5.digest "#{exported_session_key}#{SERVER_TO_CLIENT_SIGNING}"
end
def client_seal_key
@client_seal_key ||= OpenSSL::Digest::MD5.digest "#{exported_session_key}#{CLIENT_TO_SERVER_SEALING}"
end
def server_seal_key
@server_seal_key ||= OpenSSL::Digest::MD5.digest "#{exported_session_key}#{SERVER_TO_CLIENT_SEALING}"
end
def client_cipher
@client_cipher ||= Net::NTLM::Rc4.new(client_seal_key)
end
def server_cipher
@server_cipher ||= Net::NTLM::Rc4.new(server_seal_key)
end
def client_challenge
@client_challenge ||= NTLM.pack_int64le(rand(MAX64))
end
def server_challenge
@server_challenge ||= challenge_message[:challenge].serialize
end
# epoch -> milsec from Jan 1, 1601
# @see http://support.microsoft.com/kb/188768
def timestamp
@timestamp ||= 10_000_000 * (Time.now.to_i + TIME_OFFSET)
end
def use_oem_strings?
challenge_message.has_flag? :OEM
end
def negotiate_key_exchange?
challenge_message.has_flag? :KEY_EXCHANGE
end
def username
oem_or_unicode_str client.username
end
def password
oem_or_unicode_str client.password
end
def workstation
(client.workstation ? oem_or_unicode_str(client.workstation) : "")
end
def domain
(client.domain ? oem_or_unicode_str(client.domain) : "")
end
def oem_or_unicode_str(str)
if use_oem_strings?
NTLM::EncodeUtil.decode_utf16le str
else
NTLM::EncodeUtil.encode_utf16le str
end
end
def ntlmv2_hash
@ntlmv2_hash ||= NTLM.ntlmv2_hash(username, password, domain, {:client_challenge => client_challenge, :unicode => !use_oem_strings?})
end
def calculate_user_session_key!
@user_session_key = OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmv2_hash, nt_proof_str)
end
def lmv2_resp
OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmv2_hash, server_challenge + client_challenge) + client_challenge
end
def ntlmv2_resp
nt_proof_str + blob
end
def nt_proof_str
@nt_proof_str ||= OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmv2_hash, server_challenge + blob)
end
def blob
@blob ||=
begin
b = Blob.new
b.timestamp = timestamp
b.challenge = client_challenge
b.target_info = target_info
b.serialize
end
end
def target_info
@target_info ||= begin
if channel_binding
t = Net::NTLM::TargetInfo.new(challenge_message.target_info)
av_id = Net::NTLM::TargetInfo::MSV_AV_CHANNEL_BINDINGS
t.av_pairs[av_id] = channel_binding.channel_binding_token
t.to_s
else
challenge_message.target_info
end
end
end
end
end
end
|
