Class: ShadowsocksRuby::Protocols::TlsTicketProtocol

Inherits:
Object
  • Object
show all
Includes:
BufferHelper, DummyHelper
Defined in:
lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb

Overview

TLS 1.2 Obfuscation Protocol

Specification:

TLS 1.2 Reference:

Constant Summary collapse

VERSION_SSL_3_0 = 
[3, 0]
VERSION_TLS_1_0 = 
[3, 1]
VERSION_TLS_1_1 = 
[3, 2]
VERSION_TLS_1_2 = 
[3, 3]
CTYPE_ChangeCipherSpec =

Content types

0x14
CTYPE_Alert = 
0x15
CTYPE_Handshake = 
0x16
CTYPE_Application = 
0x17
CTYPE_Heartbeat = 
0x18
MTYPE_HelloRequest =

Message types

0
MTYPE_ClientHello = 
1
MTYPE_ServerHello = 
2
MTYPE_NewSessionTicket = 
4
MTYPE_Certificate = 
11
MTYPE_ServerKeyExchange = 
12
MTYPE_CertificateRequest = 
13
MTYPE_ServerHelloDone = 
14
MTYPE_CertificateVerify = 
15
MTYPE_ClientKeyExchange = 
16
MTYPE_Finished = 
20

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from BufferHelper

#tcp_receive_from_localbackend_in_buffer, #tcp_receive_from_localbackend_other_packet_helper, #tcp_receive_from_remoteserver_in_buffer, #tcp_receive_from_remoteserver_other_packet_helper

Methods included from DummyHelper

#async_recv, #raise_me, #send_data

Constructor Details

#initialize(params = {}) ⇒ TlsTicketProtocol

Returns a new instance of TlsTicketProtocol.

Parameters:

  • params (Hash) (defaults to: {}) —

    Configuration parameters

Options Hash (params):

  • :host (String) —

    shadowsocks server address, required by remoteserver protocol

  • :key (String) —

    key, required by both remoteserver and localbackend protocol

  • :compatible (Boolean) —

    compatibility with origin mode, default true

  • :obfs_param (String) —

    obfs param, optional

  • :lrucache (LRUCache) —

    lrucache, optional, it intened to be a lrucache Proxy if provided



53
54
55
56
57
58
59
60
61
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 53

def initialize params = {}
  @params = {:compatible => true}.merge(params)
  @buffer = ''
  @client_id = Random.new.bytes(32)
  @max_time_dif = 60 * 60 * 24 # time dif (second) setting
  @startup_time = Time.now.to_i - 60 * 30
  @client_data = @params[:lrucache] || LRUCache.new(:ttl => 60 * 5)
  @connected = EM::DefaultDeferrable.new
end

Instance Attribute Details

#next_protocol ⇒ Object

Returns the value of attribute next_protocol.



45
46
47
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 45

def next_protocol
  @next_protocol
end

Instance Method Details

#get_random ⇒ Object

helpers



148
149
150
151
152
153
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 148

def get_random
  verifyid = [Time.now.to_i].pack("N") << Random.new.bytes(18)
  hello = ""
  hello << verifyid # Random part 1
  hello << ShadowsocksRuby::Cipher.hmac_sha1_digest(@params[:key] + @client_id, verifyid) # Random part 2
end

#make_ext_sni(host) ⇒ Object 



314
315
316
317
318
319
320
321
322
323
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 314

def make_ext_sni host
    name_type = 0 #host_name
    server_name = [name_type, host.length].pack("Cn") << host
    server_name_list = [server_name.length].pack("n") << server_name

    type = Util.hex2bin("0000")
    data = [server_name_list.length].pack("n") << server_name_list

    return type << data
end

#recv_client_change_cipherspec_and_finish ⇒ Object 



289
290
291
292
293
294
295
296
297
298
299
300
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 289

def recv_client_change_cipherspec_and_finish
  data = async_recv 43
  if data[0, 6] !=  [CTYPE_ChangeCipherSpec, *VERSION_TLS_1_2, 0, 1, 1].pack("C*") # ChangeCipherSpec
    raise PharseError, "server_decode data error"
  end
  if data[6, 5] != [CTYPE_Handshake, *VERSION_TLS_1_2, 32].pack("C3n") # Finished
    raise PharseError, "server_decode data error"
  end
  if ShadowsocksRuby::Cipher.hmac_sha1_digest(@params[:key] + @client_id, data[0, 33]) != data[33, 10]
    raise PharseError, "server_decode data error"
  end
end

#recv_client_hello ⇒ Object 



214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 214

def recv_client_hello
  data = async_recv 3
  if data != [CTYPE_Handshake, *VERSION_TLS_1_0].pack("C3")
    if @params[:compatible]
      @buffer = data
      @no_effect = true
      return
    else
      raise PharseError, "decode error"
    end
  end

  len_client_handshake_message = async_recv(2).unpack("n")[0]
  client_handshake_message = async_recv(len_client_handshake_message)

  if (client_handshake_message.slice!(0, 2) != [MTYPE_ClientHello, 0].pack("C2"))
    raise PharseError, "tls_auth not client hello message"
  end

  len_client_hello = client_handshake_message.slice!(0, 2).unpack("n")[0]
  client_hello = client_handshake_message

  if (len_client_hello != client_hello.length )
    raise PharseError, "tls_auth wrong message size"
  end

  if (client_hello.slice!(0,2) != [*VERSION_TLS_1_2].pack("C2"))
    raise PharseError, "tls_auth wrong tls version"
  end

  verifyid = client_hello.slice!(0, 32)

  len_sessionid = client_hello.slice!(0,1).unpack("C")[0]
  if (len_sessionid < 32)
    raise PharseError, "tls_auth wrong sessionid_len"
  end

  sessionid = client_hello.slice!(0, len_sessionid)
  @client_id = sessionid

  sha1 = ShadowsocksRuby::Cipher::hmac_sha1_digest(@params[:key] + sessionid, verifyid[0, 22])
  utc_time = Time.at(verifyid[0, 4].unpack("N")[0])
  time_dif = Time.now.to_i - utc_time.to_i

  #if @params[:obfs_param] != nil
  #  @max_time_dif = @params[:obfs_param].to_i
  #end
  if @max_time_dif > 0 && (time_dif.abs > @max_time_dif or utc_time.to_i - @startup_time < - @max_time_dif / 2)
    raise PharseError, "tls_auth wrong time"
  end

  if sha1 != verifyid[22 .. -1]
    raise PharseError, "tls_auth wrong sha1"
  end

  if @client_data[verifyid[0, 22]]
    raise PharseError, "replay attack detect, id = #{Util.bin2hex(verifyid)}"
  end
  @client_data[verifyid[0, 22]] = sessionid
end

#recv_server_hello ⇒ Object 



206
207
208
209
210
211
212
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 206

def recv_server_hello
  data = async_recv(129) # ServerHello 76 + ServerChangeSipherSpec 6 + Finished 37
  verify = data[11 ... 33]
  if ShadowsocksRuby::Cipher.hmac_sha1_digest(@params[:key] + @client_id, verify) != data[33 ... 43]
    raise PharseError, "client_decode data error"
  end
end

#send_client_change_cipherspec_and_finish(data) ⇒ Object 



197
198
199
200
201
202
203
204
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 197

def send_client_change_cipherspec_and_finish data
  buf = ""
  buf << [CTYPE_ChangeCipherSpec, *VERSION_TLS_1_2, 0, 1, 1].pack("C*")
  buf << [CTYPE_Handshake, *VERSION_TLS_1_2, 32].pack("C3n") << Random.new.bytes(22)
  buf << ShadowsocksRuby::Cipher::hmac_sha1_digest(@params[:key] + @client_id, buf)
  buf << [CTYPE_Application, *VERSION_TLS_1_2, data.length].pack("C3n") << data
  send_data buf
end

#send_client_hello ⇒ Object 



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
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 155

def send_client_hello
  client_hello = ""
  
  client_hello << [*VERSION_TLS_1_2].pack("C2") # ProtocolVersion
  client_hello << get_random # Random len 32
  client_hello << [32].pack("C") << @client_id # SessionID
  client_hello << Util.hex2bin("001cc02bc02fcca9cca8cc14cc13c00ac014c009c013009c0035002f000a") # CipherSuite
  client_hello << Util.hex2bin("0100") # CompressionMethod

  ext = Util.hex2bin("ff01000100") # Extension 1 (type ff01 + len 0001 + data 00 )
  
  hosts = @params[:obfs_param] || @params[:host]
  if (hosts == nil or hosts == "")
    raise PharseError, "No :host or :obfs_param parameters"
  end
  if (("0".."9").include? hosts[-1])
    hosts = ""
  end
  hosts = hosts.split(",")
  if hosts.length != 0
    host = hosts[Random.rand(hosts.length)]
  else
    host = ""
  end
  ext << make_ext_sni(host) # Extension 2
  ext << Util.hex2bin("00170000") # Extension 3 (type 0017 + len 0000)
  ext << Util.hex2bin("002300d0") << Random.new.bytes(208) # ticket, Extension 4 (type 0023 + len 00d0 + data)
  ext << Util.hex2bin("000d001600140601060305010503040104030301030302010203") # Extension 5 (type 000d + len 0016 + data)
  ext << Util.hex2bin("000500050100000000") # Extension 6 (type 0005 + len 0005 + data)
  ext << Util.hex2bin("00120000") # Extension 7 (type 0012 + len 0000)
  ext << Util.hex2bin("75500000") # Extension 8 (type 7550 + len 0000)
  ext << Util.hex2bin("000b00020100") # Extension 9 (type 000b + len 0002 + data)
  ext << Util.hex2bin("000a0006000400170018") # Extension 10 (type 000a + len 0006 + data)

  client_hello << [ext.length].pack("n") << ext # Extension List

  client_handshake_message = [MTYPE_ClientHello, 0, client_hello.length].pack("CCn") << client_hello
  handshake_message = [CTYPE_Handshake,*VERSION_TLS_1_0, client_handshake_message.length].pack("C3n") << client_handshake_message

  send_data(handshake_message)
end

#send_data_application_pharse(data) ⇒ Object 



302
303
304
305
306
307
308
309
310
311
312
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 302

def send_data_application_pharse data
  buf = ""
  while data.length > 2048
    size = [Random.rand(65535) % 4096 + 100, data.length].min
    buf << [CTYPE_Application, *VERSION_TLS_1_2, size].pack("C3n") << data.slice!(0, size)
  end
  if data.length > 0
    buf << [CTYPE_Application, *VERSION_TLS_1_2, data.length].pack("C3n") << data
  end
  send_data buf
end

#send_server_hello ⇒ Object 



275
276
277
278
279
280
281
282
283
284
285
286
287
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 275

def send_server_hello
  data = [*VERSION_TLS_1_2].pack("C2")
  data << get_random
  data << Util.hex2bin("20") # len 32 in decimal
  data << @client_id
  data << Util.hex2bin("c02f000005ff01000100")
  data = Util.hex2bin("0200") << [data.length].pack("n") << data
  data = Util.hex2bin("160303") << [data.length].pack("n") << data # ServerHello len 86 (11 + 32 + 1 + 32 + 10)
  data << Util.hex2bin("14") << [*VERSION_TLS_1_2].pack("C2") << Util.hex2bin("000101") # ChangeCipherSpec len (6)
  data << Util.hex2bin("16") << [*VERSION_TLS_1_2].pack("C2") << Util.hex2bin("0020") << Random.new.bytes(22)
  data << ShadowsocksRuby::Cipher.hmac_sha1_digest(@params[:key] + @client_id, data) # Finished len(37)
  send_data data # len 129
end

#tcp_receive_from_localbackend_first_packet(n) ⇒ Object Also known as: tcp_receive_from_localbackend 



104
105
106
107
108
109
110
111
112
113
114
115
116
117
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 104

def tcp_receive_from_localbackend_first_packet n
  class << self
    alias tcp_receive_from_localbackend tcp_receive_from_localbackend_other_packet
  end
  recv_client_hello
  @no_effect ||= nil
  if !@no_effect
    send_server_hello
    recv_client_change_cipherspec_and_finish
    tcp_receive_from_localbackend_other_packet n
  else
    tcp_receive_from_localbackend_other_packet_helper n
  end
end

#tcp_receive_from_localbackend_other_packet(n) ⇒ Object

TLS 1.2 Application Pharse



122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 122

def tcp_receive_from_localbackend_other_packet n
  @no_effect ||= nil
  if !@no_effect
    begin
      head = async_recv 3
      if head != [CTYPE_Application, *VERSION_TLS_1_2].pack("C3")
        raise PharseError, "server_decode appdata error"
      end
      size = async_recv(2).unpack("n")[0]
    end while size == 0
    @buffer << async_recv(size)
  end

  tcp_receive_from_localbackend_other_packet_helper n
end

#tcp_receive_from_remoteserver_first_packet(n) ⇒ Object Also known as: tcp_receive_from_remoteserver 



78
79
80
81
82
83
84
85
86
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 78

def tcp_receive_from_remoteserver_first_packet n
  send_client_hello
  recv_server_hello
  @connected.succeed
  class << self
    alias tcp_receive_from_remoteserver tcp_receive_from_remoteserver_other_packet
  end
  tcp_receive_from_remoteserver_other_packet n
end

#tcp_receive_from_remoteserver_other_packet(n) ⇒ Object

TLS 1.2 Application Pharse



91
92
93
94
95
96
97
98
99
100
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 91

def tcp_receive_from_remoteserver_other_packet n
  head = async_recv 3
  if head != [CTYPE_Application, *VERSION_TLS_1_2].pack("C3")
    raise PharseError, "client_decode appdata error"
  end
  size = async_recv(2).unpack("n")[0]
  @buffer << async_recv(size)

  tcp_receive_from_remoteserver_other_packet_helper n
end

#tcp_send_to_localbackend(data) ⇒ Object 



138
139
140
141
142
143
144
145
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 138

def tcp_send_to_localbackend data
  @no_effect ||= nil
  if !@no_effect
    send_data_application_pharse data
  else
    send_data data
  end
end

#tcp_send_to_remoteserver_first_packet(data) ⇒ Object Also known as: tcp_send_to_remoteserver 



63
64
65
66
67
68
69
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 63

def tcp_send_to_remoteserver_first_packet data
  @connected.callback { send_client_change_cipherspec_and_finish data }
  class << self
    alias tcp_send_to_remoteserver tcp_send_to_remoteserver_other_packet
  end

end

#tcp_send_to_remoteserver_other_packet(data) ⇒ Object

TLS 1.2 Application Pharse



74
75
76
 
# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 74

def tcp_send_to_remoteserver_other_packet data
  @connected.callback { send_data_application_pharse data }
end