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:

  • configuration (Hash) —

    parameters

  • params (Hash) (defaults to: {}) —

    a customizable set of options

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



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# 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)
end

Instance Attribute Details

#next_protocol ⇒ Object

Returns the value of attribute next_protocol.



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

def next_protocol
  @next_protocol
end

Instance Method Details

#get_random ⇒ Object

helpers



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 145

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 311

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 286

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 211

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 203

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 194

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 152

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 299

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 272

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 103

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



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 121

def tcp_receive_from_localbackend_other_packet n
  @no_effect ||= nil
  if !@no_effect
    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]
    @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 



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# 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
  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



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 90

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 135

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 



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# File 'lib/shadowsocks_ruby/protocols/obfs/tls_ticket.rb', line 62

def tcp_send_to_remoteserver_first_packet data
  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



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

def tcp_send_to_remoteserver_other_packet data
  send_data_application_pharse data
end