#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright 2015-2015 breakwa11
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from __future__ import absolute_import, division, print_function, \
with_statement
import hashlib
import logging
import binascii
import base64
import time
import datetime
import random
import math
import struct
import hmac
import bisect
import shadowsocks
from shadowsocks import common, lru_cache, encrypt
from shadowsocks.obfsplugin import plain
from shadowsocks.common import to_bytes, to_str, ord, chr
from shadowsocks.crypto import openssl
rand_bytes = openssl.rand_bytes
def create_auth_chain_a(method):
return auth_chain_a(method)
def create_auth_chain_b(method):
return auth_chain_b(method)
def create_auth_chain_c(method):
return auth_chain_c(method)
def create_auth_chain_d(method):
return auth_chain_d(method)
def create_auth_chain_e(method):
return auth_chain_e(method)
def create_auth_chain_f(method):
return auth_chain_f(method)
obfs_map = {
'auth_chain_a': (create_auth_chain_a,),
'auth_chain_b': (create_auth_chain_b,),
'auth_chain_c': (create_auth_chain_c,),
'auth_chain_d': (create_auth_chain_d,),
'auth_chain_e': (create_auth_chain_e,),
'auth_chain_f': (create_auth_chain_f,),
}
class xorshift128plus(object):
max_int = (1 << 64) - 1
mov_mask = (1 << (64 - 23)) - 1
def __init__(self):
self.v0 = 0
self.v1 = 0
def next(self):
x = self.v0
y = self.v1
self.v0 = y
x ^= ((x & xorshift128plus.mov_mask) << 23)
x ^= (y ^ (x >> 17) ^ (y >> 26))
self.v1 = x
return (x + y) & xorshift128plus.max_int
def init_from_bin(self, bin):
if len(bin) < 16:
bin += b'\0' * 16
self.v0 = struct.unpack('<Q', bin[:8])[0]
self.v1 = struct.unpack('<Q', bin[8:16])[0]
def init_from_bin_len(self, bin, length):
if len(bin) < 16:
bin += b'\0' * 16
self.v0 = struct.unpack('<Q', struct.pack('<H', length) + bin[2:8])[0]
self.v1 = struct.unpack('<Q', bin[8:16])[0]
for i in range(4):
self.next()
def match_begin(str1, str2):
if len(str1) >= len(str2):
if str1[:len(str2)] == str2:
return True
return False
class auth_base(plain.plain):
def __init__(self, method):
super(auth_base, self).__init__(method)
self.method = method
self.no_compatible_method = ''
self.overhead = 4
def init_data(self):
return ''
def get_overhead(self, direction): # direction: true for c->s false for s->c
return self.overhead
def set_server_info(self, server_info):
self.server_info = server_info
def client_encode(self, buf):
return buf
def client_decode(self, buf):
return (buf, False)
def server_encode(self, buf):
return buf
def server_decode(self, buf):
return (buf, True, False)
def not_match_return(self, buf):
self.raw_trans = True
self.overhead = 0
if self.method == self.no_compatible_method:
return (b'E' * 2048, False)
return (buf, False)
class client_queue(object):
def __init__(self, begin_id):
self.front = begin_id - 64
self.back = begin_id + 1
self.alloc = {}
self.enable = True
self.last_update = time.time()
self.ref = 0
def update(self):
self.last_update = time.time()
def addref(self):
self.ref += 1
def delref(self):
if self.ref > 0:
self.ref -= 1
def is_active(self):
return (self.ref > 0) and (time.time() - self.last_update < 60 * 10)
def re_enable(self, connection_id):
self.enable = True
self.front = connection_id - 64
self.back = connection_id + 1
self.alloc = {}
def insert(self, connection_id):
if not self.enable:
logging.warn('obfs auth: not enable')
return False
if not self.is_active():
self.re_enable(connection_id)
self.update()
if connection_id < self.front:
logging.warn('obfs auth: deprecated id, someone replay attack')
return False
if connection_id > self.front + 0x4000:
logging.warn('obfs auth: wrong id')
return False
if connection_id in self.alloc:
logging.warn('obfs auth: duplicate id, someone replay attack')
return False
if self.back <= connection_id:
self.back = connection_id + 1
self.alloc[connection_id] = 1
while (self.front in self.alloc) or self.front + 0x1000 < self.back:
if self.front in self.alloc:
del self.alloc[self.front]
self.front += 1
self.addref()
return True
class obfs_auth_chain_data(object):
def __init__(self, name):
self.name = name
self.user_id = {}
self.local_client_id = b''
self.connection_id = 0
self.set_max_client(64) # max active client count
def update(self, user_id, client_id, connection_id):
if user_id not in self.user_id:
self.user_id[user_id] = lru_cache.LRUCache()
local_client_id = self.user_id[user_id]
if client_id in local_client_id:
local_client_id[client_id].update()
def set_max_client(self, max_client):
self.max_client = max_client
self.max_buffer = max(self.max_client * 2, 1024)
def insert(self, user_id, client_id, connection_id):
if user_id not in self.user_id:
self.user_id[user_id] = lru_cache.LRUCache()
local_client_id = self.user_id[user_id]
if local_client_id.get(client_id, None) is None or not local_client_id[client_id].enable:
if local_client_id.first() is None or len(local_client_id) < self.max_client:
if client_id not in local_client_id:
# TODO: check
local_client_id[client_id] = client_queue(connection_id)
else:
local_client_id[client_id].re_enable(connection_id)
return local_client_id[client_id].insert(connection_id)
if not local_client_id[local_client_id.first()].is_active():
del local_client_id[local_client_id.first()]
if client_id not in local_client_id:
# TODO: check
local_client_id[client_id] = client_queue(connection_id)
else:
local_client_id[client_id].re_enable(connection_id)
return local_client_id[client_id].insert(connection_id)
logging.warn(self.name + ': no inactive client')
return False
else:
return local_client_id[client_id].insert(connection_id)
def remove(self, user_id, client_id):
if user_id in self.user_id:
local_client_id = self.user_id[user_id]
if client_id in local_client_id:
local_client_id[client_id].delref()
class auth_chain_a(auth_base):
def __init__(self, method):
super(auth_chain_a, self).__init__(method)
self.hashfunc = hashlib.md5
self.recv_buf = b''
self.unit_len = 2800
self.raw_trans = False
self.has_sent_header = False
self.has_recv_header = False
self.client_id = 0
self.connection_id = 0
self.max_time_dif = 60 * 60 * 24 # time dif (second) setting
self.salt = b"auth_chain_a"
self.no_compatible_method = 'auth_chain_a'
self.pack_id = 1
self.recv_id = 1
self.user_id = None
self.user_id_num = 0
self.user_key = None
self.overhead = 4
self.client_over_head = 4
self.last_client_hash = b''
self.last_server_hash = b''
self.random_client = xorshift128plus()
self.random_server = xorshift128plus()
self.encryptor = None
def init_data(self):
return obfs_auth_chain_data(self.method)
def get_overhead(self, direction): # direction: true for c->s false for s->c
return self.overhead
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param.split('#')[0])
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
def trapezoid_random_float(self, d):
if d == 0:
return random.random()
s = random.random()
a = 1 - d
return (math.sqrt(a * a + 4 * d * s) - a) / (2 * d)
def trapezoid_random_int(self, max_val, d):
v = self.trapezoid_random_float(d)
return int(v * max_val)
def rnd_data_len(self, buf_size, last_hash, random):
if buf_size > 1440:
return 0
random.init_from_bin_len(last_hash, buf_size)
if buf_size > 1300:
return random.next() % 31
if buf_size > 900:
return random.next() % 127
if buf_size > 400:
return random.next() % 521
return random.next() % 1021
def udp_rnd_data_len(self, last_hash, random):
random.init_from_bin(last_hash)
return random.next() % 127
def rnd_start_pos(self, rand_len, random):
if rand_len > 0:
return random.next() % 8589934609 % rand_len
return 0
def rnd_data(self, buf_size, buf, last_hash, random):
rand_len = self.rnd_data_len(buf_size, last_hash, random)
rnd_data_buf = rand_bytes(rand_len)
if buf_size == 0:
return rnd_data_buf
else:
if rand_len > 0:
start_pos = self.rnd_start_pos(rand_len, random)
return rnd_data_buf[:start_pos] + buf + rnd_data_buf[start_pos:]
else:
return buf
def pack_client_data(self, buf):
buf = self.encryptor.encrypt(buf)
data = self.rnd_data(len(buf), buf, self.last_client_hash, self.random_client)
mac_key = self.user_key + struct.pack('<I', self.pack_id)
length = len(buf) ^ struct.unpack('<H', self.last_client_hash[14:])[0]
data = struct.pack('<H', length) + data
self.last_client_hash = hmac.new(mac_key, data, self.hashfunc).digest()
data += self.last_client_hash[:2]
self.pack_id = (self.pack_id + 1) & 0xFFFFFFFF
return data
def pack_server_data(self, buf):
buf = self.encryptor.encrypt(buf)
data = self.rnd_data(len(buf), buf, self.last_server_hash, self.random_server)
mac_key = self.user_key + struct.pack('<I', self.pack_id)
length = len(buf) ^ struct.unpack('<H', self.last_server_hash[14:])[0]
data = struct.pack('<H', length) + data
self.last_server_hash = hmac.new(mac_key, data, self.hashfunc).digest()
data += self.last_server_hash[:2]
self.pack_id = (self.pack_id + 1) & 0xFFFFFFFF
return data
def pack_auth_data(self, auth_data, buf):
data = auth_data
data = data + (struct.pack('<H', self.server_info.overhead) + struct.pack('<H', 0))
mac_key = self.server_info.iv + self.server_info.key
check_head = rand_bytes(4)
self.last_client_hash = hmac.new(mac_key, check_head, self.hashfunc).digest()
check_head += self.last_client_hash[:8]
if b':' in to_bytes(self.server_info.protocol_param):
try:
items = to_bytes(self.server_info.protocol_param).split(b':')
self.user_key = items[1]
uid = struct.pack('<I', int(items[0]))
except:
uid = rand_bytes(4)
else:
uid = rand_bytes(4)
if self.user_key is None:
self.user_key = self.server_info.key
encryptor = encrypt.Encryptor(
to_bytes(base64.b64encode(self.user_key)) + self.salt, 'aes-128-cbc', b'\x00' * 16)
uid = struct.unpack('<I', uid)[0] ^ struct.unpack('<I', self.last_client_hash[8:12])[0]
uid = struct.pack('<I', uid)
data = uid + encryptor.encrypt(data)[16:]
self.last_server_hash = hmac.new(self.user_key, data, self.hashfunc).digest()
data = check_head + data + self.last_server_hash[:4]
self.encryptor = encrypt.Encryptor(
to_bytes(base64.b64encode(self.user_key)) + to_bytes(base64.b64encode(self.last_client_hash)), 'rc4')
return data + self.pack_client_data(buf)
def auth_data(self):
utc_time = int(time.time()) & 0xFFFFFFFF
if self.server_info.data.connection_id > 0xFF000000:
self.server_info.data.local_client_id = b''
if not self.server_info.data.local_client_id:
self.server_info.data.local_client_id = rand_bytes(4)
logging.debug("local_client_id %s" % (binascii.hexlify(self.server_info.data.local_client_id),))
self.server_info.data.connection_id = struct.unpack('<I', rand_bytes(4))[0] & 0xFFFFFF
self.server_info.data.connection_id += 1
return b''.join([struct.pack('<I', utc_time),
self.server_info.data.local_client_id,
struct.pack('<I', self.server_info.data.connection_id)])
def on_recv_auth_data(self, utc_time):
pass
def client_pre_encrypt(self, buf):
ret = b''
ogn_data_len = len(buf)
if not self.has_sent_header:
head_size = self.get_head_size(buf, 30)
datalen = min(len(buf), random.randint(0, 31) + head_size)
ret += self.pack_auth_data(self.auth_data(), buf[:datalen])
buf = buf[datalen:]
self.has_sent_header = True
while len(buf) > self.unit_len:
ret += self.pack_client_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_client_data(buf)
return ret
def client_post_decrypt(self, buf):
if self.raw_trans:
return buf
self.recv_buf += buf
out_buf = b''
while len(self.recv_buf) > 4:
mac_key = self.user_key + struct.pack('<I', self.recv_id)
data_len = struct.unpack('<H', self.recv_buf[:2])[0] ^ struct.unpack('<H', self.last_server_hash[14:16])[0]
rand_len = self.rnd_data_len(data_len, self.last_server_hash, self.random_server)
length = data_len + rand_len
if length >= 4096:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data error')
if length + 4 > len(self.recv_buf):
break
server_hash = hmac.new(mac_key, self.recv_buf[:length + 2], self.hashfunc).digest()
if server_hash[:2] != self.recv_buf[length + 2: length + 4]:
logging.info('%s: checksum error, data %s'
% (self.no_compatible_method, binascii.hexlify(self.recv_buf[:length])))
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data uncorrect checksum')
pos = 2
if data_len > 0 and rand_len > 0:
pos = 2 + self.rnd_start_pos(rand_len, self.random_server)
out_buf += self.encryptor.decrypt(self.recv_buf[pos: data_len + pos])
self.last_server_hash = server_hash
if self.recv_id == 1:
self.server_info.tcp_mss = struct.unpack('<H', out_buf[:2])[0]
out_buf = out_buf[2:]
self.recv_id = (self.recv_id + 1) & 0xFFFFFFFF
self.recv_buf = self.recv_buf[length + 4:]
return out_buf
def server_pre_encrypt(self, buf):
if self.raw_trans:
return buf
ret = b''
if self.pack_id == 1:
tcp_mss = self.server_info.tcp_mss if self.server_info.tcp_mss < 1500 else 1500
self.server_info.tcp_mss = tcp_mss
buf = struct.pack('<H', tcp_mss) + buf
self.unit_len = tcp_mss - self.client_over_head
while len(buf) > self.unit_len:
ret += self.pack_server_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_server_data(buf)
return ret
def server_post_decrypt(self, buf):
if self.raw_trans:
return (buf, False)
self.recv_buf += buf
out_buf = b''
sendback = False
if not self.has_recv_header:
if len(self.recv_buf) >= 12 or len(self.recv_buf) in [7, 8]:
recv_len = min(len(self.recv_buf), 12)
mac_key = self.server_info.recv_iv + self.server_info.key
md5data = hmac.new(mac_key, self.recv_buf[:4], self.hashfunc).digest()
if md5data[:recv_len - 4] != self.recv_buf[4:recv_len]:
return self.not_match_return(self.recv_buf)
if len(self.recv_buf) < 12 + 24:
return (b'', False)
self.last_client_hash = md5data
uid = struct.unpack('<I', self.recv_buf[12:16])[0] ^ struct.unpack('<I', md5data[8:12])[0]
self.user_id_num = uid
uid = struct.pack('<I', uid)
if uid in self.server_info.users:
self.user_id = uid
self.user_key = self.server_info.users[uid]
self.server_info.update_user_func(uid)
else:
self.user_id_num = 0
if not self.server_info.users:
self.user_key = self.server_info.key
else:
self.user_key = self.server_info.recv_iv
md5data = hmac.new(self.user_key, self.recv_buf[12: 12 + 20], self.hashfunc).digest()
if md5data[:4] != self.recv_buf[32:36]:
logging.error('%s data uncorrect auth HMAC-MD5 from %s:%d, data %s' % (
self.no_compatible_method, self.server_info.client, self.server_info.client_port,
binascii.hexlify(self.recv_buf)
))
if len(self.recv_buf) < 36:
return (b'', False)
return self.not_match_return(self.recv_buf)
self.last_server_hash = md5data
encryptor = encrypt.Encryptor(to_bytes(base64.b64encode(self.user_key)) + self.salt, 'aes-128-cbc')
head = encryptor.decrypt(b'\x00' * 16 + self.recv_buf[16:32] + b'\x00') # need an extra byte or recv empty
self.client_over_head = struct.unpack('<H', head[12:14])[0]
utc_time = struct.unpack('<I', head[:4])[0]
client_id = struct.unpack('<I', head[4:8])[0]
connection_id = struct.unpack('<I', head[8:12])[0]
time_dif = common.int32(utc_time - (int(time.time()) & 0xffffffff))
if time_dif < -self.max_time_dif or time_dif > self.max_time_dif:
logging.info('%s: wrong timestamp, time_dif %d, data %s' % (
self.no_compatible_method, time_dif, binascii.hexlify(head)
))
return self.not_match_return(self.recv_buf)
elif self.server_info.data.insert(self.user_id, client_id, connection_id):
self.has_recv_header = True
self.client_id = client_id
self.connection_id = connection_id
else:
logging.info('%s: auth fail, data %s' % (self.no_compatible_method, binascii.hexlify(out_buf)))
return self.not_match_return(self.recv_buf)
self.on_recv_auth_data(utc_time)
self.encryptor = encrypt.Encryptor(
to_bytes(base64.b64encode(self.user_key)) + to_bytes(base64.b64encode(self.last_client_hash)), 'rc4')
self.recv_buf = self.recv_buf[36:]
self.has_recv_header = True
sendback = True
while len(self.recv_buf) > 4:
mac_key = self.user_key + struct.pack('<I', self.recv_id)
data_len = struct.unpack('<H', self.recv_buf[:2])[0] ^ struct.unpack('<H', self.last_client_hash[14:16])[0]
rand_len = self.rnd_data_len(data_len, self.last_client_hash, self.random_client)
length = data_len + rand_len
if length >= 4096:
self.raw_trans = True
self.recv_buf = b''
if self.recv_id == 1:
logging.info(self.no_compatible_method + ': over size')
return (b'E' * 2048, False)
else:
raise Exception('server_post_decrype data error')
if length + 4 > len(self.recv_buf):
break
client_hash = hmac.new(mac_key, self.recv_buf[:length + 2], self.hashfunc).digest()
if client_hash[:2] != self.recv_buf[length + 2: length + 4]:
logging.info('%s: checksum error, data %s' % (
self.no_compatible_method, binascii.hexlify(self.recv_buf[:length])
))
self.raw_trans = True
self.recv_buf = b''
if self.recv_id == 1:
return (b'E' * 2048, False)
else:
raise Exception('server_post_decrype data uncorrect checksum')
self.recv_id = (self.recv_id + 1) & 0xFFFFFFFF
pos = 2
if data_len > 0 and rand_len > 0:
pos = 2 + self.rnd_start_pos(rand_len, self.random_client)
out_buf += self.encryptor.decrypt(self.recv_buf[pos: data_len + pos])
self.last_client_hash = client_hash
self.recv_buf = self.recv_buf[length + 4:]
if data_len == 0:
sendback = True
if out_buf:
self.server_info.data.update(self.user_id, self.client_id, self.connection_id)
return (out_buf, sendback)
def client_udp_pre_encrypt(self, buf):
if self.user_key is None:
if b':' in to_bytes(self.server_info.protocol_param):
try:
items = to_bytes(self.server_info.protocol_param).split(':')
self.user_key = self.hashfunc(items[1]).digest()
self.user_id = struct.pack('<I', int(items[0]))
except:
pass
if self.user_key is None:
self.user_id = rand_bytes(4)
self.user_key = self.server_info.key
authdata = rand_bytes(3)
mac_key = self.server_info.key
md5data = hmac.new(mac_key, authdata, self.hashfunc).digest()
uid = struct.unpack('<I', self.user_id)[0] ^ struct.unpack('<I', md5data[:4])[0]
uid = struct.pack('<I', uid)
rand_len = self.udp_rnd_data_len(md5data, self.random_client)
encryptor = encrypt.Encryptor(
to_bytes(base64.b64encode(self.user_key)) + to_bytes(base64.b64encode(md5data)), 'rc4')
out_buf = encryptor.encrypt(buf)
buf = out_buf + rand_bytes(rand_len) + authdata + uid
return buf + hmac.new(self.user_key, buf, self.hashfunc).digest()[:1]
def client_udp_post_decrypt(self, buf):
if len(buf) <= 8:
return (b'', None)
if hmac.new(self.user_key, buf[:-1], self.hashfunc).digest()[:1] != buf[-1:]:
return (b'', None)
mac_key = self.server_info.key
md5data = hmac.new(mac_key, buf[-8:-1], self.hashfunc).digest()
rand_len = self.udp_rnd_data_len(md5data, self.random_server)
encryptor = encrypt.Encryptor(
to_bytes(base64.b64encode(self.user_key)) + to_bytes(base64.b64encode(md5data)), 'rc4')
return encryptor.decrypt(buf[:-8 - rand_len])
def server_udp_pre_encrypt(self, buf, uid):
if uid in self.server_info.users:
user_key = self.server_info.users[uid]
else:
uid = None
if not self.server_info.users:
user_key = self.server_info.key
else:
user_key = self.server_info.recv_iv
authdata = rand_bytes(7)
mac_key = self.server_info.key
md5data = hmac.new(mac_key, authdata, self.hashfunc).digest()
rand_len = self.udp_rnd_data_len(md5data, self.random_server)
encryptor = encrypt.Encryptor(to_bytes(base64.b64encode(user_key)) + to_bytes(base64.b64encode(md5data)), 'rc4')
out_buf = encryptor.encrypt(buf)
buf = out_buf + rand_bytes(rand_len) + authdata
return buf + hmac.new(user_key, buf, self.hashfunc).digest()[:1]
def server_udp_post_decrypt(self, buf):
mac_key = self.server_info.key
md5data = hmac.new(mac_key, buf[-8:-5], self.hashfunc).digest()
uid = struct.unpack('<I', buf[-5:-1])[0] ^ struct.unpack('<I', md5data[:4])[0]
uid = struct.pack('<I', uid)
if uid in self.server_info.users:
user_key = self.server_info.users[uid]
else:
uid = None
if not self.server_info.users:
user_key = self.server_info.key
else:
user_key = self.server_info.recv_iv
if hmac.new(user_key, buf[:-1], self.hashfunc).digest()[:1] != buf[-1:]:
return (b'', None)
rand_len = self.udp_rnd_data_len(md5data, self.random_client)
encryptor = encrypt.Encryptor(to_bytes(base64.b64encode(user_key)) + to_bytes(base64.b64encode(md5data)), 'rc4')
out_buf = encryptor.decrypt(buf[:-8 - rand_len])
return (out_buf, uid)
def dispose(self):
self.server_info.data.remove(self.user_id, self.client_id)
class auth_chain_b(auth_chain_a):
def __init__(self, method):
super(auth_chain_b, self).__init__(method)
self.salt = b"auth_chain_b"
self.no_compatible_method = 'auth_chain_b'
# NOTE
# 补全后长度数组
# 随机在其中选择一个补全到的长度
# 为每个连接初始化一个固定内容的数组
self.data_size_list = []
self.data_size_list2 = []
def init_data_size(self, key):
if self.data_size_list:
self.data_size_list = []
self.data_size_list2 = []
random = xorshift128plus()
random.init_from_bin(key)
# 补全数组长为4~12-1
list_len = random.next() % 8 + 4
for i in range(0, list_len):
self.data_size_list.append((int)(random.next() % 2340 % 2040 % 1440))
self.data_size_list.sort()
# 补全数组长为8~24-1
list_len = random.next() % 16 + 8
for i in range(0, list_len):
self.data_size_list2.append((int)(random.next() % 2340 % 2040 % 1440))
self.data_size_list2.sort()
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param.split('#')[0])
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
self.init_data_size(self.server_info.key)
def rnd_data_len(self, buf_size, last_hash, random):
if buf_size >= 1440:
return 0
random.init_from_bin_len(last_hash, buf_size)
pos = bisect.bisect_left(self.data_size_list, buf_size + self.server_info.overhead)
final_pos = pos + random.next() % (len(self.data_size_list))
# 假设random均匀分布，则越长的原始数据长度越容易if false
if final_pos < len(self.data_size_list):
return self.data_size_list[final_pos] - buf_size - self.server_info.overhead
# 上面if false后选择2号补全数组，此处有更精细的长度分段
pos = bisect.bisect_left(self.data_size_list2, buf_size + self.server_info.overhead)
final_pos = pos + random.next() % (len(self.data_size_list2))
if final_pos < len(self.data_size_list2):
return self.data_size_list2[final_pos] - buf_size - self.server_info.overhead
# final_pos 总是分布在pos~(data_size_list2.len-1)之间
if final_pos < pos + len(self.data_size_list2) - 1:
return 0
# 有1/len(self.data_size_list2)的概率不满足上一个if
if buf_size > 1300:
return random.next() % 31
if buf_size > 900:
return random.next() % 127
if buf_size > 400:
return random.next() % 521
return random.next() % 1021
class auth_chain_c(auth_chain_b):
def __init__(self, method):
super(auth_chain_c, self).__init__(method)
self.salt = b"auth_chain_c"
self.no_compatible_method = 'auth_chain_c'
self.data_size_list0 = []
def init_data_size(self, key):
if self.data_size_list0:
self.data_size_list0 = []
random = xorshift128plus()
random.init_from_bin(key)
# 补全数组长为12~24-1
list_len = random.next() % (8 + 16) + (4 + 8)
for i in range(0, list_len):
self.data_size_list0.append((int)(random.next() % 2340 % 2040 % 1440))
self.data_size_list0.sort()
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param.split('#')[0])
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
self.init_data_size(self.server_info.key)
def rnd_data_len(self, buf_size, last_hash, random):
other_data_size = buf_size + self.server_info.overhead
# 一定要在random使用前初始化，以保证服务器与客户端同步，保证包大小验证结果正确
random.init_from_bin_len(last_hash, buf_size)
# final_pos 总是分布在pos~(data_size_list0.len-1)之间
# 除非data_size_list0中的任何值均过小使其全部都无法容纳buf
if other_data_size >= self.data_size_list0[-1]:
if other_data_size >= 1440:
return 0
if other_data_size > 1300:
return random.next() % 31
if other_data_size > 900:
return random.next() % 127
if other_data_size > 400:
return random.next() % 521
return random.next() % 1021
pos = bisect.bisect_left(self.data_size_list0, other_data_size)
# random select a size in the leftover data_size_list0
final_pos = pos + random.next() % (len(self.data_size_list0) - pos)
return self.data_size_list0[final_pos] - other_data_size
class auth_chain_d(auth_chain_b):
def __init__(self, method):
super(auth_chain_d, self).__init__(method)
self.salt = b"auth_chain_d"
self.no_compatible_method = 'auth_chain_d'
self.data_size_list0 = []
def check_and_patch_data_size(self, random):
# append new item
# when the biggest item(first time) or the last append item(other time) are not big enough.
# but set a limit size (64) to avoid stack overflow.
if self.data_size_list0[-1] < 1300 and len(self.data_size_list0) < 64:
self.data_size_list0.append((int)(random.next() % 2340 % 2040 % 1440))
self.check_and_patch_data_size(random)
def init_data_size(self, key):
if self.data_size_list0:
self.data_size_list0 = []
random = xorshift128plus()
random.init_from_bin(key)
# 补全数组长为12~24-1
list_len = random.next() % (8 + 16) + (4 + 8)
for i in range(0, list_len):
self.data_size_list0.append((int)(random.next() % 2340 % 2040 % 1440))
self.data_size_list0.sort()
old_len = len(self.data_size_list0)
self.check_and_patch_data_size(random)
# if check_and_patch_data_size are work, re-sort again.
if old_len != len(self.data_size_list0):
self.data_size_list0.sort()
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param.split('#')[0])
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
self.init_data_size(self.server_info.key)
def rnd_data_len(self, buf_size, last_hash, random):
other_data_size = buf_size + self.server_info.overhead
# if other_data_size > the bigest item in data_size_list0, not padding any data
if other_data_size >= self.data_size_list0[-1]:
return 0
random.init_from_bin_len(last_hash, buf_size)
pos = bisect.bisect_left(self.data_size_list0, other_data_size)
# random select a size in the leftover data_size_list0
final_pos = pos + random.next() % (len(self.data_size_list0) - pos)
return self.data_size_list0[final_pos] - other_data_size
class auth_chain_e(auth_chain_d):
def __init__(self, method):
super(auth_chain_e, self).__init__(method)
self.salt = b"auth_chain_e"
self.no_compatible_method = 'auth_chain_e'
def rnd_data_len(self, buf_size, last_hash, random):
random.init_from_bin_len(last_hash, buf_size)
other_data_size = buf_size + self.server_info.overhead
# if other_data_size > the bigest item in data_size_list0, not padding any data
if other_data_size >= self.data_size_list0[-1]:
return 0
# use the mini size in the data_size_list0
pos = bisect.bisect_left(self.data_size_list0, other_data_size)
return self.data_size_list0[pos] - other_data_size
# auth_chain_f
# when every connect create, generate size_list will different when every day or every custom time interval which set in the config
class auth_chain_f(auth_chain_e):
def __init__(self, method):
super(auth_chain_f, self).__init__(method)
self.salt = b"auth_chain_f"
self.no_compatible_method = 'auth_chain_f'
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param.split('#')[0])
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
try:
self.key_change_interval = int(server_info.protocol_param.split('#')[1]) # config are in second
except:
self.key_change_interval = 60 * 60 * 24 # a day by second
def on_recv_auth_data(self, utc_time):
self.key_change_datetime_key = int(utc_time / self.key_change_interval)
self.key_change_datetime_key_bytes = [] # big bit first list
for i in range(7, -1, -1): # big-ending compare to c
self.key_change_datetime_key_bytes.append((self.key_change_datetime_key >> (8 * i)) & 0xFF)
self.init_data_size(self.server_info.key)
def init_data_size(self, key):
if self.data_size_list0:
self.data_size_list0 = []
random = xorshift128plus()
# key xor with key_change_datetime_key
new_key = bytearray(key)
new_key_str = ''
for i in range(0, 8):
new_key[i] ^= self.key_change_datetime_key_bytes[i]
new_key_str += chr(new_key[i])
for i in range(8, len(new_key)):
new_key_str += chr(new_key[i])
random.init_from_bin(to_bytes(new_key_str))
# 补全数组长为12~24-1
list_len = random.next() % (8 + 16) + (4 + 8)
for i in range(0, list_len):
self.data_size_list0.append(int(random.next() % 2340 % 2040 % 1440))
self.data_size_list0.sort()
old_len = len(self.data_size_list0)
self.check_and_patch_data_size(random)
# if check_and_patch_data_size are work, re-sort again.
if old_len != len(self.data_size_list0):
self.data_size_list0.sort()
