#!/usr/bin/env python
#
# 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 os
import sys
import hashlib
import logging
import binascii
import base64
import time
import datetime
import random
import struct
import zlib
import hmac
import hashlib
import shadowsocks
from shadowsocks import common, lru_cache
from shadowsocks.obfsplugin import plain
from shadowsocks.common import to_bytes, to_str, ord, chr
def create_auth_sha1(method):
return auth_sha1(method)
def create_auth_sha1_v2(method):
return auth_sha1_v2(method)
def create_auth_sha1_v3(method):
return auth_sha1_v3(method)
def create_auth_sha1_v4(method):
return auth_sha1_v4(method)
obfs_map = {
'auth_sha1': (create_auth_sha1,),
'auth_sha1_compatible': (create_auth_sha1,),
'auth_sha1_v2': (create_auth_sha1_v2,),
'auth_sha1_v2_compatible': (create_auth_sha1_v2,),
'auth_sha1_v3': (create_auth_sha1_v3,),
'auth_sha1_v3_compatible': (create_auth_sha1_v3,),
'auth_sha1_v4': (create_auth_sha1_v4,),
'auth_sha1_v4_compatible': (create_auth_sha1_v4,),
}
def match_begin(str1, str2):
if len(str1) >= len(str2):
if str1[:len(str2)] == str2:
return True
return False
class obfs_verify_data(object):
def __init__(self):
pass
class verify_base(plain.plain):
def __init__(self, method):
super(verify_base, self).__init__(method)
self.method = method
self.no_compatible_method = ''
def init_data(self):
return ''
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
if self.method == self.no_compatible_method:
return (b'E'*64, 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()
def update(self):
self.last_update = time.time()
def is_active(self):
return time.time() - self.last_update < 60 * 3
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: duplicate id')
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 2')
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
return True
class obfs_auth_data(object):
def __init__(self):
self.client_id = {}
self.startup_time = int(time.time() - 30) & 0xFFFFFFFF
self.local_client_id = b''
self.connection_id = 0
self.set_max_client(64) # max active client count
def update(self, client_id, connection_id):
if client_id in self.client_id:
self.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, 256)
def insert(self, client_id, connection_id):
if client_id not in self.client_id or not self.client_id[client_id].enable:
active = 0
for c_id in self.client_id:
if self.client_id[c_id].is_active():
active += 1
if active >= self.max_client:
logging.warn('obfs auth: max active clients exceeded')
return False
if len(self.client_id) < self.max_client:
if client_id not in self.client_id:
self.client_id[client_id] = client_queue(connection_id)
else:
self.client_id[client_id].re_enable(connection_id)
return self.client_id[client_id].insert(connection_id)
keys = self.client_id.keys()
random.shuffle(keys)
for c_id in keys:
if not self.client_id[c_id].is_active() and self.client_id[c_id].enable:
if len(self.client_id) >= self.max_buffer:
del self.client_id[c_id]
else:
self.client_id[c_id].enable = False
if client_id not in self.client_id:
self.client_id[client_id] = client_queue(connection_id)
else:
self.client_id[client_id].re_enable(connection_id)
return self.client_id[client_id].insert(connection_id)
logging.warn('obfs auth: no inactive client [assert]')
return False
else:
return self.client_id[client_id].insert(connection_id)
class auth_sha1(verify_base):
def __init__(self, method):
super(auth_sha1, self).__init__(method)
self.recv_buf = b''
self.unit_len = 8000
self.decrypt_packet_num = 0
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 # time dif (second) setting
self.no_compatible_method = 'auth_sha1'
def init_data(self):
return obfs_auth_data()
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param)
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
def pack_data(self, buf):
rnd_data = os.urandom(common.ord(os.urandom(1)[0]) % 16)
data = common.chr(len(rnd_data) + 1) + rnd_data + buf
data = struct.pack('>H', len(data) + 6) + data
adler32 = zlib.adler32(data) & 0xFFFFFFFF
data += struct.pack('<I', adler32)
return data
def pack_auth_data(self, buf):
if len(buf) == 0:
return b''
rnd_data = os.urandom(common.ord(os.urandom(1)[0]) % 128)
data = common.chr(len(rnd_data) + 1) + rnd_data + buf
data = struct.pack('>H', len(data) + 16) + data
crc = binascii.crc32(self.server_info.key) & 0xFFFFFFFF
data = struct.pack('<I', crc) + data
data += hmac.new(self.server_info.iv + self.server_info.key, data, hashlib.sha1).digest()[:10]
return data
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 = os.urandom(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', os.urandom(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 client_pre_encrypt(self, buf):
ret = b''
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_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_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) > 2:
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length >= 8192 or length < 7:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data error')
if length > len(self.recv_buf):
break
if struct.pack('<I', zlib.adler32(self.recv_buf[:length - 4]) & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data uncorrect checksum')
pos = common.ord(self.recv_buf[2]) + 2
out_buf += self.recv_buf[pos:length - 4]
self.recv_buf = self.recv_buf[length:]
if out_buf:
self.decrypt_packet_num += 1
return out_buf
def server_pre_encrypt(self, buf):
if self.raw_trans:
return buf
ret = b''
while len(buf) > self.unit_len:
ret += self.pack_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_data(buf)
return ret
def server_post_decrypt(self, buf):
if self.raw_trans:
return (buf, False)
self.recv_buf += buf
out_buf = b''
if not self.has_recv_header:
if len(self.recv_buf) < 6:
return (b'', False)
crc = struct.pack('<I', binascii.crc32(self.server_info.key) & 0xFFFFFFFF)
if crc != self.recv_buf[:4]:
return self.not_match_return(self.recv_buf)
length = struct.unpack('>H', self.recv_buf[4:6])[0]
if length > 2048:
return self.not_match_return(self.recv_buf)
if length > len(self.recv_buf):
return (b'', False)
sha1data = hmac.new(self.server_info.recv_iv + self.server_info.key, self.recv_buf[:length - 10], hashlib.sha1).digest()[:10]
if sha1data != self.recv_buf[length - 10:length]:
logging.error('auth_sha1 data uncorrect auth HMAC-SHA1')
return self.not_match_return(self.recv_buf)
pos = common.ord(self.recv_buf[6]) + 6
out_buf = self.recv_buf[pos:length - 10]
if len(out_buf) < 12:
logging.info('auth_sha1: too short, data %s' % (binascii.hexlify(self.recv_buf),))
return self.not_match_return(self.recv_buf)
utc_time = struct.unpack('<I', out_buf[:4])[0]
client_id = struct.unpack('<I', out_buf[4:8])[0]
connection_id = struct.unpack('<I', out_buf[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 \
or common.int32(utc_time - self.server_info.data.startup_time) < -self.max_time_dif / 2:
logging.info('auth_sha1: wrong timestamp, time_dif %d, data %s' % (time_dif, binascii.hexlify(out_buf),))
return self.not_match_return(self.recv_buf)
elif self.server_info.data.insert(client_id, connection_id):
self.has_recv_header = True
out_buf = out_buf[12:]
self.client_id = client_id
self.connection_id = connection_id
else:
logging.info('auth_sha1: auth fail, data %s' % (binascii.hexlify(out_buf),))
return self.not_match_return(self.recv_buf)
self.recv_buf = self.recv_buf[length:]
self.has_recv_header = True
while len(self.recv_buf) > 2:
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length >= 8192 or length < 7:
self.raw_trans = True
self.recv_buf = b''
if self.decrypt_packet_num == 0:
logging.info('auth_sha1: over size')
return (b'E', False)
else:
raise Exception('server_post_decrype data error')
if length > len(self.recv_buf):
break
if struct.pack('<I', zlib.adler32(self.recv_buf[:length - 4]) & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
logging.info('auth_sha1: checksum error, data %s' % (binascii.hexlify(self.recv_buf[:length]),))
self.raw_trans = True
self.recv_buf = b''
if self.decrypt_packet_num == 0:
return (b'E', False)
else:
raise Exception('server_post_decrype data uncorrect checksum')
pos = common.ord(self.recv_buf[2]) + 2
out_buf += self.recv_buf[pos:length - 4]
self.recv_buf = self.recv_buf[length:]
if out_buf:
self.server_info.data.update(self.client_id, self.connection_id)
self.decrypt_packet_num += 1
return (out_buf, False)
class obfs_auth_v2_data(object):
def __init__(self):
self.client_id = lru_cache.LRUCache()
self.local_client_id = b''
self.connection_id = 0
self.set_max_client(64) # max active client count
def update(self, client_id, connection_id):
if client_id in self.client_id:
self.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, client_id, connection_id):
if self.client_id.get(client_id, None) is None or not self.client_id[client_id].enable:
if self.client_id.first() is None or len(self.client_id) < self.max_client:
if client_id not in self.client_id:
#TODO: check
self.client_id[client_id] = client_queue(connection_id)
else:
self.client_id[client_id].re_enable(connection_id)
return self.client_id[client_id].insert(connection_id)
if not self.client_id[self.client_id.first()].is_active():
del self.client_id[self.client_id.first()]
if client_id not in self.client_id:
#TODO: check
self.client_id[client_id] = client_queue(connection_id)
else:
self.client_id[client_id].re_enable(connection_id)
return self.client_id[client_id].insert(connection_id)
logging.warn('auth_sha1_v2: no inactive client')
return False
else:
return self.client_id[client_id].insert(connection_id)
class auth_sha1_v2(verify_base):
def __init__(self, method):
super(auth_sha1_v2, self).__init__(method)
self.recv_buf = b''
self.unit_len = 8100
self.decrypt_packet_num = 0
self.raw_trans = False
self.has_sent_header = False
self.has_recv_header = False
self.client_id = 0
self.connection_id = 0
self.salt = b"auth_sha1_v2"
self.no_compatible_method = 'auth_sha1_v2'
def init_data(self):
return obfs_auth_v2_data()
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param)
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
def rnd_data(self, buf_size):
if buf_size > 1300:
return b'\x01'
if buf_size > 400:
rnd_data = os.urandom(common.ord(os.urandom(1)[0]) % 128)
return common.chr(len(rnd_data) + 1) + rnd_data
rnd_data = os.urandom(struct.unpack('>H', os.urandom(2))[0] % 1024)
return common.chr(255) + struct.pack('>H', len(rnd_data) + 3) + rnd_data
def pack_data(self, buf):
data = self.rnd_data(len(buf)) + buf
data = struct.pack('>H', len(data) + 6) + data
adler32 = zlib.adler32(data) & 0xFFFFFFFF
data += struct.pack('<I', adler32)
return data
def pack_auth_data(self, buf):
if len(buf) == 0:
return b''
data = self.rnd_data(len(buf)) + buf
data = struct.pack('>H', len(data) + 16) + data
crc = binascii.crc32(self.salt + self.server_info.key) & 0xFFFFFFFF
data = struct.pack('<I', crc) + data
data += hmac.new(self.server_info.iv + self.server_info.key, data, hashlib.sha1).digest()[:10]
return data
def auth_data(self):
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 = os.urandom(8)
logging.debug("local_client_id %s" % (binascii.hexlify(self.server_info.data.local_client_id),))
self.server_info.data.connection_id = struct.unpack('<Q', self.server_info.data.local_client_id)[0] % 0xFFFFFD
self.server_info.data.connection_id += 1
return b''.join([self.server_info.data.local_client_id,
struct.pack('<I', self.server_info.data.connection_id)])
def client_pre_encrypt(self, buf):
ret = b''
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_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_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) > 2:
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length >= 8192 or length < 7:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data error')
if length > len(self.recv_buf):
break
if struct.pack('<I', zlib.adler32(self.recv_buf[:length - 4]) & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data uncorrect checksum')
pos = common.ord(self.recv_buf[2])
if pos < 255:
pos += 2
else:
pos = struct.unpack('>H', self.recv_buf[3:5])[0] + 2
out_buf += self.recv_buf[pos:length - 4]
self.recv_buf = self.recv_buf[length:]
if out_buf:
self.decrypt_packet_num += 1
return out_buf
def server_pre_encrypt(self, buf):
if self.raw_trans:
return buf
ret = b''
while len(buf) > self.unit_len:
ret += self.pack_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_data(buf)
return ret
def server_post_decrypt(self, buf):
if self.raw_trans:
return (buf, False)
self.recv_buf += buf
out_buf = b''
if not self.has_recv_header:
if len(self.recv_buf) < 6:
return (b'', False)
crc = struct.pack('<I', binascii.crc32(self.salt + self.server_info.key) & 0xFFFFFFFF)
if crc != self.recv_buf[:4]:
return self.not_match_return(self.recv_buf)
length = struct.unpack('>H', self.recv_buf[4:6])[0]
if length > 2048:
return self.not_match_return(self.recv_buf)
if length > len(self.recv_buf):
return (b'', False)
sha1data = hmac.new(self.server_info.recv_iv + self.server_info.key, self.recv_buf[:length - 10], hashlib.sha1).digest()[:10]
if sha1data != self.recv_buf[length - 10:length]:
logging.error('auth_sha1_v2 data uncorrect auth HMAC-SHA1')
return self.not_match_return(self.recv_buf)
pos = common.ord(self.recv_buf[6])
if pos < 255:
pos += 6
else:
pos = struct.unpack('>H', self.recv_buf[7:9])[0] + 6
out_buf = self.recv_buf[pos:length - 10]
if len(out_buf) < 12:
logging.info('auth_sha1_v2: too short, data %s' % (binascii.hexlify(self.recv_buf),))
return self.not_match_return(self.recv_buf)
client_id = struct.unpack('<Q', out_buf[:8])[0]
connection_id = struct.unpack('<I', out_buf[8:12])[0]
if self.server_info.data.insert(client_id, connection_id):
self.has_recv_header = True
out_buf = out_buf[12:]
self.client_id = client_id
self.connection_id = connection_id
else:
logging.info('auth_sha1_v2: auth fail, data %s' % (binascii.hexlify(out_buf),))
return self.not_match_return(self.recv_buf)
self.recv_buf = self.recv_buf[length:]
self.has_recv_header = True
sendback = False
while len(self.recv_buf) > 2:
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length >= 8192 or length < 7:
self.raw_trans = True
self.recv_buf = b''
if self.decrypt_packet_num == 0:
logging.info('auth_sha1_v2: over size')
return (b'E', False)
else:
raise Exception('server_post_decrype data error')
if length > len(self.recv_buf):
break
if struct.pack('<I', zlib.adler32(self.recv_buf[:length - 4]) & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
logging.info('auth_sha1_v2: checksum error, data %s' % (binascii.hexlify(self.recv_buf[:length]),))
self.raw_trans = True
self.recv_buf = b''
if self.decrypt_packet_num == 0:
return (b'E', False)
else:
raise Exception('server_post_decrype data uncorrect checksum')
pos = common.ord(self.recv_buf[2])
if pos < 255:
pos += 2
else:
pos = struct.unpack('>H', self.recv_buf[3:5])[0] + 2
out_buf += self.recv_buf[pos:length - 4]
self.recv_buf = self.recv_buf[length:]
if pos == length - 4:
sendback = True
if out_buf:
self.server_info.data.update(self.client_id, self.connection_id)
self.decrypt_packet_num += 1
return (out_buf, sendback)
class auth_sha1_v3(verify_base):
def __init__(self, method):
super(auth_sha1_v3, self).__init__(method)
self.recv_buf = b''
self.unit_len = 8100
self.decrypt_packet_num = 0
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_sha1_v3"
self.no_compatible_method = 'auth_sha1_v3'
def init_data(self):
return obfs_auth_v2_data()
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param)
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
def rnd_data(self, buf_size):
if buf_size > 1200:
return b'\x01'
if buf_size > 400:
rnd_data = os.urandom(common.ord(os.urandom(1)[0]) % 256)
else:
rnd_data = os.urandom(struct.unpack('>H', os.urandom(2))[0] % 512)
if len(rnd_data) < 128:
return common.chr(len(rnd_data) + 1) + rnd_data
else:
return common.chr(255) + struct.pack('>H', len(rnd_data) + 3) + rnd_data
def pack_data(self, buf):
data = self.rnd_data(len(buf)) + buf
data = struct.pack('>H', len(data) + 6) + data
adler32 = zlib.adler32(data) & 0xFFFFFFFF
data += struct.pack('<I', adler32)
return data
def pack_auth_data(self, buf):
if len(buf) == 0:
return b''
data = self.rnd_data(len(buf)) + buf
data_len = len(data) + 16
crc = binascii.crc32(self.salt + self.server_info.key + struct.pack('>H', data_len)) & 0xFFFFFFFF
data = struct.pack('<I', crc) + data
data = struct.pack('>H', data_len) + data
data += hmac.new(self.server_info.iv + self.server_info.key, data, hashlib.sha1).digest()[:10]
return data
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 = os.urandom(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', os.urandom(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 client_pre_encrypt(self, buf):
ret = b''
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_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_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) > 2:
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length >= 8192 or length < 7:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data error')
if length > len(self.recv_buf):
break
if struct.pack('<I', zlib.adler32(self.recv_buf[:length - 4]) & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data uncorrect checksum')
pos = common.ord(self.recv_buf[2])
if pos < 255:
pos += 2
else:
pos = struct.unpack('>H', self.recv_buf[3:5])[0] + 2
out_buf += self.recv_buf[pos:length - 4]
self.recv_buf = self.recv_buf[length:]
if out_buf:
self.decrypt_packet_num += 1
return out_buf
def server_pre_encrypt(self, buf):
if self.raw_trans:
return buf
ret = b''
while len(buf) > self.unit_len:
ret += self.pack_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_data(buf)
return ret
def server_post_decrypt(self, buf):
if self.raw_trans:
return (buf, False)
self.recv_buf += buf
out_buf = b''
if not self.has_recv_header:
if len(self.recv_buf) < 6:
return (b'', False)
crc = struct.pack('<I', binascii.crc32(self.salt + self.server_info.key + self.recv_buf[:2]) & 0xFFFFFFFF)
if crc != self.recv_buf[2:6]:
return self.not_match_return(self.recv_buf)
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length > len(self.recv_buf):
return (b'', False)
sha1data = hmac.new(self.server_info.recv_iv + self.server_info.key, self.recv_buf[:length - 10], hashlib.sha1).digest()[:10]
if sha1data != self.recv_buf[length - 10:length]:
logging.error('auth_sha1_v3 data uncorrect auth HMAC-SHA1')
return self.not_match_return(self.recv_buf)
pos = common.ord(self.recv_buf[6])
if pos < 255:
pos += 6
else:
pos = struct.unpack('>H', self.recv_buf[7:9])[0] + 6
out_buf = self.recv_buf[pos:length - 10]
if len(out_buf) < 12:
logging.info('auth_sha1_v3: too short, data %s' % (binascii.hexlify(self.recv_buf),))
return self.not_match_return(self.recv_buf)
utc_time = struct.unpack('<I', out_buf[:4])[0]
client_id = struct.unpack('<I', out_buf[4:8])[0]
connection_id = struct.unpack('<I', out_buf[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('auth_sha1_v3: wrong timestamp, time_dif %d, data %s' % (time_dif, binascii.hexlify(out_buf),))
return self.not_match_return(self.recv_buf)
elif self.server_info.data.insert(client_id, connection_id):
self.has_recv_header = True
out_buf = out_buf[12:]
self.client_id = client_id
self.connection_id = connection_id
else:
logging.info('auth_sha1_v3: auth fail, data %s' % (binascii.hexlify(out_buf),))
return self.not_match_return(self.recv_buf)
self.recv_buf = self.recv_buf[length:]
self.has_recv_header = True
sendback = False
while len(self.recv_buf) > 2:
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length >= 8192 or length < 7:
self.raw_trans = True
self.recv_buf = b''
if self.decrypt_packet_num == 0:
logging.info('auth_sha1_v3: over size')
return (b'E', False)
else:
raise Exception('server_post_decrype data error')
if length > len(self.recv_buf):
break
if struct.pack('<I', zlib.adler32(self.recv_buf[:length - 4]) & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
logging.info('auth_sha1_v3: checksum error, data %s' % (binascii.hexlify(self.recv_buf[:length]),))
self.raw_trans = True
self.recv_buf = b''
if self.decrypt_packet_num == 0:
return (b'E', False)
else:
raise Exception('server_post_decrype data uncorrect checksum')
pos = common.ord(self.recv_buf[2])
if pos < 255:
pos += 2
else:
pos = struct.unpack('>H', self.recv_buf[3:5])[0] + 2
out_buf += self.recv_buf[pos:length - 4]
self.recv_buf = self.recv_buf[length:]
if pos == length - 4:
sendback = True
if out_buf:
self.server_info.data.update(self.client_id, self.connection_id)
self.decrypt_packet_num += 1
return (out_buf, sendback)
class auth_sha1_v4(verify_base):
def __init__(self, method):
super(auth_sha1_v4, self).__init__(method)
self.recv_buf = b''
self.unit_len = 8100
self.decrypt_packet_num = 0
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_sha1_v4"
self.no_compatible_method = 'auth_sha1_v4'
def init_data(self):
return obfs_auth_v2_data()
def set_server_info(self, server_info):
self.server_info = server_info
try:
max_client = int(server_info.protocol_param)
except:
max_client = 64
self.server_info.data.set_max_client(max_client)
def rnd_data(self, buf_size):
if buf_size > 1200:
return b'\x01'
if buf_size > 400:
rnd_data = os.urandom(common.ord(os.urandom(1)[0]) % 256)
else:
rnd_data = os.urandom(struct.unpack('>H', os.urandom(2))[0] % 512)
if len(rnd_data) < 128:
return common.chr(len(rnd_data) + 1) + rnd_data
else:
return common.chr(255) + struct.pack('>H', len(rnd_data) + 3) + rnd_data
def pack_data(self, buf):
data = self.rnd_data(len(buf)) + buf
data_len = len(data) + 8
crc = binascii.crc32(struct.pack('>H', data_len)) & 0xFFFF
data = struct.pack('<H', crc) + data
data = struct.pack('>H', data_len) + data
adler32 = zlib.adler32(data) & 0xFFFFFFFF
data += struct.pack('<I', adler32)
return data
def pack_auth_data(self, buf):
if len(buf) == 0:
return b''
data = self.rnd_data(len(buf)) + buf
data_len = len(data) + 16
crc = binascii.crc32(struct.pack('>H', data_len) + self.salt + self.server_info.key) & 0xFFFFFFFF
data = struct.pack('<I', crc) + data
data = struct.pack('>H', data_len) + data
data += hmac.new(self.server_info.iv + self.server_info.key, data, hashlib.sha1).digest()[:10]
return data
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 = os.urandom(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', os.urandom(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 client_pre_encrypt(self, buf):
ret = b''
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_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_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:
crc = struct.pack('<H', binascii.crc32(self.recv_buf[:2]) & 0xFFFF)
if crc != self.recv_buf[2:4]:
raise Exception('client_post_decrypt data uncorrect crc')
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length >= 8192 or length < 7:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data error')
if length > len(self.recv_buf):
break
if struct.pack('<I', zlib.adler32(self.recv_buf[:length - 4]) & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
self.raw_trans = True
self.recv_buf = b''
raise Exception('client_post_decrypt data uncorrect checksum')
pos = common.ord(self.recv_buf[4])
if pos < 255:
pos += 4
else:
pos = struct.unpack('>H', self.recv_buf[5:7])[0] + 4
out_buf += self.recv_buf[pos:length - 4]
self.recv_buf = self.recv_buf[length:]
if out_buf:
self.decrypt_packet_num += 1
return out_buf
def server_pre_encrypt(self, buf):
if self.raw_trans:
return buf
ret = b''
while len(buf) > self.unit_len:
ret += self.pack_data(buf[:self.unit_len])
buf = buf[self.unit_len:]
ret += self.pack_data(buf)
return ret
def server_post_decrypt(self, buf):
if self.raw_trans:
return (buf, False)
self.recv_buf += buf
out_buf = b''
if not self.has_recv_header:
if len(self.recv_buf) <= 6:
return (b'', False)
crc = struct.pack('<I', binascii.crc32(self.recv_buf[:2] + self.salt + self.server_info.key) & 0xFFFFFFFF)
if crc != self.recv_buf[2:6]:
return self.not_match_return(self.recv_buf)
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length > len(self.recv_buf):
return (b'', False)
sha1data = hmac.new(self.server_info.recv_iv + self.server_info.key, self.recv_buf[:length - 10], hashlib.sha1).digest()[:10]
if sha1data != self.recv_buf[length - 10:length]:
logging.error('auth_sha1_v4 data uncorrect auth HMAC-SHA1')
return self.not_match_return(self.recv_buf)
pos = common.ord(self.recv_buf[6])
if pos < 255:
pos += 6
else:
pos = struct.unpack('>H', self.recv_buf[7:9])[0] + 6
out_buf = self.recv_buf[pos:length - 10]
if len(out_buf) < 12:
logging.info('auth_sha1_v4: too short, data %s' % (binascii.hexlify(self.recv_buf),))
return self.not_match_return(self.recv_buf)
utc_time = struct.unpack('<I', out_buf[:4])[0]
client_id = struct.unpack('<I', out_buf[4:8])[0]
connection_id = struct.unpack('<I', out_buf[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('auth_sha1_v4: wrong timestamp, time_dif %d, data %s' % (time_dif, binascii.hexlify(out_buf),))
return self.not_match_return(self.recv_buf)
elif self.server_info.data.insert(client_id, connection_id):
self.has_recv_header = True
out_buf = out_buf[12:]
self.client_id = client_id
self.connection_id = connection_id
else:
logging.info('auth_sha1_v4: auth fail, data %s' % (binascii.hexlify(out_buf),))
return self.not_match_return(self.recv_buf)
self.recv_buf = self.recv_buf[length:]
self.has_recv_header = True
sendback = False
while len(self.recv_buf) > 4:
crc = struct.pack('<H', binascii.crc32(self.recv_buf[:2]) & 0xFFFF)
if crc != self.recv_buf[2:4]:
self.raw_trans = True
logging.info('auth_sha1_v4: wrong crc')
if self.decrypt_packet_num == 0:
logging.info('auth_sha1_v4: wrong crc')
return (b'E', False)
else:
raise Exception('server_post_decrype data error')
length = struct.unpack('>H', self.recv_buf[:2])[0]
if length >= 8192 or length < 7:
self.raw_trans = True
self.recv_buf = b''
if self.decrypt_packet_num == 0:
logging.info('auth_sha1_v4: over size')
return (b'E', False)
else:
raise Exception('server_post_decrype data error')
if length > len(self.recv_buf):
break
if struct.pack('<I', zlib.adler32(self.recv_buf[:length - 4]) & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
logging.info('auth_sha1_v4: checksum error, data %s' % (binascii.hexlify(self.recv_buf[:length]),))
self.raw_trans = True
self.recv_buf = b''
if self.decrypt_packet_num == 0:
return (b'E', False)
else:
raise Exception('server_post_decrype data uncorrect checksum')
pos = common.ord(self.recv_buf[4])
if pos < 255:
pos += 4
else:
pos = struct.unpack('>H', self.recv_buf[5:7])[0] + 4
out_buf += self.recv_buf[pos:length - 4]
self.recv_buf = self.recv_buf[length:]
if pos == length - 4:
sendback = True
if out_buf:
self.server_info.data.update(self.client_id, self.connection_id)
self.decrypt_packet_num += 1
return (out_buf, sendback)
