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@ -23,7 +23,9 @@ import hashlib |
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import logging |
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import binascii |
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import base64 |
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import time |
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import datetime |
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import random |
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import struct |
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import zlib |
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@ -38,9 +40,13 @@ def create_verify_obfs(method): |
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def create_verify_deflate(method): |
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return verify_deflate(method) |
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def create_auth_obfs(method): |
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return auth_simple(method) |
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obfs_map = { |
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'verify_simple': (create_verify_obfs,), |
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'verify_deflate': (create_verify_deflate,), |
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'auth_simple': (create_auth_obfs,), |
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} |
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def match_begin(str1, str2): |
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@ -49,7 +55,7 @@ def match_begin(str1, str2): |
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return True |
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return False |
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class sub_encode_obfs(object): |
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class obfs_verify_data(object): |
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def __init__(self): |
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self.sub_obfs = None |
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@ -60,7 +66,7 @@ class verify_base(plain.plain): |
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self.sub_obfs = None |
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def init_data(self): |
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return sub_encode_obfs() |
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return obfs_verify_data() |
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def set_server_info(self, server_info): |
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try: |
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@ -283,3 +289,248 @@ class verify_deflate(verify_base): |
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self.decrypt_packet_num += 1 |
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return out_buf |
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class client_queue(object): |
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def __init__(self, begin_id): |
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self.front = begin_id |
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self.back = begin_id |
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self.alloc = {} |
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self.enable = True |
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self.last_update = time.time() |
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def update(self): |
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self.last_update = time.time() |
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def is_active(self): |
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return time.time() - self.last_update < 60 * 3 |
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def re_enable(self, connection_id): |
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self.enable = True |
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self.alloc = {} |
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self.front = connection_id |
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self.back = connection_id |
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def insert(self, connection_id): |
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self.update() |
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if not self.enable: |
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logging.warn('auth_simple: not enable') |
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return False |
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if connection_id < self.front: |
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logging.warn('auth_simple: duplicate id') |
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return False |
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if not self.is_active(): |
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self.re_enable(connection_id) |
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if connection_id > self.front + 0x4000: |
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logging.warn('auth_simple: wrong id') |
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return False |
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if connection_id in self.alloc: |
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logging.warn('auth_simple: duplicate id 2') |
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return False |
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if self.back <= connection_id: |
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self.back = connection_id + 1 |
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self.alloc[connection_id] = 1 |
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while (self.front in self.alloc) or self.front + 0x1000 < self.back: |
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if self.front in self.alloc: |
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del self.alloc[self.front] |
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self.front += 1 |
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return True |
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class obfs_auth_data(object): |
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def __init__(self): |
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self.sub_obfs = None |
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self.client_id = {} |
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self.startup_time = int(time.time() - 30) & 0xFFFFFFFF |
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self.local_client_id = b'' |
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self.connection_id = 0 |
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def update(self, client_id, connection_id): |
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if client_id in self.client_id: |
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self.client_id[client_id].update() |
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def insert(self, client_id, connection_id): |
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max_client = 16 |
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if client_id not in self.client_id or not self.client_id[client_id].enable: |
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active = 0 |
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for c_id in self.client_id: |
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if self.client_id[c_id].is_active(): |
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active += 1 |
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if active >= max_client: |
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logging.warn('auth_simple: max active clients exceeded') |
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return False |
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if len(self.client_id) < max_client: |
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if client_id not in self.client_id: |
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self.client_id[client_id] = client_queue(connection_id) |
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else: |
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self.client_id[client_id].re_enable(connection_id) |
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return self.client_id[client_id].insert(connection_id) |
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keys = self.client_id.keys() |
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random.shuffle(keys) |
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for c_id in keys: |
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if not self.client_id[c_id].is_active() and self.client_id[c_id].enable: |
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if len(self.client_id) >= 256: |
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del self.client_id[c_id] |
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else: |
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self.client_id[c_id].enable = False |
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if client_id not in self.client_id: |
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self.client_id[client_id] = client_queue(connection_id) |
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else: |
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self.client_id[client_id].re_enable(connection_id) |
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return self.client_id[client_id].insert(connection_id) |
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logging.warn('auth_simple: no inactive client [assert]') |
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return False |
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else: |
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return self.client_id[client_id].insert(connection_id) |
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class auth_simple(verify_base): |
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def __init__(self, method): |
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super(auth_simple, self).__init__(method) |
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self.recv_buf = b'' |
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self.unit_len = 8100 |
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self.decrypt_packet_num = 0 |
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self.raw_trans = False |
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self.has_sent_header = False |
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self.has_recv_header = False |
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self.client_id = 0 |
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self.connection_id = 0 |
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def init_data(self): |
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return obfs_auth_data() |
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def pack_data(self, buf): |
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if len(buf) == 0: |
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return b'' |
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rnd_data = os.urandom(common.ord(os.urandom(1)[0]) % 16) |
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data = common.chr(len(rnd_data) + 1) + rnd_data + buf |
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data = struct.pack('>H', len(data) + 6) + data |
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crc = (0xffffffff - binascii.crc32(data)) & 0xffffffff |
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data += struct.pack('<I', crc) |
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return data |
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def auth_data(self): |
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utc_time = int(time.time()) & 0xFFFFFFFF |
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if self.server_info.data.connection_id > 0xFF000000: |
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self.server_info.data.local_client_id = b'' |
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if not self.server_info.data.local_client_id: |
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self.server_info.data.local_client_id = os.urandom(4) |
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logging.debug("local_client_id %s" % (binascii.hexlify(self.server_info.data.local_client_id),)) |
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self.server_info.data.connection_id = struct.unpack('<I', os.urandom(4))[0] & 0xFFFFFF |
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self.server_info.data.connection_id += 1 |
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return b''.join([struct.pack('<I', utc_time), |
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self.server_info.data.local_client_id, |
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struct.pack('<I', self.server_info.data.connection_id)]) |
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def client_pre_encrypt(self, buf): |
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ret = b'' |
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if not self.has_sent_header: |
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datalen = max(len(buf), common.ord(os.urandom(1)[0]) % 32 + 4) |
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ret += self.pack_data(self.auth_data() + buf[:datalen]) |
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buf = buf[datalen:] |
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self.has_sent_header = True |
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while len(buf) > self.unit_len: |
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ret += self.pack_data(buf[:self.unit_len]) |
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buf = buf[self.unit_len:] |
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ret += self.pack_data(buf) |
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return ret |
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def client_post_decrypt(self, buf): |
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if self.raw_trans: |
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return buf |
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self.recv_buf += buf |
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out_buf = b'' |
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while len(self.recv_buf) > 2: |
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length = struct.unpack('>H', self.recv_buf[:2])[0] |
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if length >= 8192: |
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self.raw_trans = True |
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self.recv_buf = b'' |
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if self.decrypt_packet_num == 0: |
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return None |
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else: |
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raise Exception('server_post_decrype data error') |
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if length > len(self.recv_buf): |
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break |
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if (binascii.crc32(self.recv_buf[:length]) & 0xffffffff) != 0xffffffff: |
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self.raw_trans = True |
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self.recv_buf = b'' |
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if self.decrypt_packet_num == 0: |
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return None |
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else: |
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raise Exception('server_post_decrype data uncorrect CRC32') |
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pos = common.ord(self.recv_buf[2]) + 2 |
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out_buf += self.recv_buf[pos:length - 4] |
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self.recv_buf = self.recv_buf[length:] |
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if out_buf: |
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self.decrypt_packet_num += 1 |
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return out_buf |
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def server_pre_encrypt(self, buf): |
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ret = b'' |
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while len(buf) > self.unit_len: |
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ret += self.pack_data(buf[:self.unit_len]) |
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buf = buf[self.unit_len:] |
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ret += self.pack_data(buf) |
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return ret |
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def server_post_decrypt(self, buf): |
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if self.raw_trans: |
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return buf |
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self.recv_buf += buf |
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out_buf = b'' |
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while len(self.recv_buf) > 2: |
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length = struct.unpack('>H', self.recv_buf[:2])[0] |
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if length >= 8192: |
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self.raw_trans = True |
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self.recv_buf = b'' |
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if self.decrypt_packet_num == 0: |
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logging.info('auth_simple: over size') |
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return b'E' |
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else: |
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raise Exception('server_post_decrype data error') |
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if length > len(self.recv_buf): |
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break |
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if (binascii.crc32(self.recv_buf[:length]) & 0xffffffff) != 0xffffffff: |
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logging.info('auth_simple: crc32 error, data %s' % (binascii.hexlify(self.recv_buf[:length]),)) |
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self.raw_trans = True |
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self.recv_buf = b'' |
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if self.decrypt_packet_num == 0: |
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return b'E' |
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else: |
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raise Exception('server_post_decrype data uncorrect CRC32') |
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pos = common.ord(self.recv_buf[2]) + 2 |
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out_buf += self.recv_buf[pos:length - 4] |
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if not self.has_recv_header: |
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if len(out_buf) < 12: |
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self.raw_trans = True |
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self.recv_buf = b'' |
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logging.info('auth_simple: too short') |
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return b'E' |
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utc_time = struct.unpack('<I', out_buf[:4])[0] |
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client_id = struct.unpack('<I', out_buf[4:8])[0] |
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connection_id = struct.unpack('<I', out_buf[8:12])[0] |
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time_dif = common.int32((int(time.time()) & 0xffffffff) - utc_time) |
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if time_dif < 60 * -3 or time_dif > 60 * 3 or common.int32(utc_time - self.server_info.data.startup_time) < 0: |
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self.raw_trans = True |
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self.recv_buf = b'' |
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logging.info('auth_simple: wrong timestamp, time_dif %d, data %s' % (time_dif, binascii.hexlify(out_buf),)) |
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return b'E' |
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elif self.server_info.data.insert(client_id, connection_id): |
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self.has_recv_header = True |
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out_buf = out_buf[12:] |
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self.client_id = client_id |
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self.connection_id = connection_id |
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else: |
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self.raw_trans = True |
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self.recv_buf = b'' |
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logging.info('auth_simple: auth fail, data %s' % (binascii.hexlify(out_buf),)) |
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return b'E' |
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self.recv_buf = self.recv_buf[length:] |
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if out_buf: |
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self.server_info.data.update(self.client_id, self.connection_id) |
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self.decrypt_packet_num += 1 |
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return out_buf |
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