def start_channel(self):
logging.info("connect to %s:%d from %s:%d use %s:%d",
self.remote_address[0], self.remote_address[1],
self.local_address[0], self.local_address[1],
self.shadow_address[0], self.shadow_address[1])
try:
start = time.time()
self.remote_stream = yield tcpclient.TCPClient().connect(
host=self.shadow_address[0], port=self.shadow_address[1])
if self.stat_cb:
self.stat_cb(self.shadow_address[0], time.time() - start)
except IOError:
logging.warning("connect shadow %s:%d failed",
self.shadow_address[0], self.shadow_address[1])
if self.stat_cb:
self.stat_cb(self.shadow_address[0], -1)
self.destroy()
raise gen.Return()
try:
data = common.chr(self.address_type)
if self.address_type == SOCKS5_ADDRESS_TYPE_HOST:
data += common.chr(len(self.remote_address[0]))
data += self.remote_address[0] + struct.pack(
"!H", self.remote_address[1])
self.remote_stream.write(self.encryptor.encrypt(data))
self.local_stream.read_until_close(
streaming_callback=self._read_from_local)
self.remote_stream.read_until_close(
streaming_callback=self._read_from_remote)
# self.destroy()
except tornado.iostream.StreamClosedError:
logging.warning("stream is closed")
def rnd_data(self, buf_size, full_buf_size):
data_len = self.rnd_data_len(buf_size, full_buf_size)
if data_len < 128:
return common.chr(data_len + 1) + os.urandom(data_len)
return common.chr(255) + struct.pack(
'<H', data_len + 1) + os.urandom(data_len - 2)
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 build_address(address):
address = address.strip(b'.')
labels = address.split(b'.')
results = []
for label in labels:
l = len(label)
if l > 63:
return None
results.append(common.chr(l))
results.append(label)
results.append(b'\0')
return b''.join(results)
def build_address(address):
address = address.strip(b'.')
labels = address.split(b'.')
results = []
for label in labels:
l = len(label)
if l > 63:
return None
results.append(common.chr(l))
results.append(label)
results.append(b'\0')
return b''.join(results)
def nonce_increment(nonce, nlen):
"""
Increase nonce by 1 in little endian
From libsodium sodium_increment():
for (; i < nlen; i++) {
c += (uint_fast16_t) n[i];
n[i] = (unsigned char) c;
c >>= 8;
}
:param nonce: string_buffer nonce
:param nlen: nonce length
:return: nonce plus by 1
"""
c = 1
i = 0
# n = create_string_buffer(nlen)
while i < nlen:
c += ord(nonce[i])
nonce[i] = chr(c & 0xFF)
c >>= 8
i += 1
return # n.raw
def _handle_stage_addr(self, data):
try:
if self._is_local:
cmd = common.ord(data[1])
if cmd == CMD_UDP_ASSOCIATE:
logging.debug('UDP associate')
if self._local_sock.family == socket.AF_INET6:
# 0x4 ipv6
header = b'\x05\x00\x00\x04'
else:
# 0x1 ipv4
header = b'\x05\x00\x00\x01'
addr, port = self._local_sock.getsockname()[:2]
addr_to_send = socket.inet_pton(self._local_sock.family,
addr)
port_to_send = struct.pack('>H', port)
# 响应 CMD_UDP_ASSOCIATE 命令，告诉客户端udp地址
self._write_to_sock(header + addr_to_send + port_to_send,
self._local_sock)
self._stage = STAGE_UDP_ASSOC
# just wait for the client to disconnect
# 这里已经返回
return
elif cmd == CMD_CONNECT:
# just trim VER CMD RSV
# 跨过socks5前面3字节，后面字节与socks5兼容，不过在addrtype字段加入了ota验证
data = data[3:]
else:
# bing命令？
logging.error('unknown command %d', cmd)
self.destroy()
return
# 服务器端初始时候解析包头，下面也是socks5请求时从第三个字节开始的地址数据
# 这里ssserver刚好兼容剩下的socks5的请求头
header_result = parse_header(data)
if header_result is None:
raise Exception('can not parse header')
addrtype, remote_addr, remote_port, header_length = header_result
# 经常看到的服务器接收到请求时候打印的日志
logging.info('connecting %s:%d from %s:%d' %
(common.to_str(remote_addr), remote_port,
self._client_address[0], self._client_address[1]))
if self._is_local is False:
# spec https://shadowsocks.org/en/spec/one-time-auth.html
# 验证ota正确性
if self._ota_enable or addrtype & ADDRTYPE_AUTH:
self._ota_enable = True
if len(data) < header_length + ONETIMEAUTH_BYTES:
logging.warn('one time auth header is too short')
return None
offset = header_length + ONETIMEAUTH_BYTES
# header后的一段hash值, 10字节one-time-auth
_hash = data[header_length:offset]
_data = data[:header_length]
# iv+key
key = self._encryptor.decipher_iv + self._encryptor.key
# 验证是否允许
if onetimeauth_verify(_hash, _data, key) is False:
logging.warn('one time auth fail')
self.destroy()
return
header_length += ONETIMEAUTH_BYTES
self._remote_address = (common.to_str(remote_addr), remote_port)
# pause reading 上送数据
self._update_stream(STREAM_UP, WAIT_STATUS_WRITING)
self._stage = STAGE_DNS
if self._is_local:
# 客户端
# forward address to remote
# 告诉浏览器，socks5验证成功
self._write_to_sock((b'\x05\x00\x00\x01'
b'\x00\x00\x00\x00\x10\x10'),
self._local_sock)
# spec https://shadowsocks.org/en/spec/one-time-auth.html
# ATYP & 0x10 == 1, then OTA is enabled.
if self._ota_enable:
# 自己实现的ota，在浏览器之类发来的socks5请求头部的addrtype中加入ADDRTYPE_AUTH
# 然后发往ssserver，修改第一字节，实际是socks5头部的第3字节
data = common.chr(addrtype | ADDRTYPE_AUTH) + data[1:]
key = self._encryptor.cipher_iv + self._encryptor.key
# 附在数据尾部? 这里的data是socks5请求报文第三字节之后的数据
data += onetimeauth_gen(data, key)
# 加密
data_to_send = self._encryptor.encrypt(data)
self._data_to_write_to_remote.append(data_to_send)
# notice here may go into _handle_dns_resolved directly
# 选择一个ssserver发送数据
self._dns_resolver.resolve(self._chosen_server[0],
self._handle_dns_resolved)
else:
# 服务端
if self._ota_enable:
# 过滤前面的远程地址和ota hmac-sha1头
data = data[header_length:]
self._ota_chunk_data(data,
self._data_to_write_to_remote.append)
elif len(data) > header_length:
# 过滤掉头部还有数据要发送
self._data_to_write_to_remote.append(data[header_length:])
# notice here may go into _handle_dns_resolved directly
# 解析dns之后remote_sock连接远端web站点
self._dns_resolver.resolve(remote_addr,
self._handle_dns_resolved)
except Exception as e:
self._log_error(e)
if self._config['verbose']:
traceback.print_exc()
self.destroy()
def _ota_chunk_data_gen(self, key, iv, data):
data = common.chr(common.ord(data[0]) | ADDRTYPE_AUTH) + data[1:]
key = iv + key
return data + onetimeauth_gen(data, key)
def _handle_stage_addr(self, data):
if self._is_local:
if self._is_tunnel:
# add ss header to data
tunnel_remote = self.tunnel_remote
tunnel_remote_port = self.tunnel_remote_port
data = common.add_header(tunnel_remote, tunnel_remote_port,
data)
else:
cmd = common.ord(data[1])
if cmd == CMD_UDP_ASSOCIATE:
logging.debug('UDP associate')
if self._local_sock.family == socket.AF_INET6:
header = b'\x05\x00\x00\x04'
else:
header = b'\x05\x00\x00\x01'
addr, port = self._local_sock.getsockname()[:2]
addr_to_send = socket.inet_pton(self._local_sock.family,
addr)
port_to_send = struct.pack('>H', port)
self._write_to_sock(header + addr_to_send + port_to_send,
self._local_sock)
self._stage = STAGE_UDP_ASSOC
# just wait for the client to disconnect
return
elif cmd == CMD_CONNECT:
# just trim VER CMD RSV
data = data[3:]
else:
logging.error('unknown command %d', cmd)
self.destroy()
return
header_result = parse_header(data)
if header_result is None:
raise Exception('can not parse header')
addrtype, remote_addr, remote_port, header_length = header_result
logging.info('connecting %s:%d from %s:%d' %
(common.to_str(remote_addr), remote_port,
self._client_address[0], self._client_address[1]))
#logging.info('connecting %s:%d from %s:%d, %s' %
# (common.to_str(remote_addr), remote_port,
# self._client_address[0], self._client_address[1], data))
if self._is_local is False:
# spec https://shadowsocks.org/en/spec/one-time-auth.html
self._ota_enable_session = addrtype & ADDRTYPE_AUTH
if self._ota_enable and not self._ota_enable_session:
logging.warn('client one time auth is required')
return
if self._ota_enable_session:
if len(data) < header_length + ONETIMEAUTH_BYTES:
logging.warn('one time auth header is too short')
return None
offset = header_length + ONETIMEAUTH_BYTES
_hash = data[header_length:offset]
_data = data[:header_length]
key = self._cryptor.decipher_iv + self._cryptor.key
if onetimeauth_verify(_hash, _data, key) is False:
logging.warn('one time auth fail')
self.destroy()
return
header_length += ONETIMEAUTH_BYTES
self._remote_address = (common.to_str(remote_addr), remote_port)
# pause reading
self._update_stream(STREAM_UP, WAIT_STATUS_WRITING)
self._stage = STAGE_DNS
if self._is_local:
# jump over socks5 response
if not self._is_tunnel:
# forward address to remote
self._write_to_sock((b'\x05\x00\x00\x01'
b'\x00\x00\x00\x00\x10\x10'),
self._local_sock)
# spec https://shadowsocks.org/en/spec/one-time-auth.html
# ATYP & 0x10 == 0x10, then OTA is enabled.
if self._ota_enable_session:
data = common.chr(addrtype | ADDRTYPE_AUTH) + data[1:]
key = self._cryptor.cipher_iv + self._cryptor.key
_header = data[:header_length]
sha110 = onetimeauth_gen(data, key)
data = _header + sha110 + data[header_length:]
data_to_send = self._cryptor.encrypt(data)
self._data_to_write_to_remote.append(data_to_send)
# notice here may go into _handle_dns_resolved directly
self._dns_resolver.resolve(self._chosen_server[0],
self._handle_dns_resolved)
else:
if self._ota_enable_session:
data = data[header_length:]
self._ota_chunk_data(data,
self._data_to_write_to_remote.append)
elif len(data) > header_length:
self._data_to_write_to_remote.append(data[header_length:])
# notice here may go into _handle_dns_resolved directly
self._dns_resolver.resolve(remote_addr, self._handle_dns_resolved)
