socks5

import asyncio

PORT = 1080


class SOCKS5Client:

    def __init__(self, reader:asyncio.StreamReader, writer:asyncio.StreamWriter):
        print('new client connection!')
        self.creader = reader
        self.cwriter = writer
        loop = asyncio.get_event_loop()
        asyncio.ensure_future(self._init(), loop=loop)

    async def _init(self):
        await self.auth()
        await self.catch_addr()
        await self.start_forwarding()

    async def auth(self):
        ver = await self.creader.read(1)
        nmeths = int.from_bytes(await self.creader.read(1) , 'little')
        meths = await self.creader.read(nmeths)
        print("auth request:\n  v: {}\n  nm: {}\n  m's: {}".format(ver, nmeths, meths))
        self.cwriter.write(b'\x05\x00')

    async def catch_addr(self):
        ver = await self.creader.read(1)
        cmd = int.from_bytes(await self.creader.read(1) , 'little')
        rsv = await self.creader.read(1)
        atype = int.from_bytes(await self.creader.read(1) , 'little')
        print('{} {} {} {}'.format(ver, cmd, rsv, atype))
        if atype == 1:
            addr_len = 4
            addr_raw = await self.creader.read(addr_len)
            addr = '.'.join(str(i) for i in addr_raw)
        elif atype == 3:
            addr_len = int.from_bytes(await self.creader.read(1) , 'little')
            addr_raw = await self.creader.read(addr_len)
            addr = addr_raw
        elif atype == 4:
            addr_len = 16
            addr_raw = await self.creader.read(addr_len)
            addr_hex = addr_raw.hex()
            addr = ':'.join(addr_hex[s:s+4] for s in range(0, 32, 4))
        port = int.from_bytes(await self.creader.read(2) , 'big')
        print(addr, port)
        if cmd == 1:
            self.sreader, self.swriter = await asyncio.open_connection(addr, port)
            bind_addr = self.swriter.get_extra_info('peername')
            print(bind_addr)
            response = b'\x05\x00\x00'
            response += atype.to_bytes(1, 'little')
            response += addr_raw
            response += port.to_bytes(2, 'big')
            print(response)
            self.cwriter.write(response)
            await self.cwriter.drain()

    async def start_forwarding(self):
        loop = asyncio.get_event_loop()
        asyncio.ensure_future(self._forwarding(self.sreader, self.cwriter), loop=loop)
        asyncio.ensure_future(self._forwarding(self.creader, self.swriter), loop=loop)

    async def _forwarding(self, reader, writer):
        while True:
            writer.write(await reader.read(64))
            await writer.drain()
            await asyncio.sleep(0.01)

    async def drop(self):
        pass


if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    loop.run_until_complete(asyncio.start_server(SOCKS5Client, port=PORT, loop=loop))
    loop.run_forever()