SSH tarpit server which accepts requests but stalls them with infinite SSH banners before accepting authentication.

ssh-tarpit.py

#!/usr/bin/env python3

import asyncio
import logging
from random import randint


LOG = logging.getLogger(__name__)

HOST = "0.0.0.0"
PORT = 2222

DELAY = 10
LENGTH = 32


async def handler(_, writer):
    ip, port = writer.get_extra_info("peername")
    LOG.info(f"%s:%d connected", ip, port)
    count = 0
    try:
        while True:
            await asyncio.sleep(DELAY)
            count += 1
            LOG.debug("%s:%d receiving line %d", ip, port, count)
            writer.write(b"%x\r\n" % randint(0, 2 ** LENGTH))
            await writer.drain()
    except ConnectionResetError:
        LOG.info(f"%s:%d disconnected (%d lines)", ip, port, count)
    except TimeoutError:
        LOG.info(f"%s:%d timed out (%d lines)", ip, port, count)
    except Exception:
        LOG.exception(f"%s:%d caused exception (%d lines)", ip, port, count)

async def main():
    server = await asyncio.start_server(handler, HOST, PORT)
    async with server:
        LOG.info("Listening at %s:%d", HOST, PORT)
        await server.serve_forever()


if __name__ == "__main__":

    import sys

    logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(message)s")
    try:
        PORT = int(sys.argv[1])
        DELAY = float(sys.argv[2])
        LENGTH = int(sys.argv[3])
    except IndexError:
        pass

    asyncio.run(main())