Source code and details: https://github.com/umutcamliyurt/PortTripper

How it works

On startup PortTripper:

  1. Scans the configured port range and builds a whitelist of ports already in use by real services (first run only).
  2. Draws a cryptographically random sample of up to -maxports ports from the range, excluding whitelisted ports. Using crypto/rand for selection means the open set is unpredictable to an attacker even if they know the configured range.
  3. Binds TCP and UDP listeners on every chosen port.
  4. On TCP: accepts connections, holds them open for a configurable duration, then drops them, wasting the scanner’s threads and file descriptors.
  5. On UDP: reads and discards datagrams without replying, so ports appear open|filtered to scanners rather than closed.

All real service ports are untouched because they are already bound before PortTripper starts, and the auto-generated whitelist tells PortTripper to skip them.

  • atzanteol@sh.itjust.worksEnglish
    1·
    4 hours ago

    I’m not sure you understand what a “honeypot” is. The entire point is to set it up somewhere public so that people try to scan and connect to it. It doesn’t protect anything. It’s designed to try to slow-down attackers who probe random systems.

    • mic_check_one_two@lemmy.dbzer0.comEnglish
      1·
      2 hours ago

      I’m not sure you understand what a honeypot is. You only listed one kind, and it is arguably the most useless kind. I don’t care about what happens outside of my WAN, because that is what a firewall is for. I only care about what happens inside the firewall. A good honeypot will act as an early warning system for a breach. It is an attractive target for people who are looking to spread to other devices on the network.

      If an attacker gets into your network, the honeypot is designed to act as an attractive target and alert you when it gets hit. I don’t care if people try to scan my WAN ports. Bots do that all the time. It’s basically a given. But with a reverse proxy, you’re only opening ports 80 and 443. Those are basically useless for an attacker, because it only tells them that you’re running something on http and https. And that could be anything.

      If I’m running a honeypot, it’s going to be to alert me if something gets breached. It’s going to run on my LAN, not my WAN. If something on my LAN suddenly starts scanning all of my server’s ports, it’s because that thing is a rogue device/attacker. I’m not interested in stalling them. I want to be automatically alerted and to completely shut them out. That’s what a good honeypot will do. A bad honeypot just wastes time and resources, instead of alerting me to the potential breach.