grongor / knock

Simple python port knocking client

Hello! 👋

I'm a backend/system software developer since ever (professionally since circa 2008), currently working for CDN77.

I love to dive deep into things most people even don't know to exist and write future-proof and performant code, mostly in Go, PHP, Java, and Python.

I'd like to add Rust to this repertoire, I just didn't find enough time yet. 😞

I know my way around Linux quite well (I consider myself a DevOps guy), definitely better than the average developer, and I can write all kinds of incredibly scary shell scripts.

I designed and managed complete CI/CD environments/pipelines/templates (TeamCity, GitLab CI, GitHub Actions, Jenkins, ...), wrote a custom BGP server (and complete monitoring solution around it), helped build a monitoring/management application that handles thousands of devices (servers, routers, DWDMs, ...) and all the data they produce/gather (critical tool for the network team), and...many other things I can't remember right now. 🙂

I actively contribute to the OSS community and maintain a few repositories myself.

knock's Issues

Add support for knockd one-time sequence files

I've added the support to my own fork: https://github.com/pro-src/knock

Generates sequences using a CSPRNG and saves them in a knockd compatible file
Reads one-time sequences from a file

Only recognisies IPv6 addresses, not IPv6 resolving hostnames

@grongor
I suggest an adjustment something like:

-   self.host = args.host
-   self.is_ipv6 = args.host.find(':') != -1
+   self.addr = socket.getaddrinfo(args.host, 0)
+   self.is_ipv6 = self.addr[0][0] == socket.AF_INET6

-   s.connect_ex((self.host, port))
+   s.connect_ex((self.addr[0][4][0], port))

The UDP option not useful without call to s.send()

@grongor
For UDP s.send(...) needed between select.select(...) and s.close(...)

    select.select([s], [s], [s], self.timeout)
+   if self.use_udp: s.send(bytes('', 'utf8'))
    s.close()

add some feature

allow user to chose what protocol to knock in each port

I have implemented it, see pull requests.

IPv6

Returning tuple from socket.getaddrinfo() too long using IPv6.

Working for IPv4 / IPv6:

        self.address_family, _, _, _, addrinfo = socket.getaddrinfo(
                host=args.host,
                port=None,
                flags=socket.AI_ADDRCONFIG
            )[0]
        
        self.ip_address = addrinfo[0]

How to hide port usage

Hello i am a noob please can you explain how can i use Knock to hide port usage, thank you

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