I prefer to pass secrets between programs through standard input

(utcc.utoronto.ca)

60 points | by ingve 12 hours ago

7 comments

  • kevin_thibedeau 11 hours ago
    > Unfortunately you're using a browser (or client library) that my anti-crawler precautions consider suspicious because it's sending inconsistent values for Sec-CH-UA-* HTTP request headers...

    The world doesn't exclusively use Chrome. Nice to see even the nerds are contributing to the closed web.

    • Alex-Programs 10 hours ago
      It's also moaning about me coming from a datacentre IP (proxy) with some vague complaints about load introduced by AI crawlers. I think this guy treats "protecting" his site as a hobby.
    • edwcross 11 hours ago
      I'm using Firefox and didn't see that message.
      • swiftcoder 11 hours ago
        Nor on Safari. I wonder what exotic browser the parent is using?
        • ErroneousBosh 11 hours ago
          Doesn't appear to be Firefox, Chrome, Chromium, Edge, or Falkon on Linux, doesn't appear to be Falkon on Haiku.

          I also wonder what they're using and where can I get some so I can break stuff too?

    • 7e 15 minutes ago
      Not working well with something that doesn't conform to the WICG User-Agent Client Hints specification is an interesting definition of "closed." More like, "I have standards." And it's hardly closed if you can get the information by using literally almost any other client.
    • efilife 11 hours ago
      I am on ungoogled chromium and I see this
    • mhitza 11 hours ago
      Also site is not accessible via Mullvad VPN.
      • figmert 10 hours ago
        I am on Mullvad (at the router), and I am able to connect.
        • mhitza 10 hours ago
          Checks out, it was my preferred exit node.
          • sn9 4 hours ago
            I had to disconnect Mullvad to load the page.
      • zxcvasd 11 hours ago
        [dead]
    • zxcvasd 11 hours ago
      [dead]
  • azornathogron 10 hours ago
    For one of my projects my server needs a private key, and it reads this from a file descriptor on startup and then closes the fd. The fd is set up by the systemd unit, which is also configured to restrict filesystem access for the server. So the server reads a key from a file that is never visible in its mount namespace.
    • computerfriend 10 hours ago
      I do something similar with LoadCredential and it is quite amazing, especially when you want to run the application as a dynamic user.
    • infogulch 3 hours ago
      If you keep the fd open maybe you could read refreshed secrets through it for live secret rotation.
  • juancn 11 hours ago
    I used to do that, I had a sort of IDE that launched a local server, bound to localhost.

    The launching process would send a random password through stdin to the child after launch, and the child would use that to authenticate the further RPC calls.

    It's surprisingly hard to intercept a process' stdin stream.

  • Dwedit 11 hours ago
    I haven't actually tested this, but aren't the input and output handles exposed on /proc/? What's stopping another process from seeing everything?
    • Lex-2008 11 hours ago
      not a Linux expert, but I believe that at the very least it's time sensitive: after consumer process reads it, it's gone from the pipe. Unlike env vars and cli argument that stay there.
    • trashb 11 hours ago
      Yes pipes are exposed /proc/$pid/fd/$thePipeFd with user permissions [0].

      Additionally command line parameters are always readable /proc/$YOUR_PROCESS_PID/cmdline [1]

      There are workarounds but it's fragile. You may accept the risks and in that case it can work for you but I wouldn't recommend it for "general security". Seems it wouldn't be considered secure if everyone did it this way, therefore is it security through obscurity?

      [0] https://unix.stackexchange.com/questions/156859/is-the-data-...

      [1] https://stackoverflow.com/questions/3830823/hiding-secret-fr...

    • Tajnymag 11 hours ago
      I guess the kernel is stopping that. I don't think permission wise you'd have the privileges to read someone else's stdin/out.
  • pvtmert 11 hours ago
    Interesting approach. I like Docker/Kubernetes way of secret mounts where you can limit user/group permissions too.

    Meanwhile, I was an avid user of the echo secret | ssh consume approach, specifically for the kerberos authentication.

    In my workflow, I saved the kerberos password to the macOS keychain, where kinit --use-keychain authenticated me seamlessly. However this wasn't the case for remote machines.

    Therefore, I have implemented a quick script that is essentially

        security find-generic-password -a "kerberos" -s "kerberos-password" -w | ssh user@host kinit user@REALM
    
    Which served me really good for the last 4~years.
  • blibble 10 hours ago
    linux has a key api that works pretty well

    man keyctl

  • stale-labs 11 hours ago
    [flagged]
    • reliefcrew 10 hours ago
      > The main practical win is that cmd args show up in `ps aux` for anyone on the system to see, whereas stdin keeps it off that list.

      For those interested, re-mounting /proc with hidepid can prevent this:

          `mount -o remount,rw,hidepid=2 /proc`