Almost every program that we run has access to the environment, so nothing stops them from curling our credentials to some nefarious server.
Why don’t we put credentials in files and then pass them to the programs that need them? Maybe coupled with some mechanism that prevents executables from reading any random file except those approved.
I have a rule that credentials in environment variables are to only ever be loaded as needed via some sort of secrets manager, optionally adding a wrapper script to do so transparently.
The whole point of passing secrets as environment variables is to avoid having things in files in plain and in known locations easy to scrape up by any malware.
Now we have people going full circle and slapping those into a
.envfile.
But how do you authenticate to your secret manager? How do you prevent evil scripts from also doing this?
I type my password, or on the work MacBook, TouchID. I’d imagine yubikeys would do too.
You could decrypt a GPG key-based file to do that.
No no see the credentials have been towed outside the environment.
The frontend fell off!
If you run a binary written with bad intentions, you’re doomed anyway.
This is the security model we have currently.
I suppose in a well configured Docker or Kubernetes environment this doesn’t matter that much. Also, in Kubernetes, “secrets” can be passed as read-only files.
CRED=$(fancy-get-cred) do-stuffdo-stuffhas${CRED}but nothing else does. wrap in a shell script.Global credentials are yuck
What’s the goal?
There are extra steps you can take to try to improve the security against malware, but using environment variables instead of hard coding isn’t really intended for that, I don’t think.
It’s just to stop accidental leaks with stuff like git and other code sharing.
CyberArk is a commercial product that attacks this problem space. It puts an agent process on the host next to your app. Only processes whose fingerprint matches those authorized to access a credential are allowed to fetch it. That fingerprint can be based on the host (known list of production hosts), the os user ID that owns the pid, the path to the executable for the pid, and probably a few more items.
Under that model your app just needs to know the environment that it wants (inject however you want) and the userid it wants to use. At runtime it reaches out to the local cyberark agent to obtain the password secret.