Say you have a script or something that gets run in cron/task scheduler and it needs a password… say to ssh to a raspberry pi elsewhere in your house.
How do you save that password in a way that automation can access it?
Some ideas:
- Plaintext file. Not a fan because its sitting unencrypted on the box somewhere.
- Environment variable. Not a fan because its still unencrypted somewhere to someone on the box (albeit likely the same user or an admin).
- A secrets manager. If I use something locally like hashicorp vault or infisical, I can get to a point where a cli/api call gets the password. Though in this case I still need a vault password/secret to get my password. So I fall back to needing one of the above to get this to work.
If the secrets manager is easily available, the secret to get into the secrets manager is available as well leading to a feeling of security by obscurity.
If someone breaks into my system via SSH/etc. then they can get the passwords either way.
… How do people normally do this? I’m not sure I actually get anything out of a secrets manager if its local and I have the disk itself encrypted before login.
What actually makes sense at a personal/home scale?
(Edit: I know using SSH key probably is better for getting to the raspberry pi, but still the question is the same idea).
Ideally, a secrets manager that you can unlock once and then give access to the secrets. You can either unlock it at boot by entering the password, or if you have a TPM, you can also do something to encrypt the main key with the TPM and then when you boot up, if all secure boot checks passes, you can decrypt that key with the TPM and unlock the secrets manager in question.
You can also store the secrets on another machine that only exposes say, the Vault API. Like a dedicated Raspberry Pi just for this function where remote access is disabled and everything, it only serves secrets. That way, you can trust the Vault logs to know when each secret was accessed and find anomalies this way.
If someone breaks in via SSH or whatever, your security already fell apart. That box can no longer be trusted for anything. Especially if they breached the root account. Doesn’t matter how big the fortress is, if you’re inside, it’s game over, it’s time to evaluate the damages and clean up.