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PufPufPuf

Compared to "traditional" password managers:

Pros:

- you don't have to store/transfer the encrypted vault (usually few kB in size)

Cons:

- can't rotate passwords if service needs you to change it (leak, periodic rotation etc.)

- it can't support two factor auth (for the manager itself)

- it does not support auto-fill (but theoretically can, through a browser extension)

- it's web only (harder to trust)

- if one of your passwords leak, it's as if your whole password vault leaked -- the attacker can just brute force "master passwords" until they arrive at the same password, after which they can generate all of your other passwords

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More cons: You still need to remember the exact spelling/variant of the URL, username and password-settings

I'll just stick with passwordstore.org and bitwarden/vaultwarden

Wdym "just brute force master passwords"? You use password + secret key to generate a password. Hardly brute-forceable.

Think about what would happen if everyone uses this tool and its known around the world.

Sure, if everyone used this, you'd have a copy of the algorithm used. But you're trying to solve for two unique variables, master password and secret key.

The basic principle still holds: "Kerckhoff's principle is the concept that a cryptographic system should be designed to be secure, even if all its details, except for the key, are publicly known" - which seems to be happening here (caveat emptor, also this should be self-hostable).

In other words, the security still hinges on the secret key, except you're not directly using the password Secr3tKey#website.example, but its hash. If everyone used this, the password strength would still be only dependent on the secret key strength, and wouldn't provide an easier avenue to a preimage (i.e. can't find the key otherwise than bruteforce; even though the explanation has some worrying confusion between hashing and encryption). Fairly straightforward, except some opsec concerns (e.g. "domain name lapses in a few years and Evil Operator starts logging the secret keys", or "site is unavailable for initial load, even though it does work offline afterwards")

If your password leaks from a single service, and I somehow know that you use this tool, I could then try all the combinations of the secret key until the service produces the same password as the one leaked. Now I have your secret key, and can derive your other passwords.

Notice how traditional password managers don't have this problem at all. If a password leaks, it tells you absolutely nothing about the other passwords.

That would still be very difficult I believe. The algorithm is CPU and Memory intensive because I'm using scrypt internally.

Yes but if I use a proper secret key, you won't be able to brute force it. You can't brute force anything 20+ chars in a billion years (inaccurate approximation)

You might also run into trouble with random password format requirements - too long, too short, not enough special characters, the wrong kind of special characters, ...

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