Show HN: Correct Horse Battery Staple password generator (opens in new tab)

I'm curious how practical an RNG attack actually is here (which absolutely isn't meant to serve as criticism of your surfacing the issue!).

In any case, I expect it's much harder than a random "free password gen!" website saving results on the sly (... which is meant to be mild criticism of your framing, but not your recommendation :-p).

shuf uses randint(), which defaults to /dev/urandom as the nonce source:

https://github.com/coreutils/coreutils/blob/v8.31/gl/lib/ran...

Your "--random-source=/dev/urandom" line is superfluous. My original line is as secure as yours.

For easier-to-remember passphrases, you can download the EFF wordlist from https://www.eff.org/files/2016/07/18/eff_large_wordlist.txt and specify that file instead of /usr/share/dict/words

> you're better off getting it to generate a 50+ character random password (including uppercase, lowercase, numbers and symbols).

Lol I wish. Almost all of the important sites I use, like various bills and loans, use terrible password schemes. One even, until recently, enforced an 8 character limit! I think they raised it to 16 iirc. Oy.

Hell, even the company I work for frequently fails my password generator settings. The arbitrary character requirements of my ~20 character password would sometimes not be satisfied when I was creating accounts in our dev system/etc. Which is annoying as hell, but I can't convince management, because our users (older) tend to use some of the worst passwords out there.. so I can understand where it's coming from.

Security & UX is hard.

I heartily disagree.

All it takes is the one time, for whatever reason, that you have to type in a string of a few dozen random characters by hand on a phone keyboard or something because you're on a new device, or cut and paste is disabled, or whatever, and you'll understand why long random passwords should be reserved for web servers and so on and never used with consumer web applications like a hotel reservation program, or rental car app, or similar.

It's just a bare minimum that you reduced, if you add some preference it's worse than that. I did some test, maybe I'm just lucky, but i got password with a word starting with b at the 3rd generation, and i got adjective-noun pair in that order at the 5th generation.

Yes, if the regeneration depends on your preference of the generated words, the words order or link between them. The individual generations independent from each other, so if your choice – how many regeneration you do - not depends on the generations outcome, for example on your birthday date or favorite number, their randomness are equal.

But randomness are not enough, it's possible the first generated version correlate with your preference and that situation does not really matter why are you stopped generating new password.

Predictability of this scheme very good, because the strict rules. All implementation using common english words. For words smaller length, easy spelling, less ambiguity are preferred. Mixing nouns verbs and adjectives are more meaningful, order also adds more meaning. Word count very limited. Preference on the separator character also very rigid. Personal preference more known, because hidding your preference on all english words very hard and mostly unconscious.

Choosing is the problem here -- it's now only as random as your preference

Eg the scheme doesn't do its job well if you don't know the word, so the dictionary can be reduced by that much

Because instead of just trusting your system, you'd also have to trust an external service to remain honest. CSPRNG is widely deemed acceptable for use as key material (unlike standard PRNGs), so there is no reason to add an external dependency.

There is always the risk that such a website is, or could become, malicious and save generated numbers for future attacks; or, it could suffer from a hardware, software, or environmental issue that reduces entropy. While I would not fully trust a website-generated random number for anything important; you can XOR a number from a website such as www.random.org with a number from your system's PRNG so that you don't have to fully trust either. Even better, you can XOR again with some dice-generated numbers, your own custom PRNGs, or whatever else you can think of. That way, as long as at least one subset of your sources has sufficient entropy, you are safe.

I don't know about GP, but I certainly do.

Mine's a more meaningful sentence, but about the same length, yes.

It doesn't take long to type a wholly-memorized sentence.

i type quickly.

Good idea, just added separators to the website.

No problem. I dig the project. Very cool.

I would recommend the default be 6 words, and let people choose down to 4, but not lower. At last that way, users know what a "secure default" looks like. Granted, it breaks the four-word "correct horse battery staple" XKCD format, but Randall was in some error with that comic anyway.

I'd imagine the risk is pretty great, for the same reason I wouldn't paste a password here that I use. Sure, you may not know who I am, but if you were the site itself you get a ton of information on me.. which is more than I'd like you to know if you _also_ know one of my passwords.

I agree, the risk is minimal. Nevertheless.. security, heh.