[bsurmanski]

I think for something this checking the source for the generation algorithm is fair game. here it is:

  function randomInt(n) {
    return Math.floor(Math.random() * n);
  }

  function randomPassword() {
    let letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    let digits = '0123456789';
    let punctuation = '!"#$%&\'()\*+,-./:;<=>?@[\\]^_`{|}~';
    let s = letters.repeat(7) + digits.repeat(4) + punctuation.repeat(3);
    let length = 14;
    let res = Array.from({length}, (() => 
      s[randomInt(s.length)])).join('');
    return res;
  }

looks like it's 14 characters long, and each character has an independent 72.8% / 8% / 19.2% chance of being a random letter / digit / punctuation. There are 94 symbols total, so 94^14 possible solutions; roughly 92 bits of entropy. Even if you assume 10 letters, 1 digit, 3 punctuations (the "likely" distribution) it's still 75 bits of entropy. You might be able to gain an advantage through knowledge of the PRNG state, but the PRNG in v8 (xorshift128+) has a period of 2^128 - 1.

So not great odds...

[mlyle]

92 bits of entropy, and the first guess peels off about 14 bits of it. Subsequent guesses a little less.

The annoying thing is, you still have to search that whole space to find the password.

But after 9 guesses, you can solve offline for the character string... it's just very expensive.

[acchow]

How does the first guess "peel off" 14 bits of entropy?

[throwaway6532]

Could you do it with a rainbow table?