nu_scripts/sourced/misc/password_generator/ReadMe.md

Nushell Password Generator "nupass"

This nushell command randomly retrieves a specified number of words from a dictionary file (English with Japanese words added by @rickcogley) less than or equal to a given parameter's length, formats the words randomly with capitalization, then separates the words with some random symbols and numbers to return a password.

To use:

1. Get the dictionary file to your system using nushell's http:

http get https://raw.githubusercontent.com/RickCogley/jpassgen/master/genpass-dict-jp.txt | save genpass-dict-jp

...which has also been included in this folder for convenience.

2. Confirm your $env.NU_LIB_DIRS location, and copy the below script 2. nupass.nu there as nupass.nu.
3. Set the script as executable like chmod +x nupass.nu
4. Specify the dictionary file's location in the script:

let dictfile = $"/path/to/my/genpass-dict-jp"

5. In the main function's flags section, confirm and edit the default symbols list, diceware delimiter and threads for par-each (double the number of your CPU cores seems to be a good sweet spot):

--symbols (-s): string = "!@#$%^&()_-+[]{}" # Symbols to use in password
--delimiter (-m): string = "-" # Delimiter for diceware
--threads (-t): int = 16  # Number of threads to use in par-each

6. Load the script with use in your config.nu, something like:

use nupass.nu

(you can specify the path as use /path/to/nupass.nu if you're not taking advantage of $env.NU_LIB_DIRS)

Reload nu, then run it to test:

nupass -h
nupass 5
nupass 6 --debug
nupass 8 -v diceware
nupass 8 -v diceware -m _
nupass 4 -v mixnmatch
nupass 6 -v alphanum
nupass 5 -l 8 

Testing

If you're making changes to the script while testing, you can just re-source the script by doing:

use nupass.nu

... which will reload the latest you have saved.

From nu version 0.79.1, you can use the standard library, and use its bench command to do a benchmark. Load the standard library by adding use std in your env.nu, reload, then assuming nupass.nu is in your path, you can benchmark like so:

std bench --rounds 10 --verbose {nupass 10}
std bench --rounds 10 --verbose {nupass 100 -v diceware}
std bench --rounds 10 --verbose {nupass 1000 -v mixnmatch}

If you change the par-each to each in the main list builders for instance, you'll see a significant performance hit. When I benchmarked nupass 100, using just each took 7 sec per round, whereas changing to par-each dropped that to about 1 sec per round.

You can tweak it a little further by setting the threads for par-each.

std bench --rounds 10 --verbose {nupass 100 -v diceware -t 8}
std bench --rounds 10 --verbose {nupass 100 -v diceware -t 16}
std bench --rounds 10 --verbose {nupass 100 -v diceware -t 32}

Caveats

I've been scripting for quite a long time, but not in nu. Input appreciated to make this more nu-esque! The script is in a decent place as of the 20230501 version.

Obviously you can just use the random chars or random integers commands but I like to have words I can read in my passwords, and I think those generated by this script have sufficient entropy.

This command doesn't let you specify a precise length.

Acknowledgements

Thanks everyone on Discord for putting up with and answering my nubie questions @amtoine, @fdncred, @jelle, @sygmei, @kubouch and for the feedback after try number 1.