A password generator for strong, low-complexity passwords

make-lc-password: A Linux shell (bash) script that suggests random, verifiably strong, easy-to-memorize passwords.

Password example:

cleave-cricks-suntan-loafed
Entropy is approx. 50 sh (bits) -; depends on script presets and your system settings

Key points:

Suggests multi-word passwords, so-called low-complexity passwords.
Low-complexity passwords consist only of words, all in lowercase characters. (Lowercase characters can be typed on virtually any keyboard.)
A low-complexity password is easy to memorize, in contrast to passwords that demand uppercase chars, digits, and special characters.
Low-complexity passwords can be mathematically shown to be strong, even in the face of very skeptic assumptions.
The passwords consist of 4 words (default) of fixed length 6 (default). The word separator is '-' (default). The defaults can be overridden.
The source of the words is the Linux system dictionary (about 100,000 words).
The tool can give the entropy of the password scheme (calculated in a conservative way).
It can also give the entropy of the dictionary the password scheme is based on (calculated in a conservative way).
Its defaults can be shown via an option and can be modified with command line options and parameters.
Advanced features:
- Can write a custom dictionary based on the system dictionary or another dictionary.
- Filtering the system dictionary can be performed with advanced regular expressions. (You can then examine and edit the custom dictionary for later use.)
- Use your custom dictionary for password suggestions.
- Check each created password suggestion against a system or custom crack dictionary. (The password is considered cracked if it matches any whole line in the crack dictionary.)
- You can set a minimum intermediate (or custom) dictionary size; and let the tool warn you if the dictionary size falls below that value.
- Supports a documented list of exit codes for integration in a tool chain.
Miscellaneous:
- Supports short (e.g., -h) and long (e.g., --help) options.
- Shows a list of example calls (use the -p or --examples options).
The tool is open source software (license: GPL 3 or later, https://gnu.org/licenses/gpl.html).
Has been developed and tested on Ubuntu 22.04.

Download: Zip archive | Script | Cryptographic signature | Public key | Folder

Preparation:

Unpack the ZIP archive (optional): unzip make-lc-passwd.zip
Check the script's authenticity: gpg --verify --keyring ./make-lc-passwd.pubkey.asc make-lc-passwd.sig.asc make-lc-passwd
(Expected output: Good signature from "Ulrich Messerle (Code Signing) <passwd-gen@pinkneutrino.com>")
Make the file executable: chmod ug+x make-lc-passwd

Usage examples:
  ./make-lc-passwd  # Suggest one password to the console
  purges-cities-leafed-nowise

  ./make-lc-passwd --numpasswords 3 --linenumbers  # Suggest 3 passwords to the console and number the lines
    1: occurs-shoots-airier-offing
    2: ironic-filets-forgot-fuller
    3: solids-tenpin-chilly-reflex

  ./make-lc-passwd --output lc-passwd-suggestion.txt  # Write one password to a file
  cat lc-passwd-suggestion.txt                        # Show contents of the file
  fizzed-awaked-cotton-goblet

  ./make-lc-passwd --entropy  # Suggest one password to the console and give actual entropy information
  Password suggestion:
    dreary-orchid-police-hamlet
  Entropy information:
    System dictionary   : 104334 words
    Custom dict.        : 7352 words (7.0%)
    Custom dict. entropy: 12.89 sh ('bits')
    Password entropy    : 50.56 sh ('bits')

  ./make-lc-passwd --help  # Get help
  Usage: make-lc-passwd [OPTION [PARAMETER]] [...]
  ...

Support:
  For eMail support, see the eMail address given in the script source.