Linux Tips and Tools

Automatic (Pronounceable) Password Generation

Use of automated tools will help ensure high-quality passwords, enhancing security. apg is one such tool, which (by default) attempts to generate pronounceable passwords. Once apg is installed, invoking it like this will produce best results:

hostname ~ # /usr/bin/apg -M NCL -k -t -m 9 -x 9 -n 10 -E OWL | egrep -v [owl]

Explanation of options:

• -M is a mode-switch, with following options which tell apg what characterset to use
  • -N numbers must be included with each password
  • -C upper-case (capital) letters must be included
  • -L lower-case letters must be included
• -k check every generated password using cracklib. Cracklib support must be compiled-in.
• -m 9 minimum password length
• -x 9 maximum password length
• -n 10 generate 10 passwords After the egrep filtering below, you will get substantially fewer than 10 results.
• -E OWL exclude letters (upper-case only possible) OWL from password. This prevents confusion with "oh" and "zero"; "ell" and "one".
• | egrep -v [owl] does the same as above, except it filters out/discards passwords with lower-case owl