Create diceware passphrase from terminal

mkdice

#!/bin/bash

#// IMPORTANT INFO
#// ! Be aware that this script works against the idea of diceware 
#// because it does not use the real randomness of an analogue dice 
#// but rests on computer pseudo randomness. Thats why the standard 
#// length is set to 3 words, what is not enough for an offline attack-
#// able passphrase, but might be ok for several online portals.
#// That means, this script suits only for mid-level passwords.

#// PREPERATION
#// You first have to download the Diceware Large List from EFF:
#// https://www.eff.org/files/2016/07/18/eff_large_wordlist.txt
#// and safe it to ~/.diceware
#// You can also use other wordlists and replace the path in the script
#// or use the parameter -f when using mkdice.
#// 
#// Then put this scriptfile to ~/bin or wherever you store your custom 
#// scripts

#// USING
#// command 'mkdice' in terminal returns a 3 word passphrase
#//
#// You can use parameters to modify the output (like 'mkdice -l 5 -sxd _')
#//
#// -l length of the passphrase, number of words used (default '3')
#// -f used diceware list (default '~/.diceware/eff_large_wordlist.txt')
#// -r source of the entropy to choose random words (default '/dev/urandom')
#// -d delimiter between the words (default '-')
#// -D delimiter between the words in the clipboard (default same as -d)
#// 
#// -x the passphrase will also be available in the clipboard (paste it with strg+v)
#// -U the first letter of each word will be Uppercase
#// -s silent, the passphrase will not be returned to the terminal (standard output)
#// -z the passphrase will be shown with zenity information (if available)

#// Its most handy to create a keyboard shortcut for your preffered command and use it
#// with -x or -z to have the passphrase available

#parameters
LENGTH=3
FILE=~/.diceware/eff_large_wordlist.txt
RANDOMSOURCE=/dev/urandom
XCOPY=false
SILENT=false
DELIMITER="-"
UPPERCASE=false
ZENITY=false
DELIMITER_XCOPY=false

while getopts sUxzl:f:r:d:D: option
do
 case "${option}"
 in
   l) LENGTH=$OPTARG;;
   f) FILE=$OPTARG;;
   r) RANDOMSOURCE=$OPTARG;;
   x) XCOPY=true;;
   s) SILENT=true;;
   d) DELIMITER=$OPTARG;;
   U) UPPERCASE=true;;
   z) ZENITY=true;;
   D) DELIMITER_XCOPY=$OPTARG;;
 esac
done

#set xcopy delimiter to normal delimiter
if [ $DELIMITER_XCOPY = false ]; then
  DELIMITER_XCOPY=$DELIMITER
fi

#loop the passphrase
for i in $(seq 1 $LENGTH)
do

  #grab random line
  line=$(sort -R --random-source=$RANDOMSOURCE $FILE | head -n 1)

  #grab word from line
  word=$(echo "$line"  | awk '{print $2}')

  #make word first letter uppercase
  if [ $UPPERCASE = true ]; then
    word=${word^}
  fi

  #merge words to phrase
  passphrase="$passphrase$DELIMITER$word"
  passphrase_xcopy="$passphrase$DELIMITER_XCOPY$word"

done

#remove delimiter
passphrase=${passphrase:${#DELIMITER}}
passphrase_xcopy=${passphrase_xcopy:${#DELIMITER_XCOPY}}

#put phrase to clipboard
if [ $XCOPY = true ]; then
  echo -n "$passphrase_xcopy" | xclip -selection c
fi

#return passphrase to output
if [ $SILENT = false ]; then
  echo $passphrase
fi

#show passphrase with zenity
if [ $ZENITY = true ]; then
  zenity --notification --text $passphrase
fi