passphrase generator using cmdline tools because wtf not

ppw

#!/bin/bash
#
# simplistic program that creates passphrases using bash. the passphrases
# are a Number of '-' separated words, ea. of max Chars, with limited post
# processing (upper case, lower case, 1337.)
#
# (c) 2019, thaddeus t. grugq <[email protected]>
#

CRACKLIB=/usr/share/dict/cracklib-small
DICT=/usr/share/dict/words


lower() {
	echo $1 | tr A-Z a-z
}

upper() {
	echo $1 | tr a-z A-Z
}

l33t() {
	echo "$1" | tr 'iletas' '1137@$'
}

qstrip() {
	echo "$1" | sed -e "s/'//g" -e 's/"//g'
}

random_word() {
	local n="$1"
	local munge="${2:-l}" # l u e

	local fname="$DICT"
	local total=$( sed -E -n "/^.{1,$n}$/p" $fname | wc -l | awk '{ print $1 }')

	while true
	do
		ndx=$RANDOM

		if [[ "$total" -lt "$ndx" ]]; then
			ndx=$(( $ndx % $total ))
		fi

		word=$(sed -E -n "/^.{1,$n}$/p" $fname | sed -n "${ndx}p")

		case $munge in
			"l"|"L")
				word=$(lower "$word")
				;;
			"u"|"U")
				word=$(upper "$word")
				;;
			"e"|"3")
				word=$(l33t "$word")
				word=$(lower "$word")
				;;
			*)
				word=$(lower "$word")
				;;
		esac

		break
	done

	echo "$(qstrip $word)"
}

gen_passphrase() {
	local num="${1:-3}"
	local len=${2:-5}
	local sep="${3:--}"
	local munge="${4:-l}"

	words=""

	for i in $(seq $num)
	do
		word=$(random_word $len $munge)

		if [[ $i -eq 1 ]]; then
			words="$word"
		else
			words="${words}${sep}$word"
		fi
	done

	echo $words
}

usage() {
	echo "ppw [-c|--chars N] [-n|--number N] [-l|--lower,-u|--upper,-e|--elite]"
	echo "    [-s|--sep C] [-k|--krack]"
	echo ""
	echo "  -c,--chars   max chars per word, default: 6"
	echo "  -n,--number  number of words, default: 4"
	echo "  -l,--lower   convert to lowercase {default}"
	echo "  -u,--upper   convert to uppercase"
	echo "  -e,--elite   convert to 1337"
	echo "  -s,--sep     separator char, default: -"
	echo "  -k,--krack   use cracklib, default /usr/share/dict/words"
	echo ""
	echo "example: "
	echo "  ppw -c 8 -n 4 -u -s @"
	echo "    JUNE@PIKE@PEABODY@FIORDS"
	echo ""
	echo "  ppw -c 9 -n 8 "
	echo "    susanna-duncan-henrys-goethe-izaaks-abrams-degeneres-murdochs"
	echo ""
	echo "  ppw -c 9 -n 5 -k "
	echo "    serviette-salver-notches-catchy-sheppard"
}

TEMP=$(getopt -o 'c:n:lues:kh' --long 'chars:,number:,lower,upper,elite,sep:,krack,help' -n 'ppw' -- "$@")

if [ $? -ne 0 ]; then
	echo 'Terminating...' >&2
	exit 1
fi

# 
eval set -- "$TEMP"
unset TEMP

while true
do
	case "$1" in
		'-c'|'--chars')
			chars=$2
			shift 2
			continue
		;;
		'-n'|'--number')
			number=$2
			shift 2
			continue
		;;
		'-l'|'--lower')
			munge="l"
			shift 
			continue
		;;
		'-u'|'--upper')
			munge="u"
			shift 
			continue
		;;
		'-e'|'--elite')
			munge="e"
			shift 
			continue
		;;
		'-s'|'--sep')
			sep=$2
			shift 2
			continue
		;;
		'-k'|'--krack')
			DICT=$CRACKLIB
			shift 
			continue
		;;
		'-h'|'--help')
			usage
			exit 1
			continue
		;;
		'--')
			shift
			break
		;;
		*)
			echo 'Internal error!' >&2
			exit 1
		;;
	esac
done

chars=${chars:-6}
number=${number:-4}
munge=${munge:-l}
sep=${sep:--}

gen_passphrase "$number" "$chars" "$sep" "$munge"