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#!/usr/bin/env sh
# Filename: makepass.sh
# Purpose: Creating random passwords.
# Authors: Dennis Eriksen <d@ennis.no>
# Bug-Reports: Email <git@dnns.no>
# License: This file is licensed under the BSD 3-Clause license.
################################################################################
# This script generates random passwords.
################################################################################
# Copyright (c) 2018-2023 Dennis Eriksen • d@ennis.no
#
# TODO: Clean up and comment.
MAX=255 # max length of passwords
RANGE_MAX=42 # max length when using random length
RANGE_MIN=8 # min length when using random length
PASS_WORDS=8 # number of words in passphrases
LOWER='abcdefghijklmnopqrstuvwxyz'
UPPER='ABCDEFGHIJKLMNOPQRSTUVWXYZ'
DIGIT='0123456789'
OTHER='!#$%&/()=?+_,.;:<>[]{}|@*-'
ALPHA=${LOWER}${UPPER}
ALNUM=${ALPHA}${DIGIT}
EVERY=${ALNUM}${OTHER}
LENGTH=${MAKEPASS_LENGTH:-0} # length of passwords. 0 means "random number between RANGE_MIN and RANGE_MAX"
NUMBER=${MAKEPASS_NUMBER:-10} # number of passwords
PRINTLEN=${MAKEPASS_PRINTLEN:-0} # print length of passwords
NORMAL=${MAKEPASS_NORMAL:-$ALNUM'_-'}
SPECIAL=${MAKEPASS_SPECIAL:-$EVERY}
WORDLIST=${MAKEPASS_WORDLIST:-/usr/share/dict/words}
XWIDTH=$(tput cols)
#
# Functions
#
# makepass-function
main() {
# Getopts
while getopts 'hl:n:p' opt; do
case $opt in
h)
help && return 0;;
l)
if ! int_in_range "$OPTARG" 0 "$MAX"; then die "-l takes a number between 0 and $MAX"; fi
LENGTH=$OPTARG;;
n)
if ! int_in_range "$OPTARG" 1 "$MAX"; then die "-n takes a number between 1 and $MAX"; fi
NUMBER=$OPTARG;;
p)
PRINTLEN=1;;
*)
die "Unknown argument";;
esac
done
shift $((OPTIND - 1))
#
# Some error-checking
#
if [ "$#" -gt 1 ]; then die "only one argument"; fi
if [ -n "$1" ]; then LENGTH=$1; fi
# Check $LENGTH and $NUMBER
if ! int_in_range "$LENGTH" 0 "$MAX"; then die "length must be a number between 0 and $MAX"; fi
if ! int_in_range "$NUMBER" 0 "$MAX"; then die "number-argument must be between and $MAX"; fi
#
# Some other work
#
if [ "$PRINTLEN" -gt 0 ]; then
if [ "$LENGTH" -lt 100 ]; then
PRINTLEN=3
else
PRINTLEN=4
fi
fi
COL_WIDTH=$(( ( LENGTH ? LENGTH : RANGE_MAX ) + 2 ))
if [ "$LENGTH" -gt 0 ]; then
COL_WIDTH=$((LENGTH + 2))
else
COL_WIDTH=$((RANGE_MAX + 2))
fi
COL_NUM=$(( XWIDTH / ( COL_WIDTH + PRINTLEN) ))
#
# Print!
#
print_columns "Normal passwords" "$NUMBER" "$NORMAL"
echo ""
print_columns "Passwords with special characters" "$((NUMBER*2/3))" "$SPECIAL"
if [ -r "$WORDLIST" ]; then
echo ""
echo "Passphrases:"
LINES=$(wc -l < "$WORDLIST")
i=0
while [ "$i" -lt $((NUMBER / 2)) ]; do
passphrase
i=$((i+=1))
done;
fi
}
# Function to print passwords in neat columns
print_columns() {
title=$1
num=$2
chars=$3
# Abuse `set` to get arrays!
# shellcheck disable=SC2046 # we want the spaces to separate items
set -- $(randstrings "$chars" "$num")
echo "${title}:"
i=0
for s in "$@"; do
i=$((i+=1))
if [ "$PRINTLEN" -gt 0 ]; then printf "%0$((PRINTLEN-1))i " "${#s}"; fi
printf "%-${COL_WIDTH}s" "$s"
if [ "$(( i % COL_NUM))" -eq 0 ]; then
echo ""
elif [ "$i" -eq "$num" ] && [ "$((i % COL_NUM))" -gt 0 ]; then
echo "";
fi
done
}
# Function to create random strings
randstrings() {
i=0
num=$2
chars="${1:-$NORMAL}"
while [ "$i" -lt "$num" ]; do
if [ "$LENGTH" -gt 0 ]; then
len="$LENGTH"
else
r=$(_RANDOM)
len=$(( r % (RANGE_MAX - RANGE_MIN + 1) + RANGE_MIN ))
fi
string=$(head -n 2 /dev/random | tr -dc '[:alpha:]' | tail -c1)
string=${string}$(head -n 100 /dev/random | tr -dc "$chars" | tail -c $((len-2)))
if [ "$len" -gt 2 ]; then
string=${string}$(head -n 2 /dev/random | tr -dc '[:alnum:]' | tail -c1)
fi
printf "%s " "$string"
i=$((i+=1))
done
}
_RANDOM() {
#N=$(head -n 2 /dev/urandom | tr -cd "[:digit:]" | tail -c 8 | sed 's/^[0]*//')
N=$(od -An -N2 /dev/random | sed 's/[ ]*[0]*//')
printf "%s" "$N"
}
# PASSPHRASE!!
passphrase() {
#string=""
#j=0
#while [ "$j" -lt "$PASS_WORDS" ]; do
# #r=$((($(_RANDOM) % LINES ) + 1))
# #string="${string}$(sed -n "${r}p" "$WORDLIST")-"
# j=$((j+=1))
#done
r=$(_RANDOM)
string="$(awk "BEGIN{srand($r);}{a[NR]=\$0}END{for(i=1; i<$PASS_WORDS; i++){x=int(rand()*NR) + 1; print a[x];}}" "$WORDLIST" | xargs printf '%s-')"
printf "%s\n" "${string%?}"
}
# Check if int and if in range
int_in_range() {
num=$1
min=$2
max=$3
# Abuse case for regex-matching of numbers with only POSIX
case "$num" in
(*[!0-9]*|'') return 1;;
(*) if [ "$min" -le "$num" ] && [ "$num" -le "$max" ]; then
return 0
fi ;;
esac
return 1
}
# Function to die
die() {
echo -- "$@"
echo -- "Maybe try running \`makepass -h\` for help"
exit 1
}
# Help-function
help() {
cat <<EOL
NAME
makepass - create several random passwords
SYNOPSIS
makepass [OPTIONS] [NUM]
If a NUM is provided, passwords will be NUM characters long.
By default \`makepass\` will output passwords from the three following classes:
- Normal passwords - random strings with letters (both lower and upper
case), numbers, and dashes and underscores.
- Passwords with special characters - random strings generated from lower
and upper case letters, numbers, and the following characters:
!#$%&/()=?+-_,.;:<>[]{}|@*
- Passphrases - if we find a dictionary, a series of eight random words
from the dictionary, separated by dashes. The number of words can not be
changed, but you do not have to use all of them. Use as mane as you want.
The first character will always be alphabetic, and the last will always be
alphanumeric.
DESCRIPTION
makepass has the following options:
-h
output this help-text
-l
length of passwords. See MAKEPASS_LENGTH below
-n
number of passwords. See MAKEPASS_NUMBER below
-p
print length of number
ENVIRONMENT
makepass examines the following environmental variables.
MAKEPASS_LENGTH
Specifies the length of passwords. Valid values are 0-255. If 0, a
random value between 8 and 42 will be used for each password. -l
overrides this environmental variable, and the argument NUM overrides
that again. So \`MAKEPASS_LENGTH=10 makepass -l 12 14\` will give
passwords that are 14 characters long, even though both -l and
MAKEPASS_LENGTH also specifies a length.
MAKEPASS_NUMBER
The number of passwords to generate. This formula is used to determine
how many passwords from each group should be generated:
- (n) normal passwords
- (n / 3 * 2 + 1) special passwords
- (n / 2) passphrases
Where n is 10 by default. Valid values for n are 1-255. Floating-poing
math is not used, so results may vary.
MAKEPASS_PRINTLEN
If 1, print length of all passwords. If 0, don't.
MAKEPASS_NORMAL
String of characters from which to generate "normal" passwords.
Defaults to:
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-
MAKEPASS_SPECIAL
String of characters from which to generate passwords with special
characters. Defaults to the same characters as in MAKEPASS_NORMAL, plus
these:
!#$%&/()=?+,.;:<>[]{}|@*
MAKEPASS_WORDLIST
Specifies the dictionary we find words for passphrases in. If this is
unset or empty, we try "/usr/share/dict/words". If that file does not
exist, no passphrases will be provided.
NOTES
This script tries hard to be POSIX compliant. But it might not be? Let me
know if you find any errors!
AUTHOR
Dennis Eriksen <https://dnns.no>
EOL
return 0
}
# RUN IT!
main "${@:-}"
## END OF FILE #################################################################
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