passwd-hash.sh

#!/bin/bash
#
# Helper script for generating salted password hashes
# Author: Stanislav V. Emets <emetssv@mail.ru>
#
# This file is part of passwd-hash.
#    Passwd-hash is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.

#    Passwd-hash is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.

#    You should have received a copy of the GNU General Public License
#    along with Foobar.  If not, see <https://www.gnu.org/licenses/>.

DEBUG=${DEBUG:-0}

if [ $DEBUG -gt 1 ]; then
    set -xe
else
    set -e
fi

# Configuration parameters, adjust it for your security policy
# like:
#   export SALT_LENGTH=10
#
# Salt lenght, default: 16
SALT_LENGTH=${SALT_LENGTH:-16}
# Hashing method, default is: SHA512
# MD5: 1, SHA256: 5, SHA512: 6
CIPHER="-${CIPHER:-'6'}"

# Generate random salt
SALT=`head /dev/urandom | tr -dc A-Za-z0-9 | head -c ${SALT_LENGTH}`

# Debug output
if [ $DEBUG -gt 0 ]; then
    echo "Salt lenght: ${SALT_LENGTH}"
    echo "Chipher: ${CIPHER}"
    echo "Random salt: \$${CIPHER/-/}\$${SALT}"
fi
if [ -z "$CIPHER" ]; then
    echo "Hash algorithm not defined!"
    exit 1
fi
if [ -z "$SALT" ]; then
    echo "Salt not generated, please check SALT_LENGTH parameter!"
    exit 2
fi

openssl passwd ${CIPHER} --salt ${SALT}