#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Creates or re-calculates Diffie-Hellman parameters

# License
# =======
#
# Copyright (C) 2015-2016 Bob Mottram <bob@robotics.uk.to>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

PROJECT_NAME='freedombone'

export TEXTDOMAIN=${PROJECT_NAME}-dhparam
export TEXTDOMAINDIR="/usr/share/locale"

HOSTNAME=
KEYLENGTH=2048
RECALCULATE="no"
FAST=''

function show_help {
    echo ''
    echo $"${PROJECT_NAME}-dhparam -h [hostname] -l [length in bits] --recalc [yes|no] --fast [yes|no]"
    echo ''
    exit 0
}

function calc_dh {
    openssl dhparam -check -text $FAST $KEYLENGTH -out ${1}
    if [ ! "$?" = "0" ]; then
        exit 3674
    fi
    chmod 640 ${1}
}

function regenerate_dh_keys {
    for file in /etc/ssl/mycerts/*
    do
        if [[ -f $file ]]; then
            filename=/etc/ssl/certs/$(echo $file | awk -F '/etc/ssl/mycerts/' '{print $2}' | awk -F '.crt' '{print $1}').dhparam
            if [ -f $filename ]; then
                calc_dh $filename
                echo $"Recalculated DH params for $filename"
            fi
        fi
    done
}

while [[ $# > 1 ]]
do
key="$1"

case $key in
    --help)
    show_help
    ;;
    -h|--hostname)
    shift
    HOSTNAME="$1"
    ;;
    -l|--dhkey)
    shift
    KEYLENGTH=${1}
    ;;
    --recalc)
    shift
    RECALCULATE=${1}
    ;;
    --fast)
    shift
    if [[ ${1} == "yes" || ${1} == "y" ]]; then
        FAST='-dsaparam'
    fi
    ;;
    *)
    # unknown option
    ;;
esac
shift
done

if [[ $RECALCULATE == "yes" || $RECALCULATE == "y" ]]; then
    regenerate_dh_keys
    exit 0
fi

if [ ! $HOSTNAME ]; then
    echo $'No hostname specified'
    exit 5728
fi

if ! which openssl > /dev/null ;then
    echo $"$0: openssl is not installed, exiting" 1>&2
    exit 5689
fi

if [ ! -d /etc/ssl/mycerts ]; then
    mkdir -p /etc/ssl/mycerts
fi

calc_dh /etc/ssl/certs/$HOSTNAME.dhparam

systemctl reload nginx
exit 0