#!/bin/bash
#  _____               _           _
# |   __|___ ___ ___ _| |___ _____| |_ ___ ___ ___
# |   __|  _| -_| -_| . | . |     | . | . |   | -_|
# |__|  |_| |___|___|___|___|_|_|_|___|___|_|_|___|
#
#                              Freedom in the Cloud
#
# Create self-signed or Let's Encrypt certificates on Debian

# License
# =======
#
# Copyright (C) 2015-2018 Bob Mottram <bob@freedombone.net>
#
# 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}-addcert
export TEXTDOMAINDIR="/usr/share/locale"

CONFIGURATION_FILE=$HOME/${PROJECT_NAME}.cfg
COMPLETION_FILE=$HOME/${PROJECT_NAME}-completed.txt

UTILS_FILES="/usr/share/${PROJECT_NAME}/utils/${PROJECT_NAME}-utils-*"
for f in $UTILS_FILES
do
    source "$f"
done

# Don't pin certs by default
PIN_CERTS=

HOSTNAME=
remove_cert=
LETSENCRYPT_HOSTNAME=
COUNTRY_CODE="US"
AREA="Apparent Free Speech Zone"
LOCATION="Freedomville"
ORGANISATION="Freedombone"
UNIT="Freedombone Unit"
EXTENSIONS=""
NODH=
DH_KEYLENGTH=2048
INSTALL_DIR=/root/build
LETSENCRYPT_SERVER='https://acme-v01.api.letsencrypt.org/directory'
MY_EMAIL_ADDRESS=

function show_help {
    echo ''
    echo $"${PROJECT_NAME}-addcert -h [hostname] -c [country code] -a [area] -l [location]"
    echo $'                    -o [organisation] -u [unit] --ca "" --nodh ""'
    echo ''
    echo $'Creates a self-signed certificate for the given hostname'
    echo ''
    echo $'     --help                     Show help'
    echo $'  -h --hostname [name]          Hostname'
    echo $'  -e --letsencrypt [hostname]   Hostname to use with Lets Encrypt'
    echo $'  -r --rmletsencrypt [hostname] Remove a Lets Encrypt certificate'
    echo $'  -s --server [url]             Lets Encrypt server URL'
    echo $'  -c --country [code]           Optional country code (eg. US, GB, etc)'
    echo $'  -a --area [description]       Optional area description'
    echo $'  -l --location [locn]          Optional location name'
    echo $'  -o --organisation [name]      Optional organisation name'
    echo $'  -u --unit [name]              Optional unit name'
    echo $'     --email [address]          Email address for letsencrypt'
    echo $'     --dhkey [bits]             DH key length in bits'
    echo $'     --nodh ""                  Do not calculate DH params'
    echo $'     --ca ""                    Certificate authority cert'
    echo ''
    exit 0
}

while [ $# -gt 1 ]
do
    key="$1"

    case $key in
        --help)
            show_help
            ;;
        -h|--hostname)
            shift
            HOSTNAME="$1"
            ;;
        -e|--letsencrypt)
            shift
            LETSENCRYPT_HOSTNAME="$1"
            ;;
        -r|--rmletsencrypt)
            shift
            LETSENCRYPT_HOSTNAME="$1"
            remove_cert=1
            ;;
        --email)
            shift
            MY_EMAIL_ADDRESS="$1"
            ;;
        -s|--server)
            shift
            LETSENCRYPT_SERVER="$1"
            ;;
        -c|--country)
            shift
            COUNTRY_CODE="$1"
            ;;
        -a|--area)
            shift
            AREA="$1"
            ;;
        -l|--location)
            shift
            LOCATION="$1"
            ;;
        -o|--organisation)
            shift
            ORGANISATION="$1"
            ;;
        -u|--unit)
            shift
            UNIT="$1"
            ;;
        --ca)
            shift
            EXTENSIONS="-extensions v3_ca"
            ORGANISATION="Freedombone-CA"
            ;;
        --nodh)
            shift
            NODH="true"
            ;;
        --dhkey)
            shift
            DH_KEYLENGTH="${1}"
            ;;
        --pin)
            shift
            PIN_CERTS="${1}"
            ;;
        *)
            # unknown option
            ;;
    esac
    shift
done

if [ ! "$HOSTNAME" ]; then
    if [ ! "$LETSENCRYPT_HOSTNAME" ]; then
        echo $'No hostname specified'
        exit 5748
    fi
fi

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

CERTFILE=$HOSTNAME

function remove_cert_letsencrypt {
    CERTFILE=$LETSENCRYPT_HOSTNAME

    # disable the site if needed
    if [ -f "/etc/nginx/sites-available/${LETSENCRYPT_HOSTNAME}" ]; then
        if grep -q "443" "/etc/nginx/sites-available/${LETSENCRYPT_HOSTNAME}"; then
            nginx_dissite "${LETSENCRYPT_HOSTNAME}"
        fi
    fi

    # remove the cert
    rm -rf "/etc/letsencrypt/live/${LETSENCRYPT_HOSTNAME}*"
    rm -rf "/etc/letsencrypt/archive/${LETSENCRYPT_HOSTNAME}*"
    rm "/etc/letsencrypt/renewal/${LETSENCRYPT_HOSTNAME}.conf"

    # restart the web server
    systemctl restart nginx
}

function add_cert_letsencrypt {
    CERTFILE=$LETSENCRYPT_HOSTNAME

    # obtain the email address for the admin user
    if [ ! "$MY_EMAIL_ADDRESS" ]; then
        if [ -f "$CONFIGURATION_FILE" ]; then
            read_config_param MY_EMAIL_ADDRESS
        fi
    fi
    if [ ! "$MY_EMAIL_ADDRESS" ]; then
        if [ -f "$COMPLETION_FILE" ]; then
            if grep -q "Admin user:" "$COMPLETION_FILE"; then
                function_check get_completion_param
                ADMIN_USER=$(get_completion_param "Admin user")
                if [ ${#ADMIN_USER} -eq 0 ]; then
                    exit 463732
                fi
                MY_EMAIL_ADDRESS=$ADMIN_USER@$HOSTNAME
            fi
        fi
    fi

    if [ ! -f /usr/bin/certbot ]; then
        apt-get -yq -t stretch-backports install certbot
        groupadd ssl-cert
        if [ ! -f /usr/bin/certbot ]; then
            echo $'LetsEncrypt certbot failed to install'
            exit 762830
        fi
    fi

    # stop the web server
    systemctl stop nginx

    chgrp -R root /etc/letsencrypt
    chmod -R 777 /etc/letsencrypt

    if ! certbot certonly -n --server "$LETSENCRYPT_SERVER" --standalone -d "$LETSENCRYPT_HOSTNAME" --renew-by-default --agree-tos --email "$MY_EMAIL_ADDRESS"; then
        echo $"Failed to install letsencrypt for domain $LETSENCRYPT_HOSTNAME"
        echo $'Also see https://letsencrypt.status.io to check for any service outages'
        chgrp -R ssl-cert /etc/letsencrypt
        chmod -R 600 /etc/letsencrypt
        chmod -R g=rX /etc/letsencrypt
        chown -R root:ssl-cert /etc/letsencrypt
        systemctl start nginx
        exit 63216
    fi

    # replace some legacy filenames
    if [ -f "/etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.bundle.crt" ]; then
        # shellcheck disable=SC2086
        mv /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.bundle.crt /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem
    fi
    if [ -f "/etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.crt" ]; then
        # shellcheck disable=SC2086
        mv /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.crt /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem
    fi
    sed -i "s|ssl_certificate /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.bundle.crt|ssl_certificate /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem|g" "/etc/nginx/sites-available/$LETSENCRYPT_HOSTNAME"
    sed -i "s|ssl_certificate /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.crt|ssl_certificate /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem|g" "/etc/nginx/sites-available/$LETSENCRYPT_HOSTNAME"

    # link the private key
    if [ -f "/etc/ssl/private/${LETSENCRYPT_HOSTNAME}.key" ]; then
        if [ ! -f "/etc/ssl/private/${LETSENCRYPT_HOSTNAME}.key.old" ]; then
            # shellcheck disable=SC2086
            mv /etc/ssl/private/${LETSENCRYPT_HOSTNAME}.key /etc/ssl/private/${LETSENCRYPT_HOSTNAME}.key.old
        else
            rm -f "/etc/ssl/private/${LETSENCRYPT_HOSTNAME}.key"
        fi
    fi
    if [ -L "/etc/ssl/private/${LETSENCRYPT_HOSTNAME}.key" ]; then
        rm "/etc/ssl/private/${LETSENCRYPT_HOSTNAME}.key"
    fi
    ln -s "/etc/letsencrypt/live/${LETSENCRYPT_HOSTNAME}/privkey.pem" "/etc/ssl/private/${LETSENCRYPT_HOSTNAME}.key"

    # link the public key
    if [ -f "/etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem" ]; then
        if [ ! -f "/etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem.old" ]; then
            # shellcheck disable=SC2086
            mv /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem /etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem.old
        else
            rm -f "/etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem"
        fi
    fi
    if [ -L "/etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem" ]; then
        rm "/etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem"
    fi
    ln -s "/etc/letsencrypt/live/${LETSENCRYPT_HOSTNAME}/fullchain.pem" "/etc/ssl/certs/${LETSENCRYPT_HOSTNAME}.pem"

    cp "/etc/letsencrypt/live/${LETSENCRYPT_HOSTNAME}/fullchain.pem" "/etc/ssl/mycerts/${LETSENCRYPT_HOSTNAME}.pem"

    update_default_domain

    # this group can be used to assign read permissions for
    # application user accounts
    chgrp -R ssl-cert /etc/letsencrypt
    chmod -R 600 /etc/letsencrypt
    chmod -R g=rX /etc/letsencrypt
    chown -R root:ssl-cert /etc/letsencrypt

    nginx_ensite "${LETSENCRYPT_HOSTNAME}"
    systemctl start nginx

    if [ "$PIN_CERTS" ]; then
        if ! "${PROJECT_NAME}-pin-cert" "$LETSENCRYPT_HOSTNAME"; then
            echo $"Certificate for $LETSENCRYPT_HOSTNAME could not be pinned"
            exit 62878
        fi
    fi
}

function add_cert_selfsigned {
    if [[ "$ORGANISATION" == "Freedombone-CA" ]]; then
        CERTFILE="ca-$HOSTNAME"
    fi

    # shellcheck disable=SC2086
    openssl req -x509 ${EXTENSIONS} -nodes -days 3650 -sha256 \
            -subj "/O=$ORGANISATION/OU=$UNIT/C=$COUNTRY_CODE/ST=$AREA/L=$LOCATION/CN=$HOSTNAME" \
            -newkey rsa:2048 -keyout "/etc/ssl/private/${CERTFILE}.key" \
            -out "/etc/ssl/certs/${CERTFILE}.crt"
    chmod 400 "/etc/ssl/private/${CERTFILE}.key"
    chmod 640 "/etc/ssl/certs/${CERTFILE}.crt"

    if [ "$PIN_CERTS" ]; then
        if ! "${PROJECT_NAME}-pin-cert" "$CERTFILE"; then
            echo $"Certificate for $CERTFILE could not be pinned"
            exit 62879
        fi
    fi
}

function generate_dh_params {
    if [ ! "$NODH" ]; then
        if [ ! -f "/etc/ssl/certs/${CERTFILE}.dhparam" ]; then
            "${PROJECT_NAME}-dhparam" -h "${CERTFILE}" --fast yes
        fi
    fi
}

function restart_web_server {
    if [ -f /etc/init.d/nginx ]; then
        /etc/init.d/nginx reload
    fi
}

function create_cert {
    if [ "$remove_cert" ]; then
        remove_cert_letsencrypt
        return
    fi

    if [ "$LETSENCRYPT_HOSTNAME" ]; then
        add_cert_letsencrypt
    else
        add_cert_selfsigned
    fi
}

create_cert
generate_dh_params
restart_web_server

exit 0