#!/bin/sh
#
# make-csr is a shell script designed to automatically generate a 
# certificate signing request (CSR) from an Apache or a Nginx vhost
#
# Author: Victor Laborie <vlaborie@evolix.fr>
# Licence: AGPLv3
#

get_domains() {
    echo "$vhostfile"|grep -q nginx
    if [ "$?" -eq 0 ]; then
        domains=$(grep -oE "^( )*[^#]+" "$vhostfile" |grep -oE "[^\$]server_name.*;$"|sed 's/server_name//'|tr -d ';'|sed 's/\s\{1,\}//'|sed 's/\s\{1,\}/\n/g'|sort|uniq)
    fi
    
    echo "$vhostfile" |grep -q apache2
    if [ "$?" -eq 0 ]; then
        domains=$(grep -oE "^( )*[^#]+" "$vhostfile" |grep -oE "(ServerName|ServerAlias).*"|sed 's/ServerName//'|sed 's/ServerAlias//'|sed 's/\s\{1,\}//'|sort|uniq)
    fi
    valid_domains=""
    nb=0
    
    echo "Valid(s) domain(s) in $vhost :"
    for domain in $domains; do
        real_ip=$(dig +short "$domain"|grep -oE "([0-9]+\.){3}[0-9]+")
        for ip in $(echo "$SRV_IP"|xargs -n1); do
            if [ "${ip}" = "${real_ip}" ]; then
                            valid_domains="$valid_domains $domain"
                        nb=$(( nb  + 1 ))
                echo "* $domain -> $real_ip"
            fi
        done
    done
    
    if [ "$nb" -eq 0 ]; then
            nb=$(echo "$domains"|wc -l)
        echo "* No valid domain found"
        echo "All following(s) domain(s) will be used for CSR creation :"
        for domain in $domains; do
            echo "* $domain"
        done
    else
        domains="$valid_domains"
    fi
    domains=$(echo "$domains"|xargs -n1)
}

make_key() {
    openssl genrsa -out "$SSL_KEY_DIR/${vhost}.key" "$SSL_KEY_SIZE" 2>/dev/null
    chown root: "$SSL_KEY_DIR/${vhost}.key"
    chmod 600 "$SSL_KEY_DIR/${vhost}.key"
}

make_csr() {
    domains="$1"
    nb=$(echo "$domains"|wc -l)
    config_file="/tmp/make-csr-${vhost}.conf"

    mkdir -p "$CSR_DIR" -m 0755
    
    if [ "$nb" -eq 1 ]; then
        cat /etc/letsencrypt/openssl.cnf - > "$config_file" <<EOF
CN=$domains
EOF
        openssl req -new -sha256 -key "$SSL_KEY_DIR/${vhost}.key" -config "$config_file" -out "$CSR_DIR/${vhost}.csr"
    elif [ "$nb" -gt 1 ]; then
        san=''
        for domain in $domains
        do
                san="$san,DNS:$domain"
        done
        san=$(echo "$san"|sed 's/,//')
        cat /etc/letsencrypt/openssl.cnf - > "$config_file" <<EOF
[SAN]
subjectAltName=$san
EOF
        openssl req -new -sha256 -key "$SSL_KEY_DIR/${vhost}.key" -reqexts SAN -config "$config_file" > "$CSR_DIR/${vhost}.csr"
    fi
    
    if [ -f "$CSR_DIR/${vhost}.csr" ]; then
        chmod 644 "$CSR_DIR/${vhost}.csr"
        mkdir -p "$SELF_SIGNED_DIR" -m 0755
        openssl x509 -req -sha256 -days 365 -in "$CSR_DIR/${vhost}.csr" -signkey "$SSL_KEY_DIR/${vhost}.key" -out "$SELF_SIGNED_DIR/${vhost}.pem"
        [ -f "$SELF_SIGNED_DIR/${vhost}.pem" ] && chmod 644 "$SELF_SIGNED_DIR/${vhost}.pem"
    fi
}

mkconf_apache() {
    mkdir -p /etc/apache2/ssl
    if [ ! -f "/etc/apache2/ssl/${vhost}.conf" ]; then
        cat > "/etc/apache2/ssl/${vhost}.conf" <<EOF
SSLEngine On
SSLCertificateFile    $SELF_SIGNED_DIR/${vhost}.pem
SSLCertificateKeyFile $SSL_KEY_DIR/${vhost}.key
EOF
    else
        sed -i "s~^SSLCertificateFile.*$~SSLCertificateFile $SELF_SIGNED_DIR/${vhost}.pem~" "/etc/apache2/ssl/${vhost}.conf"
    fi
}

mkconf_nginx() {
    mkdir -p /etc/nginx/ssl
    if [ ! -f "/etc/nginx/ssl/${vhost}.conf" ]; then
        cat > "/etc/nginx/ssl/${vhost}.conf" <<EOF
ssl_certificate $SELF_SIGNED_DIR/${vhost}.pem;
ssl_certificate_key $SSL_KEY_DIR/${vhost}.key;
EOF
    else
        sed -i "s~^ssl_certificate[^_].*$~ssl_certificate $SELF_SIGNED_DIR/${vhost}.pem;~" "/etc/nginx/ssl/${vhost}.conf"
    fi
}

main() {
    if [ "$#" -ne 1 ]; then
        echo "You need to provide one argument !" >&2
        exit 1
    fi
    vhost=$(basename "$1" .conf)
    local_ip=$(ip a|grep brd|cut -d'/' -f1|grep -oE "([0-9]+\.){3}[0-9]+")

    [ -f /etc/default/evoacme ] && . /etc/default/evoacme
    [ -z "${SSL_KEY_DIR}" ] && SSL_KEY_DIR='/etc/ssl/private'
    [ -z "${CSR_DIR}" ] && CSR_DIR='/etc/ssl/requests'
    [ -z "${CRT_DIR}" ] && CRT_DIR='/etc/letsencrypt'
    [ -z "${SELF_SIGNED_DIR}" ] && SELF_SIGNED_DIR='/etc/ssl/self-signed'
    SSL_KEY_SIZE=$(grep default_bits /etc/letsencrypt/openssl.cnf|cut -d'=' -f2|xargs)
    [ -n "${SRV_IP}" ] && SRV_IP="${SRV_IP} $local_ip" || SRV_IP="$local_ip"
    
    vhostfile=$(ls "/etc/nginx/sites-enabled/${vhost}" "/etc/nginx/sites-enabled/${vhost}.conf" "/etc/apache2/sites-enabled/${vhost}" "/etc/apache2/sites-enabled/${vhost}.conf" 2>/dev/null|head -n1)
    
    if [ ! -h "$vhostfile" ]; then
        echo "$vhost is not a valid virtualhost !" >&2
        exit 1
    fi

    if [ -f "$SSL_KEY_DIR/${vhost}.key" ]; then
        echo "$vhost key already exist, overwrite it ? (y)"
        read REPLY
        [ "$REPLY" = "Y" ] || [ "$REPLY" = "y" ] || exit 0
        rm -f "/etc/apache2/ssl/${vhost}.conf /etc/nginx/ssl/${vhost}.conf"
        [ -h "${CRT_DIR}/${vhost}/live" ] && rm "${CRT_DIR}/${vhost}/live"
    fi

    get_domains
    make_key
    make_csr "$domains"
    which apache2ctl >/dev/null && mkconf_apache
        which nginx >/dev/null && mkconf_nginx
}

main "$@"