#!/bin/bash


usage() {
    cat << EOF
    
    Usage: $(dirname $0) [-n|--principals] <principal>[,<principal>[,<principal>[,...]]] [-V|--valid-time] <TIME> [-s|--serialnumber] <INT> [-S|-serialnumber-file] <filename> [-I|--identity] [--dry-run] <identity> publickey


EOF

}
default_serialnumberfile="${HOME}/ssh-ca/serialnumbers/serialnumber"

set -- $(getopt -u -o hHn:V:s:S:I:tU --long help,host,user,principals:,valid-time:,serialnumber:,serialnumber-file:,identity:,hms,dry-run -- "$@"|| exit $?)

while : ;do
    case $1 in
        -h|--help)
            usage
            break
            ;;
        -H|host)
            host_or_user=host
            shift
            ;;
        -U|user)
            host_or_user=user
            shift
            ;;
        -n|--principals)
            shift
            principals=$1
            shift
            ;;
        -V|--valid-time)
            shift
            validtime="${1}"
            shift
            ;;
        -S|--serialnumber)
            shift
            serialnumber=$1
            shift
            ;;
        -s|--serialnumber-file)
            shift
            serialnumberfile="$1"
            shift
            ;;
        -I|--identity)
            shift
            identity=${1}
            shift
            ;;
        -t|--hms)
            # t wie token
            shift
            hms=true
            ;;
        --dry-run)
            DRY=true
            shift
            ;;
        --)
            shift
            break
            ;;
        *)
            echo wrong argument $1 >&2
            usage
            exit 1
            ;;
    esac
done

[ -z "${validtime+x}" ]         && validtime="+8W"
[ -z "${identity+x}" ]          && identity=${USER}@$(hostname -f)
[ -z "${serialnumberfile+x}" ]  && serialnumberfile=${default_serialnumberfile}
[ -z "${serialnumber+x}" ]      && serialnumber=$(sed -i -r 's/^([0-9]+)$/echo "$((\1+1))"/ge' "${serialnumberfile}"; cat "${serialnumberfile}" )
[ -z "${principals+x}" ]        && { echo "no principals given"; [ $DRY ] || usage; [ $DRY ] || exit 1; }

CABASE=~/ssh-ca
host_or_user=user
case $host_or_user in
    host)
        CAPATH=$CABASE/${host_or_user^^}_CA/${host_or_user}
        ;;
    user)
        CAPATH=$CABASE/${host_or_user^^}_CA/${host_or_user}_ca.pub
esac

if ${hms:-false};then
    echo ssh-keygen -s $CABASE/${host_or_user^^}_CA/${host_or_user}_ca.pub -n "${principals}" -V "${validtime}" -z $serialnumber -I "${identity}" "$1"
    [ $DRY ] || ssh-keygen -s $CABASE/${host_or_user^^}_CA/${host_or_user}_ca.pub -D $P11M -n "${principals}" -V "${validtime}" -z $serialnumber -I "${identity}" "$1"
else
    echo ssh-keygen -s $CABASE/${host_or_user^^}_CA/${host_or_user}_ca -n "${principals}" -V "${validtime}" -z $serialnumber -I "${identity}" "$1"
    [ $DRY ] || ssh-keygen -s $CABASE/${host_or_user^^}_CA/${host_or_user}_ca -n "${principals}" -V "${validtime}" -z $serialnumber -I "${identity}" "$1"
fi