Diskussion:Ssh knock

What do you think of this script? (A thousand apologies, not a German-speaker.)

1. !/bin/sh

dir=/var/knockdata

num=${0##*[.]}

function badknock { echo b > "$dir/$1"; } # hosts banned until lockfile removed

function ifnoknock { if ! -f "$dir/$1" ; then badknock $REMOTE_HOST; fi }

case "$num" in 1) if -f "$dir/$REMOTE_HOST" #reknock?

       then    if [[ "$(<$dir/$REMOTE_HOST)" = 'g' ]]
               then    echo 1 > "$dir/$REMOTE_HOST" #reknock!
               else    badknock "$REMOTE_HOST"
               fi
       else    echo 1 > "$dir/$REMOTE_HOST"
       fi ;;

2) ifnoknock "$REMOTE_HOST"

       if [[ "$(<$dir/$REMOTE_HOST)" = '1' ]]
       then    echo 2 > "$dir/$REMOTE_HOST"
       else    badknock "$REMOTE_HOST"
       fi ;;

3) ifnoknock "$REMOTE_HOST"

       if [[ "$(<$dir/$REMOTE_HOST)" = '2' ]]
       then    echo g > "$dir/$REMOTE_HOST"
       else    badknock "$REMOTE_HOST"
       fi ;;

t) ifnoknock "$REMOTE_HOST"

       if [[ "$(<$dir/$REMOTE_HOST)" = 'g' ]]
       then    exec /usr/sbin/sshd -i # (https://wiki.uugrn.org/Ssh_knock)
       fi ;;

esac

echo '/*/'