IPsec Manual Keying

Installation/Vorraussetzungen

Für diese Art der Verbindung wird das Programm "setkey" benötigt, dass im Paket "ipsec-tools" vorhanden ist

• apt-get install ipsec-tools

Konfigurationsdatei erstellen

• In einem beliebigen Verzeichnis eine Datei mit folgendem Inhalt erstellen

#!/usr/sbin/setkey -f
flush;
spdflush;


# ESP
add 192.168.244.2 192.168.242.1 esp 15701 -m tunnel
                        -E 3des-cbc "123456789012123456789012"
                        -A hmac-sha1 "this is the test key";

add 192.168.242.1 192.168.244.2 esp 24501 -m tunnel
                        -E 3des-cbc "123456789012123456789012"
                        -A hmac-sha1 "this is the test key";


spdadd 10.88.88.0/24 10.44.44.0/24 any -P out ipsec
           esp/tunnel/192.168.242.1-192.168.244.2/require;

spdadd 10.44.44.0/24 10.88.88.0/24 any -P in ipsec
           esp/tunnel/192.168.244.2-192.168.242.1/require;

• Auf der Gegenseite muss die selbe Datei erstellt werden, lediglich die IP-Addressen müssen vertauscht werden

Starten

• chmod + x /usr/local/sbin/tunnel.sh
• ./ /usr/local/sbin/tunnel.sh

Überprüfung des Tunnels

• setkey -D

192.168.242.1 192.168.244.2 
	esp mode=tunnel spi=24501(0x00005fb5) reqid=0(0x00000000)
	E: 3des-cbc  31323334 35363738 39303132 31323334 35363738 39303132
	A: hmac-sha1  74686973 20697320 74686520 74657374 206b6579
	seq=0x00000000 replay=0 flags=0x00000000 state=mature 
	created: Oct  5 09:31:55 2016	current: Oct  5 09:32:01 2016
	diff: 6(s)	hard: 0(s)	soft: 0(s)
	last:                     	hard: 0(s)	soft: 0(s)
	current: 0(bytes)	hard: 0(bytes)	soft: 0(bytes)
	allocated: 0	hard: 0	soft: 0
	sadb_seq=1 pid=15756 refcnt=0
192.168.244.2 192.168.242.1 
	esp mode=tunnel spi=15701(0x00003d55) reqid=0(0x00000000)
	E: 3des-cbc  31323334 35363738 39303132 31323334 35363738 39303132
	A: hmac-sha1  74686973 20697320 74686520 74657374 206b6579
	seq=0x00000000 replay=0 flags=0x00000000 state=mature 
	created: Oct  5 09:31:55 2016	current: Oct  5 09:32:01 2016
	diff: 6(s)	hard: 0(s)	soft: 0(s)
	last:                     	hard: 0(s)	soft: 0(s)
	current: 0(bytes)	hard: 0(bytes)	soft: 0(bytes)
	allocated: 0	hard: 0	soft: 0
	sadb_seq=0 pid=15756 refcnt=0

Alternative

• https://gist.github.com/vishvananda/7094676

• /usr/local/sbin/tunnel.sh

#!/bin/bash

if [ "$4" == "" ]; then
    echo "usage: $0 <local_ip> <remote_ip> <new_local_ip> <new_remote_ip>"
    echo "creates an ipsec tunnel between two machines"
    exit 1
fi

SRC="$1"; shift
DST="$1"; shift
LOCAL="$1"; shift
REMOTE="$1"; shift

KEY1=0x`dd if=/dev/urandom count=32 bs=1 2> /dev/null| xxd -p -c 64`
KEY2=0x`dd if=/dev/urandom count=32 bs=1 2> /dev/null| xxd -p -c 64`
echo KEY1 = $KEY1
echo KEY2 = $KEY2
ID=0x`dd if=/dev/urandom count=4 bs=1 2> /dev/null| xxd -p -c 8`

echo "spdflush; flush;" | sudo setkey -c
echo ip xfrm state add src $SRC dst $DST proto esp spi $ID reqid $ID mode tunnel auth sha256 $KEY1 enc aes $KEY2
sudo ip xfrm state add src $SRC dst $DST proto esp spi $ID reqid $ID mode tunnel auth sha256 $KEY1 enc aes $KEY2
echo ip xfrm state add src $DST dst $SRC proto esp spi $ID reqid $ID mode tunnel auth sha256 $KEY1 enc aes $KEY2
sudo ip xfrm state add src $DST dst $SRC proto esp spi $ID reqid $ID mode tunnel auth sha256 $KEY1 enc aes $KEY2
echo ip xfrm policy add src $LOCAL dst $REMOTE dir out tmpl src $SRC dst $DST proto esp reqid $ID mode tunnel
sudo ip xfrm policy add src $LOCAL dst $REMOTE dir out tmpl src $SRC dst $DST proto esp reqid $ID mode tunnel
echo ip xfrm policy add src $REMOTE dst $LOCAL dir in tmpl src $DST dst $SRC proto esp reqid $ID mode tunnel
sudo ip xfrm policy add src $REMOTE dst $LOCAL dir in tmpl src $DST dst $SRC proto esp reqid $ID mode tunnel
#echo 5
#sudo ip addr add $LOCAL dev lo
#echo 6
#sudo ip route add $REMOTE dev eth0 src $LOCAL


ssh $DST /bin/bash << EOF
    echo "spdflush; flush;" | sudo setkey -c
    sudo ip xfrm state add src $SRC dst $DST proto esp spi $ID reqid $ID mode tunnel auth sha256 $KEY1 enc aes $KEY2
    sudo ip xfrm state add src $DST dst $SRC proto esp spi $ID reqid $ID mode tunnel auth sha256 $KEY1 enc aes $KEY2
    sudo ip xfrm policy add src $REMOTE dst $LOCAL dir out tmpl src $DST dst $SRC proto esp reqid $ID mode tunnel
    sudo ip xfrm policy add src $LOCAL dst $REMOTE dir in tmpl src $SRC dst $DST proto esp reqid $ID mode tunnel
#    sudo ip addr add $REMOTE dev lo
#    sudo ip route add $LOCAL dev eth0 src $REMOTE
EOF