#!/bin/bash
sleep 60
export DEBIAN_FRONTEND=noninteractive
apt -y update


apt -yq install socat strongswan-starter libcharon-extra-plugins libstrongswan-extra-plugins libcharon-standard-plugins strongswan strongswan-pki iptables-persistent 

export MYDOMAIN="vpn.domain.com"

sleep 60

iptables -t nat -A POSTROUTING -s 192.168.134.0/24 -o eth0 -m policy --pol ipsec --dir out -j ACCEPT
iptables -t nat -A POSTROUTING -s 192.168.134.0/24 -o eth0 -j MASQUERADE
iptables -t mangle -A FORWARD --match policy --pol ipsec --dir in -s 192.168.134.0/24 -o eth0 -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1361:1536 -j TCPMSS --set-mss 1360
netfilter-persistent save

cat <<EOT >> /etc/sysctl.conf
net.ipv4.ip_forward=1
net.ipv4.conf.all.accept_redirects=0
net.ipv4.conf.all.send_redirects=0
net.ipv4.ip_no_pmtu_disc=1
EOT

sysctl -p

cat <<EOT > /etc/ipsec.conf
config setup
    charondebug="ike 1, knl 1, cfg 0"
    uniqueids=no

conn ikev2-vpn
    auto=add
    compress=no
    type=tunnel
    keyexchange=ikev2
    fragmentation=yes
    forceencaps=yes
    dpdaction=clear
    dpddelay=300s
    rekey=no
    left=%any
    leftid=@$MYDOMAIN
    leftcert=cert.pem
    leftsendcert=always
    leftsubnet=0.0.0.0/0
    right=%any
    rightid=%any
    rightauth=eap-mschapv2
    rightsourceip=192.168.134.0/24
    rightdns=8.8.4.4,1.1.1.1
    rightsendcert=never
    eap_identity=%identity
EOT


cat <<EOT > /etc/ipsec.secrets
: RSA "privkey.pem"
user : EAP "PassworD"
EOT

curl https://get.acme.sh | sh -s email=admin@vpn.domain.com

sleep 15

.acme.sh/acme.sh --no-color --issue --standalone -d $MYDOMAIN --key-file /etc/ipsec.d/private/privkey.pem --ca-file /etc/ipsec.d/cacerts/chain.pem --cert-file /etc/ipsec.d/certs/cert.pem --fullchain-file /etc/ipsec.d/certs/fullchain.pem --post-hook "find /etc/ipsec.d/ -name '*.pem' -type f -exec chmod 600 {} \;" --renew-hook "find /etc/ipsec.d/ -name '*.pem' -type f -exec chmod 600 {} \; -exec /usr/bin/systemctl restart ipsec \;"

sleep 5
systemctl enable ipsec
systemctl enable netfilter-persistent
ipsec restart
ipsec statusall