#!/bin/bash

# enable ip forward
echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
sysctl -p

# install wireguard, wireguard-tools and curl
sudo apt-get update && sudo apt-get install -y wireguard wireguard-tools curl

conf="/root/conf"
server="$conf/server"
user="$conf/user"

# create dir for configs && set umask
mkdir -p $server && mkdir $user && umask 077 $conf

# create server keys
wg genkey | tee $server/privatekey | wg pubkey > $server/publickey
priv=`cat $server/privatekey`
pub=`cat $server/publickey`

# create user keys
wg genkey | tee $user/privatekey | wg pubkey > $user/publickey
upriv=`cat $user/privatekey`
upub=`cat $user/publickey`

# get server ip
ip=`curl ifconfig.me`

# generate server config
cat > $server/wg0.conf <<EOF
[Interface]
PrivateKey = $priv
Address = 10.1.1.1/24
ListenPort = 51820
PostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
PostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE
[Peer]
PublicKey = $upub
AllowedIPs = 10.1.1.2/32
EOF

# generate user config
cat > $user/user.conf <<EOF
[Interface]
PrivateKey = $upriv
Address = 10.1.1.2/24
[Peer]
PublicKey = $pub
Endpoint = $ip:51820
AllowedIPs = 0.0.0.0/1, 128.0.0.0/1
EOF

# copy config to /etc/wireguard and start interface
cp $server/wg0.conf /etc/wireguard && wg-quick up wg0