wireguard-tools/contrib/ncat-client-server/client.sh

#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.

set -e
[[ $UID == 0 ]] || { echo "You must be root to run this."; exit 1; }
exec 3<>/dev/tcp/demo.wireguard.com/42912
privatekey="$(wg genkey)"
wg pubkey <<<"$privatekey" >&3
IFS=: read -r status server_pubkey server_port internal_ip <&3
[[ $status == OK ]]
ip link del dev wg0 2>/dev/null || true
ip link add dev wg0 type wireguard
wg set wg0 private-key <(echo "$privatekey") peer "$server_pubkey" allowed-ips 0.0.0.0/0 endpoint "demo.wireguard.com:$server_port" persistent-keepalive 25
ip address add "$internal_ip"/24 dev wg0
ip link set up dev wg0
if [ "$1" == "default-route" ]; then
	host="$(wg show wg0 endpoints | sed -n 's/.*\t\(.*\):.*/\1/p')"
	ip route add $(ip route get $host | sed '/ via [0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}/{s/^\(.* via [0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\).*/\1/}' | head -n 1) 2>/dev/null || true
	ip route add 0/1 dev wg0
	ip route add 128/1 dev wg0
fi