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mirror of synced 2024-11-22 13:06:02 +03:00

Add IKEv2 change address helper script

- New: IKEv2 change address helper script. This script can be used
  to change the IKEv2 VPN server's address.
This commit is contained in:
hwdsl2 2022-02-13 23:41:35 -06:00
parent 34ece8bdc4
commit 444403ba10

320
extras/ikev2changeaddr.sh Executable file
View File

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#!/bin/bash
#
# Script to change IKEv2 VPN server address
#
# The latest version of this script is available at:
# https://github.com/hwdsl2/setup-ipsec-vpn
#
# Copyright (C) 2022 Lin Song <linsongui@gmail.com>
#
# This work is licensed under the Creative Commons Attribution-ShareAlike 3.0
# Unported License: http://creativecommons.org/licenses/by-sa/3.0/
#
# Attribution required: please include my name in any derivative and let me
# know how you have improved it!
export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
exiterr() { echo "Error: $1" >&2; exit 1; }
bigecho() { echo "## $1"; }
check_ip() {
IP_REGEX='^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$'
printf '%s' "$1" | tr -d '\n' | grep -Eq "$IP_REGEX"
}
check_dns_name() {
FQDN_REGEX='^([a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$'
printf '%s' "$1" | tr -d '\n' | grep -Eq "$FQDN_REGEX"
}
check_root() {
if [ "$(id -u)" != 0 ]; then
exiterr "Script must be run as root. Try 'sudo bash $0'"
fi
}
check_os() {
os_type=centos
rh_file="/etc/redhat-release"
if grep -qs "Red Hat" "$rh_file"; then
os_type=rhel
fi
if grep -qs "release 7" "$rh_file"; then
os_ver=7
elif grep -qs "release 8" "$rh_file"; then
os_ver=8
grep -qi stream "$rh_file" && os_ver=8s
grep -qi rocky "$rh_file" && os_type=rocky
grep -qi alma "$rh_file" && os_type=alma
elif grep -qs "Amazon Linux release 2" /etc/system-release; then
os_type=amzn
os_ver=2
else
os_type=$(lsb_release -si 2>/dev/null)
[ -z "$os_type" ] && [ -f /etc/os-release ] && os_type=$(. /etc/os-release && printf '%s' "$ID")
case $os_type in
[Uu]buntu)
os_type=ubuntu
;;
[Dd]ebian)
os_type=debian
;;
[Rr]aspbian)
os_type=raspbian
;;
[Aa]lpine)
os_type=alpine
;;
*)
cat 1>&2 <<'EOF'
Error: This script only supports one of the following OS:
Ubuntu, Debian, CentOS/RHEL 7/8, Rocky Linux, AlmaLinux,
Amazon Linux 2 or Alpine Linux
EOF
exit 1
;;
esac
if [ "$os_type" = "alpine" ]; then
os_ver=$(. /etc/os-release && printf '%s' "$VERSION_ID" | cut -d '.' -f 1,2)
if [ "$os_ver" != "3.14" ] && [ "$os_ver" != "3.15" ]; then
exiterr "This script only supports Alpine Linux 3.14/3.15."
fi
else
os_ver=$(sed 's/\..*//' /etc/debian_version | tr -dc 'A-Za-z0-9')
fi
fi
}
check_libreswan() {
ipsec_ver=$(ipsec --version 2>/dev/null)
if ( ! grep -qs "hwdsl2 VPN script" /etc/sysctl.conf && ! grep -qs "hwdsl2" /opt/src/run.sh ) \
|| ! printf '%s' "$ipsec_ver" | grep -q "Libreswan"; then
cat 1>&2 <<'EOF'
Error: This script can only be used with an IPsec server created using:
https://github.com/hwdsl2/setup-ipsec-vpn
EOF
exit 1
fi
}
check_ikev2() {
if ! grep -qs "conn ikev2-cp" /etc/ipsec.d/ikev2.conf; then
cat 1>&2 <<'EOF'
Error: You must first set up IKEv2 before changing IKEv2 server address.
See: https://git.io/ikev2
EOF
exit 1
fi
}
check_utils_exist() {
command -v certutil >/dev/null 2>&1 || exiterr "'certutil' not found. Abort."
}
abort_and_exit() {
echo "Abort. No changes were made." >&2
exit 1
}
confirm_or_abort() {
printf '%s' "$1"
read -r response
case $response in
[yY][eE][sS]|[yY])
echo
;;
*)
abort_and_exit
;;
esac
}
check_cert_exists() {
certutil -L -d sql:/etc/ipsec.d -n "$1" >/dev/null 2>&1
}
check_ca_cert_exists() {
check_cert_exists "IKEv2 VPN CA" || exiterr "Certificate 'IKEv2 VPN CA' does not exist. Abort."
}
get_server_address() {
server_addr_old=$(grep -s "leftcert=" /etc/ipsec.d/ikev2.conf | cut -f2 -d=)
[ -z "$server_addr_old" ] && server_addr_old=$(grep -s "leftcert=" /etc/ipsec.conf | cut -f2 -d=)
check_ip "$server_addr_old" || check_dns_name "$server_addr_old" || exiterr "Could not get current VPN server address."
}
show_welcome() {
cat <<EOF
Welcome! Use this script to change this IKEv2 VPN server's address. A new server
certificate will be generated if necessary.
Current server address: $server_addr_old
EOF
}
get_server_ip() {
bigecho "Trying to auto discover IP of this server..."
public_ip=${VPN_PUBLIC_IP:-''}
check_ip "$public_ip" || public_ip=$(dig @resolver1.opendns.com -t A -4 myip.opendns.com +short)
check_ip "$public_ip" || public_ip=$(wget -t 3 -T 15 -qO- http://ipv4.icanhazip.com)
}
enter_server_address() {
echo "Do you want IKEv2 VPN clients to connect to this server using a DNS name,"
printf "e.g. vpn.example.com, instead of its IP address? [y/N] "
read -r response
case $response in
[yY][eE][sS]|[yY])
use_dns_name=1
echo
;;
*)
use_dns_name=0
echo
;;
esac
if [ "$use_dns_name" = "1" ]; then
read -rp "Enter the DNS name of this VPN server: " server_addr
until check_dns_name "$server_addr"; do
echo "Invalid DNS name. You must enter a fully qualified domain name (FQDN)."
read -rp "Enter the DNS name of this VPN server: " server_addr
done
else
get_server_ip
echo
read -rp "Enter the IPv4 address of this VPN server: [$public_ip] " server_addr
[ -z "$server_addr" ] && server_addr="$public_ip"
until check_ip "$server_addr"; do
echo "Invalid IP address."
read -rp "Enter the IPv4 address of this VPN server: [$public_ip] " server_addr
[ -z "$server_addr" ] && server_addr="$public_ip"
done
fi
}
check_server_address() {
if [ "$server_addr" = "$server_addr_old" ]; then
echo >&2
echo "Error: IKEv2 server address is already '$server_addr'. Nothing to do." >&2
abort_and_exit
fi
}
confirm_changes() {
cat <<EOF
You are about to change this IKEv2 VPN server's address.
Read the important notes below before continuing.
===========================================
Current server address: $server_addr_old
New server address: $server_addr
===========================================
*IMPORTANT*
After running this script, you must manually update the server address
on any existing IKEv2 client devices. For iOS clients, you'll need to
export and re-import client configuration using the IKEv2 helper script.
EOF
printf "Do you want to continue? [Y/n] "
read -r response
case $response in
[yY][eE][sS]|[yY]|'')
echo
;;
*)
abort_and_exit
;;
esac
}
create_server_cert() {
if check_cert_exists "$server_addr"; then
bigecho "Server certificate '$server_addr' already exists, skipping..."
else
bigecho "Generating server certificate..."
if [ "$use_dns_name" = "1" ]; then
certutil -z <(head -c 1024 /dev/urandom) \
-S -c "IKEv2 VPN CA" -n "$server_addr" \
-s "O=IKEv2 VPN,CN=$server_addr" \
-k rsa -g 3072 -v 120 \
-d sql:/etc/ipsec.d -t ",," \
--keyUsage digitalSignature,keyEncipherment \
--extKeyUsage serverAuth \
--extSAN "dns:$server_addr" >/dev/null 2>&1 || exiterr "Failed to create server certificate."
else
certutil -z <(head -c 1024 /dev/urandom) \
-S -c "IKEv2 VPN CA" -n "$server_addr" \
-s "O=IKEv2 VPN,CN=$server_addr" \
-k rsa -g 3072 -v 120 \
-d sql:/etc/ipsec.d -t ",," \
--keyUsage digitalSignature,keyEncipherment \
--extKeyUsage serverAuth \
--extSAN "ip:$server_addr,dns:$server_addr" >/dev/null 2>&1 || exiterr "Failed to create server certificate."
fi
fi
}
update_ikev2_conf() {
bigecho "Updating IKEv2 configuration..."
if ! grep -qs '^include /etc/ipsec\.d/\*\.conf$' /etc/ipsec.conf; then
echo >> /etc/ipsec.conf
echo 'include /etc/ipsec.d/*.conf' >> /etc/ipsec.conf
fi
sed -i -e "/^[[:space:]]\+leftcert=/d" \
-e "/^[[:space:]]\+leftid=/d" /etc/ipsec.d/ikev2.conf
if [ "$use_dns_name" = "1" ]; then
sed -i "/conn ikev2-cp/a \ leftid=@$server_addr" /etc/ipsec.d/ikev2.conf
else
sed -i "/conn ikev2-cp/a \ leftid=$server_addr" /etc/ipsec.d/ikev2.conf
fi
sed -i "/conn ikev2-cp/a \ leftcert=$server_addr" /etc/ipsec.d/ikev2.conf
}
restart_ipsec_service() {
bigecho "Restarting IPsec service..."
mkdir -p /run/pluto
service ipsec restart 2>/dev/null
}
print_client_info() {
cat <<EOF
Successfully changed IKEv2 server address!
EOF
}
ikev2changeaddr() {
check_root
check_os
check_libreswan
check_ikev2
check_utils_exist
check_ca_cert_exists
get_server_address
show_welcome
enter_server_address
check_server_address
confirm_changes
create_server_cert
update_ikev2_conf
if [ "$os_type" = "alpine" ]; then
ipsec auto --replace ikev2-cp >/dev/null
else
restart_ipsec_service
fi
print_client_info
}
## Defer until we have the complete script
ikev2changeaddr "$@"
exit 0