ipsec/l2tp-xxx

服务搭建

https://github.com/hwdsl2/setup-ipsec-vpn/tree/ca6bf9818dc9310b6140e0c3d6137206992af354#next-steps

cript for automatic setup of an IPsec VPN server on CentOS/RHEL 6, 7 and 8.
# Works on any dedicated server or virtual private server (VPS) except OpenVZ.
#
# DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC!
#
# The latest version of this script is available at:
# https://github.com/hwdsl2/setup-ipsec-vpn
#
# Copyright (C) 2015-2020 Lin Song <[email protected]>
# Based on the work of Thomas Sarlandie (Copyright 2012)
#
# 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!

# =====================================================

# Define your own values for these variables
# - IPsec pre-shared key, VPN username and password
# - All values MUST be placed inside 'single quotes'
# - DO NOT use these special characters within values: \ " '

YOUR_IPSEC_PSK='Vh9yceh'
YOUR_USERNAME='userttt'
YOUR_PASSWORD='user123456'

# Important notes:   https://git.io/vpnnotes
# Setup VPN clients: https://git.io/vpnclients

# =====================================================

export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
SYS_DT=$(date +%F-%T)

exiterr()  { echo "Error: $1" >&2; exit 1; }
exiterr2() { exiterr "'yum install' failed."; }
conf_bk() { /bin/cp -f "$1" "$1.old-$SYS_DT" 2>/dev/null; }
bigecho() { echo; echo "## $1"; echo; }

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"
}

vpnsetup() {

if ! grep -qs -e "release 6" -e "release 7" -e "release 8" /etc/redhat-release; then
  echo "Error: This script only supports CentOS/RHEL 6, 7 and 8." >&2
  echo "For Ubuntu/Debian, use https://git.io/vpnsetup" >&2
  exit 1
fi

if [ -f /proc/user_beancounters ]; then
  exiterr "OpenVZ VPS is not supported. Try OpenVPN: github.com/Nyr/openvpn-install"
fi

if [ "$(id -u)" != 0 ]; then
  exiterr "Script must be run as root. Try 'sudo sh $0'"
fi

def_iface=$(route 2>/dev/null | grep -m 1 '^default' | grep -o '[^ ]*$')
[ -z "$def_iface" ] && def_iface=$(ip -4 route list 0/0 2>/dev/null | grep -m 1 -Po '(?<=dev )(\S+)')
def_state=$(cat "/sys/class/net/$def_iface/operstate" 2>/dev/null)
if [ -n "$def_state" ] && [ "$def_state" != "down" ]; then
  case "$def_iface" in
    wl*)
      exiterr "Wireless interface '$def_iface' detected. DO NOT run this script on your PC or Mac!"
      ;;
  esac
  NET_IFACE="$def_iface"
else
  eth0_state=$(cat "/sys/class/net/eth0/operstate" 2>/dev/null)
  if [ -z "$eth0_state" ] || [ "$eth0_state" = "down" ]; then
    exiterr "Could not detect the default network interface."
  fi
  NET_IFACE=eth0
fi

[ -n "$YOUR_IPSEC_PSK" ] && VPN_IPSEC_PSK="$YOUR_IPSEC_PSK"
[ -n "$YOUR_USERNAME" ] && VPN_USER="$YOUR_USERNAME"
[ -n "$YOUR_PASSWORD" ] && VPN_PASSWORD="$YOUR_PASSWORD"

if [ -z "$VPN_IPSEC_PSK" ] && [ -z "$VPN_USER" ] && [ -z "$VPN_PASSWORD" ]; then
  bigecho "VPN credentials not set by user. Generating random PSK and password..."
  VPN_IPSEC_PSK=$(LC_CTYPE=C tr -dc 'A-HJ-NPR-Za-km-z2-9' < /dev/urandom | head -c 20)
  VPN_USER=vpnuser
  VPN_PASSWORD=$(LC_CTYPE=C tr -dc 'A-HJ-NPR-Za-km-z2-9' < /dev/urandom | head -c 16)
fi

if [ -z "$VPN_IPSEC_PSK" ] || [ -z "$VPN_USER" ] || [ -z "$VPN_PASSWORD" ]; then
  exiterr "All VPN credentials must be specified. Edit the script and re-enter them."
fi

if printf '%s' "$VPN_IPSEC_PSK $VPN_USER $VPN_PASSWORD" | LC_ALL=C grep -q '[^ -~]\+'; then
  exiterr "VPN credentials must not contain non-ASCII characters."
fi

case "$VPN_IPSEC_PSK $VPN_USER $VPN_PASSWORD" in
  *[\\\"\']*)
    exiterr "VPN credentials must not contain these special characters: \\ \" '"
    ;;
esac

bigecho "VPN setup in progress... Please be patient."

# Create and change to working dir
mkdir -p /opt/src
cd /opt/src || exit 1

bigecho "Installing packages required for setup..."

yum -y install wget bind-utils openssl tar \
  iptables iproute gawk grep sed net-tools || exiterr2

bigecho "Trying to auto discover IP of this server..."

cat <<'EOF'
In case the script hangs here for more than a few minutes,
press Ctrl-C to abort. Then edit it and manually enter IP.
EOF

# In case auto IP discovery fails, enter server's public IP here.
PUBLIC_IP=${VPN_PUBLIC_IP:-''}

[ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(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)
check_ip "$PUBLIC_IP" || exiterr "Cannot detect this server's public IP. Edit the script and manually enter it."

bigecho "Adding the EPEL repository..."

epel_url="https://dl.fedoraproject.org/pub/epel/epel-release-latest-$(rpm -E '%{rhel}').noarch.rpm"
yum -y install epel-release || yum -y install "$epel_url" || exiterr2

bigecho "Installing packages required for the VPN..."

REPO1='--enablerepo=epel'
REPO2='--enablerepo=*server-optional*'
REPO3='--enablerepo=*releases-optional*'
REPO4='--enablerepo=PowerTools'

yum -y install nss-devel nspr-devel pkgconfig pam-devel \
  libcap-ng-devel libselinux-devel curl-devel nss-tools \
  flex bison gcc make ppp || exiterr2

yum "$REPO1" -y install xl2tpd || exiterr2

if grep -qs "release 6" /etc/redhat-release; then
  yum -y remove libevent-devel
  yum "$REPO2" "$REPO3" -y install libevent2-devel fipscheck-devel || exiterr2
elif grep -qs "release 7" /etc/redhat-release; then
  yum -y install systemd-devel iptables-services || exiterr2
  yum "$REPO2" "$REPO3" -y install libevent-devel fipscheck-devel || exiterr2
else
  if [ -f /usr/sbin/subscription-manager ]; then
    subscription-manager repos --enable "codeready-builder-for-rhel-8-*-rpms"
    yum -y install systemd-devel iptables-services libevent-devel fipscheck-devel || exiterr2
  else
    yum "$REPO4" -y install systemd-devel iptables-services libevent-devel fipscheck-devel || exiterr2
  fi
fi

bigecho "Installing Fail2Ban to protect SSH..."

yum "$REPO1" -y install fail2ban || exiterr2

bigecho "Compiling and installing Libreswan..."

SWAN_VER=3.29
swan_file="libreswan-$SWAN_VER.tar.gz"
swan_url1="https://github.com/libreswan/libreswan/archive/v$SWAN_VER.tar.gz"
swan_url2="https://download.libreswan.org/$swan_file"
if ! { wget -t 3 -T 30 -nv -O "$swan_file" "$swan_url1" || wget -t 3 -T 30 -nv -O "$swan_file" "$swan_url2"; }; then
  exit 1
fi
/bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
tar xzf "$swan_file" && /bin/rm -f "$swan_file"
cd "libreswan-$SWAN_VER" || exit 1
cat > Makefile.inc.local <<'EOF'
WERROR_CFLAGS =
USE_DNSSEC = false
USE_DH31 = false
USE_NSS_AVA_COPY = true
USE_NSS_IPSEC_PROFILE = false
USE_GLIBC_KERN_FLIP_HEADERS = true
EOF
NPROCS=$(grep -c ^processor /proc/cpuinfo)
[ -z "$NPROCS" ] && NPROCS=1
make "-j$((NPROCS+1))" -s base && make -s install-base

cd /opt/src || exit 1
/bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
if ! /usr/local/sbin/ipsec --version 2>/dev/null | grep -qF "$SWAN_VER"; then
  exiterr "Libreswan $SWAN_VER failed to build."
fi

bigecho "Creating VPN configuration..."

L2TP_NET=${VPN_L2TP_NET:-'192.168.42.0/24'}
L2TP_LOCAL=${VPN_L2TP_LOCAL:-'192.168.42.1'}
L2TP_POOL=${VPN_L2TP_POOL:-'192.168.42.10-192.168.42.250'}
XAUTH_NET=${VPN_XAUTH_NET:-'192.168.43.0/24'}
XAUTH_POOL=${VPN_XAUTH_POOL:-'192.168.43.10-192.168.43.250'}
DNS_SRV1=${VPN_DNS_SRV1:-'8.8.8.8'}
DNS_SRV2=${VPN_DNS_SRV2:-'8.8.4.4'}
DNS_SRVS="\"$DNS_SRV1 $DNS_SRV2\""
[ -n "$VPN_DNS_SRV1" ] && [ -z "$VPN_DNS_SRV2" ] && DNS_SRVS="$DNS_SRV1"

# Create IPsec config
conf_bk "/etc/ipsec.conf"
cat > /etc/ipsec.conf <<EOF
version 2.0
config setup
  virtual-private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%v4:!$L2TP_NET,%v4:!$XAUTH_NET
  protostack=netkey
  interfaces=%defaultroute
  uniqueids=no
conn shared
  left=%defaultroute
  leftid=$PUBLIC_IP
  right=%any
  encapsulation=yes
  authby=secret
  pfs=no
  rekey=no
  keyingtries=5
  dpddelay=30
  dpdtimeout=120
  dpdaction=clear
  ikev2=never
  ike=aes256-sha2,aes128-sha2,aes256-sha1,aes128-sha1,aes256-sha2;modp1024,aes128-sha1;modp1024
  phase2alg=aes_gcm-null,aes128-sha1,aes256-sha1,aes256-sha2_512,aes128-sha2,aes256-sha2
  sha2-truncbug=no
conn l2tp-psk
  auto=add
  leftprotoport=17/1701
  rightprotoport=17/%any
  type=transport
  phase2=esp
  also=shared
conn xauth-psk
  auto=add
  leftsubnet=0.0.0.0/0
  rightaddresspool=$XAUTH_POOL
  modecfgdns=$DNS_SRVS
  leftxauthserver=yes
  rightxauthclient=yes
  leftmodecfgserver=yes
  rightmodecfgclient=yes
  modecfgpull=yes
  xauthby=file
  ike-frag=yes
  cisco-unity=yes
  also=shared
EOF

# Specify IPsec PSK
conf_bk "/etc/ipsec.secrets"
cat > /etc/ipsec.secrets <<EOF
%any  %any  : PSK "$VPN_IPSEC_PSK"
EOF

# Create xl2tpd config
conf_bk "/etc/xl2tpd/xl2tpd.conf"
cat > /etc/xl2tpd/xl2tpd.conf <<EOF
[global]
port = 1701
[lns default]
ip range = $L2TP_POOL
local ip = $L2TP_LOCAL
require chap = yes
refuse pap = yes
require authentication = yes
name = l2tpd
pppoptfile = /etc/ppp/options.xl2tpd
length bit = yes
EOF

# Set xl2tpd options
conf_bk "/etc/ppp/options.xl2tpd"
cat > /etc/ppp/options.xl2tpd <<EOF
+mschap-v2
ipcp-accept-local
ipcp-accept-remote
noccp
auth
mtu 1280
mru 1280
proxyarp
lcp-echo-failure 4
lcp-echo-interval 30
connect-delay 5000
ms-dns $DNS_SRV1
EOF

if [ -z "$VPN_DNS_SRV1" ] || [ -n "$VPN_DNS_SRV2" ]; then
cat >> /etc/ppp/options.xl2tpd <<EOF
ms-dns $DNS_SRV2
EOF
fi

# Create VPN credentials
conf_bk "/etc/ppp/chap-secrets"
cat > /etc/ppp/chap-secrets <<EOF
"$VPN_USER" l2tpd "$VPN_PASSWORD" *
EOF

conf_bk "/etc/ipsec.d/passwd"
VPN_PASSWORD_ENC=$(openssl passwd -1 "$VPN_PASSWORD")
cat > /etc/ipsec.d/passwd <<EOF
$VPN_USER:$VPN_PASSWORD_ENC:xauth-psk
EOF

bigecho "Updating sysctl settings..."

if ! grep -qs "hwdsl2 VPN script" /etc/sysctl.conf; then
  conf_bk "/etc/sysctl.conf"
  if [ "$(getconf LONG_BIT)" = "64" ]; then
    SHM_MAX=68719476736
    SHM_ALL=4294967296
  else
    SHM_MAX=4294967295
    SHM_ALL=268435456
  fi
cat >> /etc/sysctl.conf <<EOF
# Added by hwdsl2 VPN script
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.shmmax = $SHM_MAX
kernel.shmall = $SHM_ALL
net.ipv4.ip_forward = 1
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.all.rp_filter = 0
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.$NET_IFACE.send_redirects = 0
net.ipv4.conf.$NET_IFACE.rp_filter = 0
net.core.wmem_max = 12582912
net.core.rmem_max = 12582912
net.ipv4.tcp_rmem = 10240 87380 12582912
net.ipv4.tcp_wmem = 10240 87380 12582912
EOF
fi

bigecho "Updating IPTables rules..."

# Check if rules need updating
ipt_flag=0
IPT_FILE="/etc/sysconfig/iptables"
if ! grep -qs "hwdsl2 VPN script" "$IPT_FILE" \
   || ! iptables -t nat -C POSTROUTING -s "$L2TP_NET" -o "$NET_IFACE" -j MASQUERADE 2>/dev/null \
   || ! iptables -t nat -C POSTROUTING -s "$XAUTH_NET" -o "$NET_IFACE" -m policy --dir out --pol none -j MASQUERADE 2>/dev/null; then
  ipt_flag=1
fi

# Add IPTables rules for VPN
if [ "$ipt_flag" = "1" ]; then
  service fail2ban stop >/dev/null 2>&1
  iptables-save > "$IPT_FILE.old-$SYS_DT"
  iptables -I INPUT 1 -p udp --dport 1701 -m policy --dir in --pol none -j DROP
  iptables -I INPUT 2 -m conntrack --ctstate INVALID -j DROP
  iptables -I INPUT 3 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  iptables -I INPUT 4 -p udp -m multiport --dports 500,4500 -j ACCEPT
  iptables -I INPUT 5 -p udp --dport 1701 -m policy --dir in --pol ipsec -j ACCEPT
  iptables -I INPUT 6 -p udp --dport 1701 -j DROP
  iptables -I FORWARD 1 -m conntrack --ctstate INVALID -j DROP
  iptables -I FORWARD 2 -i "$NET_IFACE" -o ppp+ -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  iptables -I FORWARD 3 -i ppp+ -o "$NET_IFACE" -j ACCEPT
  iptables -I FORWARD 4 -i ppp+ -o ppp+ -s "$L2TP_NET" -d "$L2TP_NET" -j ACCEPT
  iptables -I FORWARD 5 -i "$NET_IFACE" -d "$XAUTH_NET" -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  iptables -I FORWARD 6 -s "$XAUTH_NET" -o "$NET_IFACE" -j ACCEPT
  # Uncomment if you wish to disallow traffic between VPN clients themselves
  # iptables -I FORWARD 2 -i ppp+ -o ppp+ -s "$L2TP_NET" -d "$L2TP_NET" -j DROP
  # iptables -I FORWARD 3 -s "$XAUTH_NET" -d "$XAUTH_NET" -j DROP
  iptables -A FORWARD -j DROP
  iptables -t nat -I POSTROUTING -s "$XAUTH_NET" -o "$NET_IFACE" -m policy --dir out --pol none -j MASQUERADE
  iptables -t nat -I POSTROUTING -s "$L2TP_NET" -o "$NET_IFACE" -j MASQUERADE
  echo "# Modified by hwdsl2 VPN script" > "$IPT_FILE"
  iptables-save >> "$IPT_FILE"
fi

bigecho "Creating basic Fail2Ban rules..."

if [ ! -f /etc/fail2ban/jail.local ] ; then
cat > /etc/fail2ban/jail.local <<'EOF'
[ssh-iptables]
enabled  = true
filter   = sshd
action   = iptables[name=SSH, port=ssh, protocol=tcp]
logpath  = /var/log/secure
EOF
fi

bigecho "Enabling services on boot..."

if grep -qs "release 6" /etc/redhat-release; then
  chkconfig iptables on
  chkconfig fail2ban on
else
  systemctl --now mask firewalld 2>/dev/null
  systemctl enable iptables fail2ban 2>/dev/null
fi

if ! grep -qs "hwdsl2 VPN script" /etc/rc.local; then
  if [ -f /etc/rc.local ]; then
    conf_bk "/etc/rc.local"
  else
    echo '#!/bin/sh' > /etc/rc.local
  fi
cat >> /etc/rc.local <<'EOF'
# Added by hwdsl2 VPN script
(sleep 15
modprobe -q pppol2tp
service ipsec restart
service xl2tpd restart
echo 1 > /proc/sys/net/ipv4/ip_forward)&
EOF
fi

bigecho "Starting services..."

# Restore SELinux contexts
restorecon /etc/ipsec.d/*db 2>/dev/null
restorecon /usr/local/sbin -Rv 2>/dev/null
restorecon /usr/local/libexec/ipsec -Rv 2>/dev/null

# Reload sysctl.conf
sysctl -e -q -p

# Update file attributes
chmod +x /etc/rc.local
chmod 600 /etc/ipsec.secrets* /etc/ppp/chap-secrets* /etc/ipsec.d/passwd*

# Apply new IPTables rules
iptables-restore < "$IPT_FILE"

# Fix xl2tpd on CentOS 7/8, if kernel module "l2tp_ppp" is unavailable
if grep -qs -e "release 7" -e "release 8" /etc/redhat-release; then
  if ! modprobe -q l2tp_ppp; then
    sed -i '/^ExecStartPre/s/^/#/' /usr/lib/systemd/system/xl2tpd.service
    systemctl daemon-reload
  fi
fi

# Restart services
mkdir -p /run/pluto
modprobe -q pppol2tp
service fail2ban restart 2>/dev/null
service ipsec restart 2>/dev/null
service xl2tpd restart 2>/dev/null

cat <<EOF
================================================
IPsec VPN server is now ready for use!
Connect to your new VPN with these details:
Server IP: $PUBLIC_IP
IPsec PSK: $VPN_IPSEC_PSK
Username: $VPN_USER
Password: $VPN_PASSWORD
Write these down. You'll need them to connect!
Important notes:   https://git.io/vpnnotes
Setup VPN clients: https://git.io/vpnclients
================================================
EOF

}

## Defer setup until we have the complete script
vpnsetup "$@"

exit 0

http://www.internet-computer-security.com/VPN-Guide/Aggressive-Mode.html

连接方式

Configure IPsec/XAuth VPN Clients
https://github.com/hwdsl2/setup-ipsec-vpn/blob/master/docs/clients-xauth.md

但是没有ubuntu的连接方式
On Ubuntu Linux you can try using "vpnc" to connect to the VPN server via IPsec/XAuth. However, because vpnc only supports IPsec "aggressive mode", it is not compatible with the default configuration set up by the VPN scripts, which supports IPsec "main mode" only. You must manually edit /etc/ipsec.conf to make it work. You can find more details at [1] [2] [3]

[1] #152 https://github.com/hwdsl2/setup-ipsec-vpn/issues/152
[2] #121 https://github.com/hwdsl2/setup-ipsec-vpn/issues/121
[3] #70 https://github.com/hwdsl2/setup-ipsec-vpn/issues/70

需要修改ipec 的配置:

cisco-unity=yes
rightid=@[mygroup2]
aggrmode=yes

其他

https://www.cnblogs.com/mikeluwen/p/10402631.html
https://www.bbsmax.com/A/gGdX6D31J4/
https://segmentfault.com/a/1190000006125737
https://github.com/hwdsl2/setup-ipsec-vpn/issues/121
https://www.jianshu.com/p/7a5a528947c5

https://www.ibm.com/developerworks/cn/linux/l-ipsec/index.html