setup

#!/bin/bash -e

echo
echo "=== Mikhail Nuzhin setting IKEv2-setup in Docker ==="
echo


function exit_badly {
  echo "$1"
  exit 1
}

IP=$(dig -4 +short myip.opendns.com @resolver1.opendns.com)

echo
echo "External IP: ${IP}"
echo

echo "*** This hostname must already resolve to this machine ***"
read -r -p "Hostname for VPN: " VPNHOST

VPNHOSTIP=$(dig -4 +short "${VPNHOST}")
[[ -n "$VPNHOSTIP" ]] || exit_badly "Cannot resolve VPN hostname: aborting"

if [[ "${IP}" != "${VPNHOSTIP}" ]]; then
  echo "Warning: ${VPNHOST} resolves to ${VPNHOSTIP}, not ${IP}"
  echo "Either you're behind NAT, or something is wrong (e.g. hostname points to wrong IP, CloudFlare proxying shenanigans, ...)"
  read -r -p "Press [Return] to continue anyway, or Ctrl-C to abort"
fi

read -r -p "VPN username: " VPNUSERNAME
while true; do
  read -r -s -p "VPN password (no quotes, please): " VPNPASSWORD
  echo
  read -r -s -p "Confirm VPN password: " VPNPASSWORD2
  echo
  [[ "${VPNPASSWORD}" = "${VPNPASSWORD2}" ]] && break
  echo "Passwords didn't match -- please try again"
done

echo '
Public DNS servers include:

176.103.130.130,176.103.130.131  AdGuard               https://adguard.com/en/adguard-dns/overview.html
176.103.130.132,176.103.130.134  AdGuard Family        https://adguard.com/en/adguard-dns/overview.html
1.1.1.1,1.0.0.1                  Cloudflare/APNIC      https://1.1.1.1
84.200.69.80,84.200.70.40        DNS.WATCH             https://dns.watch
8.8.8.8,8.8.4.4                  Google                https://developers.google.com/speed/public-dns/
208.67.222.222,208.67.220.220    OpenDNS               https://www.opendns.com
208.67.222.123,208.67.220.123    OpenDNS FamilyShield  https://www.opendns.com
9.9.9.9,149.112.112.112          Quad9                 https://quad9.net
77.88.8.8,77.88.8.1              Yandex                https://dns.yandex.com
77.88.8.88,77.88.8.2             Yandex Safe           https://dns.yandex.com
77.88.8.7,77.88.8.3              Yandex Family         https://dns.yandex.com
'

read -r -p "DNS servers for VPN users (default: 176.103.130.130,176.103.130.131): " VPNDNS
VPNDNS=${VPNDNS:-'176.103.130.130,176.103.130.131'}

grep -Fq 'MikhailNuzhin' ikev2/conf/ipsec.conf || echo "# strongSwan IPsec configuration file

config setup
  strictcrlpolicy=yes
  uniqueids=never

conn roadwarrior
  auto=add
  compress=no
  type=tunnel
  keyexchange=ikev2
  fragmentation=yes
  forceencaps=yes

  ike=aes256gcm16-prfsha384-ecp384,aes256-aes128-sha256-sha1-modp2048-modp4096-modp1024!
  esp=aes256gcm16-ecp384,aes128-aes256-sha1-sha256-modp2048-modp4096-modp1024!

  dpdaction=clear
  dpddelay=300s
  rekey=no
  left=%any
  leftid=@${VPNHOST}
  leftcert=cert.pem
  leftsendcert=always
  leftsubnet=0.0.0.0/0
  right=%any
  rightid=%any
  rightauth=eap-mschapv2
  eap_identity=%any
  rightdns=${VPNDNS}
  rightsourceip=10.101.0.0/16
  rightsendcert=never
" > ikev2/conf/ipsec.conf

grep -Fq 'MikhailNuzhin' ikev2/conf/ipsec.secrets || echo "# strongSwan IPsec secrets file

${VPNHOST} : RSA \"privkey.pem\"
${VPNUSERNAME} : EAP \"${VPNPASSWORD}\"
" > ikev2/conf/ipsec.secrets

grep -Fq 'MikhailNuzhin' ikev2/bin/run || echo "# Startup file strongSwan
#!/bin/bash

iptables -P INPUT   ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT  ACCEPT
iptables -F
iptables -t nat -F
iptables -t mangle -F
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m state --state INVALID -j DROP
iptables -I INPUT -i eth0 -m state --state NEW -m recent --set
iptables -I INPUT -i eth0 -m state --state NEW -m recent --update --seconds 300 --hitcount 60 -j DROP
iptables -A INPUT -p udp --dport  500 -j ACCEPT
iptables -A INPUT -p udp --dport 4500 -j ACCEPT
iptables -A FORWARD --match policy --pol ipsec --dir in  --proto esp -s 10.101.0.0/16 -j ACCEPT
iptables -A FORWARD --match policy --pol ipsec --dir out --proto esp -d 10.101.0.0/16 -j ACCEPT
iptables -t mangle -A FORWARD --match policy --pol ipsec --dir in -s 10.101.0.0/16 -o eth0 -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1361:1536 -j TCPMSS --set-mss 1360
iptables -t nat -A POSTROUTING -s 10.101.0.0/16 -o eth0 -m policy --pol ipsec --dir out -j ACCEPT  # exempt IPsec traffic from masquerading
iptables -t nat -A POSTROUTING -s 10.101.0.0/16 -o eth0 -j MASQUERADE
iptables -A INPUT   -j DROP
iptables -A FORWARD -j DROP

ln -f -s "/etc/letsencrypt/live/${VPNHOST}/cert.pem"    /etc/ipsec.d/certs/cert.pem
ln -f -s "/etc/letsencrypt/live/${VPNHOST}/privkey.pem" /etc/ipsec.d/private/privkey.pem
ln -f -s "/etc/letsencrypt/live/${VPNHOST}/chain.pem"   /etc/ipsec.d/cacerts/chain.pem

/usr/sbin/ipsec start --nofork
" >  ikev2/bin/run

mkdir -p ~/ikev2/connect
cd ~/ikev2/connect

cat << EOF > vpn-ios.mobileconfig
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE plist PUBLIC '-//Apple//DTD PLIST 1.0//EN' 'http://www.apple.com/DTDs/PropertyList-1.0.dtd'>
<plist version='1.0'>
<dict>
  <key>PayloadContent</key>
  <array>
    <dict>
      <key>IKEv2</key>
      <dict>
        <key>AuthenticationMethod</key>
        <string>None</string>
        <key>ChildSecurityAssociationParameters</key>
        <dict>
          <key>EncryptionAlgorithm</key>
          <string>AES-256-GCM</string>
          <key>IntegrityAlgorithm</key>
          <string>SHA2-384</string>
          <key>DiffieHellmanGroup</key>
          <integer>20</integer>
          <key>LifeTimeInMinutes</key>
          <integer>1440</integer>
        </dict>
        <key>DeadPeerDetectionRate</key>
        <string>Medium</string>
        <key>DisableMOBIKE</key>
        <integer>0</integer>
        <key>DisableRedirect</key>
        <integer>0</integer>
        <key>EnableCertificateRevocationCheck</key>
        <integer>0</integer>
        <key>EnablePFS</key>
        <true/>
        <key>ExtendedAuthEnabled</key>
        <true/>
        <key>IKESecurityAssociationParameters</key>
        <dict>
          <key>EncryptionAlgorithm</key>
          <string>AES-256-GCM</string>
          <key>IntegrityAlgorithm</key>
          <string>SHA2-384</string>
          <key>DiffieHellmanGroup</key>
          <integer>20</integer>
          <key>LifeTimeInMinutes</key>
          <integer>1440</integer>
        </dict>
        <key>OnDemandEnabled</key>
        <integer>1</integer>
        <key>OnDemandRules</key>
        <array>
          <dict>
            <key>Action</key>
            <string>Connect</string>
          </dict>
        </array>
        <key>RemoteAddress</key>
        <string>${VPNHOST}</string>
        <key>RemoteIdentifier</key>
        <string>${VPNHOST}</string>
        <key>UseConfigurationAttributeInternalIPSubnet</key>
        <integer>0</integer>
      </dict>
      <key>IPv4</key>
      <dict>
        <key>OverridePrimary</key>
        <integer>1</integer>
      </dict>
      <key>PayloadDescription</key>
      <string>Configures VPN settings</string>
      <key>PayloadDisplayName</key>
      <string>VPN</string>
      <key>PayloadIdentifier</key>
      <string>com.apple.vpn.managed.$(uuidgen)</string>
      <key>PayloadType</key>
      <string>com.apple.vpn.managed</string>
      <key>PayloadUUID</key>
      <string>$(uuidgen)</string>
      <key>PayloadVersion</key>
      <integer>1</integer>
      <key>Proxies</key>
      <dict>
        <key>HTTPEnable</key>
        <integer>0</integer>
        <key>HTTPSEnable</key>
        <integer>0</integer>
      </dict>
      <key>UserDefinedName</key>
      <string>${VPNHOST}</string>
      <key>VPNType</key>
      <string>IKEv2</string>
    </dict>
  </array>
  <key>PayloadDisplayName</key>
  <string>IKEv2 VPN configuration (${VPNHOST})</string>
  <key>PayloadIdentifier</key>
  <string>com.mackerron.vpn.$(uuidgen)</string>
  <key>PayloadRemovalDisallowed</key>
  <false/>
  <key>PayloadType</key>
  <string>Configuration</string>
  <key>PayloadUUID</key>
  <string>$(uuidgen)</string>
  <key>PayloadVersion</key>
  <integer>1</integer>
</dict>
</plist>
EOF

cat << EOF > vpn-mac.applescript
set vpnuser to text returned of (display dialog "Please enter your VPN username" default answer "")
set vpnpass to text returned of (display dialog "Please enter your VPN password" default answer "" with hidden answer)
set plist to "<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE plist PUBLIC '-//Apple//DTD PLIST 1.0//EN' 'http://www.apple.com/DTDs/PropertyList-1.0.dtd'>
<plist version='1.0'>
<dict>
  <key>PayloadContent</key>
  <array>
    <dict>
      <key>IKEv2</key>
      <dict>
        <key>AuthenticationMethod</key>
        <string>None</string>
        <key>ChildSecurityAssociationParameters</key>
        <dict>
          <key>EncryptionAlgorithm</key>
          <string>AES-256-GCM</string>
          <key>IntegrityAlgorithm</key>
          <string>SHA2-384</string>
          <key>DiffieHellmanGroup</key>
          <integer>20</integer>
          <key>LifeTimeInMinutes</key>
          <integer>1440</integer>
        </dict>
        <key>DeadPeerDetectionRate</key>
        <string>Medium</string>
        <key>DisableMOBIKE</key>
        <integer>0</integer>
        <key>DisableRedirect</key>
        <integer>0</integer>
        <key>EnableCertificateRevocationCheck</key>
        <integer>0</integer>
        <key>EnablePFS</key>
        <true/>
        <key>ExtendedAuthEnabled</key>
        <true/>
        <key>AuthName</key>
        <string>" & vpnuser & "</string>
        <key>AuthPassword</key>
        <string>" & vpnpass & "</string>
        <key>IKESecurityAssociationParameters</key>
        <dict>
          <key>EncryptionAlgorithm</key>
          <string>AES-256-GCM</string>
          <key>IntegrityAlgorithm</key>
          <string>SHA2-384</string>
          <key>DiffieHellmanGroup</key>
          <integer>20</integer>
          <key>LifeTimeInMinutes</key>
          <integer>1440</integer>
        </dict>
        <key>OnDemandEnabled</key>
        <integer>1</integer>
        <key>OnDemandRules</key>
        <array>
          <dict>
            <key>Action</key>
            <string>Connect</string>
          </dict>
        </array>
        <key>RemoteAddress</key>
        <string>${VPNHOST}</string>
        <key>RemoteIdentifier</key>
        <string>${VPNHOST}</string>
        <key>UseConfigurationAttributeInternalIPSubnet</key>
        <integer>0</integer>
      </dict>
      <key>IPv4</key>
      <dict>
        <key>OverridePrimary</key>
        <integer>1</integer>
      </dict>
      <key>PayloadDescription</key>
      <string>Configures VPN settings</string>
      <key>PayloadDisplayName</key>
      <string>VPN</string>
      <key>PayloadIdentifier</key>
      <string>com.apple.vpn.managed.$(uuidgen)</string>
      <key>PayloadType</key>
      <string>com.apple.vpn.managed</string>
      <key>PayloadUUID</key>
      <string>$(uuidgen)</string>
      <key>PayloadVersion</key>
      <integer>1</integer>
      <key>Proxies</key>
      <dict>
        <key>HTTPEnable</key>
        <integer>0</integer>
        <key>HTTPSEnable</key>
        <integer>0</integer>
      </dict>
      <key>UserDefinedName</key>
      <string>${VPNHOST}</string>
      <key>VPNType</key>
      <string>IKEv2</string>
    </dict>
  </array>
  <key>PayloadDisplayName</key>
  <string>IKEv2 VPN configuration (${VPNHOST})</string>
  <key>PayloadIdentifier</key>
  <string>com.mackerron.vpn.$(uuidgen)</string>
  <key>PayloadRemovalDisallowed</key>
  <false/>
  <key>PayloadType</key>
  <string>Configuration</string>
  <key>PayloadUUID</key>
  <string>$(uuidgen)</string>
  <key>PayloadVersion</key>
  <integer>1</integer>
</dict>
</plist>"
set tmpdir to do shell script "mktemp -d"
set tmpfile to tmpdir & "/vpn.mobileconfig"
do shell script "touch " & tmpfile
write plist to tmpfile
do shell script "open /System/Library/PreferencePanes/Profiles.prefPane " & tmpfile
delay 5
do shell script "rm " & tmpfile
EOF

cat << EOF > vpn-android.sswan
{
  "uuid": "$(uuidgen)",
  "name": "${VPNHOST}",
  "type": "ikev2-eap",
  "remote": {
    "addr": "${VPNHOST}"
  }
}
EOF

cat << EOF > vpn-ubuntu-client.sh
if [[ \$(id -u) -ne 0 ]]; then echo "Please run as root (e.g. sudo ./path/to/this/script)"; exit 1; fi

read -p "VPN username (same as entered on server): " VPNUSERNAME
while true; do
read -s -p "VPN password (same as entered on server): " VPNPASSWORD
echo
read -s -p "Confirm VPN password: " VPNPASSWORD2
echo
[ "\$VPNPASSWORD" = "\$VPNPASSWORD2" ] && break
echo "Passwords didn't match -- please try again"
done

apt-get install -y strongswan libstrongswan-standard-plugins libcharon-extra-plugins
apt-get install -y libcharon-standard-plugins || true  # 17.04+ only

ln -f -s /etc/ssl/certs/ISRG_Root_X1.pem /etc/ipsec.d/cacerts/

grep -Fq 'MikhailNuzhin' /etc/ipsec.conf || echo "
conn ikev2vpn
        ikelifetime=60m
        keylife=20m
        rekeymargin=3m
        keyingtries=1
        keyexchange=ikev2
        ike=aes256gcm16-prfsha384-ecp384!
        esp=aes256gcm16-ecp384!
        leftsourceip=%config
        leftauth=eap-mschapv2
        eap_identity=\${VPNUSERNAME}
        right=${VPNHOST}
        rightauth=pubkey
        rightid=@${VPNHOST}
        rightsubnet=0.0.0.0/0
        auto=add  # or auto=start to bring up automatically
" >> /etc/ipsec.conf

grep -Fq 'MikhailNuzhin' /etc/ipsec.secrets || echo "
\${VPNUSERNAME} : EAP \"\${VPNPASSWORD}\"
" >> /etc/ipsec.secrets

ipsec restart
sleep 5  # is there a better way?

echo "Bringing up VPN ..."
ipsec up ikev2vpn
ipsec statusall

echo
echo -n "Testing IP address ... "
VPNIP=\$(dig -4 +short ${VPNHOST})
ACTUALIP=\$(dig -4 +short myip.opendns.com @resolver1.opendns.com)
if [[ "\$VPNIP" == "\$ACTUALIP" ]]; then echo "PASSED (IP: \${VPNIP})"; else echo "FAILED (IP: \${ACTUALIP}, VPN IP: \${VPNIP})"; fi

echo
echo "To disconnect: ipsec down ikev2vpn"
echo "To reconnect:  ipsec up ikev2vpn"
echo "To connect automatically: change auto=add to auto=start in /etc/ipsec.conf"
EOF

cat << EOF > vpn-instructions.txt
== iOS ==

A configuration profile is attached as vpn-ios.mobileconfig.

Open this attachment. Then go to Settings > General > VPN & Device Management, and find the profile under 'DOWNLOADED PROFILE'.

You will be asked for your device PIN or password, and then your VPN username and password.

These instructions apply to iOS 15. Earlier (and probably later) versions of iOS will also work, but the exact setup steps may differ.


== macOS ==

In macOS Monterey, your VPN username and password must be embedded in the profile file. However, your password cannot be included in a profile sent by email for security reasons.

So: open vpn-mac.applescript and run it from Script Editor. You'll be prompted for your VPN username and password.

System Preferences will then open. Select the profile listed as 'Downloaded' on the left, and click 'Install...' in the main panel.


== Windows ==

You will need Windows 10 Pro or above. Please run the following commands in PowerShell:

\$Response = Invoke-WebRequest -UseBasicParsing -Uri https://valid-isrgrootx1.letsencrypt.org

Add-VpnConnection -Name "${VPNHOST}" \`
  -ServerAddress "${VPNHOST}" \`
  -TunnelType IKEv2 \`
  -EncryptionLevel Maximum \`
  -AuthenticationMethod EAP \`
  -RememberCredential

Set-VpnConnectionIPsecConfiguration -ConnectionName "${VPNHOST}" \`
  -AuthenticationTransformConstants GCMAES256 \`
  -CipherTransformConstants GCMAES256 \`
  -EncryptionMethod GCMAES256 \`
  -IntegrityCheckMethod SHA384 \`
  -DHGroup ECP384 \`
  -PfsGroup ECP384 \`
  -Force

# Run the following command to retain access to the local network (e.g. printers, file servers) while the VPN is connected.
# On a home network, you probably want this. On a public network, you probably don't.

Set-VpnConnection -Name "${VPNHOST}" -SplitTunneling \$True

You will need to enter your chosen VPN username and password in order to connect.


== Android ==

Download the strongSwan app from the Play Store: https://play.google.com/store/apps/details?id=org.strongswan.android

Then open the attached .sswan file, or select it after choosing 'Import VPN profile' from the strongSwan app menu. You will need to enter your chosen VPN username and password in order to >

For a persistent connection, go to your device's Settings app and choose Network & Internet > Advanced > VPN > strongSwan VPN Client, tap the gear icon and toggle on 'Always-on VPN' (these>


== Ubuntu ==

A bash script to set up strongSwan as a VPN client is attached as vpn-ubuntu-client.sh. You will need to chmod +x and then run the script as root.

EOF

cd

echo
echo "--- How to connect ---"
echo
echo "Connection instructions can be found in your home directory, '~/ikev2/connect'"

echo
echo "--- Build dokcaer image ---"
echo

docker build -t mn/ikev2 -f ~/ikev2/dockerfile .

echo
echo "--- Run docker container ---"
echo

docker-compose -f ~/ikev2/docker-compose.yml up -d

docker ps