setup-ipsec-vpn/docs/ikev2-howto.md
hwdsl2 758f0e1418 Fix IKEv2 docs
- Windows 8.x and 10 require the IKEv2 machine certificate to have
  "Client Auth" EKU in addition to "Server Auth". Otherwise it gives
  "Error 13806: IKE failed to find valid machine certificate..."
- The IKEv2 documentation has been updated to fix this issue
- Also, this Libreswan wiki page may need to be updated. @letoams
  https://libreswan.org/wiki/VPN_server_for_remote_clients_using_IKEv2
- Ref: #106. Thanks @evil-shrike!
2017-01-26 17:15:43 -06:00

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# How-To: IKEv2 VPN for Windows 7 and newer
*Read this in other languages: [English](ikev2-howto.md), [简体中文](ikev2-howto-zh.md).*
---
**IMPORTANT:** This guide is for **Advanced Users** ONLY. Other users please use <a href="clients.md" target="_blank">IPsec/L2TP</a> or <a href="clients-xauth.md" target="_blank">IPsec/XAuth</a>.
---
Windows 7 and newer releases support the IKEv2 standard through Microsoft's Agile VPN functionality. Internet Key Exchange (IKE or IKEv2) is the protocol used to set up a Security Association (SA) in the IPsec protocol suite. Compared to IKE version 1, IKEv2 has <a href="https://en.wikipedia.org/wiki/Internet_Key_Exchange#Improvements_with_IKEv2" target="_blank">multiple improvements</a> such as Standard Mobility support through MOBIKE, and improved reliability.
Libreswan can authenticate IKEv2 clients on the basis of X.509 Machine Certificates using RSA signatures. This method does not require an IPsec PSK, username or password. It can be used with:
- Windows 7, 8.x and 10
- Windows Phone 8.1 and above
- strongSwan Android VPN client
- <a href="https://github.com/gaomd/docker-ikev2-vpn-server" target="_blank">iOS (iPhone/iPad) and OS X (macOS)</a> <-- See link
The following example shows how to configure IKEv2 with Libreswan. Commands below must be run as `root`.
Before continuing, make sure you have successfully <a href="https://github.com/hwdsl2/setup-ipsec-vpn" target="_blank">set up your VPN server</a>.
1. Find the public and private IP of your server, and make sure they are not empty. It is OK if they are the same.
```bash
$ PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://ipv4.icanhazip.com)
$ PRIVATE_IP=$(ip -4 route get 1 | awk '{print $NF;exit}')
$ echo "$PUBLIC_IP"
(Check the displayed public IP)
$ echo "$PRIVATE_IP"
(Check the displayed private IP)
```
1. Add a new IKEv2 connection to `/etc/ipsec.conf`:
```bash
$ cat >> /etc/ipsec.conf <<EOF
conn ikev2-cp
left=$PRIVATE_IP
leftcert=$PUBLIC_IP
leftid=@$PUBLIC_IP
leftsendcert=always
leftsubnet=0.0.0.0/0
leftrsasigkey=%cert
right=%any
rightaddresspool=192.168.43.10-192.168.43.250
rightca=%same
rightrsasigkey=%cert
modecfgdns1=8.8.8.8
modecfgdns2=8.8.4.4
narrowing=yes
dpddelay=30
dpdtimeout=120
dpdaction=clear
auto=add
ikev2=insist
rekey=no
fragmentation=yes
ike=3des-sha1,3des-sha1;modp1024,aes-sha1,aes-sha1;modp1024,aes-sha2,aes-sha2;modp1024
phase2alg=3des-sha1,aes-sha1,aes-sha2
EOF
```
We need to add one more line to that file, based on your Libreswan version. Please run command:
```bash
$ if /usr/local/sbin/ipsec --version | grep -qs -F "3.19"; then
echo " encapsulation=yes" >> /etc/ipsec.conf
else
echo " forceencaps=yes" >> /etc/ipsec.conf
fi
```
1. Generate Certificate Authority (CA) and VPN server certificates:
Note: Specify the certificate validity period (in months) using "-v". e.g. "-v 36".
```bash
$ certutil -S -x -n "Example CA" -s "O=Example,CN=Example CA" -k rsa -g 4096 -v 36 -d sql:/etc/ipsec.d -t "CT,," -2
A random seed must be generated that will be used in the
creation of your key. One of the easiest ways to create a
random seed is to use the timing of keystrokes on a keyboard.
To begin, type keys on the keyboard until this progress meter
is full. DO NOT USE THE AUTOREPEAT FUNCTION ON YOUR KEYBOARD!
Continue typing until the progress meter is full:
|************************************************************|
Finished. Press enter to continue:
Generating key. This may take a few moments...
Is this a CA certificate [y/N]?
y
Enter the path length constraint, enter to skip [<0 for unlimited path]: >
Is this a critical extension [y/N]?
N
$ certutil -S -c "Example CA" -n "$PUBLIC_IP" -s "O=Example,CN=$PUBLIC_IP" -k rsa -g 4096 -v 36 -d sql:/etc/ipsec.d -t ",," -1 -6 -8 "$PUBLIC_IP"
A random seed must be generated that will be used in the
creation of your key. One of the easiest ways to create a
random seed is to use the timing of keystrokes on a keyboard.
To begin, type keys on the keyboard until this progress meter
is full. DO NOT USE THE AUTOREPEAT FUNCTION ON YOUR KEYBOARD!
Continue typing until the progress meter is full:
|************************************************************|
Finished. Press enter to continue:
Generating key. This may take a few moments...
0 - Digital Signature
1 - Non-repudiation
2 - Key encipherment
3 - Data encipherment
4 - Key agreement
5 - Cert signing key
6 - CRL signing key
Other to finish
> 0
0 - Digital Signature
1 - Non-repudiation
2 - Key encipherment
3 - Data encipherment
4 - Key agreement
5 - Cert signing key
6 - CRL signing key
Other to finish
> 2
0 - Digital Signature
1 - Non-repudiation
2 - Key encipherment
3 - Data encipherment
4 - Key agreement
5 - Cert signing key
6 - CRL signing key
Other to finish
> 8
Is this a critical extension [y/N]?
N
0 - Server Auth
1 - Client Auth
2 - Code Signing
3 - Email Protection
4 - Timestamp
5 - OCSP Responder
6 - Step-up
7 - Microsoft Trust List Signing
Other to finish
> 0
0 - Server Auth
1 - Client Auth
2 - Code Signing
3 - Email Protection
4 - Timestamp
5 - OCSP Responder
6 - Step-up
7 - Microsoft Trust List Signing
Other to finish
> 8
Is this a critical extension [y/N]?
N
```
1. Generate client certificate(s), and export the `.p12` file that contains the client certificate, private key, and CA certificate:
```bash
$ certutil -S -c "Example CA" -n "vpnclient" -s "O=Example,CN=vpnclient" -k rsa -g 4096 -v 36 -d sql:/etc/ipsec.d -t ",," -1 -6 -8 "vpnclient"
A random seed must be generated that will be used in the
creation of your key. One of the easiest ways to create a
random seed is to use the timing of keystrokes on a keyboard.
To begin, type keys on the keyboard until this progress meter
is full. DO NOT USE THE AUTOREPEAT FUNCTION ON YOUR KEYBOARD!
Continue typing until the progress meter is full:
|************************************************************|
Finished. Press enter to continue:
Generating key. This may take a few moments...
0 - Digital Signature
1 - Non-repudiation
2 - Key encipherment
3 - Data encipherment
4 - Key agreement
5 - Cert signing key
6 - CRL signing key
Other to finish
> 0
0 - Digital Signature
1 - Non-repudiation
2 - Key encipherment
3 - Data encipherment
4 - Key agreement
5 - Cert signing key
6 - CRL signing key
Other to finish
> 2
0 - Digital Signature
1 - Non-repudiation
2 - Key encipherment
3 - Data encipherment
4 - Key agreement
5 - Cert signing key
6 - CRL signing key
Other to finish
> 8
Is this a critical extension [y/N]?
N
0 - Server Auth
1 - Client Auth
2 - Code Signing
3 - Email Protection
4 - Timestamp
5 - OCSP Responder
6 - Step-up
7 - Microsoft Trust List Signing
Other to finish
> 0
0 - Server Auth
1 - Client Auth
2 - Code Signing
3 - Email Protection
4 - Timestamp
5 - OCSP Responder
6 - Step-up
7 - Microsoft Trust List Signing
Other to finish
> 1
0 - Server Auth
1 - Client Auth
2 - Code Signing
3 - Email Protection
4 - Timestamp
5 - OCSP Responder
6 - Step-up
7 - Microsoft Trust List Signing
Other to finish
> 8
Is this a critical extension [y/N]?
N
$ pk12util -o vpnclient.p12 -n "vpnclient" -d sql:/etc/ipsec.d
Enter password for PKCS12 file:
Re-enter password:
pk12util: PKCS12 EXPORT SUCCESSFUL
```
Repeat this step for additional VPN clients, but replace every `vpnclient` with `vpnclient2`, etc.
1. The database should now contain:
```bash
$ certutil -L -d sql:/etc/ipsec.d
Certificate Nickname Trust Attributes
SSL,S/MIME,JAR/XPI
Example CA CTu,u,u
($PUBLIC_IP) u,u,u
vpnclient u,u,u
```
Note: To delete a certificate, use `certutil -D -d sql:/etc/ipsec.d -n "Certificate Nickname"`.
1. Restart IPsec service:
```bash
$ service ipsec restart
```
1. The `vpnclient.p12` file should then be securely transferred to the VPN client device. Next steps:
#### Windows 7, 8.x and 10
Import the `.p12` file to the "Computer account" certificate store. Make sure that the client cert is placed in "Personal -> Certificates", and the CA cert is placed in "Trusted Root Certification Authorities -> Certificates".
Detailed instructions:
https://wiki.strongswan.org/projects/strongswan/wiki/Win7Certs
On the Windows computer, add a new IKEv2 VPN connection
https://wiki.strongswan.org/projects/strongswan/wiki/Win7Config
Start the new IKEv2 VPN connection, and enjoy your own VPN!
https://wiki.strongswan.org/projects/strongswan/wiki/Win7Connect
(Optional) You may enable stronger ciphers by adding <a href="https://wiki.strongswan.org/projects/strongswan/wiki/Windows7#AES-256-CBC-and-MODP2048" target="_blank">this registry key</a> and reboot.
#### Windows Phone 8.1 and above
First import the `.p12` file, then follow <a href="https://technet.microsoft.com/en-us/windows/dn673608.aspx" target="_blank">these instructions</a> to configure a certificate-based IKEv2 VPN.
#### Android 4.x and newer
Please refer to: https://wiki.strongswan.org/projects/strongswan/wiki/AndroidVpnClient
Once successfully connected, you can verify that your traffic is being routed properly by <a href="https://encrypted.google.com/search?q=my+ip" target="_blank">looking up your IP address on Google</a>. It should say "Your public IP address is `Your VPN Server IP`".
## Known Issues
The built-in VPN client in Windows 7 and newer does not support IKEv2 fragmentation. On some networks, this can cause the connection to fail, or you may be unable to open any website after connecting. If this happens, first try <a href="clients.md#troubleshooting" target="_blank">this workaround</a>. If it doesn't work, please connect using <a href="clients.md" target="_blank">IPsec/L2TP</a> or <a href="clients-xauth.md" target="_blank">IPsec/XAuth</a> mode instead.
## References
* https://libreswan.org/wiki/VPN_server_for_remote_clients_using_IKEv2
* https://libreswan.org/wiki/HOWTO:_Using_NSS_with_libreswan
* https://libreswan.org/man/ipsec.conf.5.html
* https://wiki.strongswan.org/projects/strongswan/wiki/Windows7